APOD - Astronomy Picture of the Day

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/Pluto2010_gralakF33_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100708.html)Dim World, Dark NebulaDim, distant,dwarf planet (http://en.wikipedia.org/wiki/Dwarf_planet)Pluto can be hard to spot,especially in recent months asit wanders throughthe crowded starfields (http://www.skyandtelescope.com/skytel/beyondthepage/89002802.html) of Sagittarius and the central Milky Way.But fortunately for backyardPluto hunters (http://pluto.jhuapl.edu/), it crossed infront of a dark nebula in early July.The diminutive world (http://hubblesite.org/newscenter/archive/releases/2010/06)is marked with two short lines near thecenter of this skyscape recorded from New Mexico Skieson July 5.Pluto stands out only because obscuring dark nebula Barnard 92(B92) blocks the backgroundof the Milky Way's congeries (http://antwrp.gsfc.nasa.gov/apod/ap090613.html)of faint, innumerable stars.Another of astronomerE. E. Barnard's (http://www.library.gatech.edu/search/digital_collections/barnard/sowell.html)cataloged dark markings (http://antwrp.gsfc.nasa.gov/apod/ap090522.html) on the sky,B93, is easy to pick out just left of B92.Prominent at the lower left is open star clusterNGC 6603 (http://seds.org/messier/more/m024_n6603.html).In fact, Pluto, dark nebulae, and star cluster all lie withina portion of M24, also known as theSagittarius StarCloud (http://seds.org/messier/m/m024.html), filling most of the frame.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100708.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/allsky_planck950c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100709.html) Microwave Milky Way Seen from our edge-on perspective (http://antwrp.gsfc.nasa.gov/apod/ap090926.html), the Milky Way Galaxy sprawls across the middle of this false-color, all sky view (http://www.nasa.gov/mission_pages/planck/ planck20100706-i.html). The expansive microwave map is based on 1 year's worth of data from instruments onboard the sky-surveying Planck spacecraft (http://www.nasa.gov/mission_pages/planck/ planck20100706.html). Remarkably, the bright stripe of gas and dust clouds along the galactic plane and the galaxy's enormous arcing structures seen at microwave energies (http://www.youtube.com/scienceatnasa#p/ c/09E558656CA5DF76/2/UZeBzTI5Omk) are hundreds or thousands of light-years away, while the mottled regions at the top and bottom represent the Cosmic Microwave Background (CMB) radiation, some 13.7 (http://antwrp.gsfc.nasa.gov/apod/ap030217.html) billion light-years distant (http://en.wikipedia.org/wiki/ Distance_measures_%28cosmology%29). Left over from the Big Bang (http://science.nasa.gov/astrophysics/focus-areas/ what-powered-the-big-bang/), fluctuations in the CMB reflect the origins of structure in the evolving universe (http://antwrp.gsfc.nasa.gov/apod/ap060323.html). Analyzing the microwave data, Planck scientists plan to separate the contributions of the Milky Way and CMB radiation. The work will ferret out the characteristics of the CMB (http://adsabs.harvard.edu/cgi-bin/ bib_query?1965ApJ...142..419P) across the entire sky and glean information about the make up of our Milky Way Galaxy (http://antwrp.gsfc.nasa.gov/apod/ap080606.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100709.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/TaupoPlanets_tezel900h.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100710.html) Ecliptic New Zealand Four bright celestial beacons and a faint triangle of light follow the plane of the ecliptic as it arcs high through this southern hemisphere (http://antwrp.gsfc.nasa.gov/apod/ap100115.html) night skyscape. Seen on a July winter night from Lake Taupo on New Zealand's North Island, the line-up features Venus (http://antwrp.gsfc.nasa.gov/apod/ap070704.html), Regulus (http://antwrp.gsfc.nasa.gov/apod/ap100610.html) (alpha star of Leo), Mars (http://antwrp.gsfc.nasa.gov/apod/ap100613.html), and Saturn (http://antwrp.gsfc.nasa.gov/apod/ap090904.html) from lower left to upper right. Just put your cursor over the picture to identify the planets and constellations. The delicate luminous glow of Zodiacal Light (http://antwrp.gsfc.nasa.gov/apod/ap100320.html), sunlight scattered by dust along the ecliptic, also rises above the horizon from the lower left. Of course, defined by the path of the Sun (http://en.wikipedia.org/wiki/Ecliptic) through planet Earth's sky, the ecliptic plane rides low during July nights in the northern hemisphere's (http://antwrp.gsfc.nasa.gov/apod/ap100115.html) summer skies. Tomorrow, the Moon and Sun (http://antwrp.gsfc.nasa.gov/apod/ap080920.html) will meet on the ecliptic. Along a track across the southern Pacific Ocean, the daytime sky will feature a total solar eclipse (http://eclipse.gsfc.nasa.gov/SEplot/SEplot2001/ SE2010Jul11T.GIF). Total Solar Eclipse: Times and Visibility (http://eclipse.gsfc.nasa.gov/SEmono/TSE2010/TSE2010.html) | Webcast (http://www.shelios.com/sh2010/)



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100710.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/startrails_ward.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100711.html) Warped Sky: Star Trails Panorama What's happened to the sky? A time warp, of sorts, and a digital space warp too. The time warp occurs because this image (http://www.atscope.com.au/BRO/warpedsky.html) captured in a single frame a four hour exposure of the night (http://www.youtube.com/watch?v=19M1DBubDeE) sky. As a result, prominent star trails (http://www.google.com/search?hl=en&source=hp&q=APOD+star+trails) are visible. The space warp occurs because the picture is actually a full 360 degree panorama (http://antwrp.gsfc.nasa.gov/apod/ap070508.html), horizontally compressed to fit your browser. As the Earth rotated (http://antwrp.gsfc.nasa.gov/apod/ap010110.html), stars appeared to circle (http://www.youtube.com/watch?v=QwSlkJG8gTU) both the South Celestial Pole (http://en.wikipedia.org/wiki/Celestial_pole), on the left, and the North Celestial Pole (http://antwrp.gsfc.nasa.gov/apod/ap050714.html), just below the horizon on the right. The image (http://www.atscope.com.au/BRO/warpedsky.html) captured the sky over Mudgee (http://en.wikipedia.org/wiki/Mudgee), New South Wales (http://en.wikipedia.org/wiki/New_South_Wales), Australia (http://en.wikipedia.org/wiki/Australia), including the domes of two large telescopes illuminated by red lighting. A horizontally unwarped image is visible by clicking on the image. Total Solar Eclipse Today: Times and Visibility (http://eclipse.gsfc.nasa.gov/SEmono/TSE2010/TSE2010.html) | Webcast (http://www.shelios.com/sh2010/)



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100711.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/rheajanus_cassini.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100712.html)Moons Beyond the Rings of SaturnWhat's happened to that moon of Saturn?Nothing -- Saturn's moon Rhea is just partly hidden behind Saturn's rings.In April, the robotic Cassini spacecraft now orbiting Saturn took thisnarrow-angle view (http://photojournal.jpl.nasa.gov/catalog/PIA12643) looking across theSolar System (http://spaceplace.nasa.gov/en/kids/sse_flipflop.shtml)'s mostfamous rings (http://en.wikipedia.org/wiki/Saturn%27s_rings).Rings visible in the foreground include the thinF ring (http://antwrp.gsfc.nasa.gov/apod/ap090427.html) on the outside and the much widerA and B rings (http://antwrp.gsfc.nasa.gov/apod/ap071024.html) just interior to it.Although it seems to be hoveringover the rings (http://antwrp.gsfc.nasa.gov/apod/ap071217.html), Saturn's moonJanus (http://antwrp.gsfc.nasa.gov/apod/ap061107.html) is actually far behind them. Janus (http://en.wikipedia.org/wiki/Janus) is one ofSaturn's smallermoons (http://www.youtube.com/watch?v=cdciFqa7xM0)and measures only about 180 kilometers across.Farther out from the camera is the heavily crateredRhea (http://antwrp.gsfc.nasa.gov/apod/ap060530.html), a much larger moonmeasuring 1,500 kilometers across.The top of Rhea (http://www.youtube.com/watch?v=-G_-v4JVyAA) is visible only throughgaps (http://en.wikipedia.org/wiki/Rings_of_Saturn#Cassini_Division) in the rings.The Cassini mission around Saturn hasbeen extended (http://saturn.jpl.nasa.gov/news/newsreleases/newsrelease20100203/) to2017 (http://en.wikipedia.org/wiki/2017)to better study the complex planetary system as its season changes fromequinox (http://www.youtube.com/watch?v=jXkxfJtz1NY) tosolstice (http://antwrp.gsfc.nasa.gov/apod/ap080922.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100712.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/bluemarble_stevenson.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100713.html) Mosaic: Welcome to Planet Earth Welcome to Planet Earth (http://www.astronom.si/forum/earth.html), the third planet from a star (http://en.wikipedia.org/wiki/Star) named the Sun (http://www.darkmattermag.com/august03/dark_science.htm). The Earth is shaped like a sphere (http://octopus.gma.org/space1/nav_map.html) and composed mostly of rock (http://en.wikipedia.org/wiki/Structure_of_the_Earth). Over 70 percent of the Earth's surface is water (http://antwrp.gsfc.nasa.gov/apod/ap980530.html). The planet has a relatively thin atmosphere (http://csep10.phys.utk.edu/astr161/lect/earth/atmosphere.html) composed mostly of nitrogen (http://periodic.lanl.gov/elements/7.html) and oxygen (http://periodic.lanl.gov/elements/8.html). This picture of Earth (http://grin.hq.nasa.gov/ABSTRACTS/GPN-2000-001138.html), dubbed Blue Marble (http://en.wikipedia.org/wiki/The_Blue_Marble), was taken from Apollo 17 (http://science.ksc.nasa.gov/history/apollo/apollo-17/apollo-17.html) in 1972 and features Africa and Antarctica. It is thought to be one of the most widely distributed photographs (http://neil.fraser.name/writing/earth/) of any kind. Here (http://bb.nightskylive.net/asterisk/ viewtopic.php?f=29&t=19628&start=25#p124069), the world famous image has been recast as a spectacular photomosaic (http://en.wikipedia.org/wiki/Photographic_mosaic) using over 5,000 archived images (http://antwrp.gsfc.nasa.gov/apod/image/1006/thumbnails.zip) of Earth and space. With its abundance of liquid water (http://www.epa.gov/OW/), Earth (http://www.nineplanets.org/earth.html) supports a large variety of life forms (http://cmex.ihmc.us/VikingCD/Puzzle/Evolife.htm), including potentially intelligent species such as dolphins (http://www.littletownmart.com/dolphins/) and humans (http://antwrp.gsfc.nasa.gov/apod/ap960629.html). Please enjoy your stay (http://antwrp.gsfc.nasa.gov/apod/lib/sunday_seurat.gif) on Planet Earth.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100713.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/TSE2010Easter_guisard900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100714.html)Easter Island EclipseMakemake (http://antwrp.gsfc.nasa.gov/apod/ap080716.html),a god in Easter Island mythology, may havesmiled for a moment asclouds parted long enough to reveal this glimpse ofJuly 11's total solar eclipse (http://www.spaceweather.com/eclipses/gallery_11jul10_page2.htm) to skygazers.In the foreground ofthe dramatic scene (http://astrosurf.com/sguisard/Pagim/Easter_Island_eclipse.html),the island's famous large,monolithic statues (Moai) (http://antwrp.gsfc.nasa.gov/apod/ap091012.html)share a beachside view of the shimmeringsolar corona (http://antwrp.gsfc.nasa.gov/apod/ap100316.html) and thedarkened (http://antwrp.gsfc.nasa.gov/apod/ap090730.html) daytime sky.Other opportunities to see the total phase of thiseclipseof the Sun (http://www.mreclipse.com/Special/SEprimer.html) were also hard to come by.Defined by the dark part of theMoon's shadow (http://antwrp.gsfc.nasa.gov/apod/ap070610.html), thepath of totality (http://eclipse.gsfc.nasa.gov/SEgoogle/SEgoogle2001/SE2010Jul11Tgoogle2.html) trackedeastward across thesouthern Pacific Ocean, only making significant landfall atMangaia (http://eclipse.gsfc.nasa.gov/SEmono/TSE2010/TSE2010iau/TSE2010-fig02.GIF) (Cook Islands) andEaster Island (http://eclipse.gsfc.nasa.gov/SEmono/TSE2010/TSE2010iau/TSE2010-fig04.GIF) (Isla de Pascua),ending shortly after reaching southern Chile and Argentina. But a partial eclipse phase could be enjoyed over a broader region,including many (http://www.msnbc.msn.com/id/38172384/ns/technology_and_science-space/)southern Pacific islands and wide swath of South America.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100714.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/TSE2010Calafate_pyykko900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100715.html)Andes Sunset EclipseOn July 11 (http://eclipse.gsfc.nasa.gov/SEmono/TSE2010/TSE2010.html), after a longtrek eastward (http://www.youtube.com/watch?v=3CMsiLoYRJE)across the southern Pacific Ocean, the Moon's shadow reachedlandfall (http://antwrp.gsfc.nasa.gov/apod/ap100714.html) in South America.In atotal solar eclipseclose to sunset (http://www.youtube.com/watch?v=zR6wVyBLhdE),silhouetted Moon and Sun hugged the western horizon,seen here above the Andes mountains (http://antwrp.gsfc.nasa.gov/apod/ap061202.html)near the continent'ssouthern tip (http://eclipse.gsfc.nasa.gov/SEmono/TSE2010/TSE2010iau/TSE2010-fig05.GIF).To enjoy agoodvantage point (http://www.spaceweather.com/eclipses/gallery_11jul10.htm), the photographer hiked toa windy spot about 400 meters above a lake, Lago Argentino,climbing into the picture after setting up his camera on a tripod.At left, the sky outside the shadow cone (http://antwrp.gsfc.nasa.gov/apod/ap030106.html)is still bright.Below, the lights of El Calafate, Patagonia, Argentina,shine by the lake shore.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100715.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/NGC6188_sadowski900r.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100716.html)Shaping NGC 6188Dark shapes with bright edges winging their way through dustyNGC6188 (http://www.robgendlerastropics.com/NGC6188text.html) are tens of light-years long.The emission nebula (http://fusedweb.llnl.gov/CPEP/Chart_Pages/5.Plasmas/Nebula/Emission.html) is found near the edge of anotherwise dark large molecular cloud in the southernconstellationAra (http://en.wikipedia.org/wiki/Ara_(constellation)), about 4,000 light-years away.Formed in that region only a few million years ago, the massive youngstars of (http://arxiv.org/abs/0803.2148) the embedded AraOB1 association (http://en.wikipedia.org/wiki/Stellar_association#OB_associations)sculpt (http://antwrp.gsfc.nasa.gov/apod/ap080313.html) the fantastic shapes andpower the nebular glow withstellar winds and intense ultraviolet radiation.The recentstarformation (http://archive.ncsa.uiuc.edu/Cyberia/Bima/StarForm.html) itself was likely triggered bywinds and supernova explosions, from previous generations of massivestars, that swept up and compressed the molecular gas.A false-colorHubble palette (http://hubblesite.org/gallery/behind_the_pictures/meaning_of_color/eagle.php) was used to create thethis sharp close-up (http://www.astrofotografia.com.pl/photogallery/6188/ngc6188.htm) imageand shows emission from sulfur, hydrogen, and oxygen atomsin red, green, and blue hues.At the estimated distance of NGC 6188, the picture spansabout 200 light-years.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100716.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/NGC1532_pugh900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100717.html)Galaxies in the RiverLarge galaxies grow by eating small ones.Even our own (http://antwrp.gsfc.nasa.gov/apod/ap050529.html) galaxy practicesgalactic cannibalism (http://www.virginia.edu/insideuva/2003/18/milky_way.html),absorbing small galaxies that get too close andare captured (http://arxiv.org/abs/astro-ph/0407566) bythe Milky Way's gravity.In fact, the practice is common in the universe andillustrated by this striking pair of interacting galaxiesfrom the banks of the southern constellationEridanus (http://www.hawastsoc.org/deepsky/eri/index.html)(The River (http://www.windows.ucar.edu/tour/link=/the_universe/Constellations/eridanus.html&edu=high)).Located over 50 million light years away,the large, distorted spiral NGC 1532 is seen locked in agravitationalstruggle (http://burro.cwru.edu/JavaLab/GalCrashWeb/) with dwarf galaxy NGC 1531, a struggle the smaller galaxywill eventually lose (http://antwrp.gsfc.nasa.gov/apod/ap080619.html).Seen edge-on, spiral NGC 1532 spans about 100,000 light-years.Nicely detailed in this sharp image, theNGC 1532/1531 pair (http://www.noao.edu/image_gallery/html/im0983.html) is thought to be similarto the well-studied system of face-on spiral and small companionknown as M51 (http://antwrp.gsfc.nasa.gov/apod/ap100611.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100717.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/antennae_hstdemartin.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100718.html) The Antennae Galaxies in Collision Two galaxies are squaring off in Corvus (http://chandra.harvard.edu/photo/constellations/corvus.html) and here are the latest pictures (http://www.skyfactory.org/antennae/antennae.htm). But when two galaxies collide (http://curious.astro.cornell.edu/question.php?number=351), the stars that compose them usually do not. That's because galaxies (http://bb.nightskylive.net/asterisk/viewtopic.php?f=24&t=18005) are mostly empty space and, however bright, stars only take up only a small amount of that space. During the slow, hundred million year collision (http://antwrp.gsfc.nasa.gov/apod/ap060630.html), one galaxy can still rip the other apart gravitationally, and dust (http://antwrp.gsfc.nasa.gov/apod/ap030706.html) and gas (http://antwrp.gsfc.nasa.gov/apod/ap020129.html) common to both galaxies does collide (http://www.youtube.com/watch?v=rU6_4m3WtGQ). In this clash (http://hubblesite.org/newscenter/newsdesk/archive/releases/2006/46/) of the titans (http://en.wikipedia.org/wiki/Titans), dark dust pillars (http://antwrp.gsfc.nasa.gov/apod/ap050424.html) mark massive molecular clouds (http://antwrp.gsfc.nasa.gov/apod/ap060409.html) are being compressed during the galactic encounter (http://antwrp.gsfc.nasa.gov/apod/ap001102.html), causing the rapid birth of millions of stars, some of which are gravitationally bound together in massive star clusters (http://antwrp.gsfc.nasa.gov/apod/ap021229.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100718.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/darkriverpan_andreo.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100719.html)Dark River, Wide FieldA Dark River of dust seems to run from our Galactic Center,then pool into a starfield containing photogenic sky wonders.Scrolling right will reveal many of these objects including (can you find?) the bright orange star Antares (http://antwrp.gsfc.nasa.gov/apod/ap040509.html), a blue(-eyed) horsehead nebula (http://antwrp.gsfc.nasa.gov/apod/ap090521.html), the white globular star cluster (http://en.wikipedia.org/wiki/Globular_cluster) M4 (http://antwrp.gsfc.nasa.gov/apod/ap000523.html), the bright blue star system Rho Ophiuchi (http://antwrp.gsfc.nasa.gov/apod/ap070903.html), the dark brown Pipe nebula (http://antwrp.gsfc.nasa.gov/apod/ap020526.html), the red Lagoon nebula (http://antwrp.gsfc.nasa.gov/apod/ap070716.html), the red and blue Trifid nebula (http://antwrp.gsfc.nasa.gov/apod/ap090707.html), the red Cat's Paw Nebula (http://antwrp.gsfc.nasa.gov/apod/ap100421.html), and the multicolored but still important center of our Galaxy (http://antwrp.gsfc.nasa.gov/apod/ap100625.html).This wide view (http://blog.deepskycolors.com/archive/2010/06/06/between-Sagittarius-Ophiuchus-and-Scor.html) captures in exquisite detail about 50 degrees of the nighttime sky (http://antwrp.gsfc.nasa.gov/apod/ap090925.html), 100 times the size of the full Moon, covering constellations from the Archer (http://en.wikipedia.org/wiki/Archery) (Sagittarius (http://chandra.harvard.edu/photo/constellations/sagittarius.html)) through the Snake Holder (http://en.wikipedia.org/wiki/Snake_charming) (Ophiuchus), to the Scorpion (http://en.wikipedia.org/wiki/Scorpion) (Scorpius (http://www.theonion.com/articles/your-horoscopes-week-of-june-22-2010,17648/)).The Dark River itself can be identified as the brown dust lane connected to Antares (http://en.wikipedia.org/wiki/Antares), and spans about 100 light years.Since the Dark River (http://antwrp.gsfc.nasa.gov/apod/ap090708.html) dust lane lies only about 500 light years away, it only appears as a bridge to the much more distant Galactic Center (http://www.youtube.com/watch?v=36xZsgZ0oSo), that actually lies about 25,000 light years farther away.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100719.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/lightning_kotsiopoulos.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100720.html) Lightning Over Athens Have you ever watched a lightning storm in awe? Join the crowd. Oddly, nobody knows exactly how lightning (http://en.wikipedia.org/wiki/Lightning) is produced. What is known is that charges slowly separate in some clouds causing rapid electrical discharges (lightning (http://antwrp.gsfc.nasa.gov/apod/ap070205.html)), but how electrical charges get separated in clouds remains a topic of much research. Lightning (http://www.youtube.com/watch?v=Sn65RFvJKnk) usually takes a jagged course, rapidly heating (http://en.wikipedia.org/wiki/Fulgurite) a thin column of air to about three times the surface temperature of the Sun (http://antwrp.gsfc.nasa.gov/apod/ap090405.html). The resulting shock (http://antwrp.gsfc.nasa.gov/apod/ap031115.html) wave starts supersonically (http://antwrp.gsfc.nasa.gov/apod/ap070819.html) and decays into the loud sound (http://antwrp.gsfc.nasa.gov/apod/ap100427.html) known as thunder (http://www.lightningsafety.com/nlsi_info/thunder2.html). Lightning bolts are common in clouds during rainstorms, and on average 6,000 lightning bolts (http://www.newton.dep.anl.gov/askasci/wea00/wea00239.htm) occur between clouds and the Earth every minute. Pictured above (http://www.greeksky.gr/files/photos/atmospheric/20100628Thunders.htm), an active lightning storm (http://www.greeksky.gr/files/photos/animations/20100628ThundersVideo.htm) was recorded over Athens (http://en.wikipedia.org/wiki/Athens), Greece (http://en.wikipedia.org/wiki/Greece) earlier this month.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100720.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/TSE2010_JLD4_900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100721.html)The Crown of the SunDuring a total solar eclipse,the Sun'sextensive (http://www.phy6.org/Education/wcorona.html) outer atmosphere, or corona, is an inspirational sight.Subtle shades and shimmering featuresthat engage (http://lyot.org/background/coronagraphy.html)the eye span a brightness range of over10,000 to 1, making them notoriously difficultto capture in a single photograph (http://antwrp.gsfc.nasa.gov/apod/ap021213.html).But this composite of 7 consecutive digital imagesover a range of exposure times comes close to revealingthe crown (http://en.wikipedia.org/wiki/Corona) of theSun in all its glory.The telescopic views were recorded from the Isla de Pascua(Easter Island (http://antwrp.gsfc.nasa.gov/apod/ap100714.html)) during July 11'stotal solar eclipse (http://www.spaceweather.com/eclipses/gallery_11jul10_page4.htm)and also show solar prominences extendingjust beyond the edge (http://antwrp.gsfc.nasa.gov/apod/ap080807.html) of theeclipsed (http://www.kidseclipse.com/pages/a1b3c1d0.htm)sun.Remarkably, features on the dim, near side of the New Moon can also be made out, illuminated by sunlight reflected from aFull Earth (http://space.jpl.nasa.gov/cgi-bin/wspace?tbody=399&vbody=301&month=7&day=11&year=2010&hour=19&minute=00&rfov=45&fovmul=-1&bfov=30&porbs=1&showsc=1).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100721.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/FCMeteor1860_Hernstadt96dpi.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100722.html) The Meteor of 1860 </b> Frederic Church (http://www.metmuseum.org/toah/hd/chur/hd_chur.htm) (1826-1900), American landscape painter of the Hudson River School, painted what he saw in nature. And on July 20th, 1860, he saw a spectacular string of fireball (http://antwrp.gsfc.nasa.gov/apod/ap091015.html) meteors cross the Catskill evening sky, an extremely rare Earth-grazing (http://antwrp.gsfc.nasa.gov/apod/ap090302.html) meteor procession. From New York City, poet Walt Whitman (http://whitmanarchive.org/biography/walt_whitman/index.html) (1819-1892) also wrote of the "... strange huge meteor procession, dazzling and clear, shooting over our heads" in his poem Year of Meteors (1859-60) (http://whitmanarchive.org/published/LG/1867/poems/187). But the inspiration for Whitman's words was forgotten. His astronomical reference became a mystery, the subject of scholarly debate until (http://antwrp.gsfc.nasa.gov/apod/ap051215.html) Texas State University physicists Donald Olson and Russell Doescher, English professor Marilynn Olson, and Honors Program student Ava Pope, located reports documenting the date and timing of the spectacular meteor procession. The breakthrough was spotting (http://www.txstate.edu/news/news_releases/news_archive/2010/ 06/YearOfMeteors060110.html) the connection with Church's relatively little-known painting. Fittingly, the forensic astronomy team's work (http://www.skyandtelescope.com/news/95765719.html) was just published, on the 150th anniversary of the cosmic event that inspired (http://antwrp.gsfc.nasa.gov/apod/ap010728.html) both poet and painter.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100722.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/M76_150crawford900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100723.html) Messier 76 "Nebula at the right foot of Andromeda (http://en.wikipedia.org/wiki/Andromeda_(constellation)) ... " begins the description for the 76th object in Charles Messier's 18th century Catalog of Nebulae and Star Clusters (http://www.seds.org/messier/xtra/history/m-cat.html). In fact, M76 is (http://www.seds.org/messier/m/m076.html) one of the fainter objects on the Messier list and is also known by the popular name of the "Little Dumbbell Nebula". Like its brighter namesake M27 (http://antwrp.gsfc.nasa.gov/apod/ap081217.html) (the Dumbbell Nebula), M76 is recognized as a planetary nebula (http://www.noao.edu/jacoby/pn_gallery.html) - a gaseous shroud cast off by a dying sunlike star (http://antwrp.gsfc.nasa.gov/apod/ap100221.html). The nebula itself is thought to be shaped more like a donut, while the box-like appearance (http://antwrp.gsfc.nasa.gov/apod/ap040207.html) of its brighter central region is due to our nearly edge-on view. Gas expanding more rapidly away from the donut hole produces the fainter loops of far flung material. The fainter material is emphasized in this composite image, highlighted by showing emission from hydrogen atoms in orange and oxygen atoms in complementary blue hues. The nebula's dying star can be picked out in the sharp false-color image (http://www.imagingdeepsky.com/Nebulae/M76/M76.htm) as blue-tinted star near the center of the box-like shape. Distance estimates place M76 about 3 to 5 thousand light-years away, making the nebula over a light-year (http://starchild.gsfc.nasa.gov/docs/StarChild/questions/ question19.html) in diameter.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100723.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/bandedcorona_schneider900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100724.html) Diamond Ring and Shadow Bands As the total phase of July 11's solar eclipse (http://antwrp.gsfc.nasa.gov/apod/ap100715.html) came to an end, sunlight streaming past the edge of the Moon's silhouette created the fleeting appearance of a glistening diamond ring (http://antwrp.gsfc.nasa.gov/apod/ap060330.html) in the sky. Seen through a thin cloud layer from (http://eclipse.gsfc.nasa.gov/SEgoogle/SEgoogle2001/ SE2010Jul11Tgoogle2.html) the French Polynesian atoll of Hao it also produced remarkable shadow bands, flickering (http://www.strickling.net/shadowbands.htm) across the dramatic scene. Projected onto the cloud layer, the shadow bands are parallel to the sliver of sunlight emerging from behind the Moon's edge. Caused by turbulence in (http://antwrp.gsfc.nasa.gov/apod/ap000725.html) Earth's atmosphere refracting the sliver of sunlight, the narrow bands (http://www.space.com/scienceastronomy/solarsystem/ solar_eclipse_facts.html#4) were captured in this brief, 1/400th second exposure. Shining through the cloud droplets, the sunlight also produced a luminous atmospheric corona, not to be confused with the solar corona (http://antwrp.gsfc.nasa.gov/apod/ap100721.html) seen during eclipse totality. The atmospheric corona (http://www.atoptics.co.uk/droplets/corona.htm) is centered on the bright diamond of emerging sunlight.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100724.html)

[Astronom.si]

http://www.astronom.si/forum/ (http://antwrp.gsfc.nasa.gov/apod/ap100725.html) Happy People Dancing on Planet Earth What are these humans doing? Dancing. (http://en.wikipedia.org/wiki/Dancing) Many humans (http://en.wikipedia.org/wiki/Human) on Earth exhibit periods of happiness, and one method of displaying happiness is dancing. Happiness and dancing transcend political boundaries (http://en.wikipedia.org/wiki/Image:World_happiness.png) and occur in practically every human society. Above, Matt Harding (http://en.wikipedia.org/wiki/Matt_Harding) traveled through many nations on Earth, started dancing, and filmed the result. The video (http://www.wherethehellismatt.com/videos.shtml) is perhaps a dramatic example that humans (http://antwrp.gsfc.nasa.gov/apod/ap100117.html) from all over planet Earth (http://antwrp.gsfc.nasa.gov/apod/ap100713.html) feel a common bond (http://www.scienceclarified.com/Ca-Ch/Chemical-Bond.html) as part of a single species (http://www.wsu.edu:8001/vwsu/gened/learn-modules/top_longfor/timeline/timeline.html). Happiness (http://en.wikipedia.org/wiki/Happiness) is frequently contagious -- few people are able to watch the above video (http://youtube.com/watch?v=zlfKdbWwruY) without smiling (http://www.wikihow.com/Smile).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100725.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/asteroidscomets_lakdawalla.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100726.html)Lutetia: The Largest Asteroid Yet VisitedAs humans explore the universe, the record for largest asteroid visited by a spacecraft has increased yet again. Earlier this month, ESA's roboticRosetta spacecraft (http://www.esa.int/esaMI/Rosetta/ESAHVF7708D_0.html) zipped past the asteroid 21 Lutetiataking data and snapping images (http://www.esa.int/esaMI/Rosetta/SEM44DZOFBG_0.html) in an effort to betterdetermine the history of the asteroid and the origin of itsunusual colors (http://www.planetary.org/blog/article/00002592/). Although of unknown composition,Lutetia (http://www.youtube.com/watch?v=8-wFNrDMVus) is not massive enough for gravity to pull it into a sphere.Pictured above (http://www.planetary.org/blog/article/00002585/) on the upper right, the 100-kilometer acrossLutetia is shown (http://www.youtube.com/watch?v=4m1hWPJK7PQ) in comparison with the other nine asteroids and four comets that have been visited, so far, by human-launched spacecraft.Orbiting in the main asteroid belt,Lutetia (http://en.wikipedia.org/wiki/21_Lutetia)shows itself to be a heavily cratered remnant of the early Solar System.The Rosetta spacecraft (http://en.wikipedia.org/wiki/Rosetta_(spacecraft)) isnow continuing (http://www.esa.int/SPECIALS/Rosetta/SEMRZF1PGQD_0.html) ontocomet Churyumov-Gerasimenko (http://en.wikipedia.org/wiki/67P/Churyumov-Gerasimenko) where a landing is planned for 2014.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100726.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/mwbryce_cooper.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100727.html)The Milky Way Over Bryce CanyonWhat are those strange rock structures?They are towers and walls of sedimentary rock that are particularly plentiful inBryce Canyon (http://en.wikipedia.org/wiki/Bryce_Canyon) in Utah (http://en.wikipedia.org/wiki/Utah),USA (https://www.cia.gov/library/publications/the-world-factbook/geos/us.html).The rock columns may rise higher than 50 meters and are calledhoodoos (http://en.wikipedia.org/wiki/Hoodoo_(geology)).On the far left isThor (http://en.wikipedia.org/wiki/Thor)'s Hammer,perhaps the most famoushoodoo (http://www.youtube.com/watch?v=CBmeOzSzKoY).The tall rock columns were carved, most typically, when a unusually dense cap of rock provided a layer of protection to rock underneath from rain-basederosion (http://www.youtube.com/watch?v=zE4j-vScBwo). In the above panoramic picture (http://www.launchphotography.com/Milky_Way_Bryce_panorama.jpg) taken earlier this month and compressed horizontally, the foreground rocks were momentarily illuminated by a roving spotlight.Visible in the background are a fewwater clouds (http://antwrp.gsfc.nasa.gov/apod/ap090203.html)a few kilometers away hovering over the nearby Earth.Visible well beyond that are thousands ofindividually discernible stars (http://antwrp.gsfc.nasa.gov/apod/ap990113.html)averaging a few hundredlight years (http://starchild.gsfc.nasa.gov/docs/StarChild/questions/question19.html) away in the nearbyMilky Way Galaxy (http://cass.ucsd.edu/public/tutorial/MW.html).Far in the distance lie billions of stars that are thousands of light years away and compose the faintly glowing arch that is the visiblecentral band (http://antwrp.gsfc.nasa.gov/apod/ap090729.html) of the flat disk of our Milky Way. Over many years, wind and rain will eventually cause the tops of thehoodoos (http://en.wikipedia.org/wiki/File:Cappadocia_Turkey_2.jpg) to topple, whereafter theunderlying column will likely completely erode away.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100727.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/m20_gendler.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100728.html) The Trifid Nebula is Stars and Dust Unspeakable beauty and unimaginable bedlam can be found together in the Trifid Nebula (http://www.seds.org/messier/m/m020.html). Also known as M20, this photogenic nebula (http://www.robgendlerastropics.com/M20-Mosaic.html) is visible (http://antwrp.gsfc.nasa.gov/apod/ap011229.html) with good binoculars towards the constellation of Sagittarius. The energetic processes of star formation (http://antwrp.gsfc.nasa.gov/apod/ap030816.html) create not only the colors but the chaos (http://en.wikipedia.org/wiki/Chaos_%28physics%29). The red-glowing gas (http://antwrp.gsfc.nasa.gov/apod/ap980828.html) results from high-energy starlight striking interstellar hydrogen (http://periodic.lanl.gov/elements/1.html) gas. The dark dust (http://antwrp.gsfc.nasa.gov/apod/ap030706.html) filaments (http://antwrp.gsfc.nasa.gov/apod/ap010928.html) that lace M20 (http://antwrp.gsfc.nasa.gov/apod/ap970828.html) were created in the atmospheres of cool giant stars (http://www.astro.keele.ac.uk/workx/starlife/StarpageS_26M.html) and in the debris (http://antwrp.gsfc.nasa.gov/apod/ap091025.html) from supernovae (http://imagine.gsfc.nasa.gov/docs/science/know_l1/supernovae.html) explosions. Which bright young stars light up the blue reflection nebula (http://antwrp.gsfc.nasa.gov/apod/reflection_nebulae.html) is still being investigated (http://adsabs.harvard.edu/abs/1986AJ.....92.1125L). The light from M20 (http://en.wikipedia.org/wiki/Trifid_Nebula) we see today left perhaps 3,000 years ago, although the exact distance remains unknown. Light takes about 50 years to cross M20 (http://www.youtube.com/watch?v=aolbM62bfNA).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100728.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/BeltOfVenusPan_ward600h.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100729.html)Sunset, Shadowrise From central Australia,this serene (http://www.atscope.com.au/BRO/gallery64.html)360 degree panorama follows a clear horizon astwilight (http://antwrp.gsfc.nasa.gov/apod/ap071227.html) began on May 28.At left, a bright western sky is still illuminated bythe setting Sun.But sweeping right, toward a view centered on thecountryside's dominating sandstoneformation called Uluru (http://www.environment.gov.au/parks/uluru/index.html) orAyers Rock (http://antwrp.gsfc.nasa.gov/apod/ap080628.html),the sky takes on progressively darker huesand subtle colors.Behind Uluru is theshadowof planet Earth (http://www.webexhibits.org/causesofcolor/14E.html) itself,a dark blue arch rising in the east.Cast through the dense atmosphere and still close to the horizon,Earth's long shadow is bounded above by a pinkishglow or antitwilight arch (http://amsglossary.allenpress.com/glossary/search?id=antitwilight-arch1).Known as the Belt of Venus (http://antwrp.gsfc.nasa.gov/apod/ap060615.html),the lovely color of the antitwilight arch is due tobackscattering of reddened light from the setting Sun.On that night, a nearly fullMoon also rose (http://antwrp.gsfc.nasa.gov/apod/ap081122.html) above Earth's shadowin the eastern sky.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100729.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/TSERapaNui_blanchard900h.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100730.html) Eclipse on the Beach As the New Moon's shadow slid (http://www.youtube.com/watch?v=HiQLa1YS4ro) across the southern Pacific on July 11, people gathered along the white, sandy Anakena Beach (http://www.pbs.org/wgbh/nova/easter/explore/ anakenabeach.html) on the north side of Easter Island to watch a total solar eclipse (http://www.mreclipse.com/Special/SEprimer.html). The experience was captured in this tantalizing composite image, constructed from a sequence of 50 consecutive exposures. At their center is the totally eclipsed Sun surrounded by a shimmering solar corona (http://antwrp.gsfc.nasa.gov/apod/ap100721.html). From the well chosen viewpoint, palm trees appear in silhouette against a darkened sky and the faint light reflected in the water. Of course, towering above (http://antwrp.gsfc.nasa.gov/apod/ap100714.html) the onlookers, at the boundaries of land, ocean, and sky (http://antwrp.gsfc.nasa.gov/apod/ap091012.html) are Moai, the island's mysterious monolithic statues (http://www.pbs.org/wgbh/nova/easter/civilization/ giants.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100730.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1007/FourPlanetSunset_hao.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100731.html) Four Planet Sunset This mesmerizing sunset photo was taken from the summit of volcanic Mount Lawu (http://www.joglosemar.co.id/mt_lawu.html), 3,265 meters above sea level, on July 21. The view looks west, toward the city lights of Surakarta (aka Solo), Central Java, Indonesia (http://maps.google.com/maps?f=q&source=s_q&hl=en&geocode= &q=Surakarta,+Central+Java,+Indonesia &sll=-7.149949,110.871277&sspn=1.536981,1.768799&ie=UTF8 &hq=&hnear=Surakarta,+Central+Java,+Indonesia&t=h &ll=-7.57216,110.823212&spn=0.767776,0.884399&z=9). Two other volcanic peaks, sharp Merapi (left) and Merbabu lie along the colorful horizon. Four planets shine in the twilight sky above them. Spread out near the plane of the ecliptic (http://antwrp.gsfc.nasa.gov/apod/ap100710.html) are Mercury (http://solarsystem.nasa.gov/planets/ profile.cfm?Object=Mercury), Venus (http://solarsystem.nasa.gov/planets/ profile.cfm?Object=Venus), Mars (http://solarsystem.nasa.gov/planets/ profile.cfm?Object=Mars), and Saturn (http://solarsystem.nasa.gov/planets/ profile.cfm?Object=Saturn), along with bright Regulus (http://antwrp.gsfc.nasa.gov/apod/ap060619.html), alpha star of the constellation Leo. For help finding them, just put your cursor over the picture. In fact, these four planets still shine in western skies at sunset, with Venus, Mars, and Saturn grouped much more tightly this weekend (http://spaceweather.com/images2010/31jul10/ skymap_north.gif) and in early August (http://www.pa.msu.edu/abrams/nightskynotes/). By August 12 (http://spaceweather.com/images2010/12aug10/ skymap_north.gif), a young crescent Moon will join the four planet sunset.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100731.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/venus4_magellan.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100801.html)Venus' Once Molten SurfaceIf you could look across Venus withradar (http://spaceplace.jpl.nasa.gov/srtm_makemap3.htm) eyes, what might you see?This computer reconstruction of the surface ofVenus (http://www.nineplanets.org/venus.html) was created from data from theMagellan (http://nssdc.gsfc.nasa.gov/planetary/magellan.html) spacecraft. Magellan (http://www.fordham.edu/halsall/mod/1519magellan.html) orbited Venus (http://antwrp.gsfc.nasa.gov/apod/venus.html) and usedradar (http://www.naic.edu/~isradar/is/aboutis/radar.html) to map ourneighboring (http://en.wikipedia.org/wiki/Venus)planet (http://www.youtube.com/watch?v=mNgZA2Xkx-4)'ssurface between 1990 and 1994.Magellan (http://www.jpl.nasa.gov/magellan/guide.html) found manyinteresting surface (http://www.youtube.com/watch?v=LYK9rbVpOcI) features,including the large circular domes (http://antwrp.gsfc.nasa.gov/apod/ap980120.html),typically 25-kilometers across, that are depicted above. Volcanism (http://www.geo.mtu.edu/volcanoes/)is thought to have created thedomes (http://adsabs.harvard.edu/abs/1995GeoRL..22.2781B), although the precise mechanism remains unknown.Venus (http://antwrp.gsfc.nasa.gov/apod/ap040623.html)' surface is so hot andhostile that no surface probe (http://antwrp.gsfc.nasa.gov/apod/ap990124.html)has lasted more than a few minutes.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100801.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/prometheusdips_cassini.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100802.html)Prometheus Creating Saturn Ring StreamersWhat's causing those strange dark streaks in the rings of Saturn?Prometheus (http://en.wikipedia.org/wiki/Prometheus_(moon)). Specifically, an orbital dance involvingSaturn's moon Prometheus (http://www.planetary.org/explore/topics/saturn/prometheus.html) keeps creating unusual light and dark streamers in theF-Ring (http://en.wikipedia.org/wiki/Saturn%27s_rings#F_Ring) of Saturn.Now Prometheus (http://antwrp.gsfc.nasa.gov/apod/ap041217.html) orbits Saturn just inside the thinF-ring (http://www.planetary.org/explore/topics/saturn/rings.html), but ventures into its inner edge about every 15 hours.Prometheus' gravity thenpulls the closestring particles (http://www.youtube.com/watch?v=6JdzjXlvBYE) toward the 80-km moon. The result is not only a stream of brightring particles (http://antwrp.gsfc.nasa.gov/apod/ap050525.html) but also adark ribbon (http://antwrp.gsfc.nasa.gov/apod/ap081208.html) where ring particles used to be. Since Prometheusorbits faster than the ring particles, the icy moon pulls out a new streamer every pass. Above, several streamers or kinks are visible at once.The abovephotograph (http://www.ciclops.org/view/6411/Fleeing_the_Scene?js=1) was taken in June by the robotic Cassini Spacecraft orbitingSaturn (http://bb.nightskylive.net/asterisk/viewtopic.php?f=24&t=18015).The oblong moon Prometheus is visible on the far left.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100802.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/planetdish_cherney.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100803.html)The Planet and the Radio DishWhat planet is this? Although seemingly something out ofThe Little Prince (http://en.wikipedia.org/wiki/The_Little_Prince),the planet is actually Earth.More specifically, it is a small part of theEarth (http://antwrp.gsfc.nasa.gov/apod/ap091123.html) incorporated into a four imagestereographic "Little Planet " projection (http://en.wikipedia.org/wiki/Stereographic_projection).The central fisheyeimage (http://www.terrastro.com/galleries/new-south-wales/the-dish/) points down, while the surrounding wide-angleimages (http://www.terrastro.com/galleries/new-south-wales/the-dish/) were taken at a 30 degree tilt and added digitally later.Earth-anchored items surrounding the image center include greengrass (http://en.wikipedia.org/wiki/Grass),dark shadows (http://www.youtube.com/watch?v=Dpr6IfYW5Lg), andtrees (http://antwrp.gsfc.nasa.gov/apod/ap100629.html) near and far. At the image top ("noon" if the planet were a clock) is the well-litParkes Radio Telescop (http://www.parkes.atnf.csiro.au/)edish (http://www.imdb.com/title/tt0205873/) inNew South Wales (http://en.wikipedia.org/wiki/New_South_Wales),Australia (https://www.cia.gov/library/publications/the-world-factbook/geos/as.html).The surrounding sky contains many jewels of the night including theMoon (http://antwrp.gsfc.nasa.gov/apod/ap051113.html) at 9 pm, the plane of ourMilky Way Galaxy (http://antwrp.gsfc.nasa.gov/apod/ap080713.html) at 1:30 pm and 7 pm, and theSmall Magellanic Cloud (http://antwrp.gsfc.nasa.gov/apod/ap071001.html) galaxy at 5 pm.A full field interactive version of this scene can be foundhere (http://www.terrastro.com/wp-content/uploads/2010/07/16.The-Dish.swf).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100803.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/shadowcone_fischer.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100804.html) Eclipse Shadow Cone Over Patagonia Sometimes, during a total eclipse (http://www.earthview.com/tutorial/causes.htm) of the Sun, a strange shadow of darkness (http://antwrp.gsfc.nasa.gov/apod/ap990830.html) can be seen stretching off into the distance. Called shadow cones, they are visible because the Earth's atmosphere (http://csep10.phys.utk.edu/astr161/lect/earth/atmosphere.html) is not completely transparent, scattering sunlight and hence appearing blue (http://www.obscure.org/physics-faq/General/BlueSky/blue_sky.html) during the day. Shadow cones are particularly dramatic (http://www.youtube.com/watch?v=dPpiulzizAU) for eclipses near the horizon (http://antwrp.gsfc.nasa.gov/apod/ap080504.html), as geometry creates a long corridor (http://antwrp.gsfc.nasa.gov/apod/ap031127.html) of sun-blocked air. Visible above (http://twitpic.com/24i4ov) is a shadow cone caught (http://tse2009.ts.funpic.de/pataintro.html) during a sunset total solar (http://antwrp.gsfc.nasa.gov/apod/ap100730.html) eclipse visible last month (http://www.astro.uni-bonn.de/~dfischer/stories/tse2010/) from Patagonia (http://en.wikipedia.org/wiki/Patagonia), Argentina (http://en.wikipedia.org/wiki/Argentina). The eclipsed Sun (http://antwrp.gsfc.nasa.gov/apod/ap100715.html) itself still appears bright around the edges of the Moon because of light from the surrounding corona (http://antwrp.gsfc.nasa.gov/apod/ap100721.html). A few minutes later, the Moon began to move away from the Sun as both set behind distant Andes (http://en.wikipedia.org/wiki/Andes) mountains.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100804.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/Lagoon_ssro900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100805.html) M8: The Lagoon Nebula This beautiful cosmic cloud is a popular stop on telescopic tours of the constellation Sagittarius (http://www.hawastsoc.org/deepsky/sgr/index.html). Eighteenth century cosmic tourist Charles Messier (http://www.seds.org/messier/xtra/history/biograph.html) cataloged the bright nebula as M8 (http://www.seds.org/messier/m/m008.html). Modern day astronomers recognize the Lagoon Nebula as an active stellar nursery about 5,000 light-years distant, in the direction of the center (http://antwrp.gsfc.nasa.gov/apod/ap090925.html) of our Milky Way Galaxy. Remarkable features can be traced through this sharp picture (http://www.starshadows.com/gallery/display.cfm?imgID=364), showing off the Lagoon's filaments of glowing gas and dark dust clouds. Twisting near (http://antwrp.gsfc.nasa.gov/apod/ap990925.html) the center of the Lagoon, the bright hourglass shape (http://hubblesite.org/newscenter/newsdesk/archive/ releases/1996/38/) is the turbulent result of extreme stellar winds and intense starlight. The alluring view is a color composite of both broad and narrow band images captured while M8 was high in dark, Chilean skies (http://antwrp.gsfc.nasa.gov/apod/ap080507.html). It records the Lagoon with a bluer hue than typically represented in images dominated (http://antwrp.gsfc.nasa.gov/apod/ap091006.html) by the red light of the region's hydrogen emission. At the nebula's estimated distance, the picture spans (http://chandra.harvard.edu/photo/scale_distance.html) about 30 light-years.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100805.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/northSunAug1_sdo900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100806.html) The Not So Quiet Sun After a long solar minimum (http://science.nasa.gov/science-news/science-at-nasa/2009/ 01apr_deepsolarminimum/), the Sun is no longer so quiet (http://solar-center.stanford.edu/art/music.html). On August 1, this extreme ultraviolet snapshot (http://www.nasa.gov/topics/solarsystem/ sunearthsystem/main/News080210-cme.html) of the Sun from the Solar Dynanimcs Observatory captured a complex burst (http://www.nasa.gov/multimedia/videogallery/ index.html?media_id=16939864) of activity playing across the Sun's northern hemisphere. The false-color image shows the hot solar plasma (http://www.youtube.com/watch?v=sLkGSV9WDMA) at temperatures ranging from 1 to 2 million kelvins (http://lamar.colostate.edu/~hillger/temps.htm). Along with the erupting filaments and prominences, a small(!) solar flare spawned in the active region at the left was accompanied by a coronal mass ejection (CME (http://antwrp.gsfc.nasa.gov/apod/ap070206.html)), a billion-ton cloud of energetic particles headed for planet Earth. Making the 93 million mile trip (http://antwrp.gsfc.nasa.gov/apod/ap981212.html) in only two days, the CME impacted Earth's magnetosphere (http://www.phy6.org/Education/wms1.html), triggering a geomagnetic storm (http://spaceweather.com/) and both northern (http://www.spaceweather.com/aurora/ gallery_01aug10_page3.htm) and southern (http://www.spaceweather.com/submissions/ large_image_popup.php?image_name=Tom-Luttrell-_MG_4158_1281016824.jpg) auroral displays.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100806.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/regenbogen360grd_thinius_1c600h.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100807.html) Rainbow at Sunset Where is the Sun when you see a rainbow? Behind you, of course (http://eo.ucar.edu/rainbows/). But you can see both a rainbow and the Sun (far right) side by side in this graceful panorama recorded on July 28. The cloudy sunset view covers a full 360 degrees around the horizon, composed using 20 individual images taken from an observatory on the outskirts (http://de.wikipedia.org/w/index.php? title=Datei:Iopb15.jpg&filetimestamp=20080302190044) of Potsdam, Germany. The rainbow itself is produced by sunlight internally reflected (http://www.atoptics.co.uk/rainbows/primrays.htm) in rain drops from the direction opposite the Sun back toward the observer (http://www.atoptics.co.uk/rainbows/primcone.htm). As the sunlight passes through the drops, from air to water and back to air again, longer wavelengths (redder colors) are refracted or bent (http://micro.magnet.fsu.edu/primer/java/prism/) less than shorter wavelengths (bluer colors), separating the sunlight into the colors of the rainbow. This sharp picture captures the full, bright, primary rainbow arc as well as more subtle effects (http://www.atoptics.co.uk/bows.htm). You can see a partial, dimmer, secondary rainbow arc above and left of the primary, and faint arcs just inside the primary rainbow called supernumerary rainbows (http://www.atoptics.co.uk/rainbows/supers.htm).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100807.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/neptune_voyager2.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100808.html) Two Hours Before Neptune Two hours before closest approach to Neptune (http://en.wikipedia.org/wiki/Neptune) in 1989, the Voyager (http://voyager.jpl.nasa.gov/spacecraft/index.html) 2 robot spacecraft snapped this (http://nssdc.gsfc.nasa.gov/photo_gallery/photogallery-neptune.html) picture (http://nssdc.gsfc.nasa.gov/photo_gallery/caption/neptune_clouds.txt). Clearly visible (http://photojournal.jpl.nasa.gov/catalog/PIA00058) for the first time were long light-colored cirrus (http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/cld/cldtyp/hgh/crs.rxml)-type clouds floating high in Neptune's atmosphere (http://en.wikipedia.org/wiki/Neptune#Atmosphere). Shadows of these clouds can even be seen on lower cloud decks. Most of Neptune's atmosphere (http://antwrp.gsfc.nasa.gov/apod/ap960507.html) is made of hydrogen (http://www.slate.com/id/2258112/entry/2257782/) and helium (http://periodic.lanl.gov/elements/2.html), which is invisible. Neptune (http://antwrp.gsfc.nasa.gov/apod/ap060618.html)'s blue color therefore comes from smaller amounts of atmospheric methane (http://www.youtube.com/watch?v=25BE42PzZZc), which preferentially absorbs red light. Neptune (http://www.astronom.si/forum/neptune.html) has the fastest winds in the Solar System (http://www.nineplanets.org/overview.html), with gusts reaching 2000 kilometers per hour. Speculation holds that diamonds (http://www.sdnhm.org/exhibits/diamonds/facts.html) may be created in the dense hot conditions that exist under the clouds-tops of Uranus (http://antwrp.gsfc.nasa.gov/apod/ap010826.html) and Neptune (http://www.youtube.com/watch?v=PSJub1A1aIk).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100808.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/irasghost_hst.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100809.html) IRAS 05437+2502: An Enigmatic Star Cloud from Hubble What's lighting up nebula IRAS 05437+2502? No one is sure. Particularly enigmatic is the bright upside-down V that defines the upper edge of this floating mountain of interstellar dust (http://antwrp.gsfc.nasa.gov/apod/ap030706.html), visible near the image center. In general, this ghost-like nebula (http://antwrp.gsfc.nasa.gov/apod/ap071031.html) involves a small star forming region filled with dark dust (http://antwrp.gsfc.nasa.gov/apod/ap090615.html) that was first noted in images taken by the IRAS satellite (http://en.wikipedia.org/wiki/IRAS) in infrared light (http://www.youtube.com/watch?v=WUF8_3uPNNU) in 1983. Shown above (http://www.spacetelescope.org/images/potw1008a/) is a spectacular, recently released image from the Hubble Space Telescope (http://www.spacetelescope.org/extras/interactive_hubble/) that, although showing many new details, has not uncovered a clear cause of the bright sharp arc (http://antwrp.gsfc.nasa.gov/apod/ap991129.html). One hypothesis holds that the glowing arc (http://antwrp.gsfc.nasa.gov/apod/ap040610.html) was created by a massive star (http://bb.nightskylive.net/asterisk/viewtopic.php?f=24&t=18010) that somehow attained a high velocity (http://www.youtube.com/watch?v=j3mTPEuFcWk) and has now left the nebula. Small, faint IRAS 05437+2502 (http://pro.tok2.com/~aq6a-ink/ms/usa3db/05437.htm) spans only 1/18th of a full moon toward the constellation of the Bull (Taurus (http://stardate.org/nightsky/constellations/taurus.html)).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100809.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/titanearthdunes_cassini.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100810.html) The Sand Dunes of Titan Why do some sand dunes on Titan appear backwards? Central Titan (http://en.wikipedia.org/wiki/Titan_(moon)), it turns out, is covered by sand (http://en.wikipedia.org/wiki/Sand), some of which appears strange. Images from the Cassini spacecraft (http://www.youtube.com/watch?v=GCGwN1rQIQs) currently orbiting Saturn (http://bb.nightskylive.net/asterisk/viewtopic.php?f=24&t=18015) have uncovered long rows of huge sand dunes (http://antwrp.gsfc.nasa.gov/apod/ap090420.html) near Titan's equator that rise as high as 300 meters. Shadows indicate that most dune shapes are created by wind blowing from the west. The problem is, the typical wind at Titan (http://antwrp.gsfc.nasa.gov/apod/ap050117.html)'s equator blows from the east. One recent hypothesis (http://www.space.com/scienceastronomy/titan-sand-dunes-backward-winds-100729.html) that might solve this grainy conundrum posits that the only winds strong (http://www.youtube.com/watch?v=f_ybMvQZBMI) enough to move sand and create dunes occur during rare equinox (http://antwrp.gsfc.nasa.gov/apod/ap090930.html)es and blow strongly from the west. The above images (http://saturn.jpl.nasa.gov/news/cassinifeatures/feature20100729/) show a radar swath of Titan (http://www.youtube.com/watch?v=LHLEgznLOL4)'s equatorial sand dunes at the top, while similar sand dunes that formed in Namibia (http://en.wikipedia.org/wiki/Namibia) on Earth at the bottom. Why central Titan is even covered by so much sand (http://antwrp.gsfc.nasa.gov/apod/ap100119.html) is still being investigated.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100810.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/crepuscular_voigts.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100811.html) Crepuscular Rays Over Lake Michigan What could cause such rays of dark? Dark sky rays were caught in spectacular fashion earlier last month from Pentwater (http://en.wikipedia.org/wiki/Pentwater,_Michigan), Michigan (http://en.wikipedia.org/wiki/Michigan), USA (http://www.cia.gov/cia/publications/factbook/geos/us.html), looking west over Lake Michigan (http://en.wikipedia.org/wiki/Lake_Michigan). The cause is something surprisingly familiar: shadows (http://antwrp.gsfc.nasa.gov/apod/ap040926.html). Clouds near the horizon can block sunlight (http://www.youtube.com/watch?v=mQfZ_WD8iA8) from reflecting off air, making columns outward from the Sun (http://www.nineplanets.org/sol.html) appear unusually dark (http://antwrp.gsfc.nasa.gov/apod/ap090623.html). Cloud shadow (http://antwrp.gsfc.nasa.gov/apod/ap020227.html)s can be thought of as the complement of the more commonly highlighted crepuscular rays (http://www.ems.psu.edu/~demark/471/CrepuscularRays.html), also visible above, where sunlight pours though cloud holes (http://www.youtube.com/watch?v=LgnXiQ_xouA). Sometimes, on the opposite side of the sky, anticrepuscular rays (http://antwrp.gsfc.nasa.gov/apod/ap081116.html) can also be seen.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100811.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/perseid_100808_ladanyi.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100812.html) Perseid Prelude Each August, as planet Earth swings through dust trailing along the orbit of periodic comet Swift-Tuttle (http://www.oarval.org/section3_16.htm), skygazers can enjoy the Perseids Meteor Shower (http://antwrp.gsfc.nasa.gov/apod/ap070812.html). The shower should build to its peak now (http://science.nasa.gov/science-news/science-at-nasa/ 2010/05aug_perseids/), best seen from later tonight after moonset, until dawn tomorrow morning when Earth moves through the denser part of the wide dust trail. But shower meteors have been spotted for many days, like this bright Perseid streaking through skies near Lake Balaton (http://antwrp.gsfc.nasa.gov/apod/ap090924.html), Hungary on August 8. In the foreground is the region's Church of St. Andrew ruin, with bright Jupiter dominating the sky to its right. Two galaxies lie in the background of the wide-angle, 3 frame panorama; our own Milky Way's luminous arc (http://antwrp.gsfc.nasa.gov/apod/ap100625.html), and the faint smudge of the more distant Andromeda Galaxy (http://antwrp.gsfc.nasa.gov/apod/ap040131.html) just above the ruin's leftmost wall. If you watch for Perseid meteors tonight, be sure and check out the early evening sky show too, featuring bright planets (http://antwrp.gsfc.nasa.gov/apod/ap100731.html) and a young crescent Moon near the western horizon after sunset (http://science.nasa.gov/media/medialibrary/2010/08/05/ skymap_12aug10.gif).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100812.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/NGC5566_leshin900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100813.html) Arp 286: Trio in Virgo A remarkable telescopic composition in yellow and blue, this scene features (http://sleshin.startlogic.com/stargazergallery/ main.php?g2_itemId=363&g2_imageViewsIndex=0) a trio of interacting galaxies almost 90 million light-years away, toward the constellation Virgo (http://www.hawastsoc.org/deepsky/vir/index.html). On the left, two, spiky (http://spider.ipac.caltech.edu/staff/kaspar/obs_mishaps/ images/int_reflection2.html), foreground Milky Way stars echo the trio galaxy hues, a reminder that stars in our own galaxy are like those in the distant island universes (http://www.aip.org/history/cosmology/ideas/island.htm). Predominately yellow, with sweeping spiral arms and dust lanes, NGC 5566, is enormous, about 150,000 light-years across. Just below it lies small, blue NGC 5569. Near center, the third galaxy, NGC 5560, is multicolored and apparently stretched and distorted by its interaction with NGC 5566. The galaxy trio is also included in Halton Arp's 1966 Atlas of Peculiar Galaxies (http://nedwww.ipac.caltech.edu/level5/Arp/frames.html) as Arp 286. Of course, such cosmic interactions (http://burro.astr.cwru.edu/JavaLab/GalCrashWeb/ backgrnd.html) are now appreciated as (http://antwrp.gsfc.nasa.gov/apod/ap071101.html) a common part of the evolution of galaxies (http://arxiv.org/abs/astro-ph/9908269v1).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100813.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/perseids2010_verstraaten600h.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100814.html) Night of the Perseids On the night (http://www.youtube.com/watch?v=M4-IL8GHmlk) of August 12, from moonset until dawn was a good time to see meteors. Enthusiasts watched (http://www.spaceweather.com/meteors/ gallery_12aug10_page5.htm) as comet dust rained on planet Earth, streaking through dark skies during the annual Perseid Meteor Shower (http://antwrp.gsfc.nasa.gov/apod/ap100812.html). Anticipating the shower approaching its peak (http://www.imo.net/live/perseids2010/), astronomer Marco Verstraaten recorded a series of exposures capturing meteors over a period of 6 hours using a wide angle lens from a not-so-dark site in the Netherlands. Combining them still produced this dramatic night sky view with many colorful meteor streaks. The starry backdrop includes the Milky Way and even the faint Andromeda Galaxy, right of center. Although the comet dust particles are traveling parallel to each other, the shower meteors clearly seem to radiate from a spot on the sky in the eponymous constellation Perseus (http://meteorshowersonline.com/perseids.html). The radiant effect is due to perspective (http://mathforum.org/sum95/math_and/perspective/ perspect.html), as the parallel tracks appear to converge at a distance. Bright stars in Perseus extend into the gap between the foreground trees.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100814.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/marshills_mgs.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100815.html) Layered Hills in Arabia Terra on Mars Why are some hills on Mars (http://bb.nightskylive.net/asterisk/viewtopic.php?f=24&t=18018) so layered? The answer is still under investigation. Clearly, dark windblown sand (http://antwrp.gsfc.nasa.gov/apod/ap010226.html) surrounds outcropping of light sedimentary rock (http://en.wikipedia.org/wiki/Sedimentary_rock) across the floor of crater Arabia Terra (http://www.msss.com/mars_images/moc/dec00_seds/8N7W/). The light rock (http://antwrp.gsfc.nasa.gov/apod/ap030815.html) clearly appears structured into many layers (http://science.nasa.gov/headlines/y2000/ast04dec_2.htm), the lowest of which is likely very old. Although the dark sand forms dunes (http://antwrp.gsfc.nasa.gov/apod/ap010815.html), rippled dunes of lighter colored sand are easier to see surrounding the stepped mesas (http://en.wikipedia.org/wiki/Mesa). Blown sand (http://antwrp.gsfc.nasa.gov/apod/ap090420.html) possibly itself eroded (http://adsabs.harvard.edu/abs/2002GeoRL..29x..32E) once-larger mesas into the layered hills (http://adsabs.harvard.edu/abs/2008JGRE..11312001F). Most of the layered shelves (http://antwrp.gsfc.nasa.gov/apod/ap001205.html) are wide enough to drive a truck (http://inventors.about.com/library/inventors/bltruck.htm) around. The above image (http://www.msss.com/mars_images/moc/2003/12/01/index.html), showing an area about 3 kilometers across, was taken in 2003 October by the now defunct Mars Global Surveyor spacecraft (http://en.wikipedia.org/wiki/Mars_Global_Surveyor) orbiting Mars (http://mars.jpl.nasa.gov/).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100815.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/perseids_boucher.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100816.html) Meteors Over Quebec Meteors streaked through the sky above many of Earth's cities last week, but nobody was hurt, and no damage has been reported. The assault from space (http://en.wikipedia.org/wiki/Meteor_shower) appeared to originate from someplace in the constellation (http://stars.astro.illinois.edu/sow/const.html) of Perseus (http://en.wikipedia.org/wiki/Perseus_(constellation)), and included millions of small projectiles (http://antwrp.gsfc.nasa.gov/apod/ap011117.html) hurtling toward Earth at over 200,000 kilometers per hour. Pictured above, people gathered at ASTROLab du Mont-Megantic (http://www.astrolab-parc-national-mont-megantic.org/) in southern Quebec (http://en.wikipedia.org/wiki/Quebec), Canada (http://en.wikipedia.org/wiki/Canada) gazed helplessly toward the sky last Thursday night as they themselves were unable to stop the meteor onslaught (http://www.youtube.com/watch?v=jr-EiUSUnhw). Fortunately, Earth's defense (http://www.spaceguarduk.com/), consisting of a planet-wise blanket of air (http://www.srh.noaa.gov/srh/jetstream/atmos/layers.htm) over 100-kilometers thick, obliterated the attacking projectiles (http://spaceweather.com/meteors/gallery_12aug10.htm) by using friction generated by their own speed to heat them into disintegration. The large triangle (http://antwrp.gsfc.nasa.gov/apod/ap080701.html) in the foreground, although impressive in appearance, was not part of the Earth's meteor defense system. The space attack (http://antwrp.gsfc.nasa.gov/apod/ap080103.html) was expected as part of the annual Perseids meteor shower (http://bb.nightskylive.net/asterisk/viewtopic.php?f=24&t=18013) as the Earth passed through sand-sized debris left over from the sun-orbiting Comet Swift-Tuttle (http://antwrp.gsfc.nasa.gov/apod/ap960219.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100816.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/jewelbox_willasch.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100817.html)NGC 4755: A Jewel Box of StarsThe great variety of star colors in this open cluster (http://www.seds.org/messier/open.html) underlies its name: The Jewel Box (http://www.seds.org/messier/xtra/ngc/n4755.html). One of the bright central stars is a red supergiant (http://antwrp.gsfc.nasa.gov/apod/ap100106.html),in contrast to the many blue stars that surround it. The cluster (http://adsabs.harvard.edu/abs/1963MNRAS.126...11F), also known as Kappa Crucis (http://adsabs.harvard.edu/abs/1984A%26AS...56..373D) contains just over 100 stars, and is about 10 million years old. Open clusters (http://antwrp.gsfc.nasa.gov/apod/open_clusters.html) are younger, contain few stars, and contain a much higher fraction of blue stars than do globular (http://antwrp.gsfc.nasa.gov/apod/globular_clusters.html)clusters (http://bb.nightskylive.net/asterisk/viewtopic.php?f=24&t=18009). This Jewel Box (http://en.wikipedia.org/wiki/Jewel_Box_%28star_cluster%29) lies about 6,400 light-years away, so the light that we see today was emitted from the cluster before even the Great Pyramids (http://www.pbs.org/wgbh/nova/pyramid/) in Egypt (http://en.wikipedia.org/wiki/Egypt) were built. The Jewel Box, pictured above (http://astro-cabinet.com/showimage.php?&image=NGC4755_3_10m-RGB_final.jpg&lang=english), spans about 20 light-years, and can be seen with binoculars towards the southern constellation of the cross(Crux (http://www.astronomical.org/constellations/cru.html)).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100817.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/sandplanets_claro.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100818.html) Crescent Moon and Planets Over Portugal Sometimes, it's fun to share the sky. Although it might appear that the two sky enthusiasts (http://antwrp.gsfc.nasa.gov/apod/ap040808.html) on the ridge are sharing only a crescent moon between them, three bright planets (http://antwrp.gsfc.nasa.gov/apod/ap050913.html) also stand before them. The brightest point in the sky is the planet Venus (http://en.wikipedia.org/wiki/Venus), while reddish Mars (http://bb.nightskylive.net/asterisk/viewtopic.php?f=24&t=18018) floats above it, and Saturn (http://www.nasa.gov/worldbook/saturn_worldbook.html) shines off to its right. In the foreground are picturesque clumps of sand of the beach (http://www.youtube.com/watch?v=PS59Y3IR-SQ) at Costa da Caparica (http://en.wikipedia.org/wiki/Costa_da_Caparica), before the reflecting waters of the Atlantic Ocean (http://www.faqs.org/docs/factbook/geos/zh.html). The evening picked to planet gaze was a particularly good one as the Perseids meteor shower (http://spaceweather.com/meteors/gallery_12aug10.htm) was also reaching its peak. Fortunately, this evening sky was not unique to Alamada (http://en.wikipedia.org/wiki/Almada), Portugal (http://en.wikipedia.org/wiki/Portugal) last Thursday, but visible to sky enthusiasts the world over (http://antwrp.gsfc.nasa.gov/apod/ap100713.html) last week. These planets will all remain visible (http://www.skyandtelescope.com/observing/ataglance/) at sunset this week, although Venus will sink to the horizon as it closes in on the setting Sun.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100818.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/PelicanIC5067_hallas900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100819.html)Pelican Nebula Close-up The prominent ridge of emission featured inthis intenselycolorful skyscape (http://astrophoto.com/Pelican.htm) is designated IC 5067 (http://antwrp.gsfc.nasa.gov/apod/ap061227.html).Part of a largeremissionnebula (http://www.noao.edu/image_gallery/emission_nebulae.html) with a distinctive shape, popularly calledThe Pelican Nebula (http://antwrp.gsfc.nasa.gov/apod/ap061130.html), the ridge spans about10 light-years and follows thecurve of the cosmic pelican's head and neck.Fantastic, dark shapes inhabiting the vieware clouds of cool gas and dustsculpted by (http://www.noao.edu/outreach/press/pr03/pr0308.html)energetic radiation from hot, massive stars.But stars are also forming within the dark shapes.In fact, twin jets emerging from the tip of the central,dark tendril (http://astrophoto.com/PelCU.jpg)are the telltale signs of an embedded protostar cataloged asHerbig-Haro (http://en.wikipedia.org/wiki/Herbig-Haro_objects)555.The Pelican Nebula itself, also known as IC 5070,is about 2,000 light-years away.To find (http://antwrp.gsfc.nasa.gov/apod/ap070702.html) it, look northeast of brightstar Deneb (http://antwrp.gsfc.nasa.gov/apod/ap070920.html) in thehigh flying constellation Cygnus.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100819.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/NGC1365_pugh900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100820.html) NGC 1365: Majestic Island Universe Barred spiral galaxy (http://www.seds.org/messier/spir.html) NGC 1365 is truly a majestic island universe (http://antwrp.gsfc.nasa.gov/apod/ap100109.html) some 200,000 light-years across. Located a mere 60 million light-years away toward the chemical constellation Fornax (http://www.hawastsoc.org/deepsky/for/index.html), NGC 1365 is a dominant member of the well-studied Fornax galaxy cluster (http://heritage.stsci.edu/2005/09/supplemental.html). This impressively sharp color image (http://www.martinpughastrophotography.id.au/Galaxies/ NGC1365.htm) shows intense star forming regions at the ends of the bar and along the spiral arms, and details of dust lanes cutting across the galaxy's bright core. At the core lies a supermassive black hole. Astronomers think NGC 1365's (http://arxiv.org/abs/0907.2602) prominent bar plays a crucial role in the galaxy's evolution (http://hubblesite.org/newscenter/archive/releases/ 1999/34/), drawing gas and dust into a star-forming maelstrom and ultimately feeding material into the central black hole (http://hubblesite.org/newscenter/archive/releases/ 2000/22).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100820.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/PerseidStorm_arn900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100821.html) Perseid Storm Storms on the distant horizon and comet dust raining through the heavens above are combined in this alluring nightscape (http://barn.zenfolio.com/p1068266116). The scene was recorded (http://www.cloudynights.com/ubbthreads/showflat.php/ Number/3985299) in the early hours of August 13 from the Keota Star Party site on the Pawnee National Grasslands (http://www.fs.fed.us/r2/recreation/map/colorado/ index.shtml) of northeastern Colorado, USA. Looking east across the prairie, the composite (http://barn.zenfolio.com/p1068266116/h3e4cb2d#h3e4cb2d) of 8 consecutive exposures each 30 seconds long captures the flash of lightning (http://antwrp.gsfc.nasa.gov/apod/ap100720.html) and a bright Perseid meteor (http://antwrp.gsfc.nasa.gov/apod/ap100812.html). On the right, even the clouds can't block the light from brilliant planet Jupiter (http://solarsystem.nasa.gov/planets/ profile.cfm?Object=Jupiter), whose mythological namesake (http://www.pantheon.org/articles/j/jupiter.html) knew how to handle both lightning bolts and meteors. Of course, this meteor's streak points back toward the shower's radiant (http://antwrp.gsfc.nasa.gov/apod/ap100814.html) in the heroic constellation Perseus, sharing a starry background that includes the Pleiades (http://antwrp.gsfc.nasa.gov/apod/ap071122.html) star cluster poised above the storm clouds. Just above the bright meteor lies the faint Andromeda Galaxy (http://www.seds.org/messier/m/m031.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100821.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/hoag_hst.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100822.html) Hoag's Object: A Strange Ring Galaxy Is this one galaxy or two? This question came to light in 1950 when astronomer Art Hoag (http://en.wikipedia.org/wiki/Arthur_Allen_Hoag) chanced upon this unusual extragalactic object (http://bb.nightskylive.net/asterisk/viewtopic.php?f=24&t=18005). On the outside is a ring (http://antwrp.gsfc.nasa.gov/apod/ap051022.html) dominated by bright blue stars, while near the center lies a ball of much redder stars that are likely much older. Between the two is a gap (http://antwrp.gsfc.nasa.gov/apod/ap040702.html) that appears almost completely dark. How Hoag's Object (http://adsabs.harvard.edu/abs/1990ApJ...348..448W) formed remains unknown, although similar objects have now been identified and collectively labeled (http://mergers.galaxyzoo.org/) as a form of ring galaxy (http://antwrp.gsfc.nasa.gov/apod/ap010612.html). Genesis hypotheses include a galaxy collision (http://nedwww.ipac.caltech.edu/level5/Struck/frames.html) billions of years ago and the gravitational affect of a central bar (http://antwrp.gsfc.nasa.gov/apod/ap080622.html) that has since vanished (http://adsabs.harvard.edu/doi/10.1007/s10569-010-9289-z). The above (http://heritage.stsci.edu/2002/21/caption.html) photo (http://hubblesite.org/gallery/album/galaxy/pr2002021a/) taken by the Hubble Space Telescope (http://antwrp.gsfc.nasa.gov/apod/ap010806.html) in July 2001 reveals unprecedented details of Hoag's Object and may yield a better understanding (http://nedwww.ipac.caltech.edu/level5/Rings/Rings17_2.html). Hoag's Object spans about 100,000 light years (http://chandra.harvard.edu/photo/cosmic_distance.html) and lies about 600 million light years (http://starchild.gsfc.nasa.gov/docs/StarChild/questions/question19.html) away toward the constellation (http://www.astro.wisc.edu/~dolan/constellations/extra/constellations.html) of the Snake (Serpens (http://en.wikipedia.org/wiki/Serpens_(constellation))). Coincidentally, visible in the gap (at about one o'clock) is yet another ring galaxy (http://antwrp.gsfc.nasa.gov/apod/ap040426.html) that likely lies far in the distance (http://antwrp.gsfc.nasa.gov/apod/ap020901.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100822.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/mwshadow_cherney.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100823.html) A Milky Way Shadow at Loch Ard Gorge Have you ever seen the Milky Way's glow create shadows? To do so, conditions need to be just right. First and foremost, the sky must be relatively clear of clouds so that the long band (http://antwrp.gsfc.nasa.gov/apod/ap070930.html) of the Milky Way's central disk (http://cass.ucsd.edu/public/tutorial/MW.html) can be seen. The surroundings must be very near to completely dark, with no bright artificial lights visible (http://antwrp.gsfc.nasa.gov/apod/ap010827.html) anywhere. Next, the Moon (http://antwrp.gsfc.nasa.gov/apod/ap051113.html) cannot be anywhere above the horizon, or its glow will dominate the landscape. Last, the shadows (http://antwrp.gsfc.nasa.gov/apod/ap090415.html) can best be caught on long camera exposures (http://antwrp.gsfc.nasa.gov/apod/ap060915.html). In the above image (http://www.terrastro.com/galleries/milky-way-shadow/) taken in Port Campbell National Park (http://en.wikipedia.org/wiki/Port_Campbell_National_Park), Victoria (http://en.wikipedia.org/wiki/Victoria,_Australia), Australia (http://en.wikipedia.org/wiki/Australia), seven 15-second images of the ground and de-rotated sky (http://antwrp.gsfc.nasa.gov/apod/ap010110.html) were digitally added to bring up the needed light and detail. In the foreground lies Loch Ard Gorge (http://en.wikipedia.org/wiki/Loch_Ard_Gorge), named after a ship that tragically ran aground in 1878 (http://en.wikipedia.org/wiki/1878). The two rocks pictured are the remnants of a collapsed arch and are named Tom and Eva after the only two people who survived that Loch Ard ship (http://en.wikipedia.org/wiki/Loch_Ard_(ship)) wreck. A close inspection of the water just before the rocks (http://www.youtube.com/watch?v=QgNtzFtm-m8) will show shadows in light thrown by our Milky Way galaxy (http://bb.nightskylive.net/asterisk/viewtopic.php?f=24&t=18006). Low clouds are visible moving through the serene scene in this movie (http://vimeo.com/14054461).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100823.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/abell1689_hst.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100824.html) Galaxy Cluster Abell 1689 Magnifies the Dark Universe What's the matter with this cluster of galaxies? To find out what forms matter takes in the Abell 1689 cluster (http://antwrp.gsfc.nasa.gov/apod/ap040627.html) requires not only deep images from telescopes like the Hubble Space Telescope (http://hubblesite.org/the_telescope/hubble_essentials/), but detailed computer modeling (http://bb.nightskylive.net/asterisk/viewforum.php?f=35) as well. To start, almost every fuzzy yellow patch in the above image (http://hubblesite.org/newscenter/archive/releases/2010/26/image/a/) is an entire galaxy. A close inspection, however, shows that many background galaxies are strangely magnified and distorted into long curving arcs (http://antwrp.gsfc.nasa.gov/apod/ap090921.html) by the gravitational lens (http://en.wikipedia.org/wiki/Gravitational_lens) deflections of the cluster. Computer analyses of the placement (http://www.youtube.com/watch?v=2-My9CChyBw) and smoothness of these arcs indicate that in addition to the matter in the galaxies you can see, the cluster must also contain a significant amount of dark matter (http://chandra.harvard.edu/xray_astro/dark_matter/index5.html) such as the model digitally superposed in purple (http://en.wikipedia.org/wiki/Purple). Now Abell 1689 (http://en.wikipedia.org/wiki/Abell_1689) remains enigmatic because the arcs are so numerous and diverse that no single dark matter (http://astro.berkeley.edu/~mwhite/darkmatter/dm.html) model has emerged that can explain them all (http://adsabs.harvard.edu/abs/2010arXiv1008.2758L) and still remain consistent with dark matter models needed to constrain their motion. Still, the detailed information available from clusters of galaxies (http://antwrp.gsfc.nasa.gov/apod/clusters_of_galaxies.html) like Abell 1689 gives hope that one day full solutions will be found that will not only fully reveal the dark matter in clusters (http://antwrp.gsfc.nasa.gov/apod/ap080917.html), but also reveal the amounts of dark energy (http://en.wikipedia.org/wiki/Dark_energy) in the universe (http://adsabs.harvard.edu/abs/2008AmJPh..76..265N) needed to lie along the line of sight to the distant arcs (http://antwrp.gsfc.nasa.gov/apod/ap040217.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100824.html)

[Astronom.si]

http://www.astronom.si/forum/ (http://antwrp.gsfc.nasa.gov/apod/ap100825.html) HD 10180: Richest Yet Planetary System Discovered Do other rich planetary systems exist? Our Solar System has the most planets of any known star, most probably because it is so hard to detect planets around other stars (http://en.wikipedia.org/wiki/Extrasolar_planet). Sensitive measurements, though, have now uncovered (http://www.eso.org/public/news/eso1035/) a slight but complex wobble of the Sun-like star HD 10180 (http://en.wikipedia.org/wiki/HD_10180) indicating that it has at least five planets (http://antwrp.gsfc.nasa.gov/apod/ap080521.html) and possibly more, making it the richest extra-solar planetary system (http://exoplanet.eu/) yet known. HD 10180's planets were discovered in years of data using the sensitive HARPS spectrograph (http://www.eso.org/sci/facilities/lasilla/instruments/harps/) attached to the ESO's 3.6-meter telescope (http://www.eso.org/sci/facilities/lasilla/telescopes/3p6/index.html) in La Silla (http://en.wikipedia.org/wiki/La_Silla), Chile (http://en.wikipedia.org/wiki/Chile). The planetary system (http://www.eso.org/public/news/eso1035/) appears quite different than our Solar System (http://nineplanets.org/overview.html), since all of HD 10180's discovered planets have Neptune (http://www.astronom.si/forum/neptune.html)-like masses but orbit inside the distance of Mars. An artist's depiction of flying into this system is shown in the above video (http://www.eso.org/public/videos/eso1035b/). In the future, more sensitive data taken over longer time periods may extend the star-wobble detection technique into the realm of uncovering more distant and more Earth-like planets (http://antwrp.gsfc.nasa.gov/apod/ap090923.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100825.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/m27_MRussell900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100826.html)M27: Not a Comet While hunting for comets in the skies above 18th century France,astronomer Charles Messier (http://www.seds.org/messier/xtra/history/biograph.html)diligently kept a list of the thingshe encountered that were definitely not comets.This is number 27 on hisnowfamous not-a-comet list (http://www.seds.org/messier/xtra/history/m-cat.html).In fact, 21st century astronomers would identify it as aplanetarynebula (http://www.seds.org/messier/planetar.html), but it's not a planet either, even though it mayappear round (http://antwrp.gsfc.nasa.gov/apod/ap030614.html) andplanet-like in a small telescope.Messier 27 (M27) is an excellent example of agaseous emission nebula (http://www.astro.washington.edu/balick/WFPC2/) createdas a sun-like star runs out (http://antwrp.gsfc.nasa.gov/apod/ap100221.html)of nuclear fuel in its core.The nebula forms as the star's outer layers are expelled intospace, with a visible glow generated by atoms excited by the dyingstar's intense but invisibleultraviolet light (http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html).Known by the popular name of theDumbbellNebula (http://www.seds.org/messier/m/m027.html), the beautifullysymmetric interstellar gas cloud is over 2.5 light-years across andabout 1,200 light-years away in theconstellationVulpecula (http://hawastsoc.org/deepsky/vul/index.html).This impressive colorcomposite (http://www.telescopes.cc/m27.htm) highlights details withinthe well-studied central region and fainter, seldom imagedfeatures in the nebula's outer halo (http://antwrp.gsfc.nasa.gov/apod/ap100509.html).It includes narrowband images recorded usingfilters sensitive to emission from oxygen atoms, shown inblue-green hues, and hydrogen atoms in red.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100826.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/VeMaSpicaDesert_tafreshi900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100827.html)Brighter Than Mars Even though you may have just read an emailclaiming (http://www.snopes.com/science/astronomy/brightmars.asp) Mars will be incredibly bright tonight,the brightest star on the horizon is not Mars.From central Iran on August 24th,the brightest star in thistwilightdesert skyview (http://www.twanight.org/newTWAN/photos.asp?ID=3002683)is Venus, aka the Evening Star.But a bright Mars is in the picture, just above and rightof more brilliant Venus (http://www.digitalsky.org.uk/venus/shadow-of-venus.html).Despite claims in the internet'sannually returning Mars Hoax (http://science.nasa.gov/science-news/science-at-nasa/2010/25aug_marshoax/)that Mars will be as big and bright as the Full Moon,this celestial scenario is very similar to the western sky you cansee tonight.Along with Mars, the still beautiful vista includes Spica,alpha star of theconstellationVirgo (http://www.hawastsoc.org/deepsky/vir/index.html), above and leftof Venus (http://solarsystem.nasa.gov/planets/profile.cfm?Object=Venus).Farther right of Venus,Saturn peeks (http://solarsystem.nasa.gov/planets/profile.cfm?Object=Saturn) through the sunset'sfading glow just above the clouds.Near the opposite horizon, the Full Moon illuminating thedesert is about 400,000 times brighterthan Mars (http://beamartian.jpl.nasa.gov/welcome).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100827.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/CoronalHaug2010_sdo900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100828.html)Hole in the SunThis ominous, dark shape sprawling across the face of the Sunis a coronal hole (http://helios.gsfc.nasa.gov/chole.html) --a low density region extending abovethe surface where the solar magnetic field opens freely intointerplanetary space.Studied extensivelyfromspace (http://vestige.lmsal.com/TRACE/POD/Sunscapes.html) since the 1960s inultraviolet andx-ray light (http://imagine.gsfc.nasa.gov/docs/science/know_l2/sun.html), coronal holes are known to be the source ofthe high-speedsolar wind (http://www.spaceweathercenter.org/living_with_a_star/06/06.html), atoms and electronswhich flow outward (http://www.astrobio.net/pressrelease/3269/streams-of-the-sun) along the openmagnetic field lines (http://solar.physics.montana.edu/YPOP/Spotlight/Magnetic/).During periods of low activity,coronal holes typically coverregions just above the Sun's poles.But this extensive coronal holedominated the Sun's northern hemisphere earlier this week, capturedhere in extreme ultraviolet light by cameras onboardthe Solar Dynamics Observatory (http://sdo.gsfc.nasa.gov/).The solar wind streaming from this coronal holetriggered auroral displayson planet Earth (http://www.spaceweather.com/submissions/large_image_popup.php?image_name=Kjetil-Skogli-KSBH10_7826_1282754369.jpg).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100828.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/localcloud_frisch.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100829.html) The Local Fluff The stars are not alone. In the disk of our Milky Way Galaxy (http://antwrp.gsfc.nasa.gov/apod/milky_way.html) about 10 percent of visible matter is in the form of gas, called the interstellar medium (http://www-ssg.sr.unh.edu/ism/what1.html) (ISM). The ISM is not uniform (http://en.wikipedia.org/wiki/Local_Bubble), and shows patchiness (http://antwrp.gsfc.nasa.gov/apod/ap990503.html) even near our Sun (http://en.wikipedia.org/wiki/Sun). It can be quite difficult to detect the local ISM (http://en.wikipedia.org/wiki/Local_Interstellar_Cloud) because it is so tenuous and emits so little light. This mostly hydrogen gas, however, absorbs some very specific colors that can be detected in the light of the nearest stars (http://antwrp.gsfc.nasa.gov/apod/ap010318.html). A working map of the local ISM (http://antwrp.gsfc.nasa.gov/apod/ap980225.html) within 10 light-years based on recent observations is shown above. These observations show that our Sun is moving (http://antwrp.gsfc.nasa.gov/apod/ap020217.html) through a Local Interstellar Cloud (http://en.wikipedia.org/wiki/Local_Interstellar_Cloud) as this cloud flows outwards from the Scorpius-Centaurus Association (http://en.wikipedia.org/wiki/Scorpius-Centaurus_Association) star forming region. Our Sun may exit the Local Interstellar Cloud, also called the Local Fluff, during the next 10,000 years. Much remains unknown about the local ISM (http://csep10.phys.utk.edu/astr162/lect/milkyway/ism.html), including details of its distribution, its origin, and how it affects the Sun (http://bb.nightskylive.net/asterisk/viewtopic.php?f=24&t=18012) and the Earth (http://www.astronom.si/forum/earth.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100829.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/comancheoutcrop_spirit.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100830.html) Comanche Outcrop on Mars Indicates Hospitable Past Could life once have survived on Mars? Today, neither animal (http://tolweb.org/tree/) nor plant (http://en.wikipedia.org/wiki/Plant) life from Earth (http://antwrp.gsfc.nasa.gov/apod/ap070325.html) could survive for very long on Mars (http://antwrp.gsfc.nasa.gov/apod/mars.html) because at least one key ingredient -- liquid water (http://antwrp.gsfc.nasa.gov/apod/ap980530.html) -- is essentially absent on the red planet's rusty surface. Although evidence from the martian rovers (http://marsrovers.jpl.nasa.gov/home/index.html) indicates that long ago Mars might (http://antwrp.gsfc.nasa.gov/apod/ap040303.html) once have had liquid water on its surface, that water might also have been too acidic (http://www.ehow.com/list_6383560_dangers-acidic-water.html) for familiar life forms to thrive. Recently, however, a newly detailed analysis of an unusual outcropping of rock and soil chanced upon in 2005 by the robotic Spirit rover (http://antwrp.gsfc.nasa.gov/apod/ap051214.html) has uncovered a clue indicating that not all of Mars was always so acidic. The mound in question, dubbed Comanche (http://www.nasa.gov/mission_pages/mer/multimedia/gallery/pia10126-label.html) Outcrop and visible near the top of the above image (http://photojournal.jpl.nasa.gov/catalog/PIA13175), appears to contain unusually high concentrations of elements such as magnesium iron carbonate (http://en.wikipedia.org/wiki/Carbonate). The above image (http://photojournal.jpl.nasa.gov/catalog/PIA13175) is shown in colors exaggerated to highlight the differences in composition. Since these carbonates (http://en.wikipedia.org/wiki/Carbonates_on_Mars) dissolve (http://www.youtube.com/watch?v=uDBWUV6aTQE) in acid, the persistence of these mounds indicates that water perhaps less acidic (http://en.wikipedia.org/wiki/Acid) and more favorable for life (http://www.astro.wisc.edu/~townsend/static.php?ref=diploma-3) might have once flowed across Mars. More detailed analyses and searches for other signs will surely continue.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100830.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1008/gcenter_fernandez_annotated.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100831.html) The Annotated Galactic Center The sky toward the center of our Galaxy (http://en.wikipedia.org/wiki/Galactic_center) is filled with a wide variety of celestial wonders (http://antwrp.gsfc.nasa.gov/apod/ap090925.html), many of which are visible from a dark location with common binoculars (http://www.nightskyinfo.com/binoculars/). Constellations near the Galactic Center (http://www.youtube.com/watch?v=36xZsgZ0oSo) include Sagittarius (http://www.hawastsoc.org/deepsky/sgr/index.html), Libra (http://www.hawastsoc.org/deepsky/lib/index.html), Scorpius (http://www.hawastsoc.org/deepsky/sco/index.html), Scutum (http://www.hawastsoc.org/deepsky/sct/index.html), and Ophiuchus (http://www.hawastsoc.org/deepsky/oph/index.html). Nebulas include Messier (http://en.wikipedia.org/wiki/Charles_Messier) objects M8 (http://antwrp.gsfc.nasa.gov/apod/ap100805.html), M16 (http://antwrp.gsfc.nasa.gov/apod/ap090208.html), M20 (http://antwrp.gsfc.nasa.gov/apod/ap090707.html), as well as the Pipe (http://antwrp.gsfc.nasa.gov/apod/ap020526.html) and Cat's Paw (http://antwrp.gsfc.nasa.gov/apod/ap100421.html) nebulas. Visible open star clusters (http://en.wikipedia.org/wiki/Open_cluster) include M6 (http://antwrp.gsfc.nasa.gov/apod/ap990106.html), M7 (http://antwrp.gsfc.nasa.gov/apod/ap091108.html), M21 (http://en.wikipedia.org/wiki/Messier_21), M23 (http://en.wikipedia.org/wiki/Messier_23), M24 (http://antwrp.gsfc.nasa.gov/apod/ap040921.html), and M25 (http://antwrp.gsfc.nasa.gov/apod/ap090831.html), while globular star cluster (http://antwrp.gsfc.nasa.gov/apod/globular_clusters.html) M22 (http://antwrp.gsfc.nasa.gov/apod/ap010703.html) is also visible. A hole in the dust toward the Galactic Center (http://antwrp.gsfc.nasa.gov/apod/ap011229.html) reveals a bright region filled with distant stars known as Baade's Window (http://antwrp.gsfc.nasa.gov/apod/ap071219.html), which is visible between M7 (http://antwrp.gsfc.nasa.gov/apod/ap040222.html) and M8 (http://antwrp.gsfc.nasa.gov/apod/ap070804.html). Moving your cursor over the above image the will bring up an un-annotated version.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100831.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/earthmoon_messenger.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100901.html) Earth and Moon from MESSENGER What does Earth look like from the planet Mercury? The robotic spacecraft MESSENGER (http://messenger.jhuapl.edu/the_mission/index.html) found out as it looked toward the Earth (http://antwrp.gsfc.nasa.gov/apod/ap070325.html) during its closest approach to the Sun (http://en.wikipedia.org/wiki/Sun) about three months ago. The Earth and Moon (http://antwrp.gsfc.nasa.gov/apod/ap080903.html) are visible as the double spot on the lower left of the above image. Now MESSENGER was not at Mercury when it took the above image, but at a location (http://www.youtube.com/watch?v=otF2FjpCyZk) from which the view would be similar. From Mercury, both the Earth (http://antwrp.gsfc.nasa.gov/apod/ap030526.html) and its comparatively large moon (http://antwrp.gsfc.nasa.gov/apod/ap011015.html) will always appear as small circles of reflected sunlight and will never show a crescent (http://antwrp.gsfc.nasa.gov/apod/ap091213.html) phase. MESSENGER has zipped right by Mercury (http://antwrp.gsfc.nasa.gov/apod/ap080121.html) three times (http://antwrp.gsfc.nasa.gov/apod/ap081008.html) since being launched (http://antwrp.gsfc.nasa.gov/apod/ap040814.html) in 2004, and is scheduled to enter orbit around the innermost planet in March of 2011.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100901.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/ngc7635_jurasevich_900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100902.html)The Bubble NebulaBlown by the wind from a massive star, this interstellarapparition has a surprisinglyfamiliar shape (http://www.exploratorium.edu/ronh/bubbles/bubbles.html).Cataloged as NGC 7635, it is also known simplyas TheBubble Nebula (http://heritage.stsci.edu/1998/31/index.html).Although it looks delicate, the 10 light-year diameterbubble offers evidence ofviolent processes (http://antwrp.gsfc.nasa.gov/apod/ap080117.html) at work.Above and right of the Bubble's center is a hot,O-type star (http://antwrp.gsfc.nasa.gov/apod/ap070726.html), several hundred thousandtimes more luminous and approximately 45 times more massivethan the Sun.A fierce stellar wind and intense radiation from thatstar has blasted out thestructure of glowing gas (http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1995A%26A...295..509C)against denser materialin a surrounding (http://antwrp.gsfc.nasa.gov/apod/ap060428.html)molecularcloud (http://archive.ncsa.uiuc.edu/Cyberia/Bima/GMC.html).The intriguing Bubble Nebula lies a mere11,000 light-years away toward the boastful constellationCassiopeia (http://www.hawastsoc.org/deepsky/cas/index.html).A false-colorHubble palette (http://hubblesite.org/gallery/behind_the_pictures/meaning_of_color/eagle.php) was used to createthis sharp image andshows emission from sulfur, hydrogen, and oxygen atoms in red,green, and blue hues. The image data (http://www.starimager.com/Image%20Gallery%20Pages/Celestial%20Oddities/ngc%207635%20Bubble%20Nebula_false%20color_1250.ht ml)was recorded using a small telescope underclear, steady skies, from Mount Wilson Observatory.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100902.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/SMC_jarzyna_900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100903.html)The Small Cloud of MagellanPortuguese navigatorFerdinand Magellan (http://www.fordham.edu/halsall/mod/1519magellan.html) and his crew had plentyof time to study the southern sky during thefirst circumnavigation of planet Earth.As a result, two celestial wonderseasily visible for southern hemisphere skygazersare known as the Clouds of Magellan.These cosmic clouds are now understood to be dwarfirregular galaxies,satellitesof our larger spiral (http://www.atlasoftheuniverse.com/sattelit.html) Milky Way Galaxy.The SmallMagellanic Cloud (http://www.seds.org/messier/xtra/ngc/smc.html)actually spans 15,000 light-years or soand contains several hundred million stars.About 210,000 light-years away in the constellationTucana (http://www.hawastsoc.org/deepsky/tuc/),it is more distant than other known Milky Waysatellite galaxies, including theCanis Major (http://www.seds.org/messier/more/cma_dw.html)andSagittariusDwarf (http://www.seds.org/messier/more/sagdeg.html) galaxies and theLargeMagellanic Cloud (http://www.seds.org/messier/xtra/ngc/lmc.html).Thissharp image (http://www.starrysite.com/index.php?site=galleryitem,218) also includes two foreground globularstar clusters NGC 362 (bottom right) and 47 Tucanae.Spectacular 47 Tuc (http://antwrp.gsfc.nasa.gov/apod/ap080826.html)anaeis a mere 13,000 light-years away and seen here to the left of theSmall Magellanic Cloud (http://coolcosmos.ipac.caltech.edu/cosmic_classroom/multiwavelength_astronomy/multiwavelength_museum/smc.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100903.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/NGC7129_crawford900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100904.html)Young Suns of NGC 7129Young suns still lie within dusty NGC 7129 (http://coolcosmos.ipac.caltech.edu/image_galleries/legacy/spitzer_n7129/caption.html), some3,000 light-years away toward the royalconstellationCepheus (http://www.astropix.com/HTML/E_SUM_N/CEPHEUSO.HTM).While these stars (http://arxiv.org/abs/0907.4252)are at a relatively tender age, only a few million years old, it is likelythat our own Sun formed in a similar stellar nursery somefive billion years ago.Most noticeable in thesharp, (zoomable) image (http://www.imagingdeepsky.com/Nebulae/NGC7129/NGC7129.htm) are thelovely bluish dust cloudsthat reflect (http://antwrp.gsfc.nasa.gov/apod/ap011228.html) the youthful starlight,but the smaller, deepred crescent shapes are also markers of energetic,young stellar objects.Known asHerbig-Haro (http://en.wikipedia.org/wiki/Herbig-Haro_object)objects, their shape and color ischaracteristic of glowing hydrogen gasshocked byjets (http://sparky.rice.edu/~hartigan/movies.html) streaming away from newborn stars.Ultimately the natal gas and dust in the regionwill be dispersed, thestarsdrifting apart (http://en.wikipedia.org/wiki/Open_cluster#Eventual_fate) as the loosecluster orbits the center of the Galaxy.At the estimated distance ofNGC 7129 (http://www.noao.edu/outreach/aop/observers/n7129.html), this telescopic view spansabout 40 light-years.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100904.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/0904/blackhole_hobart.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100905.html) GRO J1655-40: Evidence for a Spinning Black Hole In the center of a swirling whirlpool of hot gas is likely a beast that has never been seen directly: a black hole (http://cosmology.berkeley.edu/Education/BHfaq.html). Studies of the bright light emitted by the swirling gas (http://antwrp.gsfc.nasa.gov/apod/ap980723.html) frequently indicate not only that a black hole (http://antwrp.gsfc.nasa.gov/htmltest/rjn_bht.html) is present, but also likely attributes. The gas surrounding GRO J1655-40, for example, has been found to display an unusual flickering (http://www.sciencedaily.com/releases/2001/05/010502075229.htm) at a rate of 450 times a second. Given a previous mass estimate (http://adsabs.harvard.edu/abs/1997ApJ...477..876O) for the central object of seven times the mass of our Sun (http://antwrp.gsfc.nasa.gov/apod/sun.html), the rate of the fast flickering (http://arxiv.org/abs/astro-ph/0001167) can be explained (http://adsabs.harvard.edu/abs/2001ApJ...552L..49S) by a black hole (http://antwrp.gsfc.nasa.gov/apod/black_holes.html) that is rotating (http://www.youtube.com/watch?v=mXzwtp-KaoI) very rapidly. What physical mechanisms actually cause the flickering (http://heasarc.gsfc.nasa.gov/docs/xte/learning_center/discover_0896.html) -- and a slower quasi-periodic oscillation (QPO) -- in accretion disks (http://antwrp.gsfc.nasa.gov/apod/ap991219.html) surrounding black holes (http://antwrp.gsfc.nasa.gov/apod/ap010119.html) and neutron stars (http://www.astro.umd.edu/~miller/nstar.html) remains a topic of much research.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100905.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/vltlaser_beletsky.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100906.html) A Laser Strike at the Galactic Center Why are these people shooting a powerful laser into the center of our Galaxy? Fortunately, this is not meant to be the first step in a Galactic (http://en.wikipedia.org/wiki/Babylon_5) war (http://www.youtube.com/watch?v=e1nUn6vT1yc). Rather, astronomers at the Very Large Telescope (http://antwrp.gsfc.nasa.gov/apod/ap000707.html) (VLT) site in Chile (http://en.wikipedia.org/wiki/Chile) are trying to measure the distortions of Earth's ever changing atmosphere (http://antwrp.gsfc.nasa.gov/apod/ap000725.html). Constant imaging of high-altitude atoms excited by the laser -- which appear like an artificial star (http://antwrp.gsfc.nasa.gov/apod/ap050207.html) -- allow astronomers to instantly measure atmospheric blurring (http://www2.keck.hawaii.edu/optics/lgsao/lgsbasics.html). This information is fed back to a VLT telescope mirror which is then slightly deformed (http://en.wikipedia.org/wiki/Adaptive_optics) to minimize this blurring. In this case, a VLT was observing our Galaxy's center (http://www.astro.ucla.edu/~tanner/gcintro.html), and so Earth's atmospheric blurring in that direction was needed. As for inter-galaxy warfare (http://en.wikipedia.org/wiki/Star_wars), when viewed from our Galaxy's center (http://antwrp.gsfc.nasa.gov/apod/ap050403.html), no casualties are expected. In fact, the light from this powerful laser (http://www.eso.org/public/outreach/press-rel/pr-2007/pr-27-07.html) would combine with light from our Sun to together appear only as bright (http://www.oreilly.com/catalog/alien/chapter/ch07.html) as a faint and distant star.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100906.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/endeavourposter_nasa.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100907.html)Space Shuttle Tribute Poster: EndeavourThey are some of the most complex machines (http://spaceflight.nasa.gov/shuttle/upgrades/upgrades5.html) ever built.From a standing start they can launch a school (http://en.wikipedia.org/wiki/The_Magic_School_Bus)-bus sized object up so high and moving so fast that it won't fall (http://en.wikipedia.org/wiki/Low_Earth_orbit) back down.They have launched numerous revolutionary satellites (http://en.wikipedia.org/wiki/Satellites) that enable humans to communicate (http://antwrp.gsfc.nasa.gov/apod/ap100111.html) across the globe, to better understand Earth's atmosphere (http://en.wikipedia.org/wiki/Upper_Atmosphere_Research_Satellite), and to peer into the distance universe (http://www.stsci.edu/hst/HST_overview/).They are NASA's Space Shuttles (http://spaceflight.nasa.gov/shuttle/upgrades/upgrades5.html), and NASA has recently released large digital posters (http://www.universetoday.com/72687/downloadable-shuttle-tribute-posters/) to honor them.While the inaugural flight (http://antwrp.gsfc.nasa.gov/apod/ap990411.html) was in 1981, the shuttle fleet is aging and is now nearing (http://www1.nasa.gov/mission_pages/transition/home/index.html) retirement.Pictured above (http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=48499), the space shuttle Endeavour (http://antwrp.gsfc.nasa.gov/apod/ap100209.html) is shown rising to orbit (http://antwrp.gsfc.nasa.gov/apod/ap080316.html), with patches (http://history.nasa.gov/shuttle_patches.html) for each of its missions shown in a spiral.Endeavour (http://en.wikipedia.org/wiki/Space_Shuttle_Endeavour) was named for the HMS Endeavour (http://en.wikipedia.org/wiki/HMS_Endeavour), a British research ship that explored the south Pacific Ocean in the 1700s, depicted on the lower right.On the upper right are panoramic windows (http://antwrp.gsfc.nasa.gov/apod/ap100224.html) delivered by Endeavour to the International Space Station (http://antwrp.gsfc.nasa.gov/apod/ap091207.html) earlier this year.In the background near the top is the NGC 602 (http://antwrp.gsfc.nasa.gov/apod/ap100403.html) nebula as imaged by the Hubble Space Telescope (http://www.nasa.gov/mission_pages/hubble/main/index.html), which was serviced by Endeavour in 1993. Posters for (http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=48495) all (http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=48496) of (http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=48497) the (http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=48498) shuttles (http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=48499), including Atlantis (http://www-pao.ksc.nasa.gov/kscpao/images/large/2010-4450.jpg), Challenger (http://www-pao.ksc.nasa.gov/kscpao/images/large/2010-4451.jpg), Columbia (http://www-pao.ksc.nasa.gov/kscpao/images/large/2010-4452.jpg), Discovery (http://www-pao.ksc.nasa.gov/kscpao/images/large/2010-4453.jpg), Endeavour (http://www-pao.ksc.nasa.gov/kscpao/images/large/2010-4454.jpg) are available.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100907.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/ngc4911_hst.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100908.html)NGC 4911: Spiral Diving into a Dense ClusterWhy are there faint rings around this spiral galaxy?Possibly because the galaxy,NGC 4911 (http://heritage.stsci.edu/2010/24/caption.html), is being pulled at by its neighbors as it falls into the enormousComa Cluster of Galaxies (http://antwrp.gsfc.nasa.gov/apod/ap100502.html).If NGC 4911 ends up like most of the galaxies in thecentral Coma cluster, it will become a yellowishelliptical galaxy (http://en.wikipedia.org/wiki/Elliptical_galaxy),losing not only its outer layers, but dust, gas, and its cadre of surroundingsatellite galaxies (http://www.atlasoftheuniverse.com/sattelit.html) as well.Currently, however, this process (http://en.wikipedia.org/wiki/Galaxy_formation_and_evolution) is just beginning.Visible in the above deep image (http://www.spacetelescope.org/images/opo1024a/) from theHubble Space Telescope (http://www.youtube.com/watch?v=SpkrVw_E6Nw) are NGC 4911's bright nucleus, distorted spiral arms laced with dark dust, clusters of recently formed stars, unusual faint outer rings, dwarf companion galaxies, and even faintglobular clusters (http://antwrp.gsfc.nasa.gov/apod/globular_clusters.html) of stars.Far in the distance (http://bb.nightskylive.net/asterisk/viewtopic.php?f=24&t=18004) many unassociated galaxies (http://antwrp.gsfc.nasa.gov/apod/ap040309.html)from the early universe (http://adsabs.harvard.edu/abs/2008AmJPh..76..265N) are visible, some even throughNGC 4911 (http://en.wikipedia.org/wiki/NGC_4911) itself.The Coma Cluster (http://arxiv.org/abs/0906.4443) contains over 1,000 galaxies making it among the most massive objects known.NGC 4911 can be found (http://en.wikipedia.org/wiki/File:Comacl_zentrum600.png) to the lower left of the great cluster's center.



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[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/BubblesTrunk_andreo600h.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100909.html)Cepheus: Trunk to BubbleStar clusters, glowing nebulaeand dark dust cloudsaboundin Cepheus (http://www.astropix.com/HTML/E_SUM_N/CEPHEUSO.HTM), royal constellation ofthe northern hemisphere.You can follow them in amazing detail across this broadskyscape (http://blog.deepskycolors.com/nebulas.html),a mosaic of telescopic images spanning about 17 degrees.Beginning at the lower left, the large emission nebulais cataloged as IC 1396 (http://antwrp.gsfc.nasa.gov/apod/ap090819.html).Hundreds of light-years across and about 3,000 light-years distant,it contains a dark, winding, tendril-shaped feature popularly knownas the Elephant's Trunk (http://antwrp.gsfc.nasa.gov/apod/ap081226.html).Near the top middle, the bright nebula with an embedded star clusteris NGC 7380 (http://seds.org/messier/xtra/ngc/n7380.html).At the upper right lies NGC 7635(the Bubble Nebula (http://antwrp.gsfc.nasa.gov/apod/ap100902.html)) andstar cluster M52 (http://antwrp.gsfc.nasa.gov/apod/ap091030.html).Put your cursor over the picture to see a labeled versionof the field.Many of the objects highlighted have a designation from thesecond version of theSharplesscatalog (http://galaxymap.org/cgi-bin/sharpless.py?s=1) (Sh2) and theBarnard catalog (http://www.library.gatech.edu/search/digital_collections/barnard/index.html) (B) of dark nebulae.Associated with star formation, the sites are telltale markers alongthe region's complex (http://arxiv.org/abs/0809.4761) of giantmolecular clouds (http://www.nasa.gov/mission_pages/spitzer/news/spitzer-20090812.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100909.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/vela_lorenzi_c0.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100910.html)Vela Supernova RemnantThe plane of our Milky Way Galaxy runs through thiscomplexand beautiful skyscape (http://astrosurf.com/lorenzi/ccd/vela_HaOIIIRGB.htm).At the northwestern edge of the constellationVela (http://www.hawastsoc.org/deepsky/vel/index.html)(the Sails) the four frame mosaic is over 10 degrees wide,centered on the glowing filaments of theVelaSupernova Remnant (http://fuse.pha.jhu.edu/~wpb/hstvela/hstvela.html), the expanding debris cloud from thedeath explosion of a massive star.Light from the supernova explosionthat created (http://antwrp.gsfc.nasa.gov/apod/ap960612.html) the Vela remnantreached Earth about 11,000 years ago.In addition to the shocked filaments of glowing gas, the cosmiccatastrophe also left behind an incredibly dense,rotating stellar core, the Vela Pulsar (http://antwrp.gsfc.nasa.gov/apod/ap000609.html).Some 800 light-years distant, the Vela remnant is likelyembedded (http://antwrp.gsfc.nasa.gov/apod/ap020217.html)in a larger and older supernova remnant, theGum Nebula (http://antwrp.gsfc.nasa.gov/apod/ap060519.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100910.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/ngc5055_gabany_sm.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100911.html) Star Streams and the Sunflower Galaxy A bright spiral galaxy of the northern sky, Messier 63 (http://seds.org/messier/m/m063.html) is about 25 million light-years distant in the loyal constellation Canes Venatici (http://en.wikipedia.org/wiki/Canes_Venatici). Also cataloged as NGC 5055, the majestic island universe (http://antwrp.gsfc.nasa.gov/apod/ap100109.html) is nearly 100,000 light-years across, about the size of our own Milky Way (http://antwrp.gsfc.nasa.gov/apod/ap080104.html). Known by the popular moniker, The Sunflower Galaxy, M63 sports a bright yellowish core and sweeping blue spiral arms, streaked with cosmic dust lanes and dotted with pink star forming regions. This deep exposure also reveals (http://www.cosmotography.com/images/small_ngc5055.html) an enormous but dim arc extending far into the halo above the brighter galactic plane. A collaboration of professional and amateur astronomers has shown the arc to be consistent with the stellar stream from a smaller satellite galaxy, tidally disrupted as it merged with M63 during the last 5 billion years. Their discovery is part of an increasing body of evidence (http://arxiv.org/abs/1003.4860) that the growth of large spirals by cannibalizing smaller galaxies (http://www.cosmotography.com/images/ galaxy_cannibalism.html) is commonplace in the nearby Universe (http://www.cosmotography.com/images/ stellar_stream_survey_science_highlights.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100911.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/oklo15_curtin.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100912.html)Oklo: Ancient African Nuclear ReactorsThe remnants ofnuclear reactors (http://www.howstuffworks.com/nuclear-power.htm) nearly two billion years old werefound in the 1970s in Africa. These reactors (http://oklo.curtin.edu.au/)are thought to have occurred naturally.No natural reactors exist today, as the relative density offissile (http://www.nrc.gov/reading-rm/basic-ref/glossary/fissile-material.html)uranium (http://periodic.lanl.gov/elements/92.html)has now decayed below that needed for a sustainable reaction.Pictured above (http://oklo.curtin.edu.au/when.cfm) is Fossil Reactor 15, located inOklo (http://en.wikipedia.org/wiki/Oklo),Gabon (https://www.cia.gov/library/publications/the-world-factbook/geos/gb.html).Uranium oxide (http://en.wikipedia.org/wiki/Uraninite)remains are visible as the yellowish rock. Oklo (http://www.curtin.edu.au/curtin/centre/waisrc/OKLO/Where/Where.html) by-products are being used today toprobe the stability of thefundamental constants (http://en.wikipedia.org/wiki/Fine_structure_constant) over cosmologicaltime (http://adsabs.harvard.edu/abs/2006APS..SES.BC001G)and distance scalesand to develop more effective means for disposing of human-manufacturednuclear waste (http://www.nwtrb.gov/).



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[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/zodiacal_dobesberger.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100913.html)Zodiacal Light Over NamibiaAn unusual triangle of light is visible this time of year just before dawn,in the northern hemisphere.Once considered a false dawn (http://en.wikipedia.org/wiki/Zodiacal_light), this triangle of light is actuallyzodiacal light (http://home.wanadoo.nl/marco.langbroek/zodiac.html), light reflected frominterplanetary dust particles (http://antwrp.gsfc.nasa.gov/apod/ap010813.html). The bright reflecting triangle (http://www.youtube.com/watch?v=bL1OCcorbJc) is clearly visible on the right of theabove horizontally-compressed image taken just after sunset from Namibia (http://en.wikipedia.org/wiki/Namibia) in the southern hemisphere in 2009 June.The centralband (http://antwrp.gsfc.nasa.gov/apod/ap090127.html) of ourMilky Way Galaxy (http://antwrp.gsfc.nasa.gov/apod/ap070930.html) on the left first mirrors the zodiacal band on the right but then curves around the sky. The faint smudges inside the arch of the Milky Way are the Large and Small Magellanic Clouds.Zodiacal dust (http://coolcosmos.ipac.caltech.edu/cosmic_classroom/cosmic_reference/zodydust.html)orbits the Sun (http://en.wikipedia.org/wiki/Sun)predominantly in the same plane as the planets: theecliptic (http://antwrp.gsfc.nasa.gov/apod/ap001014.html). Zodiacal light (http://www.as.wvu.edu/~jel/skywatch/skw9810h.html) is so bright in the north this time of year because thedust band (http://antwrp.gsfc.nasa.gov/apod/ap000517.html) is orientednearly vertical at sunrise, so that the thick air near thehorizon (http://antwrp.gsfc.nasa.gov/apod/ap100216.html) does not blockout relatively bright reflecting dust. Zodiacal light (http://antwrp.gsfc.nasa.gov/apod/ap020915.html) is also bright forpeople (http://antwrp.gsfc.nasa.gov/apod/ap100725.html)in Earth's northern hemisphere in March and April just after sunset.In the southern hemisphere,zodiacal light (http://www.as.wvu.edu/~jel/skywatch/skw9810h.html) is mostnotable (http://antwrp.gsfc.nasa.gov/apod/ap100320.html) after sunset in late summer,and brightest before sunrise in late spring.



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[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/llpegspiral_hst.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100914.html) An Extraordinary Spiral from LL Pegasi What created the strange spiral structure on the left? No one is sure, although it is likely related to a star in a binary star (http://antwrp.gsfc.nasa.gov/apod/ap970219.html) system entering the planetary nebula (http://en.wikipedia.org/wiki/Planetary_nebula) phase, when its outer atmosphere is ejected. The huge spiral spans about a third of a light year (http://chandra.harvard.edu/photo/cosmic_distance.html) across and, winding four or five complete turns, has a regularity that is without precedent. Given the expansion rate of the spiral (http://en.wikipedia.org/wiki/Spiral) gas, a new layer must appear about every 800 years, a close match to the time it takes for the two stars to orbit each other. The star system that created it is most commonly known as LL Pegasi, but also AFGL 3068. The unusual structure itself has been cataloged as IRAS 23166+1655 (http://en.wikipedia.org/wiki/IRAS_23166%2B1655). The above image (http://www.spacetelescope.org/images/potw1020a/) was taken in near- infrared (http://science.hq.nasa.gov/kids/imagers/ems/infrared.html) light by the Hubble Space Telescope (http://antwrp.gsfc.nasa.gov/apod/ap090525.html). Why the spiral glows (http://www.math.smith.edu/phyllo//Applets/Spiral/Spiral330.html) is itself a mystery, with a leading hypothesis being illumination by light reflected from nearby stars.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100914.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/venusmoon_pascual.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100915.html) Clouds, Birds, Moon, Venus Sometimes the sky above can become quite a show. Last week, for example, the Moon and Venus converged (http://bb.nightskylive.net/asterisk/viewtopic.php?f=29&t=21078), creating quite a sight (http://antwrp.gsfc.nasa.gov/apod/ap100516.html) by itself for sky enthusiasts (http://antwrp.gsfc.nasa.gov/apod/ap050913.html) around the globe (http://www.youtube.com/watch?v=X5DqY_q86xQ). From some locations, though, the sky was even more picturesque. In the above image taken last week from Spain (http://en.wikipedia.org/wiki/Spain), a crescent Moon and the planet Venus, on the far right, were captured during sunset posing against a deep blue sky. In the foreground, dark storm cloud (http://antwrp.gsfc.nasa.gov/apod/ap080122.html)s loom across the image bottom, while a white anvil cloud (http://antwrp.gsfc.nasa.gov/apod/ap040218.html) shape appears above. Black specks dot the frame, caused by a flock of birds (http://www.youtube.com/watch?v=81wFZavdhPU) taking flight. Very soon after this picture was taken, however, the birds passed by, the storm ended, and Venus and the Moon set. The Moon and Venus have now separated, although Venus will remain visible (http://www.almanac.com/sun/rise/) at sunset for the rest of this month.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100915.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/Veil_pugh_900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100916.html)The Veil NebulaDelicate in appearance, these filaments of shocked, glowing gas,draped in planet Earth's sky toward the constellation of Cygnus,make up theVeil Nebula (http://spider.seds.org/spider/Misc/veil.html).The nebula is a largesupernova remnant (http://chandra.harvard.edu/xray_sources/supernovas.html), an expandingcloud born of the death explosion of a massive star.Light from the original supernova explosion likely reachedEarth over 5,000 years ago.Also known as the Cygnus Loop, theVeil Nebula (http://archive.stsci.edu/fuse/scisumm/sci_cyglpstar.html) now spans nearlynearly 3 degrees or about 6 times the diameter ofthe full Moon.That translates to over 70 light-years atat its estimated distance of 1,500 light-years.In fact, the Veil is so large its brighter parts arerecognized as separate nebulae, including TheWitch's Broom (http://antwrp.gsfc.nasa.gov/apod/ap070101.html)(NGC 6960) at the bottom ofthis stunning skyview (http://www.martinpughastrophotography.id.au/Nebulae/Veil_Nebula_FLI.htm) andPickering's Triangle (http://antwrp.gsfc.nasa.gov/apod/ap080701.html) (NGC 6979)below and right of center.At the top is the haunting IC 1340 (http://antwrp.gsfc.nasa.gov/apod/ap081101.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100916.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/AuroraPrelude_takasaka600h.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100917.html) Northern Lights over Prelude Lake Curtains of shimmering (http://antwrp.gsfc.nasa.gov/apod/ap091219.html) green light sprawl across this gorgeous night skyscape. In the foreground lies the peaceful Prelude Lake, located about 30 kilometers east of Yellowknife, Northwest Territories, Canada. From high northern latitudes (http://www.gedds.alaska.edu/AuroraForecast/) these mesmerizing northern lights, also known as the aurora borealis (http://odin.gi.alaska.edu/FAQ/), are becoming a more familiar sight (http://spaceweather.com/aurora/gallery_01sep10.htm). As the September 23rd equinox approaches, nights grow longer and a favorable season for aurora (http://science.nasa.gov/science-news/science-at-nasa/2002/ 23sep_auroraseason/) begins. Recorded on September 11 (http://www.blue-moon.ca/2010sep.html), this panoramic scene spans about 180 degrees. Brighter stars peering through the auroral glow at the left form the recognizable northern asterism, the Big Dipper (http://antwrp.gsfc.nasa.gov/apod/ap050218.html). A more compact Pleiades star cluster (http://antwrp.gsfc.nasa.gov/apod/ap071122.html) shines at the far right.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100917.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/pano3s2aa_tafreshi600w.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100918.html) Opposite the Sun Chances are the brightest star (http://science.nasa.gov/science-news/science-at-nasa/2010/ 15sep_jupiter/) you've seen lately is actually planet Jupiter. Jupiter rules (http://www.jpl.nasa.gov/news/ news.cfm?release=2010-293) the sky in this labeled view of a starry September night (http://www.twanight.org/newTWAN/ photos.asp?ID=3002746) from the Alborz mountains in Iran, complete with the trail of a red flashlight illuminating the mountain road. On September 21st (Universal Time (http://www.usno.navy.mil/USNO/astronomical-applications/ astronomical-information-center/universal-time)) Jupiter will be at opposition, the point opposite the Sun (http://astronomy.swin.edu.au/cosmos/O/Opposition) along its orbit, rising just as the Sun sets. For this opposition (http://www.skyandtelescope.com/observing/highlights/ 102951429.html), Jupiter will be slightly brighter and closer to planet Earth than in any year since 1963. Much fainter and also approaching its own opposition on September 21st, is the distant planet Uranus. Very near Jupiter on the sky, the fainter planet is easy to spot in binoculars (similar to the inset view), well above and right of brilliant Jupiter and about as bright as one of Jupiter's own Galilean moons (http://antwrp.gsfc.nasa.gov/apod/ap091023.html). Remarkably close to the opposition of both planets, the point on the sky exactly opposite the Sun on September 23rd is marked the Vernal Equinox (http://en.wikipedia.org/wiki/Equinox). On that date, a Full Moon will join the celestial scene. Of course (http://starchild.gsfc.nasa.gov/docs/StarChild/questions/ question3.html), any Full Moon is also (http://www.astro.wisc.edu/~dolan/java/ MoonPhase.html) at opposition.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100918.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/carinablue_hst.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100919.html)Dark Clouds of the Carina NebulaWhat dark forms lurk in the mists of the Carina Nebula?These ominous figures are actually molecular clouds (http://en.wikipedia.org/wiki/Molecular_clouds), knots of molecular gas and dust (http://antwrp.gsfc.nasa.gov/apod/ap030706.html) so thick they have become opaque (http://antwrp.gsfc.nasa.gov/apod/ap080323.html). In comparison, however, these clouds (http://www.youtube.com/watch?v=YDNiYGuzZPM) are typically much less dense than Earth's atmosphere (http://www.windows.ucar.edu/tour/link=/earth/Atmosphere/layers.html). Pictured above is part of the most detailed image of the Carina Nebula (http://antwrp.gsfc.nasa.gov/apod/ap090524.html) ever taken, a part where dark molecular clouds (http://antwrp.gsfc.nasa.gov/apod/ap050110.html) are particularly prominent. The image has recently been retaken and then re-colored (http://heritage.stsci.edu/2010/29/bio/bio_primary.html) based on light emitted by oxygen.The entire Carina Nebula (http://en.wikipedia.org/wiki/Carina_Nebula) spans over 300 light years (http://chandra.harvard.edu/photo/cosmic_distance.html) and lies about 7,500 light-years away in the constellation (http://www.ianridpath.com/startales/startales3.htm) of Carina.NGC 3372, known as the Great Nebula in Carina (http://antwrp.gsfc.nasa.gov/apod/ap990719.html), is home to massive stars and changing nebula. Eta Carinae (http://en.wikipedia.org/wiki/Eta_Carinae), the most energetic star in the nebula, was one of the brightest stars in the sky in the 1830s, but then faded dramatically (http://www.aavso.org/vsots_etacar). Wide-field annotated and zoomable versions of the larger image composite are also available.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100919.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/aurora_salomonsen.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100920.html)Aurora Over NorwayAuroras can make spectacular sights.Photographed above (http://www.flickr.com/photos/salomonsen/4998417812/) last weekend, flowing multi-colored auroras helped illuminate a busy sky above Troms? (http://en.wikipedia.org/wiki/Troms?),Norway (http://en.wikipedia.org/wiki/Norway).Besides thespectacular aurora (http://www.youtube.com/watch?v=icugqEEOgkg) pictured above, the photographer caught three satellites streaks, one airplane streak, and afriend (http://maryt.files.wordpress.com/2008/06/boy-s-best-friend-posters.jpg) trying tocapture (http://spaceweather.com/aurora/gallery_01sep10.htm)the same sight.Although auroras (http://www.exploratorium.edu/learning_studio/auroras/) might first appear to be moonlit clouds,they only add light to the sky and do notblock background stars from view.Called northern lights (http://en.wikipedia.org/wiki/Aurora_(astronomy)) in the northern hemisphere,auroras (http://www.geo.mtu.edu/weather/aurora/) are caused bycollisions betweencharged particles (http://www-spof.gsfc.nasa.gov/Education/Ielect.html) from themagnetosphere (http://en.wikipedia.org/wiki/Magnetosphere)and air molecules high in the Earth's atmosphere.If viewed from space, auroras can beseen to glow (http://antwrp.gsfc.nasa.gov/apod/ap000916.html) inX-ray (http://chandra.harvard.edu/xray_astro/xrays.html) and ultraviolet light as well. Predictable auroras (http://www.gedds.alaska.edu/AuroraForecast/)might occur a few days after apowerful magnetic event (http://antwrp.gsfc.nasa.gov/apod/ap031029.html)has been seen on the Sun.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100920.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/starryrhone_vangogh.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100921.html) Starry Night Over the Rhone How can the majesty of the night sky best be captured in a painting? This was a continual challenge for Vincent van Gogh (http://en.wikipedia.org/wiki/Vincent_van_Gogh), a famous painter in the late 1800s who pioneered stirring depictions of star filled skies (http://antwrp.gsfc.nasa.gov/apod/ap091011.html) into several of his works. Pictured above is van Gogh's Starry Night Over the Rhone (http://en.wikipedia.org/wiki/Starry_Night_Over_the_Rhone), where the French town of Arles is depicted complete with gas lights reflecting off the Rhone river (http://en.wikipedia.org/wiki/Rhône_River). van Gogh's night sky appears alive with turbulent (http://www.nature.com/news/2006/060703/full/news060703-17.html) stellar images contrasting with lofty (http://www.youtube.com/watch?v=TopJpfhbvNQ) dark blue hues. Above the river, one can discern the stars of the familiar Big Dipper asterism. Following a line connecting the two Big Dipper stars on the right (http://antwrp.gsfc.nasa.gov/apod/ap070108.html), the North Star Polaris (http://antwrp.gsfc.nasa.gov/apod/ap991006.html) could be easily found (http://antwrp.gsfc.nasa.gov/apod/image/1009/starryrhone_vangogh_annotated.jpg), the height of which can then be estimated and actually gives the latitude (http://en.wikipedia.org/wiki/Latitude) where the painting was created.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100921.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/shuttleshadow_atkinson.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100922.html)Discovery Rollout ShadowWho goes there (http://en.wikipedia.org/wiki/Who_Goes_There%3F)? Although the spotlighted figure in white might not be identifiable by itself, surely the huge shadow behind it makes its identity clear: thespace shuttle (http://antwrp.gsfc.nasa.gov/apod/ap100907.html). Specifically, it was thespace shuttle Discovery (http://www.nasa.gov/centers/kennedy/shuttleoperations/orbiters/orbitersdis.html) being rolled out last March in preparation for launch.As captured above (http://www.nancyatkinson.com/blog/2010/03/24/beyond-a-shadow-of-a-doubt-the-space-shuttle-is-gorgeous/), an unusualmonstrous shadow (http://www.youtube.com/watch?v=Ju8Cgk6sbQY) on passing fog was created during apicturesque night unveiling.While on theshuttle Crawler-Transporter (http://antwrp.gsfc.nasa.gov/apod/ap020304.html), one of the largest tracked vehicles (http://antwrp.gsfc.nasa.gov/apod/ap060708.html) on Earth, the shuttle moved at about 2 km per hour from the main assembly building to the launch pad at NASA'sKennedy Space Center (http://www.nasa.gov/centers/kennedy/about/history/index.html) inFlorida (http://en.wikipedia.org/wiki/Florida),USA (https://www.cia.gov/library/publications/the-world-factbook/geos/us.html).About a month later, in its penultimate planned mission,Discovery roared (http://antwrp.gsfc.nasa.gov/apod/ap050727.html) off the launch pad anddelivered needed supplies (http://en.wikipedia.org/wiki/STS-131) and equipment to theInternational Space Station (http://www.ehow.com/how_2289621_view-international-space-station.html).Yesterday, Discovery reached Launch Pad 39A (http://en.wikipedia.org/wiki/Launch_pad_39A) in preparation for its last planned mission (http://www.nasa.gov/mission_pages/shuttle/main/index.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100922.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/sdoEquinox_0171_c900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100923.html) Equinox and the Iron Sun Today, the Sun crosses the celestial equator heading south at 03:09 Universal Time (http://www.usno.navy.mil/USNO/astronomical-applications/ astronomical-information-center/universal-time). Known as an equinox, this astronomical event (http://www.phy6.org/stargaze/Sseason.htm) marks the first day of autumn in the northern hemisphere and spring in the south. Equinox means equal night (http://hyperphysics.phy-astr.gsu.edu/Hbase/eclip.html#c5). With the Sun on the celestial equator, Earth dwellers (http://antwrp.gsfc.nasa.gov/apod/ap030923.html) will experience nearly (http://www.usno.navy.mil/USNO/astronomical-applications/ astronomical-information-center/equinoxes) 12 hours of daylight and 12 hours of darkness. Of course, in the north the days continue to grow shorter, the Sun marching (http://antwrp.gsfc.nasa.gov/apod/ap040320.html) lower in the sky as winter approaches. To celebrate (http://sdo.gsfc.nasa.gov/data/) the equinox, consider this view of the Sun in extreme ultraviolet light from the Sun staring Solar Dynamics Observatory (http://sdo.gsfc.nasa.gov/). Recorded yesterday, the false-color image shows emission from highly ionized iron atoms (http://www.uky.edu/Projects/Chemcomics/ index.html). Loops and arcs trace the glowing plasma (http://sdo.gsfc.nasa.gov/gallery/ main.php?v=item&id=32) suspended in magnetic fields above solar active regions (http://www.spaceweatherlive.com/ index.php?zon=beelden&SDO=AIA-171&lang=EN).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100923.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/harvestmoon100922_abraham900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100924.html) Equinox and the Harvest Moon Did you enjoy the moonlight last night? The Full Moon closest to autumnal equinox and the beginning of Fall is traditionally known as the Harvest Moon (http://earthsky.org/astronomy-essentials/ harvest-moon-2), rising opposite the Sun and illuminating fields at harvest time after sunset. This year's northern hemisphere autumnal equinox occurred yesterday, September 23rd (http://antwrp.gsfc.nasa.gov/apod/ap100923.html), at 03:09 Universal Time. The Moon was at its full phase (http://en.wikipedia.org/wiki/Lunar_phase) a mere 6 hours later -- exceptionally close for a Harvest Moon! (http://science.nasa.gov/science-news/science-at-nasa/2010/ 22sep_harvestmoon/) Of course, the Moon still shines brightly through the night in surrounding days. In this picture from September 22nd, the lunar orb (http://lro.gsfc.nasa.gov/moonfacts.html) dominates the sky above a ruined church in Zs&aacute;mb&eacute;k, Hungary . Shining nearby, the brightest star is actually Jupiter, also opposite the Sun (http://antwrp.gsfc.nasa.gov/apod/ap100918.html), seen here through thin clouds just left of the church wall.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100924.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/IC1805Crop_santiago800.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100925.html) Melotte 15 in the Heart Cosmic clouds (http://antwrp.gsfc.nasa.gov/apod/ap080715.html) seem to form fantastic shapes (http://antwrp.gsfc.nasa.gov/apod/ap080502.html) in the central regions of emission nebula IC 1805. Of course, the clouds are sculpted by stellar winds and radiation from massive hot stars in the nebula's newborn (http://chandra.harvard.edu/edu/formal/stellar_ev/ story/index9.html) star cluster, Melotte (http://adsabs.harvard.edu/full/1962QJRAS...3...48.) 15. About 1.5 million years young, the cluster stars are near the center in this colorful skyscape (http://www.pbase.com/dsantiago/image/128072224), along with dark dust clouds (http://hubblesite.org/newscenter/newsdesk/archive/ releases/2006/13/) silhouetted against glowing atomic gas (http://antwrp.gsfc.nasa.gov/apod/ap071102.html). A composite of narrow and broad band telescopic images, the view spans about 40 light-years and includes emission from hydrogen in green, sulfur in red, and oxygen in blue hues. Wider field (http://antwrp.gsfc.nasa.gov/apod/ap040917.html) images reveal that IC 1805's simpler, overall outline suggests its popular name - The Heart Nebula (http://www.atlasoftheuniverse.com/nebulae/ic1805.html). IC 1805 is located about 7,500 light years away toward the constellation Cassiopeia (http://en.wikipedia.org/wiki/ Cassiopeia_(constellation)).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100925.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/tadpole_hst.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100926.html) Arp 188 and the Tadpole's Tidal Tail Why does this galaxy have such a long tail? In this stunning vista recorded with the Hubble Space Telescope's Advanced Camera for Surveys (http://hubblesite.org/sci.d.tech/nuts_.and._bolts/ instruments/acs/), distant galaxies form a dramatic backdrop for disrupted spiral galaxy Arp (http://nedwww.ipac.caltech.edu/level5/Arp/frames.html) 188, the Tadpole Galaxy. The cosmic (http://antwrp.gsfc.nasa.gov/apod/ap040123.html) tadpole is a mere 420 million light-years distant toward the northern constellation Draco (http://www.astro.wisc.edu/~dolan/ constellations/constellations/Draco.html). Its eye-catching tail is about 280 thousand light-years long and features massive, bright blue star clusters. One story (http://www.boop.org/jan/justso/) goes that a more compact intruder galaxy crossed in front of Arp 188 - from left to right in this view - and was slung around behind the Tadpole (http://en.wikipedia.org/wiki/Tadpole_Galaxy) by their gravitational attraction. During the close encounter (http://antwrp.gsfc.nasa.gov/apod/ap041121.html), tidal forces drew out the spiral galaxy's (http://www.cita.utoronto.ca/~dubinski/tflops/) stars, gas, and dust forming the spectacular tail. The intruder (http://antwrp.gsfc.nasa.gov/apod/ap970224.html) galaxy itself, estimated to lie about 300 thousand light-years behind the Tadpole, can be seen through foreground spiral arms at the lower left. Following (http://www.exploratorium.edu/frogs/) its terrestrial namesake (http://www.offwell.free-online.co.uk/ metindex.htm), the Tadpole Galaxy will likely lose its tail (http://adsabs.harvard.edu/abs/1972ApJ...178..623T) as it grows older, the tail's star clusters forming smaller satellites of the large spiral galaxy.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100926.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/neonsaturnaurora_cassini.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100927.html)The Dancing Auroras of SaturnWhat drives auroras on Saturn?To help find out, scientists have sorted through hundreds of infrared images of Saturn (http://en.wikipedia.org/wiki/Saturn) taken by the Cassini spacecraft (http://www.esa.int/esaMI/Cassini-Huygens/SEMD6E2VQUD_0.html) for other purposes, trying to find enough aurora images to correlate changes and make movies (http://www.youtube.com/watch?v=fzwiTspxtrg).Once made, some movies clearly show that Saturnian auroras (http://antwrp.gsfc.nasa.gov/apod/ap081119.html) can change not only with the angle of the Sun, but also as the planet rotates.Furthermore, some auroral changes (http://www.youtube.com/watch?v=7AmyfuJDMlY) appear related to waves in Saturn's magnetosphere (http://en.wikipedia.org/wiki/Magnetosphere) likely caused by Saturn's moons.Pictured above (http://photojournal.jpl.nasa.gov/catalog/PIA13402), a false-colored image taken in 2007 shows Saturn in three bands of infrared light. The rings reflect (http://antwrp.gsfc.nasa.gov/apod/ap070627.html) relatively blue sunlight, while the planet itself glows in comparatively low energy red. A band of southern aurora (http://antwrp.gsfc.nasa.gov/apod/ap050222.html) in visible in green.Inspection of many more Saturnian images may well lead to an even better understanding of both Saturn's and Earth's auroras (http://antwrp.gsfc.nasa.gov/apod/ap100701.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100927.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/southernvortex_venusexpress.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100928.html) Venus' South Polar Vortex What's happening over the South Pole of Venus? To find out, scientists have been studying images taken by the robotic Venus Express spacecraft (http://www.esa.int/SPECIALS/Venus_Express/SEMBD3808BE_0.html) when it passes over the lower spin axis of Earth's overheated twin. Surprisingly, recent images from Venus Express (http://en.wikipedia.org/wiki/Venus_Express) do not confirm previous sightings (http://antwrp.gsfc.nasa.gov/apod/ap070501.html) of a double storm system there, but rather found a single unusual swirling cloud vortex. In the above recently released image (http://www.europlanet-eu.org/outreach/images/stories/ep/news/epsc2010/piccioniimage2.jpg) sequence taken in infrared light and digitally compressed, darker areas correspond to higher temperatures and hence lower regions of Venus' atmosphere. Also illuminating are recently (http://www.youtube.com/watch?v=mrMEsQkmRQI) released movies (http://www.youtube.com/watch?v=nwmkINj1wAQ), which show similarities between Venus' southern vortex (http://antwrp.gsfc.nasa.gov/apod/ap070501.html) and the vortex that swirls over the South Pole of Saturn (http://antwrp.gsfc.nasa.gov/apod/ap061113.html). Understanding the peculiar dynamics (http://planetary.org/blog/article/00002679/) of why, at times, two eddies appear, while at other times a single peculiar eddy appears, may give insight into how hurricanes (http://antwrp.gsfc.nasa.gov/apod/ap050829.html) evolve on Earth, and remain a topic of research for some time. In three months, the European Venus Express (http://www.esa.int/SPECIALS/Venus_Express/) spacecraft will be joined around Venus by the Japanese Akatsuki (http://en.wikipedia.org/wiki/Akatsuki_(Planet-C)) satellite.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100928.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/moonplane_thomas.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100929.html)An Airplane in Front of the MoonIf you look closely at the Moon, you will see a large airplane in front of it. Well, not always. OK, hardly ever. But if you wait for days with your camera attached to a Moon tracker (http://home.hiwaay.net/~krcool/Astro/moon/howtophoto/index.htm) in a place where airplanes (http://antwrp.gsfc.nasa.gov/apod/ap010129.html) are known to pass, you might catch a good photograph (http://antwrp.gsfc.nasa.gov/apod/ap070605.html) of it. Well, if you're lucky (http://www.youtube.com/watch?v=-xDehLpmmQw). OK, extremely lucky. The above image (http://www.iceinspace.com.au/iotw.html?iotwid=137) was taken (http://www.iceinspace.com.au/forum/showthread.php?t=65931) two weeks ago over South East (http://en.wikipedia.org/wiki/South_East_Queensland) Queensland (http://en.wikipedia.org/wiki/Queensland), Australia (http://en.wikipedia.org/wiki/Australia) using an exposure time (http://en.wikipedia.org/wiki/Shutter_speed) of 1/250th of a second and, in the words of the photographer, "a nerve of steel (http://obviousmag.org/archives/uploads/2008/08041703_blog.uncovering.org_hine.jpeg)".



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100929.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1009/coreshine_spitzer_crop.jpg (http://antwrp.gsfc.nasa.gov/apod/ap100930.html) Coreshine from a Dark Cloud Stars and their planets (http://www.cfa.harvard.edu/COMPLETE/learn/ star_and_planet_formation.html) are born in cold, dark, interstellar clouds of gas and dust (http://antwrp.gsfc.nasa.gov/apod/ap090425.html). While exploring (http://www.sciencemag.org/cgi/content/full/329/5999/ 1622) the clouds at infrared wavelengths (http://coolcosmos.ipac.caltech.edu/), astronomers have made a surprising discovery -- dozens of cases where dense cloud cores shine by reflecting infrared starlight. Based on archival Spitzer Space Telescope (http://www.spitzer.caltech.edu/) data, these panels illustrate the newly described phenomenon, known as coreshine (http://www.spitzer.caltech.edu/news/ 1195-feature10-16-Shining-Starlight-on-the-Dark-Cocoons-of-Star-Birth). At longer infrared wavelengths (right) the core of cloud Lynds (http://cdsads.u-strasbg.fr/cgi-bin/ nph-bib_query?1962ApJS....7....1L&db_key=AST&nosetcookie=1) 183 is dark, but at shorter infrared wavelengths (left) the core clearly shines, scattering light (http://www.spitzer.caltech.edu/images/ 3390-sig10-020b-An-Unexpected-Scattering-of-Light) from nearby stars. As seen in these panels, the elongated core covers a mere 1.5 light-years. The scattering requires dust grains that are about 10 times larger than previously thought to exist in the clouds, about 1 micron in size instead of 0.1 micron. For comparison, a human hair is about 100 microns thick. The larger dust grains indicated by coreshine could change models of the early phases of star and planet formation, a still mysterious process hidden within the interstellar clouds (http://www.mpia.de/Public/menu_q2e.php?Aktuelles/PR/2010/ PR100923/PR_100923_en.html). Dark nebula Lynds 183 lies around 325 light-years away in the constellation Serpens.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap100930.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/GJ581gIllustration_cook900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101001.html)Zarmina's WorldA mere 20 light-years away in the constellation Libra,red dwarf star Gliese 581 (http://antwrp.gsfc.nasa.gov/apod/ap070426.html)has received much scrutiny by astronomers in recent years.Earthbound telescopes had detected the signatures ofmultiple planets orbiting the cool sun, two at least close to thesystem's habitable zone (http://en.wikipedia.org/wiki/Habitable_zone#Circumstellar_habitable_zone) --the region where an Earth-likeplanet can have liquid water on its surface.Now a team headed bySteven Vogt (UCO Lick (http://www.ucolick.org/)), andPaul Butler (DTM Carnagie Inst. (http://www.dtm.ciw.edu/))has announced the detection (http://www.nsf.gov/news/news_images.jsp?cntn_id=117765&org=NSF)of another planet,this one squarely in the system's habitable zone.Based on 11 years of data,their work (http://arxiv.org/abs/1009.5733)offers a very compellingcase for the firstpotentially habitable planet found (http://www.nasa.gov/topics/universe/features/gliese_581_feature.html)around a very nearby star.Shown in thisartist's illustration (http://www.nasa.gov/topics/universe/features/Gliese_581.html) of the inner part of theexoplanetary system, the planet is designated Gliese 581g, but Vogt'smore personal name is Zarmina's world, after his wife.The best fit to the data indicate the planet has a circular 37 dayorbit, an orbital radius of only 0.15AU (http://en.wikipedia.org/wiki/Astronomical_unit),and a mass 3.1 times the Earth's.Modeling includes estimates of a planet radius of 1.5,and gravity at the planet's surface of 1.1 to 1.7 inEarth units (http://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.html).Findinga habitable planet (http://kepler.nasa.gov/) so close by suggeststhere aremany others (http://exoplanet.eu/catalog.php)in our Milky Way galaxy.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101001.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/LagoonClose_hst_c0.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101002.html)Hubble's LagoonLike brush strokes (http://antwrp.gsfc.nasa.gov/apod/ap060805.html) on a canvas,ridges of color seem toflowacross this scene (http://www.spacetelescope.org/images/heic1015a/).But here, the canvas is nearly 3 light-years wide andthe colors map emission from ionized gas in the LagoonNebula, recorded by the Hubble Space Telescope'sAdvanced Camera for Surveys (http://hubblesite.org/the_telescope/nuts_.and._bolts/instruments/acs/).Also known as M8, the nebula is astar forming region (http://arxiv.org/abs/1005.1148)about 5,000 light-years distant in the constellationSagittarius.Hubble's remarkably sharp,close-upview (http://www.spacetelescope.org/images/heic1015a/) reveals undulatingshapes sculpted by the energetic light and winds from theregion's new born stars.Of course (http://www.spacetelescope.org/videos/heic1015a/),the Lagoon nebula is a popular target for earthbound skygazers, too.It features a prominent dust lane and bright hourglass shape insmall telescopes with wider fields of view (http://antwrp.gsfc.nasa.gov/apod/ap100805.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101002.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/iotruecolor_galileo.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101003.html) Io in True Color The strangest moon in the Solar System (http://www.nineplanets.org/overview.html) is bright yellow. This picture (http://photojournal.jpl.nasa.gov/catalog/PIA02308), an attempt to show how Io would appear in the "true colors" perceptible to the average human eye, was taken in 1999 July by the Galileo spacecraft (http://solarsystem.nasa.gov/galileo/mission/spacecraft.cfm) that orbited Jupiter from 1995 to 2003. Io's colors derive from sulfur (http://periodic.lanl.gov/elements/16.html) and molten silicate rock (http://www.windows2universe.org/earth/geology/min_types.html). The unusual surface of Io (http://antwrp.gsfc.nasa.gov/apod/ap961029.html) is kept very young by its system of active volcanoes (http://antwrp.gsfc.nasa.gov/apod/ap960805.html). The intense tidal gravity (http://en.wikipedia.org/wiki/Tidal_force) of Jupiter (http://www.solarviews.com/eng/jupiter.htm) stretches Io (http://www.youtube.com/watch?v=KXeIll6YYQs) and damps wobbles caused by Jupiter's other Galilean moons (http://antwrp.gsfc.nasa.gov/apod/ap001118.html). The resulting friction (http://www.pa.uky.edu/~phy211/Friction_book.html) greatly heats Io (http://en.wikipedia.org/wiki/Io_%28moon%29)'s interior, causing molten rock (http://antwrp.gsfc.nasa.gov/apod/ap070918.html) to explode through the surface. Io's volcanoes (http://www.youtube.com/watch?v=GdkOngxCqQo) are so active that they are effectively turning the whole moon inside out. Some of Io (http://www.nineplanets.org/io.html)'s volcanic lava is so hot it glows in the dark (http://adsabs.harvard.edu/cgi-bin/nph- bib_query?bibcode=1998Icar..135..181M).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101003.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/plainmars_opportunity.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101004.html) Rolling Across the Rocky Plains of Mars You stare out across the rocky plains of Mars. Before you, in every direction, is dark sand and bright rock. Although little has changed here for millions of years, no one has ever seen this view (http://photojournal.jpl.nasa.gov/catalog/PIA13416) before. You are being sent on a long journey (http://www.youtube.com/watch?v=6tJBO1yt4hM) to a distant crater, the largest crater in the region. Your human overlords (http://marsrover.nasa.gov/people/) back on planet Earth (http://antwrp.gsfc.nasa.gov/apod/ap100713.html) wonder if the impact that created this distant crater might have also uncovered unique clues to the distant past (http://en.wikipedia.org/wiki/Water_on_Mars) of Earth's neighboring planet, clues that might reveal if life (http://en.wikipedia.org/wiki/Water_on_Mars#Does_Mars_have_enough_water_for_life .3F) ever existed here. Breaking the monotony (http://antwrp.gsfc.nasa.gov/apod/ap061017.html), visible toward the image center, an unusual rock sticks out from the landscape. Quite possibly, this rock (http://photojournal.jpl.nasa.gov/catalog/PIA13395) is not from this world, and you divert to inspect (http://photojournal.jpl.nasa.gov/catalog/PIA13417) it. You are the robotic Opportunity rover (http://www.youtube.com/watch?v=MgrOmRQuaCY), and you are the eyes for countless humans (http://www.nocaptionneeded.com/wp-content/uploads/2009/02/3d-glasses-life.jpeg) following your trek back on planet Earth. Rolling about a football field (http://www.youtube.com/watch?v=5S3WfNDD59Y?) a day, you might reach Endeavour crater (http://en.wikipedia.org/wiki/Endeavour_crater) sometime in 2012. If you survive (http://marsrovers.jpl.nasa.gov/newsroom/pressreleases/20100730a.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101004.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/orionwide_tljj.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101005.html)Horsehead and Orion NebulasThe dark Horsehead Nebula (http://antwrp.gsfc.nasa.gov/apod/ap081126.html) and the glowingOrion Nebula (http://antwrp.gsfc.nasa.gov/apod/ap090826.html) are contrasting cosmic vistas.Adrift 1,500 light-years away in one ofthe night sky's (http://antwrp.gsfc.nasa.gov/apod/ap030207.html)most recognizableconstellations (http://en.wikipedia.org/wiki/Constellation),they appear in opposite corners of the abovestunning mosaic (http://www.flickr.com/photos/stevel_uk/5034573378/).The familiar Horsehead (http://en.wikipedia.org/wiki/Horsehead_Nebula)nebula appears as a dark cloud, a small silhouettenotched against the long red glow at the lower left.Alnitak (http://www.gb.nrao.edu/~rmaddale/Education/OrionTourCenter/belt.html) is the easternmost star inOrion's belt (http://antwrp.gsfc.nasa.gov/apod/ap090210.html) and is seen as thebrightest star to the left of theHorsehead (http://drawsketch.about.com/library/bl-step-horsehead.htm).Below Alnitak is theFlame Nebula (http://antwrp.gsfc.nasa.gov/apod/ap070202.html), with clouds ofbright emission anddramatic (http://antwrp.gsfc.nasa.gov/apod/ap090929.html) dark dust lanes.The magnificent emission region, theOrion Nebula (http://en.wikipedia.org/wiki/Orion_nebula) (aka M42), lies at the upper right.Immediately to its left is a prominent bluishreflection nebula (http://antwrp.gsfc.nasa.gov/apod/reflection_nebulae.html) sometimes called the Running Man.Pervasive tendrils (http://antwrp.gsfc.nasa.gov/apod/ap090224.html)of glowing hydrogen gas are easilytraced (http://www.youtube.com/watch?v=NWNWaWUxS5g)throughout the region.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101005.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/auroraalaska_alsop.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101006.html)Aurora Over AlaskaAre those green clouds or aurora?Photographed above (http://www.flickr.com/photos/pmalsop/5034105388/) two weeks ago, puffy green aurora help the Moon (http://antwrp.gsfc.nasa.gov/apod/moon.html) illuminate the serene Willow Lake and the snowy Wrangell (http://en.wikipedia.org/wiki/Wrangell_Mountains) and Saint Elias Mountains (http://en.wikipedia.org/wiki/Saint_Elias_Mountains) in eastern Alaska (http://www.state.ak.us/), USA (https://www.cia.gov/library/publications/the-world-factbook/geos/us.html).Although auroras (http://www.exploratorium.edu/learning_studio/auroras/) might first appear to be moonlit clouds, they only add light to the sky (http://www.youtube.com/watch?v=FcfWsj9OnsI) and do not block background stars from view. Called northern lights (http://antwrp.gsfc.nasa.gov/apod/ap050916.html) in the northern hemisphere, auroras (http://www.geo.mtu.edu/weather/aurora/) are caused by collisions between charged particles (http://www-spof.gsfc.nasa.gov/Education/Ielect.html) from the magnetosphere and air moleculeshigh in the Earth's atmosphere.If viewed from space, auroras can be seen to glow (http://antwrp.gsfc.nasa.gov/apod/ap100701.html) in X-ray (http://chandra.harvard.edu/xray_astro/xrays.html) and ultraviolet light as well. Predictable auroras (http://www.gedds.alaska.edu/AuroraForecast/) likely occur a few days after a powerful magnetic event (http://antwrp.gsfc.nasa.gov/apod/ap010924.html) has been seen on the Sun (http://en.wikipedia.org/wiki/Sun).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101006.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/hartley2pacman_fernandez900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101007.html)Pacman and HartleyTouring (http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=103p&orb=1)the solar system with a 6 yearorbital period (http://pdssbn.astro.umd.edu/comet_data/periodic_comets.html), smallcomet Hartley 2 (http://www.skyandtelescope.com/observing/home/102632669.html)(103/P Hartley) will make its closest approach toplanet Earth on October 20 and its closest approach tothe Sun on October 28.It may become a naked-eye comet, just visible in clear, dark skies.Meanwhile the comet has been a tempting telescopic target,seen here with (http://www.castillosdesoria.com/astropics/imagen.asp?id=1&seccion=1&id_prod=249)an alluring green coma as it shares the frame with emissionnebula NGC 281 (http://antwrp.gsfc.nasa.gov/apod/ap081210.html) and stars ofthe constellation Cassiopeia on October 2.The nebula's gaping profile defined by dust clouds against the redglow suggests its moreplayful (http://www.google.com/pacman/) moniker,the Pacman Nebula.An apparent short bright streak shows the comet's motion against thebackground stars during the hour of accumulated exposure time.Over the next few days Comet Hartley 2's motion will alsocarry it acrossa field of view featuring the famousdouble star cluster (http://antwrp.gsfc.nasa.gov/apod/ap091204.html) in Perseus.On November 4 (http://www.nasa.gov/mission_pages/epoxi/epoxi20101004.html)a spacecraft from planet Earth willactually fly within about 700 kilometers ofthe comet's nucleus (http://hubblesite.org/newscenter/archive/releases/2010/35/image/a/).Now dubbed EPOXI (http://epoxi.umd.edu/),that spacecraft was formerly knownas Deep Impact (http://antwrp.gsfc.nasa.gov/apod/ap080903.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101007.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/UranusJupiter_knappert600h.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101008.html) Two Planet Opposition In late September, two planets were opposite the Sun (http://antwrp.gsfc.nasa.gov/apod/ap100918.html) in Earth's sky, Jupiter and Uranus. Consequently closest to Earth, at a distance (http://www.haydenplanetarium.org/universe/duguide/ app_light_travel_time_dista.php) of only 33 light-minutes and 2.65 light-hours respectively, both were good targets for telescopic observers. Recorded on September 27, this well-planned composite of consecutive multiple exposures captured both gas giants in their remarkable celestial line-up accompanied by their brighter moons. The faint greenish disk of distant planet Uranus is near the upper left corner. Of the tilted (http://antwrp.gsfc.nasa.gov/apod/ap041118.html) planet's 5 larger moons (http://antwrp.gsfc.nasa.gov/apod/ap030115.html), two can be spotted (http://antwrp.gsfc.nasa.gov/apod/image/1010/UranusJupiter_knappert_detail.jpg) just above and left of the planet's disk. Both discovered by 18th century British astronomer Sir William Herschel and later named for characters in Shakespeare's A Midsummer Night's Dream, Oberon (http://antwrp.gsfc.nasa.gov/apod/ap990227.html) is farthest left, with Titania (http://antwrp.gsfc.nasa.gov/apod/ap000930.html) closer in. At the right side of the frame is ruling gas giant Jupiter, flanked along a line by all four of its Galilean satellites (http://antwrp.gsfc.nasa.gov/apod/ap001118.html). Farthest from Jupiter is Callisto (http://antwrp.gsfc.nasa.gov/apod/ap020120.html), with Europa (http://antwrp.gsfc.nasa.gov/apod/ap090308.html) and Io (http://antwrp.gsfc.nasa.gov/apod/ap101003.html) all left of the planet's disk, while Ganymede (http://antwrp.gsfc.nasa.gov/apod/ap090920.html) stands alone at the right.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101008.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/ngc6934_hst_900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101009.html)Globular Star Cluster NGC 6934Globlularstar clusters (http://en.wikipedia.org/wiki/Globular_cluster) roam the halo of our Milky Way Galaxy.Gravitationallybound (http://astronomy2009.nasa.gov/topics_jun.htm), these spherical groupings oftypically several hundred thousand stars are ancient,older than the stars of the galactic disk.In fact, measurements of globular clusterages constrain (http://map.gsfc.nasa.gov/universe/uni_age.html)the age of the Universe (it must be older than the stars in it!) andaccurate cluster distance determinationsprovide a rung on the astronomical distance ladder.Globular star clusterNGC 6934 (http://spider.seds.org/spider/MWGC/n6934.html)itself lies about 50,000 light-years away in the constellationDelphinus (http://www.hawastsoc.org/deepsky/del/index.html).At that distance,this sharpimage (http://www.spacetelescope.org/images/potw1023a/) from Hubble's Advanced Camera for Surveys spansabout 50 light-years.The cluster stars are estimated to be some 10billion (http://www.kokogiak.com/megapenny/nine.asp) years old.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101009.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/aldrinseismometer_apollo11.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101010.html) Moonquakes Surprisingly Common Why are there so many moonquakes? A recent reanalysis of seismometers (http://en.wikipedia.org/wiki/Seismometer) left on the moon by the Apollo (http://history.nasa.gov/ap11ann/introduction.htm) moon landings (http://www.youtube.com/watch?v=RMINSD7MmT4) has revealed a surprising number of moonquakes occurring within 30 kilometers of the surface. In fact, 28 moonquakes (http://adsabs.harvard.edu/abs/2005AGUFM.P51A0915N) were detected in data recorded between 1972 and 1977. These moonquakes (http://science.nasa.gov/headlines/y2006/15mar_moonquakes.htm) were not only strong enough to move furniture (http://www.maltwood.uvic.ca/hoft/timeline.html) but the stiff rock of the moon continued vibrating for many minutes, significantly longer than the soft rock earthquakes on Earth. The cause of the moonquakes (http://adsabs.harvard.edu/abs/2006epsc.conf..301F) remains unknown, with one hypothesis holding that landslides (http://earthquake.usgs.gov/learning/glossary.php?termID=105&alpha=L) in craters cause the vibrations. Regardless of the source, future moon buildings need to be built to withstand the frequent shakings. Pictured above (http://grin.hq.nasa.gov/ABSTRACTS/GPN-2000-001102.html) in 1969, Apollo 11 astronaut Buzz Aldrin (http://en.wikipedia.org/wiki/Buzz_Aldrin) stands besides a recently deployed lunar seismometer, looking back toward the lunar landing module (http://antwrp.gsfc.nasa.gov/apod/ap030920.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101010.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/ngc2683_hst.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101011.html)NGC 2683: Spiral Edge-OnDoes spiral galaxy NGC 2683 have a bar across its center?Being so nearly like our own barred Milky Way Galaxy, one might guess it has.Being so nearly edge-on, however, it is hard to tell (http://adsabs.harvard.edu/abs/2009AJ....138.1082K).Either way, this gorgeous island universe, catalogedasNGC 2683 (http://www.seds.org/~spider/spider/Misc/n2683.html), lies a mere20 million light-years distant in the northern constellation of the Cat(Lynx (http://www.ianridpath.com/startales/lynx.htm)).NGC 2683 is seen nearly edge-on (http://antwrp.gsfc.nasa.gov/apod/ap010510.html) inthiscosmic vista (http://quarks.maynau.com/nova/ext/n2683-viewmode.shtml), with more distant galaxies (http://bb.nightskylive.net/asterisk/viewtopic.php?f=24&t=18005) scattered in the background.Blended light from a large population of old yellowish stars formsthe remarkably bright galactic core (http://antwrp.gsfc.nasa.gov/apod/ap080427.html).Starlight silhouettes the dust lanes along winding spiral arms, dottedwith the telltale blue glow (http://antwrp.gsfc.nasa.gov/apod/ap081209.html) of young star clusters in this galaxy (http://en.wikipedia.org/wiki/NGC_2683)'s star forming regions.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101011.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/darkshadows_cassini.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101012.html) Saturn: Light, Dark, and Strange What's creating those dark bands on Saturn? Sometimes it takes a little sleuthing (http://en.wikipedia.org/wiki/The_No._1_Ladies%27_Detective_Agency) to figure out the how and why of a picture (http://photojournal.jpl.nasa.gov/catalog/PIA12734) taken by the Saturn-orbiting Cassini (http://www.nasa.gov/mission_pages/cassini/spacecraft/index.html) spacecraft. Let's see. That large orb on the left must be Saturn (http://antwrp.gsfc.nasa.gov/apod/ap090930.html) itself. Those arcs on the right are surely the rings (http://antwrp.gsfc.nasa.gov/apod/ap071024.html). The dark band running diagonally must be the shadow of Saturn on the rings. That leaves the unusual dark bands superposed on Saturn's disk -- are they the shadows of the rings? A punctilious (http://en.wiktionary.org/wiki/punctilious) detective would conclude that they are not. If one looks carefully, the rings arc (http://www.youtube.com/watch?v=73UCCHjoQrM) from behind the planet on the lower left, around to the right, and therefore must pass on the camera side of the planet on the upper left. So the rings themselves cause the dark streaks on Saturn. These rings segments appear dark because they are in the shadow of Saturn (http://antwrp.gsfc.nasa.gov/apod/ap090111.html). The night part of Saturn shows a faint glow because of sunlight reflected from other parts of the rings. Got it? (http://blogs.discovermagazine.com/badastronomy/2010/10/06/saturn-brain-bender/) Unfortunately, if it weren't for the tile floor, tomorrow's picture would be even harder to understand.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101012.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/hubblemuseum_esa.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101013.html) Science Museum Hubble Will the Hubble Space Telescope (HST) end up in a museum? Probably not, as when it finally goes bust, current plans (http://en.wikipedia.org/wiki/Hubble_Space_Telescope#Orbital_decay) call for it to be de-orbited into an ocean. But this won't stop likenesses of the famous floating observatory (http://antwrp.gsfc.nasa.gov/apod/ap090525.html) from appearing in science museums around the globe, sometimes paired with amazing pictures (http://www.google.com/images?hl=en&biw=1087&bih=903&tbs=isch%3A1&sa=1&q=%2Bsite%3Aapod.nasa.gov+Hubble) it has taken. Pictured above (http://spacetelescope.org/images/ann1011a/), in a celebration of the 20th anniversary (http://hubblesite.org/hubble_20/) of the launching of Hubble, a replica of the telescope was given a picturesque setting in the Italian Istituto Veneto di Scienze, Lettere ed Arti (http://www.istitutoveneto.it/) in their beautiful and historic Palazzo Loredan (http://it.wikipedia.org/wiki/Palazzo_Loredan_dell%27Ambasciatore). The scene there appears perhaps a bit surreal (http://en.wikipedia.org/wiki/Surrealism) as the deep space imager appears over a terrestrial tile floor, surrounded by the busts of famous thinkers, and under arches (http://en.wikipedia.org/wiki/Another_World_(M._C._Escher)) reminiscent of Escher (http://en.wikipedia.org/wiki/M._C._Escher). If you're lucky, it may even be possible to find an exhibition (http://hubblesource.stsci.edu/exhibits/traveling/index_02.php) of Hubble images near you (http://www.spacetelescope.org/projects/20anniversary/events/). And if no HST model appears there, you could always build your own (http://hubblesite.org/the_telescope/hand-held_hubble/paper-intermediate.php).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101013.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/DoubleCometHeart_andreo600w.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101014.html) Clusters, Hartley, and the Heart An alluring Comet Hartley 2 cruised through (http://www.youtube.com/watch?v=EY85SS893TQ) planet Earth's night sky on October 8, passing within about a Full Moon's width of the famous double star cluster in Perseus. The much anticipated celestial photo-op (http://antwrp.gsfc.nasa.gov/apod/ap101007.html) was recorded here in a 3 frame mosaic with greenish comet and the clusters h and Chi Persei (http://antwrp.gsfc.nasa.gov/apod/ap091204.html) placed at the left. The well-chosen, wide field of view spans about 7 degrees. It extends across the constellation boundary into Cassiopeia, all the way to the Heart Nebula (IC 1805) (http://antwrp.gsfc.nasa.gov/apod/ap090214.html) at the far right. To capture the cosmic moment, a relatively short 5 minute exposure was used to freeze the moving comet in place, but a longer exposure with a narrow-band filter was included in the central and right hand frames. The narrow-band exposure brings out the fainter reddish glow (http://antwrp.gsfc.nasa.gov/apod/ap080424.html) of the nebula's atomic hydrogen gas, in contrast to the cometary (http://antwrp.gsfc.nasa.gov/apod/ap050111.html) coma's kryptonite (http://www.uky.edu/Projects/Chemcomics/html/ gs_6_74_cu.html) green. In the past few days, comet watchers have reported (http://www.skyandtelescope.com/observing/home/ 102632669.html) that Hartley 2 has become just visible to the unaided eye for experienced observers from dark, clear sites. On October 20, the comet will (http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=103p&orb=1) make its closest approach to Earth, passing within about 17 million kilometers. On November 4, a NASA spacecraft (http://epoxi.umd.edu/) will fly by the comet's small nucleus (http://hubblesite.org/newscenter/archive/releases/2010/35/ image/a/) estimated to be only 1.5 kilometers in diameter.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101014.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/ngc2170_vista900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101015.html)Vista with NGC 2170Drifting through the one-horned constellationMonoceros (http://www.hawastsoc.org/deepsky/mon/index.html),these dusty streamersand new born stars (http://www.eso.org/public/news/eso1039/)are part of the active Monoceros R2 star-forming region, embeddedin a giant molecular cloud.The cosmic scene was recorded by theVISTA (http://www.eso.org/public/teles-instr/surveytelescopes/vista.html) surveytelescope innear-infrared (http://coolcosmos.ipac.caltech.edu/cosmic_classroom/ir_tutorial/irregions.html) light.Visible light images showdusty NGC 2170 (http://antwrp.gsfc.nasa.gov/apod/ap060805.html), seen herejust right of center, as a complex of bluish reflection nebulae.But this penetratingnear-infraredview reveals (http://www.eso.org/public/videos/eso1039b/) telltalesigns of ongoing star formation and massive young stars otherwisehidden by the dust.Energetic winds and radiation from the hot young starsreshape the natal interstellar clouds.Close on the sky to the star-forming OrionNebula (http://antwrp.gsfc.nasa.gov/apod/ap100410.html), the Monoceros R2 region is almost twice as far away,about 2700 light-years distant.At that distance, this vista spans about 80 light-years.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101015.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/LMC_gleason_950c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101016.html) The Large Cloud of Magellan The 16th century Portuguese navigator Ferdinand Magellan (http://en.wikipedia.org/wiki/Ferdinand_Magellan) and his crew had plenty of time to study the southern sky during the first circumnavigation (http://www.fordham.edu/halsall/mod/1519magellan.html) of planet Earth. As a result, two fuzzy cloud-like objects easily visible to southern hemisphere skygazers are known as the Clouds of Magellan (http://antwrp.gsfc.nasa.gov/apod/ap060809.html), now understood to be satellite galaxies of our much larger, spiral Milky Way galaxy. About 180,000 light-years distant in the constellation Dorado (http://www.hawastsoc.org/deepsky/dor/), the Large Magellanic Cloud (LMC) is seen here in a remarkably deep, colorful composite image, starlight from the central (http://antwrp.gsfc.nasa.gov/apod/ap080409.html) bluish bar contrasting with the telltale reddish glow of ionized atomic hydrogen gas (http://antwrp.gsfc.nasa.gov/apod/ap060518.html). Spanning about 15,000 light-years or so, it is the most massive of the Milky Way's satellite galaxies (http://www.atlasoftheuniverse.com/sattelit.html) and is the home of the closest supernova (http://heritage.stsci.edu/1999/04/) in modern times, SN 1987A. The prominent patch at top left is 30 Doradus, also know as the magnificent Tarantula Nebula (http://antwrp.gsfc.nasa.gov/apod/ap090916.html). The giant star-forming region is about 1,000 light-years across.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101016.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/ngc346_hst.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101017.html) NGC 346 in the Small Magellanic Cloud How and why are all these stars forming? Found among the Small Magellanic Cloud's (SMC's) clusters and nebulae NGC 346 (http://www.youtube.com/watch?v=mafzlGtnnk0) is a star forming region about 200 light-years across, pictured above (http://hubblesite.org/newscenter/newsdesk/archive/releases/ 2005/04/) by the Hubble Space Telescope. A satellite galaxy (http://www.atlasoftheuniverse.com/sattelit.html) of the Milky Way, the Small Magellanic Cloud (SMC (http://antwrp.gsfc.nasa.gov/apod/ap100903.html)) is a wonder of the southern sky, a mere 210,000 light-years distant in the constellation of the Toucan (Tucana (http://www.hawastsoc.org/deepsky/tuc/)). Exploring NGC 346 (http://hubblesite.org/newscenter/newsdesk/archive/releases/ 2005/04/fastfacts/), astronomers have identified a population of embryonic stars strung along (http://hubblesite.org/newscenter/newsdesk/archive/releases/ 2005/04/video/a) the dark, intersecting dust lanes visible here on the right. Still collapsing within their natal clouds (http://antwrp.gsfc.nasa.gov/apod/ap040529.html), the stellar infants' (http://starchild.gsfc.nasa.gov/docs/StarChild/ StarChild.html) light is reddened by the intervening dust. A small (http://antwrp.gsfc.nasa.gov/apod/ap041116.html), irregular galaxy, the SMC itself represents a type of galaxy more common in the early Universe (http://bb.nightskylive.net/asterisk/viewtopic.php?f=24&t=18002). But these small galaxies are thought to be a building blocks (http://antwrp.gsfc.nasa.gov/apod/ap031117.html) for the larger galaxies present today. Within the SMC (http://antwrp.gsfc.nasa.gov/apod/ap100705.html), stellar nurseries like NGC 346 (http://adsabs.harvard.edu/abs/2010arXiv1010.0340C) are also thought to be similar to those found in the early Universe (http://antwrp.gsfc.nasa.gov/apod/ap040929.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101017.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/sunbug_soho.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101018.html) It Came from the Sun What's that coming over (http://en.wikipedia.org/wiki/It_Came_from_Outer_Space) the edge of the Sun? What might appear at first glance to be some sort of Sun monster (http://www.youtube.com/watch?v=ErFsW4-FDWw) is actually a solar prominence (http://en.wikipedia.org/wiki/Solar_prominence). The above prominence (http://sohowww.nascom.nasa.gov/pickoftheweek/old/16apr2010/), captured by the Sun-orbiting SOHO satellite earlier this year during an early stage of its eruption (http://antwrp.gsfc.nasa.gov/apod/ap100510.html), rapidly became one of the largest ever (http://antwrp.gsfc.nasa.gov/apod/ap100418.html) on record. Even as pictured, the prominence is huge -- the Earth (http://antwrp.gsfc.nasa.gov/apod/ap091123.html) would easily fit inside. A solar prominence (http://solar.physics.montana.edu/YPOP/Program/hfilament.html) is a thin cloud of solar gas held just above the surface by the Sun's magnetic field (http://solarscience.msfc.nasa.gov/the_key.shtml). A quiescent prominence (http://antwrp.gsfc.nasa.gov/apod/ap970127.html) typically lasts about a month, while an eruptive prominence (http://www.youtube.com/watch?v=OyIxC1nJPQ0) like the one developing above may erupt within hours into a Coronal Mass Ejection (http://helios.gsfc.nasa.gov/cme.html) (CME), expelling hot gas into the Solar System (http://csep10.phys.utk.edu/astr161/lect/solarsys/scale.html). Although very hot, prominences typically appear dark (http://antwrp.gsfc.nasa.gov/apod/ap010129.html) when viewed against the Sun (http://www.nineplanets.org/sol.html), since they are slightly cooler than the surface. As our Sun evolves toward Solar maximum (http://en.wikipedia.org/wiki/Solar_maximum) over the next three years, more large eruptive prominence (http://www.youtube.com/watch?v=2cneQyjQNK8)s are expected.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101018.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/prometheusrising_cassini.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101019.html)Prometheus Rising Through Saturn's F RingWhat is that dark streak below Prometheus?Although it may look like a shadow or a trail blazed by sweeping up material,computer simulations indicate (http://adsabs.harvard.edu/abs/2005Natur.437.1326M) that the dark streak is better understood as an empty path pulled away by the gravity of Saturn's small moon. The particles don't followPrometheus (http://www.youtube.com/watch?v=2mX2Xpnst9w) so much as glide sideways past where Prometheus used to be.One dark streamer (http://www.planetary.org/blog/article/00002697/)is created during each pass of Prometheus through theF-ring (http://www.planetary.org/explore/topics/saturn/rings.html) that itshepherds (http://www.youtube.com/watch?v=fdUlpeUFfxI).The streamers (http://antwrp.gsfc.nasa.gov/apod/ap100802.html) wereunpredicted and first discovered in 2004 on high resolutionimages taken by the roboticCassini spacecraft (http://en.wikipedia.org/wiki/Cassini-Huygens) orbiting Saturn. Close inspection of the surface of Prometheus itself in theabove image (http://www.flickr.com/photos/ugordan/5042705878/) shows interestingstructure and craters (http://antwrp.gsfc.nasa.gov/apod/ap100405.html).The Cassini (http://antwrp.gsfc.nasa.gov/apod/ap971016.html) spacecraft <ahref="ap031210.html">a<ahref="ap040301.html">r<ahref="ap040430.html">r<ahref="ap040531.html">i<ahref="ap040614.html">v<ahref="ap040702.html">e<ahref="ap090111.html">dat Saturn in 2004 and, as it continues to function well, is now expected to continue (http://www.jpl.nasa.gov/news/news.cfm?release=2010-039) to send back data and images from the distant ringed world until 2017.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101019.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/prometheusrising_cassini.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101019.html) Prometheus Rising Through Saturn's F Ring What is that dark streak below Prometheus? Although it may look like a shadow or a trail blazed by sweeping up material, computer simulations indicate (http://adsabs.harvard.edu/abs/2005Natur.437.1326M) that the dark streak is better understood as an empty path pulled away by the gravity of Saturn's small moon. The particles don't follow Prometheus (http://www.youtube.com/watch?v=2mX2Xpnst9w) so much as glide sideways past where Prometheus used to be. One dark streamer (http://www.planetary.org/blog/article/00002697/) is created during each pass of Prometheus through the F-ring (http://www.planetary.org/explore/topics/saturn/rings.html) that it shepherds (http://www.youtube.com/watch?v=fdUlpeUFfxI). The streamers (http://antwrp.gsfc.nasa.gov/apod/ap100802.html) were unpredicted and first discovered in 2004 on high resolution images taken by the robotic Cassini spacecraft (http://en.wikipedia.org/wiki/Cassini–Huygens) orbiting Saturn. Close inspection of the surface of Prometheus itself in the above image (http://www.flickr.com/photos/ugordan/5042705878/) shows interesting structure and craters (http://antwrp.gsfc.nasa.gov/apod/ap100405.html). The Cassini (http://antwrp.gsfc.nasa.gov/apod/ap971016.html) spacecraft a (http://www.astronom.si/forum/ap031210.html)r (http://www.astronom.si/forum/ap040301.html)r (http://www.astronom.si/forum/ap040430.html)i (http://www.astronom.si/forum/ap040531.html)v (http://www.astronom.si/forum/ap040614.html)e (http://www.astronom.si/forum/ap040702.html)d (http://www.astronom.si/forum/ap090111.html) at Saturn in 2004 and, as it continues to function well, is now expected to continue (http://www.jpl.nasa.gov/news/news.cfm?release=2010-039) to send back data and images from the distant ringed world until 2017.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101019.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/venussunset_tezel.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101020.html) Venus Just After Sunset Is that Venus or an airplane? A common ponderable (http://curious.astro.cornell.edu/topten.php) for sky enthusiasts is deciding if that bright spot near the horizon is the planet Venus. Usually, an airplane will show itself by moving significantly (http://antwrp.gsfc.nasa.gov/apod/ap050913.html) in a few moments. Venus will set only slowly as the Earth turns. Still, the identification would be easier if Venus did not keep shifting its position each night. Pictured above (http://www.twanight.org/newTWAN/photos.asp?ID=3001233), Venus was captured on 44 different nights (http://www.twanight.org/newTWAN/photos.asp?ID=3002807) during 2006 and 2007 over the Bolu (http://en.wikipedia.org/wiki/Bolu) mountains in Turkey (http://en.wikipedia.org/wiki/Turkey), when Earth's sister planet appeared exclusively in the evening sky (http://en.wikipedia.org/wiki/Evening_star). The average spacing of the images was about five days, while the images were always taken with the Sun (http://bb.nightskylive.net/asterisk/viewtopic.php?f=24&t=18012) about seven degrees below the horizon. That bright spot toward the west in your evening sky (http://earthsky.org/tonight) this month might be neither Venus nor an airplane, but Mars (http://www.jodrellbank.manchester.ac.uk/astronomy/nightsky/).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101020.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/MWP1Web_Goldman900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101021.html)Methuselah Nebula MWP1The lovely, symmetric planetary nebula (http://dg-imaging.astrodon.com/gallery/display.cfm?imgID=230)cataloged as MWP1 lies some4,500 light-years away in the northern constellationCygnus (http://antwrp.gsfc.nasa.gov/apod/ap070920.html) the Swan.One of the largestplanetary nebulae (http://en.wikipedia.org/wiki/Planetary_nebula)known, it spans about 15light-years.Based on its expansion rate (http://antwrp.gsfc.nasa.gov/apod/ap990916.html)the nebula has an age of 150 thousand years,a cosmic blink of an eye (http://antwrp.gsfc.nasa.gov/apod/ap100506.html)in the 10 billion year life of a sun-like star.But planetary nebulae represent a very brief final phase inin stellarevolution (http://chandra.harvard.edu/edu/formal/stellar_ev/), as the nebula's central star shrugs offits outer layers to become a hot white dwarf.In fact, planetary nebulae ordinarily only lastfor 10 to 20 thousand years.As a result, trulyancient MWP1 (http://adsabs.harvard.edu/abs/1996ApJS..107..255T)offers a beautifulchallenge to astronomers studying the evolution of its central star.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101021.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/NGC7822_H2cFleming750.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101022.html) NGC 7822 in Cepheus Pillars of gas, dust, and young, hot stars seem to fill the gaping maw of NGC 7822. At the edge of a giant molecular cloud (http://archive.ncsa.illinois.edu/Cyberia/Bima/ GMC.html) toward the northern constellation Cepheus (http://www.astropix.com/HTML/E_SUM_N/CEPHEUSO.HTM), the glowing star forming region lies about 3,000 light-years away. Within the nebula, bright edges and dark shapes are highlighted in this colorful skyscape (http://www.flemingastrophotography.com/nebulae.html). The image includes data from both broadband and narrowband (http://antwrp.gsfc.nasa.gov/apod/ap060324.html) filters, mapping emission from atomic oxygen, hydrogen, and sulfur into blue, green, and red hues. The atomic emission is powered by (http://antwrp.gsfc.nasa.gov/apod/ap051223.html) the energetic radiation from the hot stars, whose powerful winds and radiation also sculpt and erode the denser pillar shapes. Stars could still be forming inside the pillars (http://antwrp.gsfc.nasa.gov/apod/ap020104.html) by gravitational collapse (http://hyperphysics.phy-astr.gsu.edu/hbase/astro/ gravc.html#c1), but as the pillars are eroded away, any forming stars will ultimately be cutoff from their reservoir of star stuff (http://hubblesite.org/newscenter/archive/releases/1995/ 44/image/a/). This field spans around 60 light-years at the estimated distance of NGC 7822.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101022.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/Orion2010_andreo600h.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101023.html)Orion: Head to ToeCradled in cosmic dust and glowing hydrogen,stellarnurseries (http://archive.ncsa.uiuc.edu/Cyberia/Bima/StarForm.html) in Orion theHunter (http://www.clarkfoundation.org/astro-utah/vondel/slimone.html)lie atthe edge (http://www.seds.org/messier/more/oricloud.html) of a giant molecular cloud some 1,500 light-years away.Spanning nearly 25 degrees, this breath-taking vistastretches across the well-known constellationfrom head to toe(left to right (http://homepage.mac.com/kvmagruder/bcp/literature/frost.htm)).The Great OrionNebula (http://en.wikipedia.org/wiki/Orion_Nebula), the closest large star forming region, is right of center.To its left are theHorsehead Nebula (http://antwrp.gsfc.nasa.gov/apod/ap100513.html),M78 (http://antwrp.gsfc.nasa.gov/apod/ap100302.html), andOrion's belt (http://antwrp.gsfc.nasa.gov/apod/ap061229.html) stars.Sliding your cursor over the picture will also findred giant Betelgeuse (http://antwrp.gsfc.nasa.gov/apod/ap100106.html) at the hunter's shoulder,bright blue Rigel (http://stars.astro.illinois.edu/sow/rigel.html)at his foot, and the glowing Lambda Orionis(Meissa (http://www.gb.nrao.edu/~rmaddale/Education/OrionTourCenter/meissa.html)) nebula at the far left, near Orion's head.Of course, the Orion Nebula and bright stars areeasy to see (http://antwrp.gsfc.nasa.gov/apod/ap030207.html) with theunaided eye, but dust clouds and emission from the extensive interstellargas in this nebula-rich (http://antwrp.gsfc.nasa.gov/apod/ap070106.html) complex,are too faint and much harder to record.In this mosaic of broadband telescopic images, additional imagedata acquired with a narrowhydrogen alpha (http://antwrp.gsfc.nasa.gov/apod/ap051223.html) filter was used tobring out the pervasive tendrils of energizedatomic hydrogen gas and the arc of the giantBarnard's Loop (http://antwrp.gsfc.nasa.gov/apod/ap060417.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101023.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/trencher2_smd.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101024.html) A Bucket-Wheel Excavator on Earth Please wait while one of the largest mobile machines in the world crosses the road. The machine pictured above is a bucket-wheel excavator (http://en.wikipedia.org/wiki/Bucket-wheel_excavator) used in modern surface mining (http://en.wikipedia.org/wiki/Surface_mining). Machines like this (http://www.tk-mining.com/Data/WebEditor/produkte/BWE.pdf) have given humanity the ability to mine minerals and change (http://en.wikipedia.org/wiki/Mountaintop_removal) the face of planet Earth in new and dramatic ways. Some open pit mines, for example, are visible from orbit. The largest excavators (http://en.wikipedia.org/wiki/Bagger_288) are over 200 meters long and 100 meters high, now dwarfing the huge NASA Crawler (http://antwrp.gsfc.nasa.gov/apod/ap020304.html) that transports (http://antwrp.gsfc.nasa.gov/apod/ap060708.html) space shuttles to the launch pads. Bucket-wheel excavators (http://www.swapmeetdave.com/Humor/Workshop/Trencher.htm) can dig a hole the length of a football field to over 25 meters deep in a single day. They (http://www.youtube.com/watch?v=oWlcqdPJEPg) may take a while to cross a road, though, with a top speed under one kilometer per hour.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101024.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/mooncabeus_lcross.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101025.html)Water Ice Detected Beneath Moon's SurfaceIs there enough water on the moon to sustain future astronauts?The question has important implications if humanity hopes to use the Moon as a future outpost. Last year (http://antwrp.gsfc.nasa.gov/apod/ap091118.html), to help find out, scientists crashed (http://www.youtube.com/watch?v=mVyEOFfv_lo) the moon-orbiting LCROSS spacecraft (http://lcross.arc.nasa.gov/mission.htm) into a permanently shadowed crater near the Moon's South Pole. New analyses (http://www.sciencemag.org/cgi/content/full/330/6003/434) of the resulting plume from Cabeus crater (http://antwrp.gsfc.nasa.gov/apod/ap091008.html) indicate more water than previously thought, possibly about six percent.Additionally (http://planetary.org/blog/article/00002728/), an instrument (http://lunar.gsfc.nasa.gov/lend.html) on the separate LRO spacecraft (http://lunar.gsfc.nasa.gov/) that measures neutrons indicates that even larger lunar expanses -- most not even permanently shadowed -- may also contain a significant amount of buried frozen water.Pictured above (http://uanews.org/node/34940) from LRO, areas in false-color blue indicate the presence of soil relatively rich in hydrogen (http://periodic.lanl.gov/elements/1.html), which is thought likely bound to sub-surface water ice. Conversely, the red areas are likely dry. The location of the Moon's South Pole (http://antwrp.gsfc.nasa.gov/apod/ap951128.html) is also digitally marked on the image. How deep beneath the surface the ice crystals (http://en.wikipedia.org/wiki/File:Snow_crystals.jpg) permeate is still unknown, as well as how difficult it would be to mine (http://rimg.geoscienceworld.org/cgi/content/extract/60/1/597) the crystals and purify them into drinking water (http://antwrp.gsfc.nasa.gov/apod/ap050401.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101025.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/hartleydouble_eder.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101026.html)Comet Hartley Passes a Double Star ClusterMost star clusters are singularly impressive. Open clusters (http://antwrp.gsfc.nasa.gov/apod/open_clusters.html) NGC 869 and NGC 884, however, are doubly impressive. Also known as "h and chi Persei", this unusual double cluster (http://www.seds.org/messier/xtra/ngc/n0869.html), shown above, is bright enough to be seen from a dark location without even binoculars (http://en.wikipedia.org/wiki/Binoculars). Although their discovery surely predates written history (http://en.wikipedia.org/wiki/Recorded_history), the Greek astronomer Hipparchus (http://en.wikipedia.org/wiki/Hipparchus) notably cataloged the double cluster (http://antwrp.gsfc.nasa.gov/apod/ap090103.html). The clusters are over 7,000 light years (http://starchild.gsfc.nasa.gov/docs/StarChild/questions/question19.html) distant toward the constellation (http://en.wikipedia.org/wiki/Constellation) of Perseus, but are separated by only hundreds of light years.Captured earlier this month, the bright comet 103P/Hartley (http://en.wikipedia.org/wiki/103P/Hartley), informally called Comet Hartley (http://en.wikipedia.org/wiki/Malcolm_Hartley) 2, passed well in front but only a few degrees away from the famous double cluster.Comet Hartley 2 (http://antwrp.gsfc.nasa.gov/apod/ap101014.html), visible on the right, is now fading but still discernable (http://scully.cfa.harvard.edu/~cgi/ReturnPrepEph?d=c&o=0103P) to northern observers with binoculars.No binoculars are needed, of course, if you go right up to the comet's nucleus (http://antwrp.gsfc.nasa.gov/apod/ap100104.html), as is the plan for NASA's EPOXI (http://en.wikipedia.org/wiki/EPOXI) spacecraft (http://epoxi.umd.edu/) on November 4.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101026.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/0909/UVAndromeda_swiftH600.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101027.html)Ultraviolet AndromedaThis stunning vista represents the highest resolution imageever made of theAndromeda Galaxy (aka M31) at ultravioletwavelengths (http://www.nasa.gov/mission_pages/swift/bursts/uv_andromeda.html).Recorded by NASA's Swift satellite (http://antwrp.gsfc.nasa.gov/apod/ap080328.html),the mosaic is composed of 330 individual images coveringa region 200,000 light-years wide.It shows about 20,000 sources (http://svs.gsfc.nasa.gov/vis/a010000/a010400/a010485/index.html),dominated by hot, young starsand dense star clusters that radiate strongly inenergeticultraviolet (http://science.hq.nasa.gov/kids/imagers/ems/uv.html) light.Of course, the AndromedaGalaxy (http://astrophysics.gsfc.nasa.gov/outreach/podcast/wordpress/index.php/2009/09/16/swift-sees-andromeda-in-a-new-light/)is the closest large spiral galaxyto our own Milky Way, at a distance of some 2.5 million light-years.Just slide your cursor over the image to compare the appearanceof thisgorgeous island universe (http://antwrp.gsfc.nasa.gov/apod/ap080124.html)in optical light with its ultraviolet portrait.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101027.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/mirachs_ayiomamitis_c800.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101028.html) Mirach's Ghost As far as ghosts (http://upload.wikimedia.org/wikipedia/commons/d/df/ Edward-kelly-987x1275.jpg) go, Mirach's Ghost isn't really that scary (http://en.wikipedia.org/wiki/Halloween). In fact, Mirach's Ghost (http://www.daviddarling.info/encyclopedia/M/ Mirachs_Ghost.html) is just a faint, fuzzy galaxy, well known to astronomers, that happens to be seen nearly along the line-of-sight to Mirach (http://www.astro.uiuc.edu/~kaler/sow/mirach.html), a bright star. Centered in this star field (http://www.perseus.gr/Astro-DSO-NGC-0404.htm), Mirach is also called Beta Andromedae (http://www.astro.wisc.edu/~dolan/constellations/ constellations/Andromeda.html). About 200 light-years distant, Mirach is a red giant (http://en.wikipedia.org/wiki/Red_giant) star, cooler than the Sun but much larger and so intrinsically much brighter than our parent star. In most telescopic views, glare and diffraction spikes (http://en.wikipedia.org/wiki/Diffraction_spike) tend to hide things that lie near Mirach and make the faint, fuzzy galaxy look like a ghostly internal reflection of the almost overwhelming starlight. Still, appearing (http://antwrp.gsfc.nasa.gov/apod/image/0810/mirachs_ayiomamitis_label.jpg) in this sharp image just above and to the right of Mirach, Mirach's Ghost is cataloged as galaxy NGC 404 (http://arxiv.org/abs/1003.4985) and is estimated to be some 10 million light-years away.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101028.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/GhostShipTrails_kotsiopoulos.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101029.html) Star Trails and the Captain's Ghost Look closely at this surreal nightscape (http://www.greeksky.gr/files/photos/landscapes/ 20100322ShipTrails.htm). In the dreamlike scene, star trails arc (http://antwrp.gsfc.nasa.gov/apod/ap061202.html) over an old ship (http://www.rc.umd.edu/rchs/reader/rime1.html) run aground on a beach near Gytheio, Peloponnesus in southern Greece. Could that be the captain's ghost haunting (http://www.gutenberg.org/ebooks/41) the beach, gazing forlornly (http://www.heise.de/ix/raven/Literature/Lore/ TheRaven.html) at the decaying wreck, hovering over starlight reflected in still water? Actually, the ephemeral shape is the photographer. Instead of a single long exposure to record the motion (http://antwrp.gsfc.nasa.gov/apod/ap100212.html) of the stars as the Earth rotates (http://antwrp.gsfc.nasa.gov/apod/ap070519.html) on its axis, the picture is composed of 90 consecutive images, each exposure 90 seconds long. Digitally stacking the individual exposures then reconstructs the star trails (http://antwrp.gsfc.nasa.gov/apod/ap060915.html). It also creates a ghostly, semi-transparent figure of the photographer who was captured standing on the beach in only one of the exposures.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101029.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/VdB141_leshin900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101030.html)Ghost of the Cepheus FlareSpooky shapes seem to hauntthis starry expanse (http://sleshin.startlogic.com/stargazergallery/main.php?g2_itemId=379&g2_imageViewsIndex=1),drifting through the night in the royal constellationCepheus (http://www.dibonsmith.com/cep_con.htm).Of course, the shapes are cosmic dust clouds faintly visiblein dimly reflected starlight.Far from your ownneighborhood (http://earthobservatory.nasa.gov/) on planet Earth, theylurk (http://science.nasa.gov/science-news/science-at-nasa/2010/27oct_artemis/) at the edge of theCepheus Flare (http://arxiv.org/abs/0809.4761)molecular cloud complex some 1,200 light-years away.Over 2 light-years across the ghostly nebula known asvdB 141 (http://www.noao.edu/image_gallery/html/im1060.html)or Sh2-136 (http://galaxymap.org/cgi-bin/details.py?id=21415&t=hii&s=4_p34.0xp31.0&name=S136)is near the center of the field.The core of the dark cloud on the right is collapsing and islikely a binary star system in theearly stages (http://arxiv.org/abs/0910.1894) of formation.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101030.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1010/ngc2080_hst.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101031.html) Halloween and the Ghost Head Nebula Halloween's origin (http://www.history.com/topics/Halloween) is ancient and astronomical. Since the fifth century BC, Halloween (http://en.wikipedia.org/wiki/Halloween) has been celebrated as a cross-quarter day (http://en.wikipedia.org/wiki/Cross-quarter_day), a day halfway between an equinox (http://antwrp.gsfc.nasa.gov/apod/ap000923.html) (equal day / equal night) and a solstice (http://antwrp.gsfc.nasa.gov/apod/ap971221.html) (minimum day / maximum night in the northern hemisphere). With a modern calendar (http://webexhibits.org/calendars/year-countries.html), however, the real cross-quarter day (http://www.whyy.org/tv12/franklinfacts/oct3100ff.html) will occur next week. Another cross-quarter day is Groundhog's Day (http://en.wikipedia.org/wiki/Groundhog_Day). (http://www.youtube.com/watch?v=eZbtAFq7dP8) Halloween's modern celebration retains historic roots (http://www.neopagan.net/Halloween-Origins.html) in dressing to scare away the spirits of the dead. Perhaps a fitting tribute to this ancient holiday is this view of the Ghost Head Nebula (http://photojournal.jpl.nasa.gov/catalog/PIA04226) taken with the Hubble Space Telescope (http://antwrp.gsfc.nasa.gov/apod/ap010806.html). Similar to the icon of a fictional (http://en.wikipedia.org/wiki/Casper_the_Friendly_Ghost) ghost (http://en.wikipedia.org/wiki/Ghost), NGC 2080 is actually a star forming region (http://www.astronom.si/forum/stellar_nurseries.html) in the Large Magellanic Cloud (http://antwrp.gsfc.nasa.gov/apod/ap100514.html), a satellite galaxy of our own Milky Way Galaxy (http://antwrp.gsfc.nasa.gov/apod/milky_way.html). The Ghost Head Nebula spans about 50 light-years (http://chandra.harvard.edu/photo/cosmic_distance.html) and is shown in representative colors.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101031.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1011/volcanosky_perrot.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101101.html) The Milky Way Over the Peak of the Furnace On Reunion Island (http://en.wikipedia.org/wiki/Réunion), it is known simply as "The Volcano." To others, it is known as the Piton de la Fournaise (http://en.wikipedia.org/wiki/Piton_de_la_Fournaise), which is French for the Peak of the Furnace. It is one of the most active volcanoes (http://www.volcanolive.com/active2.html) in the world. The Volcano started a new eruption last month by spewing hot lava (http://www.lucperrot.fr/sa/eruption.jpg) bombs (http://en.wikipedia.org/wiki/Volcanic_bomb) as high as 10 meters into the air from several vents. Pictured above (http://www.lucperrot.fr/?multimedia/eruption_volcan_vr), the recent eruption was caught before (http://www.youtube.com/watch?v=HEzkfrwZ-vI) a star filled southern sky, appearing somehow contained beneath the arching band of our Milky Way Galaxy (http://bb.nightskylive.net/asterisk/viewtopic.php?f=24&t=18006). Also visible in the background sky is the Pleiades (http://antwrp.gsfc.nasa.gov/apod/ap091014.html) open star cluster (http://antwrp.gsfc.nasa.gov/apod/open_clusters.html), the constellation of Orion (http://antwrp.gsfc.nasa.gov/apod/ap100329.html), the brightest star Sirius (http://stars.astro.illinois.edu/sow/sirius.html), and the neighboring Large (http://antwrp.gsfc.nasa.gov/apod/ap101016.html) and Small (http://antwrp.gsfc.nasa.gov/apod/ap100903.html) Magellanic Cloud galaxies (http://antwrp.gsfc.nasa.gov/apod/ap100514.html). (Can you find them (http://bb.nightskylive.net/asterisk/discuss_apod.php?date=101101)?) The Piton de la Fournaise erupted for months in 2006, and for days in 2007, 2008, and in January of 2010 (http://www.youtube.com/watch?v=kc1TTJuRKxA). Nobody knows how long the current eruption (http://bigthink.com/ideas/24511) will last, or when The Volcano will erupt next.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101101.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1011/spicules_nso.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101102.html)Spicules: Jets on the SunImagine a pipe as wide as a state and as long as the Earth. Now imagine that this pipe is filled withhot gas moving (http://antwrp.gsfc.nasa.gov/apod/ap970904.html) 50,000 kilometers per hour. Further imagine that this pipe is not made of metal but a transparentmagnetic field (http://solar.physics.montana.edu/YPOP/Spotlight/Magnetic/). You are envisioning just one of thousands of youngspicules on the active Sun (http://antwrp.gsfc.nasa.gov/apod/ap090405.html). Pictured above is one of the highestresolution image yet of these enigmatic solar flux tubes. Spicules (http://www.space.com/scienceastronomy/star_quakes_40728.html) line the above frame ofsolar active region 11092 (http://www.youtube.com/watch?v=VyaqxKkSCpU) that crossed the Sun (http://bb.nightskylive.net/asterisk/viewtopic.php?f=24&t=18012) last month, but are particularly evident converging on the sunspot (http://antwrp.gsfc.nasa.gov/apod/ap051106.html) on the lower left.Time-sequenced images (http://www.youtube.com/watch?v=U1WsC1TR-x8) have recently shown thatspicules (http://antwrp.gsfc.nasa.gov/apod/ap081102.html) last about five minutes,starting out astall tubes (http://antwrp.gsfc.nasa.gov/apod/ap050216.html)of rapidly rising gas but eventuallyfading as the gas peaks and falls back down to theSun (http://en.wikipedia.org/wiki/Sun). What determines the creation and dynamics of spicules (http://adsabs.harvard.edu/abs/2010ApJ...708.1579C) remains a topic of active research.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101102.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1011/necklace_corradi900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101103.html)The Necklace NebulaThe small constellationSagitta (http://www.hawastsoc.org/deepsky/sge/index.html)sports this large piece of cosmicjewelry, dubbed the Necklace Nebula.The newlydiscovered (http://arxiv.org/abs/1009.1043)example of a ring-shaped (http://antwrp.gsfc.nasa.gov/apod/ap080918.html) planetary nebula isabout 15,000 light-years distant.Its bright ring with pearls of glowing gas is halfa light-year across.Planetary nebulae (http://en.wikipedia.org/wiki/Planetary_nebula)are created by sun-like stars in afinalphase (http://www.astro.washington.edu/users/balick/WFPC2/) of stellar evolution.But the Necklace Nebula's central star, near the center of a ringstrongly tilted to our line of sight, has also been shown to bebinary (http://astro.unl.edu/naap/ebs/animations/ebs.html),a close system of two stars with an orbital periodof just over a day.Astronomers estimating the apparentage (http://antwrp.gsfc.nasa.gov/apod/ap101021.html) of the ring to bearound 5,000 years, also find more distant gas cloudsperpendicular to the ring plane, seen here at the upper left andlower right.Those clouds were likely ejected about 5,000 years before theclouds forming the necklace.This false color image combines emission fromionized (http://csep10.phys.utk.edu/astr162/lect/light/ionization.html) hydrogen inblue, oxygen in green, and nitrogen in red.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101103.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1011/iss025e010008_900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101104.html) Night Lights Constellations of lights sprawl across this night scene (http://spaceflight.nasa.gov/gallery/images/station/crew-25/ html/iss025e010008.html), but they don't belong in the skies of planet Earth (http://www.darksky.org/mc/ page.do?sitePageId=118982&orgId=idsa). Instead, the view looks down from the International Space Station (http://www.nasa.gov/mission_pages/station/main/onthestation/ facts_and_figures.html) as it passed over the United States along the northern Gulf Coast on October 29. A Russian Soyuz spacecraft (http://antwrp.gsfc.nasa.gov/apod/ap080514.html) is docked in the foreground. Behind its extended solar panels, some 360 kilometers below, are the recognizable (http://antwrp.gsfc.nasa.gov/apod/ap030411.html) city lights of New Orleans. Looking east along the coast to the top of the frame finds Mobile, Alabama while Houston city lights stand out to the west, toward the bottom. North (left) of New Orleans, a line of lights tracing central US highway I55 connect to Jackson, Mississippi and Memphis, Tennessee. Of course, the lights follow the population centers, but not everyone lives on planet Earth (http://earthobservatory.nasa.gov/IOTD/view.php?id=896) all the time these days. November 2nd marked (http://www.nasa.gov/externalflash/ expedition_10_years/) the first decade (http://www.nasa.gov/mission_pages/station/living/ 10years.) of continuous human presence in space on board the International Space Station.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101104.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1011/hartleymontage1x5_epoxi900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101105.html) Comet Hartley 2 Flyby Follow these 5 frames clockwise starting from the top left to track the view from (http://www.nasa.gov/mission_pages/epoxi/images/ sunshine1.html) the EPOXI mission (http://www.nasa.gov/mission_pages/epoxi/index.html) spacecraft as it approached, passed under, and then looked back at the nucleus of comet Hartley 2 (http://antwrp.gsfc.nasa.gov/apod/ap101026.html) on November 4. Its closest approach distance was about 700 kilometers. In fact, this encounter was the fifth time (http://photojournal.jpl.nasa.gov/catalog/PIA13576) a spacecraft from planet Earth has imaged a comet close-up. But Hartley 2's nucleus is definitely the smallest one so far, its long axis spanning (http://www.nasa.gov/mission_pages/epoxi/images/ sunshine-3.html) only about 2 kilometers (1.2 miles). Though Hartley 2 is small, these stunning images showing jets of dust and gas indicate an impressively active surface. The jets are seen originating from the rough surface areas, with sunlight illuminating the nucleus from the right. Remarkably, rough areas at both ends of the elongated nucleus are joined by a narrower, smooth waist. The EPOXI mission (http://www.nasa.gov/mission_pages/epoxi/ epoxi20101025.html) reuses the Deep Impact spacecraft that launched a probe impacting the nucleus of comet Tempel 1 (http://antwrp.gsfc.nasa.gov/apod/ap050915.html) in 2005.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101105.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1011/IC1396RolfGeissinger_900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101106.html)The Elephant's Trunk in IC 1396Like an illustration in a galacticJust So Story (http://www.boop.org/jan/justso/), theElephant's Trunk Nebulawinds through the emission nebula and young star clustercomplex IC 1396 (http://antwrp.gsfc.nasa.gov/apod/ap050908.html), in the high and far offconstellationofCepheus (http://www.astropix.com/HTML/E_SUM_N/CEPHEUSO.HTM).Of course, the cosmic elephant's trunk is over 20 light-years long.This composite (http://www.stern-fan.de/Seiten/galerie_Bild_IC1396_Elefant-Detail.html)was recorded throughnarrow band (http://antwrp.gsfc.nasa.gov/apod/ap071102.html) filtersthat transmit the light from ionized hydrogen, sulfur,and oxygenatoms (http://csep10.phys.utk.edu/astr162/lect/light/absorption.html) in the region.The resulting image highlights the bright swept-back ridgesthat outline pockets of coolinterstellar (http://www-ssg.sr.unh.edu/ism/what1.html)dust and gas.Such embedded, dark,tendril-shaped clouds (http://antwrp.gsfc.nasa.gov/apod/ap070218.html) contain theraw material forstar formation (http://archive.ncsa.uiuc.edu/Cyberia/Bima/StarForm.html) and hideprotostars within (http://antwrp.gsfc.nasa.gov/apod/ap050409.html) the obscuring cosmic dust.Nearly 3,000light-yearsdistant (http://heasarc.gsfc.nasa.gov/docs/cosmic/), the relatively faintIC1396 complex (http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1996A%26A...309..581W&db_key=AST&high=3af6c03e8102807) covers alarge region (http://antwrp.gsfc.nasa.gov/apod/ap050908.html)on the sky, spanning over 5 degrees.This dramatic close-up covers a 2 degree wide field,about the size (http://antwrp.gsfc.nasa.gov/apod/ap061228.html) of 4 Full Moons.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101106.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1011/cenA_hst.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101107.html) The Center of Centaurus A A fantastic jumble of young blue star clusters, gigantic glowing gas clouds, and imposing dark dust (http://antwrp.gsfc.nasa.gov/apod/lib/glossary.html#dust) lanes surrounds the central region of the active galaxy Centaurus A. This mosaic of Hubble Space Telescope images (http://hubblesite.org/newscenter/newsdesk/archive/releases/1998/14/) taken in blue, green, and red light has been processed to present a natural color picture of this cosmic maelstrom. Infrared images (http://coolcosmos.ipac.caltech.edu/cosmic_classroom/ir_tutorial/what_is_ir.html) from the Hubble have also shown that hidden at the center of this activity are what seem to be disks of matter spiraling into a black hole (http://antwrp.gsfc.nasa.gov/apod/ap970516.html) with a billion times the mass of the Sun! Centaurus A (http://www.seds.org/messier/xtra/ngc/n5128.html) itself is apparently the result of a collision of two galaxies (http://antwrp.gsfc.nasa.gov/apod/ap020202.html) and the left over debris is steadily being consumed by the black hole (http://antwrp.gsfc.nasa.gov/apod/ap971107.html). Astronomers believe that such black hole central engines (http://antwrp.gsfc.nasa.gov/apod/ap020309.html) generate the radio, X-ray, and gamma-ray energy (http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html) radiated by Centaurus A (http://www.youtube.com/watch?v=wYQoNHc1hug) and other active galaxies. But for an active galaxy (http://en.wikipedia.org/wiki/Active_galactic_nucleus) Centaurus A (http://antwrp.gsfc.nasa.gov/apod/ap040624.html) is close, a mere 10 million light-years (http://chandra.harvard.edu/photo/cosmic_distance.html) away, and is a relatively convenient laboratory for exploring these powerful sources of energy (http://antwrp.gsfc.nasa.gov/apod/ap000706.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101107.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1011/hartley2close_epoxi.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101108.html)700 Kilometers Below Comet Hartley 2What kind of comet is this?Last week, NASA's robotic EPOXI spacecraft (http://epoxi.umd.edu/1mission/index.shtml) whizzed past Comet 103P/Hartley (http://en.wikipedia.org/wiki/103P/Hartley), also known as Comet Hartley 2, and recorded images (http://www.youtube.com/watch?v=5IlnueAk1dM) and data that are both strange and fascinating.EPOXI was near its closest approach -- about 700 kilometers away -- when it snapped the above picture (http://epoxi.umd.edu/3gallery/20101104_Five_c.shtml).As expected, the comet has indeed shown itself (http://antwrp.gsfc.nasa.gov/apod/ap101105.html) to be a tumbling iceberg orbiting the Sun between Earth and Jupiter.However, unexpected features on the images have raised many questions.For example, where are all the craters?Why is there a large smooth area around the middle?How much of Comet Hartley 2 (http://www.nasa.gov/mission_pages/epoxi/index.html) is a loose pile (http://en.wikipedia.org/wiki/Rubble_pile) of dust and ice shards?Future analyses and comparisons to other (http://antwrp.gsfc.nasa.gov/apod/ap070422.html) comet

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1011/ngc4452_hst.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101109.html) NGC 4452: An Extremely Thin Galaxy Why is there a line segment on the sky? In one of the more precise alignments known in the universe, what is pictured above is actually a disk galaxy being seen almost perfectly edge on. The image from the Hubble Space Telescope (http://www.youtube.com/watch?v=SpkrVw_E6Nw) is a spectacular visual reminder of just how thin (http://antwrp.gsfc.nasa.gov/apod/ap100225.html) disk (http://antwrp.gsfc.nasa.gov/apod/ap060612.html) galaxies (http://antwrp.gsfc.nasa.gov/apod/ap970228.html) can be. NGC 4452, a galaxy in the nearby Virgo Cluster of Galaxies (http://antwrp.gsfc.nasa.gov/apod/ap080708.html), is so thin that it is actually difficult to determine (http://adsabs.harvard.edu/abs/1989ApJ...339..783H) what type of disk galaxy it is. Its lack of a visible dust lane indicates that it is a low-dust lenticular galaxy (http://en.wikipedia.org/wiki/Lenticular_galaxy), although it is still possible that a view from on top would reveal spiral structure. The unusual stellar line segment (http://blogs.discovermagazine.com/badastronomy/2010/11/08/galaxy-on-edge/) spans about 35,000 light years (http://chandra.harvard.edu/photo/cosmic_distance.html) from end to end. Near NGC 4452 (http://www.spacetelescope.org/images/potw1029a/)'s center is a slight bulge of stars, while hundreds of background galaxies (http://antwrp.gsfc.nasa.gov/apod/ap091209.html) are visible far in the distance. Galaxies that appear this thin are rare mostly because our Earth must reside (nearly) in the extrapolated planes (http://www.lon-capa.org/~mmp/applist/si/plane.htm) of their thin galactic disks. Galaxies that actually are this thin are relatively common -- for example our own Milky Way Galaxy (http://www.atlasoftheuniverse.com/galaxy.html) is thought to be about this thin (http://antwrp.gsfc.nasa.gov/apod/ap100215.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101109.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1011/bubble_fermi.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101110.html) Huge Gamma Ray Bubbles Found Around Milky Way Did you know that our Milky Way Galaxy has huge bubbles emitting gamma rays from the direction of the galactic center? Neither did anybody. As the data from the Earth-orbiting Fermi satellite (http://en.wikipedia.org/wiki/Fermi_Gamma-ray_Space_Telescope) began acuminating (http://antwrp.gsfc.nasa.gov/apod/ap080828.html) over the past (http://antwrp.gsfc.nasa.gov/apod/ap090321.html) two years (http://antwrp.gsfc.nasa.gov/apod/ap100318.html), however, a large and unusual feature toward our Galaxy (http://cass.ucsd.edu/public/tutorial/MW.html)'s center became increasingly evident. The two bubbles are visible together as the red and white spotted oval surrounding the center of the above all sky image, released yesterday (http://www.nasa.gov/mission_pages/GLAST/news/new-structure.html). The plane (http://antwrp.gsfc.nasa.gov/apod/ap090926.html) of our Galaxy runs horizontally across the image center. Assuming the bubbles emanate from our Galaxy's center, the scale of the bubbles is huge, rivaling the entire Galaxy in size, and spanning about 50,000 light years (http://chandra.harvard.edu/photo/cosmic_distance.html) from top to bottom. Earlier indications of the bubbles has been found on existing all sky maps in the radio (http://antwrp.gsfc.nasa.gov/apod/ap050205.html), microwave (http://antwrp.gsfc.nasa.gov/apod/ap030217.html), and X-ray (http://antwrp.gsfc.nasa.gov/apod/ap990503.html). The cause of the bubbles is presently unknown (http://arxiv.org/abs/1005.5480), but will likely be researched for years to come.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101110.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1011/APOD2010-11-10_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101111.html)Two Views, Two CrescentsVenus (http://antwrp.gsfc.nasa.gov/apod/ap050107.html) rose in a glowing dawnsky on November 5th, just before the Sun.For early morning risers, its brilliantcrescent phase (http://astrosun2.astro.cornell.edu/academics/courses//astro201/venus_phase.htm)was best appreciated with binoculars or a small telescope.On that day the crescent Venus also appeared in close conjunction withanother lovely crescent (http://antwrp.gsfc.nasa.gov/apod/ap090424.html) that hugs theeastern horizon in planet Earth's morning skies, the waningcrescent Moon (http://astrosun2.astro.cornell.edu/academics/courses//astro201/moon_phase.htm).The celestial photo-op is captured here from two locations.Left,separated by (http://ofpink.wordpress.com/2010/11/05/moon-and-venus-and-an-incredible-sunrise-above-a-sea-of-clouds/) less than a degree, the two crescents hover abovea sea of clouds.The picture was recorded from an Alpine mountain pass not far fromTurin, Italy.On the right (http://www.twanight.org/newTWAN/photos.asp?ID=3002891&PrevNext=latest)is a sharp telephoto view taken before an earlier sunrise,farther east in the Alborz Mountains (http://antwrp.gsfc.nasa.gov/apod/ap080503.html)of Iran.In steady skies the slender Moon is still sliding toward Venus,the bright planet'scompactcrescent (http://www.twanight.org/newTWAN/photos.asp?ID=3002813) just clearing the mountainous horizon.For now, the crescent phase of Venus remains easy to enjoywith binoculars in November's dawn skies.The first observations of the phases of Venus, made byGalileo with his telescope (http://csep10.phys.utk.edu/astr161/lect/history/galileo.html)in 1610, agreed with the predictions of the heliocentricCopernican (http://galileo.rice.edu/sci/theories/copernican_system.html) model of the Solar System.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101111.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1011/IRIS_IAC80_DLopez900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101112.html)NGC 7023: The Iris NebulaLike delicate cosmic petals, these clouds of interstellar dust and gashave blossomed 1,300 light-years away in the fertilestar fields of the constellation Cepheus (http://www.astropix.com/HTML/E_SUM_N/CEPHEUSO.HTM).Sometimes called the Iris Nebula and dutifullycataloged asNGC 7023 (http://darkhorseobservatory.org/product.php?ProductID=146&CategoryID=31),this is not the only nebula in thesky to evoke the imagery of flowers (http://antwrp.gsfc.nasa.gov/apod/ap080214.html).Still, thisbeautifuldigital image (http://www.iac.es/telescopes/IAM/Nov10_ing.html) shows off the Iris Nebula's range ofcolors and symmetries in impressive detail. Within the Iris, dusty nebular material surrounds a hot,young star.The dominant color of the brighter reflection nebula is blue,characteristicof dust (http://leo.astronomy.cz/mix/mix.html) grains reflecting starlight.Centralfilaments (http://www.spacetelescope.org/news/heic0915/) of the dusty clouds glow with a faint reddishphotoluminesence as some dust grainseffectivelyconvert (http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1989ApJ...347L..25W&db_key=AST&high=3bc4bede8e21358) the star's invisibleultraviolet (http://imagers.gsfc.nasa.gov/ems/uv.html)radiation to visible red light.Infrared observations (http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?2000A%26A...354L..17M&db_key=AST&nosetcookie=1)indicate that this nebula may containcomplex carbon molecules known asPAHs (http://legacy.spitzer.caltech.edu/features/articles/20050627.shtml).As shown here, the bright blue portion of the Iris Nebula is about sixlight-years across.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101112.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1011/m66_croman_900c1.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101113.html) Spiral Galaxy M66 Big beautiful spiral galaxy M66 (http://seds.org/messier/m/m066.html) lies a mere (http://hubblesite.org/newscenter/archive/ releases/2010/37/) 35 million light-years away. About 100 thousand light-years across, the gorgeous island universe is well known to astronomers as a member of the Leo Triplet (http://antwrp.gsfc.nasa.gov/apod/ap060309.html) of galaxies. In M66, pronounced dust lanes and young, blue star clusters sweep along spiral arms (http://antwrp.gsfc.nasa.gov/apod/ap100413.html) dotted with the tell-tale glow of pink star forming regions. This colorful and deep view (http://www.rc-astro.com/photo/id1189.html) also reveals faint extensions beyond the brighter galactic disk. Of course, the bright, spiky (http://spider.ipac.caltech.edu/staff/kaspar/obs_mishaps/ images/int_reflection2.html) stars lie in the foreground, within our own Milky Way Galaxy, but many, small, distant background galaxies (http://www.noao.edu/outreach/aop/observers/ bggalaxies.html) can be seen in the cosmic snapshot. Gravitational interactions (http://burro.case.edu/JavaLab/GalCrashWeb/ backgrnd.html) with its neighboring galaxies have likely influenced the shape of spiral galaxy M66.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101113.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1011/universes_pickover.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101114.html)Multiverses: Do Other Universes Exist?Do nearly exact copies of you exist in other universes? If one or more of the multiverse hypotheses (http://en.wikipedia.org/wiki/Multiverse) is correct, then quite possibly they do. In the above computer-enhanced illustration (http://sprott.physics.wisc.edu/pickover/every.jpg), independent universes are shown as independent circles or spheres (http://antwrp.gsfc.nasa.gov/apod/ap050130.html). Spheres may be causally disconnected from all other spheres, meaning no communications can pass between them. Some spheres may contain different realizations of our universe, while others may have different physical laws (http://bb.nightskylive.net/asterisk/viewforum.php?f=39). An entire set of parallel universes (http://arxiv.org/abs/quant-ph/0104033) is called a multiverse (http://bb.nightskylive.net/asterisk/viewtopic.php?f=39&t=21958). The human eye (http://science.howstuffworks.com/eye1.htm) might represent the possibility that realizations of some multiverse hypotheses (http://space.mit.edu/home/tegmark/crazy.html) might only exist in the human mind (http://www.straightdope.com/classics/a2_127.html).One criticism of multiverse hypotheses (http://en.wikipedia.org/wiki/Many-worlds_interpretation) is that they are frequently difficult to test. Some multiverse hypotheses (http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2006JCAP...01..017G) may therefore be great fun to think about but not practically falsifiable (http://en.wikipedia.org/wiki/Falsifiability) and therefore have no predictive scientific value.



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[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1011/cupolaview_iss14.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101115.html) Home from Above There's no place like home (http://www.youtube.com/watch?v=3YKn53vWIHA). Peering out of the windows of the International Space Station (http://antwrp.gsfc.nasa.gov/apod/ap091207.html) (ISS), astronaut Tracy Caldwell Dyson (http://www.jsc.nasa.gov/Bios/htmlbios/caldwell.html) takes in the planet on which we were all born, and to which she would soon return. About 350 kilometers up, the ISS is high enough so that the Earth's horizon appears clearly curved (http://www.newton.dep.anl.gov/askasci/ast99/ast99605.htm). Astronaut Dyson's windows show some of Earth's complex clouds (http://antwrp.gsfc.nasa.gov/apod/ap071230.html), in white, and life giving atmosphere and oceans, in blue (http://www.sciencemadesimple.com/sky_blue.html). The space station orbits the Earth about once every 90 minutes. It is not difficult for people living below to look back toward the ISS (http://antwrp.gsfc.nasa.gov/apod/ap100523.html). The ISS (http://antwrp.gsfc.nasa.gov/apod/ap080604.html) can frequently be seen as a bright point of light drifting overhead (http://www.youtube.com/watch?v=KXltH3Sw45k) just after sunset. Telescopes can even resolve the overall structure (http://antwrp.gsfc.nasa.gov/apod/ap080524.html) of the space station. The above image (http://twitpic.com/2sapus) was taken in late September from the ISS's Cupola (http://en.wikipedia.org/wiki/Cupola_(ISS)) window bay. Dr. Dyson is a lead vocalist in the band Max (http://en.wikipedia.org/wiki/Max_Q_(astronaut_band)) Q (http://www.youtube.com/watch?v=S-DLc9CRYYc).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101115.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1011/ngc7252_eso.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101116.html) Atoms-for-Peace Galaxy Collision Is this what will become of our Milky Way Galaxy? Perhaps if we collide with the Andromeda Galaxy (http://www.youtube.com/watch?v=PrIk6dKcdoU) in a few billion years, it might. Pictured above is NGC 7252, a jumble of stars created by a huge collision (http://en.wikipedia.org/wiki/Andromeda-Milky_Way_collision) between two large galaxies. The collision will take hundreds of millions of years and so is effectively caught frozen in time in the above image (http://www.eso.org/public/news/eso1044/). The resulting pandemonium (http://antwrp.gsfc.nasa.gov/apod/ap090802.html) has been dubbed the Atoms-for-Peace (http://en.wikipedia.org/wiki/Atoms_for_Peace) galaxy because of its similarity to a cartoon (http://www.cfo.doe.gov/me70/manhattan/images/AtomLabeledLarge.gif) of a large atom. The above image (http://www.eso.org/public/news/eso1044/) was taken recently by the MPG/ESO 2.2 meter telescope (http://www.eso.org/sci/facilities/lasilla/telescopes/2p2/) in Chile (http://en.wikipedia.org/wiki/Chile). NGC 7252 (http://adsabs.harvard.edu/abs/2010MNRAS.407...43C) spans about 600,000 light years and lies about 220 million light years (http://chandra.harvard.edu/photo/cosmic_distance.html) away toward the constellation (http://www.iau.org/public/constellations/) of the Water Bearer (Aquarius). Since the sideways velocity of the Andromeda Galaxy (http://antwrp.gsfc.nasa.gov/apod/ap090510.html) (M31) is presently unknown, no one really knows for sure if the Milky Way will ever collide with M31 (http://adsabs.harvard.edu/abs/2008MNRAS.386..461C).



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[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1011/ngc7252_eso.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101116.html) Atoms-for-Peace Galaxy Collision Is this what will become of our Milky Way Galaxy? Perhaps if we collide with the Andromeda Galaxy (http://www.youtube.com/watch?v=PrIk6dKcdoU) in a few billion years, it might. Pictured above is NGC 7252, a jumble of stars created by a huge collision (http://en.wikipedia.org/wiki/Andromeda–Milky_Way_collision) between two large galaxies. The collision will take hundreds of millions of years and so is effectively caught frozen in time in the above image (http://www.eso.org/public/news/eso1044/). The resulting pandemonium (http://antwrp.gsfc.nasa.gov/apod/ap090802.html) has been dubbed the Atoms-for-Peace (http://en.wikipedia.org/wiki/Atoms_for_Peace) galaxy because of its similarity to a cartoon (http://www.cfo.doe.gov/me70/manhattan/images/AtomLabeledLarge.gif) of a large atom. The above image (http://www.eso.org/public/news/eso1044/) was taken recently by the MPG/ESO 2.2 meter telescope (http://www.eso.org/sci/facilities/lasilla/telescopes/2p2/) in Chile (http://en.wikipedia.org/wiki/Chile). NGC 7252 (http://adsabs.harvard.edu/abs/2010MNRAS.407...43C) spans about 600,000 light years and lies about 220 million light years (http://chandra.harvard.edu/photo/cosmic_distance.html) away toward the constellation (http://www.iau.org/public/constellations/) of the Water Bearer (Aquarius). Since the sideways velocity of the Andromeda Galaxy (http://antwrp.gsfc.nasa.gov/apod/ap090510.html) (M31) is presently unknown, no one really knows for sure if the Milky Way will ever collide with M31 (http://adsabs.harvard.edu/abs/2008MNRAS.386..461C).



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[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1011/leaforion_miyasaka.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101117.html)Frosted Leaf OrionSometimes, you can put some night sky in your art. Captured above Japan (http://en.wikipedia.org/wiki/Japan) earlier this month, a picturesque night sky was photographed behind a picturesque frosted leaf. The reflecting ice crystals on the leaf coolly mimic the shining stars far in the background. The particular background sky on this 48-second wide angle exposure (http://www.flickr.com/photos/43894176@N07/5150022192/), however, might appear quite interesting and familiar. On the far left, although hard to find, appears a streaking meteor (http://earthsky.org/astronomy-essentials/earthskys-meteor-shower-guide).Below and to the right of the meteor appears a longer and brighter streak of an airplane. The bright star on the left is the dog-star Sirius (http://en.wikipedia.org/wiki/Sirius), the brightest star on the night sky.To Sirius' right appears the constellation of Orion (http://160.114.99.91/astrojan/orion.htm), including the three linear belt stars below the red giant Betelgeuse (http://antwrp.gsfc.nasa.gov/apod/ap100106.html). The bright patch of light further to the right is the Pleiades (http://antwrp.gsfc.nasa.gov/apod/ap091014.html) open star cluster (http://antwrp.gsfc.nasa.gov/apod/open_clusters.html). Similar views including the constellation Orion (http://antwrp.gsfc.nasa.gov/apod/ap101023.html) can be seen above much of the northern hemisphere for the next several months, although you might have to provide your own leaf.



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[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1011/pleiadesSky_JOhn600h.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101118.html)Sisters of the Dusty SkyHurtling through a cosmic dust cloud some 400 light-years away,the lovely Pleiades (http://antwrp.gsfc.nasa.gov/apod/ap071122.html) orSeven Sisters (http://www.naic.edu/~gibson/pleiades/pleiades_myth.html)star cluster is well-known for its striking bluereflection nebulae (http://antwrp.gsfc.nasa.gov/apod/ap011228.html).In the dusty sky toward the constellation Taurus and theOrion Arm (http://www.atlasoftheuniverse.com/5000lys.html)of our Milky Way Galaxy, thisremarkable image (http://www.flickr.com/photos/neutronman/5179785056/) shows the famousstar cluster at the upper left.But lesser known dusty nebulae lie along the region's fertilemolecular cloud (http://www.astropix.com/HTML/SHOW_DIG/Taurus_Molecular_Cloud.HTM),within the 10 degree wide field,including the bird-like visage ofLBN 777 (http://tvdavisastropics.com/astroimages-1_000066.htm)near center.Small bluish reflection nebula VdB 27 at the lower right isassociated with the young, variable starRY Tau (http://antwrp.gsfc.nasa.gov/apod/ap050923.html).At the distance of the Pleiades,the 5 panel mosaic (http://downthewormhole.blogspot.com/2010/11/bird-and-sisters.html)spans nearly 70 light-years.



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[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1011/cygnusNeb_geissinger800.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101119.html) Nebulae in the Northern Cross Explore a beautiful and complex region of nebulae strewn along the plane of our Milky Way Galaxy (http://antwrp.gsfc.nasa.gov/apod/ap091125.html) in this widefield skyscape. The image emphasizes cosmic gas clouds in a 25 by 25 degree view centered on the Northern Cross, the famous asterism (http://www.seds.org/Maps/Const/asterism.html) in the constellation Cygnus. Bright, hot, supergiant star Deneb (http://www.astro.uiuc.edu/~kaler/sow/deneb.html) at the top of the cross, Sadr (http://antwrp.gsfc.nasa.gov/apod/ap070104.html) near the center, and beautiful Albireo (http://bf-astro.com/albireo/Albireo.htm) run diagonally through the scene. Popular telescopic tour destinations such as the North America (http://antwrp.gsfc.nasa.gov/apod/ap090630.html) and Pelican (http://antwrp.gsfc.nasa.gov/apod/ap061130.html) emission regions, the Butterfly Nebula (http://www.allaboutastro.com/Butterflynebula.html) (IC 1318), and the Crescent (http://antwrp.gsfc.nasa.gov/apod/ap090915.html) and Veil nebulae (http://antwrp.gsfc.nasa.gov/apod/ap100916.html) can be identified by placing your cursor over the image. Silhouetted by the glowing interstellar (http://espg.sr.unh.edu/ism/what1.html) clouds and crowded star fields, the dark Northern Coal Sack (http://antwrp.gsfc.nasa.gov/apod/) also stands out, part of a series of obscuring dust clouds forming the Great Rift (http://antwrp.gsfc.nasa.gov/apod/ap100625.html) in the Milky Way. These Northern Cross nebulosities are all located about 2,000 light-years away. Along with the Sun, they lie within the Orion spiral arm (http://www.atlasoftheuniverse.com/5000lys.html) of our galaxy.



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http://antwrp.gsfc.nasa.gov/apod/image/1011/stephquintet_hwilson900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101120.html)Stephan's QuintetThe first identified compact galaxy group,Stephan's Quintet (http://en.wikipedia.org/wiki/Stephan%27s_Quintet) is featured inthiseye-catching image (http://hwilson.zenfolio.com/p187515715/h18520d37#h18520d37) constructed with data drawn fromthe extensive Hubble Legacy Archive (http://hla.stsci.edu/).About 300 million light-years away, only four galaxies of the groupare actually locked in a cosmic dance of repeated close encounters.The odd man out iseasy to spot (http://hubblesite.org/newscenter/archive/releases/2009/25/image/c/), though.The fourinteracting galaxies (http://hubblesite.org/newscenter/archive/releases/2001/22/video/)(NGC 7319, 7318A, 7318B, and 7317 (http://hubblesite.org/newscenter/archive/releases/2001/22/image/h/format/large_web/))have an overall yellowish castand tend to have distortedloops and tails (http://antwrp.gsfc.nasa.gov/apod/ap090426.html), grown under theinfluence of disruptive gravitational tides (http://antwrp.gsfc.nasa.gov/apod/ap081115.html).But the larger bluish galaxy, NGC 7320,is much closer than the others.Just 40 million light-years distant, it isn't part of theinteracting group.In fact, individual stars in the foreground galaxy can be seen inthe sharp Hubble view, hinting that it is much closer thanthe others.Stephan's Quintet lies within the boundaries of the high flyingconstellationPegasus (http://www.hawastsoc.org/deepsky/peg/index.html).



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http://antwrp.gsfc.nasa.gov/apod/image/1011/ngc6357_hst.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101121.html)A Massive Star in NGC 6357For reasons unknown, NGC 6357 is forming some of the most massive stars ever discovered. One such massive star, near the center ofNGC 6357 (http://antwrp.gsfc.nasa.gov/apod/ap061220.html), isframed above (http://www.spacetelescope.org/news/heic0619/) carving out its owninterstellar castle with its energetic light from surrounding gas and dust.In the greater nebula (http://antwrp.gsfc.nasa.gov/apod/ap081009.html),the intricate patterns are caused bycomplex interactions (http://www.youtube.com/watch?v=qybUFnY7Y8w) betweeninterstellar winds (http://csep10.phys.utk.edu/astr162/lect/sun/wind.html),radiation pressures (http://en.wikipedia.org/wiki/Radiation_pressure),magnetic fields (http://www-spof.gsfc.nasa.gov/Education/whmfield.html), andgravity (http://www-scf.usc.edu/~kallos/gravity.htm). The overall glow of the nebula results from theemission (http://antwrp.gsfc.nasa.gov/apod/emission_nebulae.html) of light fromionized (http://csep10.phys.utk.edu/astr162/lect/light/ionization.html)hydrogen (http://en.wikipedia.org/wiki/Hydrogen) gas. Near the more obviousCat's Paw (http://antwrp.gsfc.nasa.gov/apod/ap100421.html) nebula,NGC 6357 houses the open star clusterPismis 24 (http://en.wikipedia.org/wiki/NGC_6357#Pismis_24),home to many of these tremendously bright and blue stars. The central part ofNGC 6357 (http://adsabs.harvard.edu/abs/2004AJ....127.2826B) shown spans about 10 light yearsand lies about 8,000light years (http://chandra.harvard.edu/photo/cosmic_distance.html) away toward the constellation of theScorpion.



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http://antwrp.gsfc.nasa.gov/apod/image/1011/marsdunes_mro.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101122.html) A Dark Dune Field in Proctor Crater on Mars Was this image taken with a telescope or a microscope? Perhaps this clue will help: if the dark forms were bacteria (http://www.ucmp.berkeley.edu/bacteria/bacteria.html), they would each span over football field across. What is actually being seen are large sand dunes on the floor of Proctor Crater (http://en.wikipedia.org/wiki/Proctor_%28Martian_crater%29) on Mars. The above picture (http://photojournal.jpl.nasa.gov/catalog/PIA13613) was taken by HiRISE camera (http://en.wikipedia.org/wiki/HiRISE) on board the Mars Reconnaissance Orbiter (http://www.nasa.gov/mission_pages/MRO/mission/index.html) (MRO), a robot spacecraft currently in orbit around Mars. The dark rippled dunes (http://www.youtube.com/watch?v=fsX7qmrqu_0) likely formed more recently than the lighter rock (http://en.wikipedia.org/wiki/List_of_soft_rock_musicians) forms they appear to cover, and are thought to slowly shift (http://antwrp.gsfc.nasa.gov/apod/ap090420.html) in response to pervasive wind (http://antwrp.gsfc.nasa.gov/apod/ap990112.html)s. The dunes (http://hirise.lpl.arizona.edu/PSP_004077_1325) arise (http://hirise-pds.lpl.arizona.edu/PDS/EXTRAS/RDR/PSP/ORB_004000_004099/PSP_004077_1325/PSP_004077_1325_RED.abrowse.jpg) from a complex relationship between the sandy surface and high winds (http://antwrp.gsfc.nasa.gov/apod/ap011017.html) on Mars. Similar dunes (http://antwrp.gsfc.nasa.gov/apod/ap010226.html) were first seen in Proctor Crater by Mariner 9 (http://solarsystem.nasa.gov/missions/profile.cfm?MCode=Mariner_09) more than 35 years ago.



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http://antwrp.gsfc.nasa.gov/apod/image/1011/hartley2jets2_epoxi.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101123.html) Gas and Snow Jets from Comet Hartley 2



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http://astronom.si/forum/ (http://antwrp.gsfc.nasa.gov/apod/ap101124.html) Flowing Auroras Over Norway



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http://antwrp.gsfc.nasa.gov/apod/image/1011/vdb13stardust_falesiedi900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101125.html) Stardust in Aries This composition in stardust (http://antwrp.gsfc.nasa.gov/apod/ap030706.html) covers almost 2 degrees on the sky, close to the border of the zodiacal constellation Aries (http://www.hawastsoc.org/deepsky/ari/index.html) and the plane of our Milky Way (http://antwrp.gsfc.nasa.gov/apod/ap090613.html) Galaxy. At the lower right of the gorgeous skyscape is a dusty blue reflection nebula surrounding a bright star cataloged as (http://adsabs.harvard.edu/abs/1966AJ.....71..990V) van den Bergh 13 (vdB 13), about 1,000 light-years away. At that estimated distance, the cosmic canvas (http://nuke.alessandrofalesiedi.com/HomePage/tabid/484/ Default.aspx) is over 30 light-years across. Also surrounded by scattered blue starlight, vdB 16 lies toward the upper left, while dark dusty (http://antwrp.gsfc.nasa.gov/apod/ap070511.html) nebulae sprawl across the scene. Near the edge of a large molecular cloud (http://archive.ncsa.uiuc.edu/Cyberia/Bima/GMC.html), they can hide (http://antwrp.gsfc.nasa.gov/apod/ap061006.html) the newly formed stars (http://www.nasa.gov/mission_pages/spitzer/multimedia/ spitzer20070829b.html) and young stellar objects or protostars from prying optical telescopes. Collapsing due to self-gravity (http://hyperphysics.phy-astr.gsu.edu/hbase/ astro/gravc.html), the protostars form (http://archive.ncsa.uiuc.edu/Cyberia/Bima/StarForm.html) around dense cores embedded in the molecular cloud.



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[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1011/n2024_block900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101126.html) Flame Nebula Close-Up Of course, the Flame Nebula is not on fire. Also known as NGC 2024 (http://www.astropix.com/HTML/B_WINTER/ NGC2024.HTM), the nebula's suggestive reddish color is due to the glow of hydrogen (http://antwrp.gsfc.nasa.gov/apod/lib/lament.html) atoms at the edge of the giant Orion (http://antwrp.gsfc.nasa.gov/apod/ap070125.html) molecular cloud complex some 1,500 light-years away. The hydrogen atoms have been ionized (http://csep10.phys.utk.edu/astr162/lect/light/ ionization.html), or stripped of their electrons, and glow as the atoms and electrons recombine. But what ionizes the hydrogen (http://casswww.ucsd.edu/public/tutorial/ISM.html) atoms? In this close-up view (http://www.caelumobservatory.com/gallery/n2024.shtml), the central dark lane of absorbing interstellar dust stands out in silhouette against the hydrogen glow (http://antwrp.gsfc.nasa.gov/apod/ap080424.html) and actually hides the true source of the Flame Nebula's energy from optical telescopes. Behind the dark lane lies a cluster of hot, young stars, seen at infrared wavelengths (http://www.astro.caltech.edu/palomar/flame.html) through the obscuring dust. A young, massive star in that cluster is the likely source (http://arxiv.org/abs/astro-ph/0303029) of energetic ultraviolet radiation that ionizes the hydrogen gas in the Flame Nebula.



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http://antwrp.gsfc.nasa.gov/apod/image/1011/NGC4216_crawford900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101127.html) Star Streams of NGC 4216 Some 40 million light-years distant, edge-on (http://antwrp.gsfc.nasa.gov/apod/ap100304.html) spiral galaxy NGC 4216 is nearly 100,000 light-years across, about the size of our own Milky Way (http://antwrp.gsfc.nasa.gov/apod/ap080606.html). Found in the dense Virgo Galaxy Cluster (http://www.atlasoftheuniverse.com/galgrps/ vir.html), NGC 4216 is centered in this deep telescopic portrait (http://www.imagingdeepsky.com/Galaxies/NGC4216/ NGC4216.htm) flanked by fellow Virgo cluster members NGC 4206 (right) and NGC 4222. Like other large spirals, including the Milky Way, NGC 4216 has grown by cannibalizing (http://www.cosmotography.com/images/ galaxy_cannibalism.html) smaller satellite galaxies. In fact, this view has caught it in the act, with still distinct satellite galaxies showing faint star streams extending (http://antwrp.gsfc.nasa.gov/apod/ap080619.html) for thousands of light-years into the halo of NGC 4216. Taken as part of a survey hunting for star streams (http://www.cosmotography.com/images/ stellar_stream_survey_science_highlights.html) in nearby spirals, the image was recorded with a small telescope and camera able to convincingly detect faint, extended features. Having trouble spotting the star streams? Slide your cursor over the image to see a composite negative (http://antwrp.gsfc.nasa.gov/apod/ap070728.html) view. The streams should more easily stand out as dark swaths against a white background.



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http://antwrp.gsfc.nasa.gov/apod/image/1011/anticrepuscular_britton.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101128.html)Anticrepuscular Rays Over Colorado



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http://antwrp.gsfc.nasa.gov/apod/image/1011/jupiterstorm_gemini.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101129.html) Dark Belt Reappearing on Jupiter



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http://antwrp.gsfc.nasa.gov/apod/image/1011/thundercell_heavey.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101130.html) A Supercell Thunderstorm Cloud Over Montana



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http://antwrp.gsfc.nasa.gov/apod/image/1012/phoboslimb_marsexpress.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101201.html)Martian Moon Phobos from Mars Express



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[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1012/103P_101127ligustri900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101202.html) Hartley 2 Star Cluster Tour Early in November, small but active (http://planetary.org/blog/article/00002781/) Comet Hartley 2 (103/P Hartley) became the fifth comet (http://photojournal.jpl.nasa.gov/catalog/PIA13576) imaged close-up by a spacecraft from planet Earth (http://www.nasa.gov/mission_pages/epoxi/index.html). Continuing its own tour of the solar system (http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=103p&orb=1) with a 6 year orbital period (http://pdssbn.astro.umd.edu/comet_data/ periodic_comets.html), Hartley 2 is now appearing in the nautical constellation (http://www.hawastsoc.org/deepsky/pup/index.html) Puppis. Still a target for binoculars or small telescopes from dark sky locations, the comet is captured in this composite image from November 27, sharing the rich 2.5 degree wide field of view (http://antwrp.gsfc.nasa.gov/apod/image/1012/103P_101127ligustri_label.jpg) with some star clusters well known (http://antwrp.gsfc.nasa.gov/apod/ap060910.html) to earthbound skygazers. Below and right of the comet's alluring green coma lies bright M47 (http://www.seds.org/messier/m/m047.html), a young open star cluster some 80 milion years old, about 1,600 light-years away. Below and left open cluster M46 is (http://www.seds.org/messier/m/m046.html) older, around 300 million years of age, and 5,400 light-years distant. Hartley 2's short, faint tail even extends up and right toward another fainter star cluster in the scene, NGC 2423. On November 27, Comet Hartley 2 was about 2.25 light-minutes (http://www.haydenplanetarium.org/universe/duguide/ app_light_travel_time_dista.php) from Earth. Sweeping toward the bottom (http://picasaweb.google.com/astroligu/ CometeDiRolandoLigustriCASTItalia#5545806047210206 514) of this field, by November 28 the comet's path (http://www.skyandtelescope.com/observing/home/ 102632669.html) had carried it between M46 and M47.



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http://antwrp.gsfc.nasa.gov/apod/image/1012/m33_konrad_900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101203.html) M33: Triangulum Galaxy The small, northern constellation Triangulum (http://www.hawastsoc.org/deepsky/tri/index.html) harbors this magnificent face-on spiral galaxy, M33. Its popular names include the Pinwheel Galaxy or just the Triangulum Galaxy (http://www.seds.org/messier/m/m033.html). M33 is over 50,000 light-years in diameter, third largest in the Local Group (http://atlasoftheuniverse.com/localgr.html) of galaxies after the Andromeda Galaxy (M31), and our own Milky Way. About 3 million light-years from the Milky Way, M33 is itself thought to be a satellite of the Andromeda Galaxy (http://antwrp.gsfc.nasa.gov/apod/ap021021.html) and astronomers (http://arxiv.org/abs/astro-ph?papernum=0506609) in these two galaxies would likely have spectacular views of each other's grand spiral star systems. As for the view from planet Earth, this sharp, detailed image (http://www.astrofotografie-laupheim.de/ bilder.php?bild_anzeige=382&urubrik=) nicely shows off M33's blue star clusters and pinkish star forming (http://antwrp.gsfc.nasa.gov/apod/ap061123.html) regions that trace the galaxy's loosely wound spiral arms. In fact, the cavernous NGC 604 (http://www.seds.org/messier/more/m033_n604.html) is the brightest star forming region, seen here at about the 4 o'clock position from the galaxy center. Like M31, M33's population of well-measured variable stars have helped make this nearby spiral a cosmic yardstick (http://cfa-www.harvard.edu/~kstanek/DIRECT/) for establishing (http://adsabs.harvard.edu/cgi-bin/ bib_query?1926ApJ....63..236H) the distance scale (http://antwrp.gsfc.nasa.gov/diamond_jubilee/ debate96.html) of the Universe.



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http://antwrp.gsfc.nasa.gov/apod/image/1012/SpiralRays_erisoty.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101204.html) Sunset at the Spiral Jetty In dwindling twilight (http://antwrp.gsfc.nasa.gov/apod/ap030424.html) at an August day's end, these broad dark bands appeared in the sky for a moment, seen from Robert Smithson's Spiral Jetty (http://www.diaart.org/sites/main/spiraljetty) on the eastern shore of Utah's Great Salt Lake (http://epod.usra.edu/blog/2010/07/ spiral-jetty-and-great-salt-lake.html). Outlined by rays of sunlight known as crepuscular rays (http://www.atoptics.co.uk/atoptics/ray1.htm), they are actually shadows cast by clouds near the distant western horizon, the setting Sun having disappeared from direct view behind them. The cloud shadows are parallel, but seem to converge in the distance because of perspective (http://www.atoptics.co.uk/atoptics/rayform.htm). Coiled in the salt-encrusted lake surface, Smithson's most famous earthwork (http://www.robertsmithson.com/introduction/ introduction.htm) provides a dramatic contrast to the converging lines. The Spiral Jetty was constructed in 1970, when the water level was unusually low and was completely submerged in a few years as the level rose. Now just above water again, it has spent much of its existence submerged in the briny lake (http://earthobservatory.nasa.gov/IOTD/ view.php?id=4148).



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http://antwrp.gsfc.nasa.gov/apod/image/1012/moonrisemk_connelley.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101205.html)Moonrise Through Mauna Kea's Shadow



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http://antwrp.gsfc.nasa.gov/apod/image/1012/monolake_wikipedia.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101206.html) Mono Lake: Home to the Strange Microbe GFAJ-1



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http://antwrp.gsfc.nasa.gov/apod/image/1012/bhlens_riazuelo.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101207.html) Too Close to a Black Hole



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http://antwrp.gsfc.nasa.gov/apod/image/1012/intrepid_opportunity.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101208.html)Intrepid Crater on Mars



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http://antwrp.gsfc.nasa.gov/apod/image/1012/lrg_ngc3031gabany900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101209.html) M81 and Arp's Loop One of the brightest galaxies in planet Earth's sky and similar in size to the Milky Way (http://www.atlasoftheuniverse.com/galaxy.html), big, beautiful spiral M81 (http://antwrp.gsfc.nasa.gov/apod/ap060707.html) lies 11.8 million light-years away in the northern constellation Ursa Major. This deep image (http://www.cosmotography.com/images/small_ngc3031.html) of the region reveals details in the bright yellow core, but at the same time follows fainter features along the galaxy's gorgeous blue spiral arms and sweeping dust lanes. It also follows the expansive, arcing feature, known as Arp's loop, that seems to rise from the galaxy's disk at the right. Studied in the 1960s, Arp's loop has been thought to be a tidal tail (http://antwrp.gsfc.nasa.gov/apod/ap100926.html), material pulled out of M81 by gravitational interaction with its large neighboring galaxy M82 (http://antwrp.gsfc.nasa.gov/apod/ap100324.html). But a recent investigation (http://arxiv.org/abs/1004.1610) demonstrates that much of Arp's loop likely lies within our own galaxy. The loop's colors in visible and infrared (http://coolcosmos.ipac.caltech.edu/) light match the colors of pervasive (http://antwrp.gsfc.nasa.gov/apod/ap080512.html) clouds of dust, relatively unexplored (http://www.galaxyimages.com/UNP_IFNebula.html) galactic cirrus only a few hundred light-years above the plane of the Milky Way. Along with the Milky Way's stars, the dust clouds lie in the foreground of this remarkable view. M81's dwarf companion galaxy, Holmberg IX (http://heritage.stsci.edu/2008/02/caption.html), can be seen just above and left of the large spiral. On the sky, this image spans about 0.5 degrees, about the size of the Full Moon.



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http://antwrp.gsfc.nasa.gov/apod/image/1012/MoonMarsZubenel900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101210.html) A Twilight Occultation A thin, one day old (http://antwrp.gsfc.nasa.gov/apod/ap050513.html) crescent Moon hugged the western horizon after sunset on Monday, December 6. The Moon also occulted or passed in front of Mars (http://antwrp.gsfc.nasa.gov/apod/ap100505.html). But only some well-placed skygazers along a band through North America were able to catch this lunar occultation's (http://www.lunar-occultations.com/iota/planets/ 1206mars.htm) final act in fading twilight. For example, this telephoto image (http://www.twanight.org/newTWAN/ photos.asp?ID=3002957&PrevNext=latest) nicely captures the Mars as a pinprick of light, shortly after it emerged from behind the crescent Moon's sunlit edge. The luminous skyview is from De Soto, Kansas in the central US. Of course, this month's upcoming total lunar eclipse (http://antwrp.gsfc.nasa.gov/apod/ap070308.html) will entertain a much wider audience of Moon enthusiasts (http://antwrp.gsfc.nasa.gov/apod/ap060909.html) during the night of December 20/21 (http://eclipse.gsfc.nasa.gov/OH/ OH2010.html#LE2010Dec21T).



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http://antwrp.gsfc.nasa.gov/apod/image/1012/GeminidMojave2009_pacholka.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101211.html) Meteor in the Desert Sky Created as planet Earth sweeps through dusty debris from mysterious, asteroid-like, 3200 Phaethon (http://science.nasa.gov/science-news/science-at-nasa/ 2010/06dec_geminids/), the annual Geminid Meteor Shower should be the best meteor shower of the year. The Geminids are (http://www.nasa.gov/connect/chat/geminids2010.html) predicted to peak on the night of December 13/14, but you can start watching for Geminid meteors (http://earthsky.org/astronomy-essentials/ earthskys-meteor-shower-guide) this weekend. The best viewing is after midnight in a dark, moonless sky, with the shower's radiant (http://antwrp.gsfc.nasa.gov/apod/ap080103.html) constellation Gemini well above the horizon - a situation that favors skygazers in the northern hemisphere (http://antwrp.gsfc.nasa.gov/apod/ap091218.html). In this picture (http://www.twanight.org/newTWAN/ photos.asp?ID=3002960&PrevNext=latest) from the 2009 Geminid shower, a bright meteor with a greenish tinge flashes (http://antwrp.gsfc.nasa.gov/apod/ap091219.html) through the sky over the Mojave Desert near Barstow, California, USA. Recognizable in the background are bright stars in the northern asterism known as the Big Dipper (http://antwrp.gsfc.nasa.gov/apod/ap070108.html), framing the meteor streak.



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http://antwrp.gsfc.nasa.gov/apod/image/1012/leonids99_casado.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101212.html) Leonids Above Torre de la Guaita



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http://antwrp.gsfc.nasa.gov/apod/image/1012/moonvenus_taheri.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101213.html) Contemplating the Sky



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http://antwrp.gsfc.nasa.gov/apod/image/1012/deltalaunch_cooper.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101214.html) Launch of a Delta IV Heavy



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http://astronom.si/forum/ (http://antwrp.gsfc.nasa.gov/apod/ap101215.html) A Huge Solar Filament Erupts



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http://antwrp.gsfc.nasa.gov/apod/image/1012/geminidsKPNO_harvey900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101216.html)Geminids over Kitt PeakTwo large telescope domes stand in the foreground ofthis night sky view (http://davidharveyphotography.blogspot.com/2010/12/geminids.html) fromKitt Peak NationalObservatory (http://www.noao.edu/kpno/), near Tucson, Arizona, USA.The dramatic scene was recorded early Tuesday morning,near the peak of December'sGeminid Meteor Shower (http://antwrp.gsfc.nasa.gov/apod/ap101211.html).With dome slit open,the building closest to the camera houses the 2.3 Meter (90 inch)BokTelescope (http://james.as.arizona.edu/~psmith/90inch/90inch.html)operated by Steward Observatory, University of Arizona.Behind the Bok is theMayall 4Meter (http://www.noao.edu/outreach/kptour/mayall.html) telescope dome.Of course, no telescopes were needed toenjoythe meteors (http://spaceweather.com/meteors/gallery_14dec10.htm) streaking through the sky!The composite image consists of 13 exposures each 15 seconds long,taken with a wide angle lens over a period of about 2 hoursduring Kitt Peak's warm, clear, night.An annual celestial event, this meteor showeris the result of planet Earth plowingthrough dust from mysterious, asteroid-like object3200 Phaethon (http://science.nasa.gov/science-news/science-at-nasa/2010/06dec_geminids/).



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http://antwrp.gsfc.nasa.gov/apod/image/1012/Geminid2010Fireball_abolfath.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101217.html) A Meteor Moment Intensely bright, this fireball meteor (http://www.torgheh.ir/en/) flashed through Tuesday's cold, clear, early morning skies over the Karakas Mountains in central Iran, near the peak of the annual Geminid Meteor Shower (http://science.nasa.gov/science-news/science-at-nasa/ 2010/06dec_geminids/). To capture the meteor moment (http://spaceweather.com/meteors/ gallery_14dec10_page2.htm) and wintery night skyscape (http://www.twanight.org/newTWAN/ galleries.asp?Sort=Photographer&Value=Amir%20H.%20Abolfath&page=1), the photographer's camera was fixed to a tripod, its shutter open for about 1.5 minutes. During that time, the multitude of stars slowly traced short, arcing trails (http://antwrp.gsfc.nasa.gov/apod/ap100618.html) through the sky, a reflection of planet Earth's daily rotation (http://antwrp.gsfc.nasa.gov/apod/ap070519.html) on its axis. The meteor's brilliant dash through the scene was brief, though. Changing color as it went, it also left a reddish swirl of hot, glowing gas near the center of its path. The mountains appear in silhouette against the steady glow of distant city lights (http://antwrp.gsfc.nasa.gov/apod/ap081005.html).



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http://antwrp.gsfc.nasa.gov/apod/image/1012/ngc7000_pugh800.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101218.html) North America and the Pelican Here lie familiar shapes in unfamiliar locations (http://www.atlasoftheuniverse.com/nebclust.html). On the left is an emission nebula (http://seds.org/messier/nebula.html) cataloged as NGC 7000, famous partly because it resembles our fair planet's continent of North America. The emission region to the right of the North America Nebula (http://antwrp.gsfc.nasa.gov/apod/ap081028.html) is IC 5070, also known for its suggestive outlines as the Pelican Nebula (http://antwrp.gsfc.nasa.gov/apod/ap061130.html). Separated by a dark cloud of obscuring dust, the two bright nebulae are about 1,500 light-years away. At that distance, the 4 degree wide field of view spans 100 light-years. This spectacular cosmic portrait (http://www.martinpughastrophotography.id.au/Nebulae/ NGC7000.htm) combines narrow band images (http://antwrp.gsfc.nasa.gov/apod/ap060324.html) of the region in a false-color palette to highlight bright ionization fronts (http://antwrp.gsfc.nasa.gov/apod/ap100819.html) with fine details of dark, dusty forms in silhouette. Emission from atomic hydrogen, sulfur, and oxygen is captured in the narrow band data. These nebulae can be seen (http://www.youtube.com/watch?v=LtKUuAM3zDY) with binoculars from a dark location. Look northeast (http://antwrp.gsfc.nasa.gov/apod/ap101119.html) of bright star Deneb in the constellation Cygnus the Swan.



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http://antwrp.gsfc.nasa.gov/apod/image/1012/m82_hst.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101219.html) M82: Galaxy with a Supergalactic Wind



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http://antwrp.gsfc.nasa.gov/apod/image/1012/solsticeeclipse_lodriguss.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101220.html)A Lunar Eclipse on Solstice Day



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http://antwrp.gsfc.nasa.gov/apod/image/1012/wintersolstice_pivato.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101221.html)Tyrrhenian Sea and Solstice Sky



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http://antwrp.gsfc.nasa.gov/apod/image/1012/ic342_henry900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101222.html) Hidden Galaxy IC 342 Similar (http://antwrp.gsfc.nasa.gov/apod/ap101209.html) in size to other large, bright spiral galaxies, IC 342 (http://www.seds.org/~spider/spider/LG/i0342.html) is a mere 7 million light-years distant in the long-necked, northern constellation Camelopardalis (http://www.hawastsoc.org/deepsky/cam/ index.html). A sprawling island universe (http://antwrp.gsfc.nasa.gov/apod/ap051222.html), IC 342 would otherwise be a prominent galaxy in our night sky (http://antwrp.gsfc.nasa.gov/apod/ap060413.html), but it is almost hidden from view behind the veil of stars, gas and dust clouds in the plane of our Milky Way galaxy (http://antwrp.gsfc.nasa.gov/apod/ap100320.html). Even though IC 342's light is dimmed by intervening cosmic clouds (http://www-ssg.sr.unh.edu/ism/what1.html), this remarkably sharp telescopic image traces the galaxy's own obscuring dust, blue star clusters, and glowing pink star forming regions along spiral arms that Wind far from the galaxy's core. IC 342 (http://www.astro.spbu.ru/staff/dio/IC342/IC342E.html) may have undergone a recent burst (http://arxiv.org/abs/astro-ph/0305552) of star formation activity and is close enough (http://seds.org/messier/xtra/ngc/ maffei1g.html) to have gravitationally influenced the evolution of the local group (http://seds.org/messier/more/local.html) of galaxies and the Milky Way.



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http://antwrp.gsfc.nasa.gov/apod/image/1012/tle2010_hetlage900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101223.html) The Solstice Moon's Eclipse A big, bright, beautiful Full Moon slid (http://antwrp.gsfc.nasa.gov/apod/ap080220.html) into planet Earth's shadow early Tuesday morning. Remarkably, the total lunar eclipse (http://science.nasa.gov/science-news/science-at-nasa/ 2010/17dec_solsticeeclipse/) coincided with the date of the December Solstice (http://antwrp.gsfc.nasa.gov/apod/ap101221.html). During the eclipse (http://antwrp.gsfc.nasa.gov/apod/ap101220.html), the best viewing in North America found the coppery lunar disc high in a cold winter sky, the Moon reddened by light filtering into the Earth's dark central shadow or umbra (http://antwrp.gsfc.nasa.gov/apod/ap080820.html). The light comes from all the sunsets and sunrises, seen from a lunar perspective (http://science.nasa.gov/science-news/science-at-nasa/ 2003/04nov_lunareclipse2105/) around the edges of a silhouetted Earth (http://antwrp.gsfc.nasa.gov/apod/ap070302.html). Passing closer to the center of the umbra, the Moon's southern hemisphere (left) appears darker in this eclipse image, recorded from Deerlick Astronomy (http://www.deerlickgroup.com/) Village, Georgia, USA. The picture is a digital composite, a separate longer exposure added to an eclipse frame to capture the surrounding star field.



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[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1012/StartrailsViking_heden.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101224.html) Star Trails in the North Pointing skyward, the wall of this ruined Viking church still stands after a thousand winters, near the town of Vallentuna, Sweden. The time exposure records the scene on December 14th as stars leave graceful arcing trails during a long night, reflecting planet Earth's daily rotation on its axis (http://antwrp.gsfc.nasa.gov/apod/ap090909.html). The Earth's axis points (http://solar.physics.montana.edu/YPOP/Classroom/Lessons/ Sundials/skydome.html) toward Polaris, the North Star, near the center of the concentric trails (http://antwrp.gsfc.nasa.gov/apod/ap100212.html). Welcomed by skygazers (http://www.twanight.org/heden) on this winter's night, a bright meteor from the annual Geminid meteor shower (http://antwrp.gsfc.nasa.gov/apod/ap101216.html) also flashes through the frame. The meteor cuts across the star trails just above the lower church wall. Contributing to the beautiful composition, meteor streak and church apex both gesture toward the North Celestial Pole (http://blog.deepskycolors.com/archive/2010/11/10/ polaris-and-the-North-Celestial-Pole.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101224.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1012/M78LoopLDN1622_andreoHaLRGBh600.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101225.html) Decorating the Sky Bright stars, clouds of dust and glowing nebulae decorate (http://antwrp.gsfc.nasa.gov/apod/ap081225.html) this cosmic scene, a skyscape just north of Orion's belt (http://antwrp.gsfc.nasa.gov/apod/ap061229.html). Close to the plane of our Milky Way (http://antwrp.gsfc.nasa.gov/apod/ap091225.html) Galaxy, the wide field view spans about 5.5 degrees. Striking bluish M78 (http://antwrp.gsfc.nasa.gov/apod/ap100302.html), a reflection nebula, is at the left. M78's tint is due to dust preferentially reflecting the blue light of hot, young stars. In colorful contrast, the red sash of glowing hydrogen gas sweeping through the center is part of the region's faint but extensive emission nebula (http://antwrp.gsfc.nasa.gov/apod/ap101023.html) known as Barnard's Loop. At right, a dark dust cloud forms a prominent silhouette cataloged as LDN 1622 (http://antwrp.gsfc.nasa.gov/apod/ap070511.html). While M78 and the complex Barnard's Loop are some 1,500 light-years away, LDN 1622 is likely to be much closer, only about 500 light-years distant from our fair planet Earth.



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http://antwrp.gsfc.nasa.gov/apod/image/1012/snowyorion_alexander.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101226.html) Sideways Orion Over Snowy Ireland



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http://antwrp.gsfc.nasa.gov/apod/image/1012/milliongalaxies_2mass.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101227.html) One Million Galaxies



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http://antwrp.gsfc.nasa.gov/apod/image/1012/skylights_tezel.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101228.html)Skylights Over Libya



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http://antwrp.gsfc.nasa.gov/apod/image/1012/tle2010_gonzalez900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101229.html)Eclipse at MoonsetHugging the horizon, a dark red Moon greetedearly morning skygazers in easternAtlantic regions on December 21, as the total phase of 2010'sSolstice Lunar Eclipse (http://science.nasa.gov/science-news/science-at-nasa/2010/17dec_solsticeeclipse/) began nearmoonset (http://antwrp.gsfc.nasa.gov/apod/ap061104.html).This well composed image of thegeocentric (http://antwrp.gsfc.nasa.gov/apod/ap0904171.html) celestialevent is a composite of multiple exposures followingthe progression of the eclipse fromTenerife (http://antwrp.gsfc.nasa.gov/apod/ap100320.html), Canary Islands.Initially reflecting brightly on a sea of clouds andthe ocean's surface itself, the Moon sinks deeperinto eclipse (http://www.spaceweather.com/eclipses/gallery_21dec10_page2.htm) as it movesfrom left to right across the sky.Oppositethe Sun (http://www.mreclipse.com/Special/LEprimer.html), the Moon was immersed in the darkest partof Earth's shadow as it approached the western horizon,just before sunrise came to Tenerife.



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[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1012/n2170_block900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101230.html)Still Life with NGC 2170In this beautifulcelestial still life (http://www.caelumobservatory.com/gallery/n2170.shtml)composed with a cosmic brush, dusty nebulaNGC 2170 (http://spider.seds.org/ngc/revngcic.cgi?NGC2170)shines at the upper left.Reflecting the light of nearby hot stars, NGC 2170is joined (http://antwrp.gsfc.nasa.gov/apod/image/0608/ngc2170_seip_f56lbl.jpg)by other bluish reflection (http://antwrp.gsfc.nasa.gov/apod/ap041204.html) nebulae,a compact red emission (http://antwrp.gsfc.nasa.gov/apod/ap040629.html) region,and streamers of obscuring dust against a backdrop of stars.Like the common household itemsstill life painters (http://www.artlex.com/ArtLex/s/still-life/1701-1850.html)often choose for their subjects, the clouds of gas, dust, and hot starspictured here are also commonly found in this setting - a massive, star-forming molecular cloud (http://antwrp.gsfc.nasa.gov/apod/ap101015.html)in the constellationMonoceros (http://www.hawastsoc.org/deepsky/mon/index.html).The giantmolecularcloud (http://archive.ncsa.uiuc.edu/Cyberia/Bima/GMC.html), Mon R2, is impressively close,estimated (http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?2005A%26A...430..523W&db_key=AST&nosetcookie=1)to be only 2,400 light-years or so away.At that distance, this canvas would be about 15 light-years across.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101230.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1012/analemma2010_ladanyi_c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap101231.html) Analemma 2010 Looking back (http://antwrp.gsfc.nasa.gov/apod/calendar/allyears.html) on the year, have you wondered where the Sun was in the sky each day during 2010 at exacty 9am UT (http://www.usno.navy.mil/USNO/astronomical-applications/ astronomical-information-center/universal-time/)? Of course you have. Search no further for the answer! It was somewhere along this celestial figure 8 curve known as an analemma (https://pantherfile.uwm.edu/kahl/www/Images/Weather/Other/ analemma.html). Recorded from a residential backyard in the small town of Veszprem, Hungary, this composite analemma (http://www.twanight.org/newTWAN/photos.asp?ID=3002966) image consists of 36 separate exposures of the Sun made at 9:00 UT, spaced throughout the year, plus a background image made without a solar filter. The background image was taken on the sunny afternoon of October 9 (13:45 UT). On the left is the photographer's shadow. The positions of the Sun at the 2010 solstice dates (http://www.usno.navy.mil/USNO/astronomical-applications/ data-services/earth-seasons/) are at the upper (June 21) and lower (December 21) extremes of the analemma curve (http://www.perseus.gr/Astro-Solar-Analemma.htm). On the equinox dates (March 20, September 23) the Sun was along the curve (http://www.twigsdigs.com/sundials/office/) half way between the solstices. The tilt of planet Earth's axis and the variation in speed as it moves around its elliptical orbit combine to produce the graceful analemma curve (http://www.analemma.com/Pages/framesPage.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap101231.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1101/n6946_block900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110101.html) Fireworks Galaxy NGC 6946 Celebrate the New Year with the Fireworks Galaxy! Also known as NGC 6946, the big, beautiful spiral galaxy (http://www.seds.org/messier/spir.html) is located just 10 million light-years away, behind a veil of foreground dust and stars in the high and far-off constellation of Cepheus (http://www.astropix.com/HTML/E_SUM_N/ CEPHEUSO.HTM). From our vantage point in the Milky Way Galaxy (http://antwrp.gsfc.nasa.gov/apod/ap080606.html), we see NGC 6946 face-on (http://www.seds.org/messier/xtra/ngc/n6946.html). In this colorful cosmic portrait (http://www.caelumobservatory.com/gallery/n6946.shtml), the galaxy's colors change from the yellowish light of old stars in the core to young blue star clusters and reddish star forming regions along the loose, fragmented spiral arms. NGC 6946 is bright in infrared light (http://dg-imaging.astrodon.com/gallery/ display.cfm?imgID=223) and rich in gas and dust, exhibiting a furious rate of star formation. Nearly 40,000 light-years across, the nearby spiral is fittingly referred to as the Fireworks Galaxy (http://www.gemini.edu/node/116). Over the last 100 years, at least nine supernovae, the death explosions (http://antwrp.gsfc.nasa.gov/apod/ap060728.html) of massive stars, were discovered (http://www.astrosurf.com/snweb2/ 2008/08S_/08S_Home.htm) in NGC 6946. By comparison, the average rate for supernovae in the Milky Way is about 1 per century.



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http://antwrp.gsfc.nasa.gov/apod/image/1101/eclipse99_mir.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110102.html) Looking Back at an Eclipsed Earth



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http://antwrp.gsfc.nasa.gov/apod/image/1101/winterhexagon_westlake_annotated.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110103.html)Winter Hexagon Over Stagecoach Colorado



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http://antwrp.gsfc.nasa.gov/apod/image/1101/greenflash_manzona.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110104.html)A Green Flash from the Sun



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http://antwrp.gsfc.nasa.gov/apod/image/1101/eclipse110104_isstransit_legault800.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110105.html) Eclipsing the Sun Skywatchers (http://bb.nightskylive.net/asterisk/ viewtopic.php?f=29&t=22472) throughout much of Europe, North Africa, and Central Asia, were treated to the first eclipse of the new year on January 4, a partial eclipse of the Sun (http://eclipse.gsfc.nasa.gov/OH/OH2011.html#SE2011Jan04P). But traveling to the area around Muscat, capital city of Oman, photographer Thierry Legault planned to simultaneously record two eclipses on that date, calculating (http://www.calsky.com/) from that position, for a brief moment, both the Moon and the International Space Station could be seen in silhouette, crossing the Sun (http://antwrp.gsfc.nasa.gov/apod/ap100523.html). His sharp, 1/5000th second exposure is shown here (http://legault.perso.sfr.fr/ eclipse110104_solar_transit.html), capturing planet Earth's (http://antwrp.gsfc.nasa.gov/apod/ap050430.html) two largest satellites against the bright solar disk. As the partial solar eclipse unfolded (http://shadowandsubstance.com/), the space station (above and left of center) zipped across the scene in less than 1 second, about 500 kilometers from the photographer's telescope and camera. Of course, the Moon was 400 thousand kilometers away. Complete with sunspots (http://antwrp.gsfc.nasa.gov/apod/ap991021.html), the Sun was 150 million kilometers distant.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap110105.html)

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http://antwrp.gsfc.nasa.gov/apod/image/1101/pse2011graz_polzl900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110106.html)Sunrise, MoonriseFor many Europeans, the Sun and New Moon rose togetheron January 4 in apartial solar eclipse (http://shadowandsubstance.com/).Arriving close on the heels of the new year,it was the first of a series of four(!) partial solareclipsesdue in 2011 (http://eclipse.gsfc.nasa.gov/OH/OH2011.html).This composite image documents (http://www.astrofotos.at/cms/index.php?option=com_zoom&Itemid=30&page=view&catid=4&PageNo=1&key=4&hit=1)the gracefulcelestial event (http://bb.nightskylive.net/asterisk/viewtopic.php?f=29&t=22472&start=25) in colorfulmorning skies over Graz, Austria.Beginning before sunrise, frames were taken to record the positionand progress of the eclipse every 15 minutes.As Sun and Moon rose above (http://antwrp.gsfc.nasa.gov/apod/ap050503.html)the eastern horizon, the town ofGraz is seen bathed in warming sunlight only partially blocked bythe New Moon, spreading beneath the town's landmark clock tower.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap110106.html)

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http://antwrp.gsfc.nasa.gov/apod/image/1101/pse2011novosibirsk_yuferev900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110107.html) Sunset, Moonset Seen from (http://antwrp.gsfc.nasa.gov/apod/ap110106.html) central and northern Asia, the Sun and New Moon set together on January 4, in a partial solar eclipse (http://www.mreclipse.com/Special/SEprimer.html). Close to its maximum phase, the eclipse is captured near the moment of sunset in this wintry scene from the bank of the Berd River near Novosibirsk (http://www.twanight.org/newTWAN/ galleries.asp?Sort=Site&Value=Novosibirsk&page=1), Siberia, Russia. An evocative view in fading light, the picture looks toward (http://www.twanight.org/newTWAN/photos.asp?ID=3002995) the western horizon across a snowy, frozen landscape. Along with (http://antwrp.gsfc.nasa.gov/apod/ap110105.html) offset Sun and Moon, the dimmly lit sky includes an industrial smoke plume and airplane contrail.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap110107.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1101/helix_henry900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110108.html) NGC 7293: The Helix Nebula A mere seven hundred light years from Earth, in the constellation Aquarius (http://hawastsoc.org/deepsky/aqr/index.html), a sun-like star is dying. Its last few thousand years have produced the Helix Nebula (http://www.seds.org/messier/xtra/ngc/n7293.html) (NGC 7293), a well studied and nearby example of a Planetary Nebula (http://en.wikipedia.org/wiki/Planetary_nebula), typical of this final phase of stellar evolution. A total of 10 hours of exposure time have gone in to creating this remarkably deep view (http://www.cvastro.org/clearview/helix.htm) of the nebula. It shows details of the Helix's brighter inner region (http://antwrp.gsfc.nasa.gov/apod/ap030510.html), about 3 light-years across, but also follows fainter outer halo (http://www.ing.iac.es/~rcorradi/HALOES/) features that give the nebula a span of well over six light-years. The white dot at the Helix's center is this Planetary Nebula's hot, central star (http://hubblesite.org/newscenter/archive/releases/1997/38/ background/#background-info-1). A simple looking nebula at first glance, the Helix is now understood to have a surprisingly complex geometry (http://hubblesite.org/newscenter/archive/releases/2004/ 32/image/e/).



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http://antwrp.gsfc.nasa.gov/apod/image/1101/antikythera_wikipedia.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110109.html) The Antikythera Mechanism



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http://antwrp.gsfc.nasa.gov/apod/image/1101/sunhalo_rosen.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110110.html) A Sun Halo Beyond Stockholm



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http://antwrp.gsfc.nasa.gov/apod/image/1101/tarantula_salemme.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110111.html) The Cosmic Web of the Tarantula Nebula



Več... (http://antwrp.gsfc.nasa.gov/apod/ap110111.html)

[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1101/SeaGullLHaRGB_sidonio800.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110112.html)The Seagull NebulaThis broad expanse of glowing gas and dust presentsa bird-like visage to astronomersfrom planet Earth (http://antwrp.gsfc.nasa.gov/apod/ap090411.html),suggesting its popular moniker -The Seagull Nebula (http://www.celestialwonders.com/nebulae/Gum_20090227.html).This portrait (http://www.pbase.com/strongmanmike2002/the_sea_gull_nebula)of the cosmic bird covers a 1.6 degree wide swathacross the plane of the Milky Way,nearthe direction (http://www.eanet.com/kodama/astro/2007/0216a/index.htm) of Sirius, alphastar of the constellation Canis Major.Of course, the region includes objects with othercatalogdesignations (http://galaxymap.org/cgi-bin/gum.py?s=1): notablyNGC 2327 (http://www.skyfactory.org/ic2177/ic2177.htm),a compact, dusty emission regionwith an embedded massive star that forms the bird's head(aka the Parrot Nebula, above center).IC 2177 (http://www.astropix.com/HTML/B_WINTER/IC2177.HTM)forms the sweeping arc of the seagull's wings.Dominated by thereddish glow (http://antwrp.gsfc.nasa.gov/apod/ap080424.html) of atomic hydrogen,the complex of gas and dust clouds with brightyoung stars spans over 100 light-years at an estimated3,800 light-year distance.



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http://antwrp.gsfc.nasa.gov/apod/image/1101/NGC3521_hstGendler900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110113.html) NGC 3521 Close Up Gorgeous spiral galaxy NGC 3521 is a mere 35 million light-years distant, toward the constellation Leo (http://www.universetoday.com/21173/ leo/). Spanning some 50,000 light-years, its central region is shown in this dramatic image (http://www.robgendlerastropics.com/ NGC3521-HST-Gendler.html), constructed from data drawn from the Hubble Legacy Archive (http://hla.stsci.edu/). The close-up view highlights this galaxy's characteristic (http://adsabs.harvard.edu/abs/ 1982MNRAS.201.1021E) multiple, patchy, irregular spiral arms laced with dust and clusters of young, blue stars. In constrast (http://antwrp.gsfc.nasa.gov/apod/ap101209.html), many other spirals exhibit grand, sweeping arms. A relatively bright galaxy in planet Earth's sky, NGC 3521 is (http://www.astrosurf.com/antilhue/ngc3521.htm) easily visible in small telescopes, but often overlooked by amateur imagers in favor of other Leo spiral galaxies, like M66 and M65 (http://antwrp.gsfc.nasa.gov/apod/ap060309.html).



Več... (http://antwrp.gsfc.nasa.gov/apod/ap110113.html)

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http://antwrp.gsfc.nasa.gov/apod/image/1101/quadqumis_tafreshi900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110114.html)Quadrantids over QumisThe Quadrantid Meteor Shower (http://spaceweather.com/meteors/quadrantids/quadrantids.html)is an annual event for planet Earth'snorthern hemisphere skygazers.It usually peaks briefly in the cold, early morning hours of January 4.The shower is named for itsradiant point (http://antwrp.gsfc.nasa.gov/apod/ap070812.html) on the sky within theold, astronomically obsolete constellationQuadransMuralis (http://www.ianridpath.com/startales/quadrans.htm).That position is situated near the boundaries of the modernconstellations Hercules, Bootes, and Draco.In this haunting time exposure (http://www.twanight.org/newTWAN/photos.asp?ID=3003009&Sort=Photographer),two quadrantid meteor streaks are capturedcrossing trails (http://antwrp.gsfc.nasa.gov/apod/ap101224.html)left by rising starsof the constellations Virgo and Corvus, but Saturnleaves the brightest "star" trail.The meteor streaks, one bright and one faint, are nearly parallelabove and right of center in the frame.Fittingly, the old cistern structure in the foreground liesabove the nowburied city of Qumis (http://www.livius.org/he-hg/hecatompylos/hecatompylos.html).Known as a city of many gates, Qumis (in Greek historyHecatompylos (http://en.wikipedia.org/wiki/Hecatompylos)),was founded 2300 years ago in ancient Persia.



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http://antwrp.gsfc.nasa.gov/apod/image/0805/antarcticeclipse_bruenjes_big.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110115.html) A Total Eclipse at the End of the World



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[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1101/47Tuc_DW900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110116.html)Globular Star Cluster 47 TucGlobular star cluster 47 Tucanae is a jewel of the southern sky.Also knownas NGC 104 (http://www.seds.org/messier/xtra/ngc/n0104.html), it roamsthe halo (http://csep10.phys.utk.edu/astr162/lect/milkyway/components.html) of our Milky Way Galaxyalong with some 200 other globular star clusters (http://en.wikipedia.org/wiki/Globular_cluster).The second brightest globular cluster (afterOmega Centauri (http://antwrp.gsfc.nasa.gov/apod/ap100331.html))as seen from planet Earth, it lies about 13,000 light-years away andcan be spotted naked-eye near theSmall Magellanic Cloud (http://antwrp.gsfc.nasa.gov/apod/ap100903.html)in the constellation ofthe Toucan (http://www.hawastsoc.org/deepsky/tuc/).The dense cluster is made up of several millionstars (http://antwrp.gsfc.nasa.gov/apod/ap080906.html) in avolume (http://www.astronomycafe.net/qadir/ask/a11508.html)only about 120 light-years across.Red giant stars (http://antwrp.gsfc.nasa.gov/apod/ap081218.html)on the outskirts of the cluster are easy to pick out as yellowish stars inthis sharptelescopic portrait (http://astro-cabinet.com/showimage.php?image=NGC104_60m_LRGB.jpg&lang=english).Globular cluster 47 Tuc is also home to exoticx-ray binary (http://antwrp.gsfc.nasa.gov/apod/ap050721.html) star systems.



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http://antwrp.gsfc.nasa.gov/apod/image/1101/PlanetSounio_kotsiopoulos.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110117.html) Night and Day above Almost Planet Sounio



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http://antwrp.gsfc.nasa.gov/apod/image/1101/galaxygarden_lesage.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110118.html) Kona Galaxy Garden



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[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1101/saturnestorm_dauvergnecassini_c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110119.html)Saturn StormLate last year, a new, remarkablybright storm erupted (http://www.skyandtelescope.com/observing/highlights/112507364.html) inSaturn's northern hemisphere.Amateurastronomers (http://alpo-j.asahikawa-med.ac.jp/Latest/Saturn.htm) first spotted it in early December, withthe ringed gas giant rising in planet Earth's predawn sky.OrbitingSaturn (http://www.ciclops.org/ir_index/133/In_Orbit), the Cassini spacecraft was able torecord this close-up of thecomplexdisturbance (http://blogs.discovermagazine.com/badastronomy/2010/12/28/a-saturnian-storm-larger-than-worlds/) from a distance of 1.8 millionkilometers on December 24th.Over time, the stormhas evolved (http://astrosurf.com/planetessaf/saturne/saturn_2010-NTrZ-storm.html), spreadingsubstantially in longitude,and now stretches (http://saturn.cstoneind.com/)far around the planet.Saturn's (http://solarsystem.nasa.gov/planets/profile.cfm?Object=Saturn&Display=OverviewLong)thin rings are also seen slicing acrossthis space-based (http://antwrp.gsfc.nasa.gov/apod/ap071023.html) view,casting broad shadows on the planet's southern hemisphere.



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[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1101/M31_XMM_HERSCHEL_r900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110120.html)The Once and Future Stars of AndromedaThe big, beautiful Andromeda Galaxy (http://antwrp.gsfc.nasa.gov/apod/ap061228.html),aka M31, is a spiral galaxy amere 2.5 million light-years away.Two space-based observatories have combined to producethis intriguing composite image of Andromeda,at wavelengths outside thevisible spectrum (http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html).The remarkable view (http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=48186)follows the locations of this galaxy'sonce and future stars (http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=48188).In reddish hues, image data from the largeHerschel infrared (http://antwrp.gsfc.nasa.gov/apod/ap091016.html)observatory traces enormous lanes of dust,warmed by stars, sweeping along Andromeda's spiral arms.The dust, in conjunction with the galaxy's interstellar gas,comprises the raw material for futurestar formation (http://antwrp.gsfc.nasa.gov/apod/ap101022.html).X-ray data from the XMM-Newton (http://antwrp.gsfc.nasa.gov/apod/ap040130.html)observatory in bluepinpoint Andromeda's X-ray binary (http://antwrp.gsfc.nasa.gov/apod/ap000121.html)star systems.These systems likely contain neutron stars or stellar massblack holes that represent final stages in stellar evolution.More than twice the size of our own Milky Way (http://antwrp.gsfc.nasa.gov/apod/ap080606.html),the Andromeda Galaxy is over 200,000 light-years across.



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[Astronom.si]

http://antwrp.gsfc.nasa.gov/apod/image/1101/MosaicCintOrio_martinez900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110121.html)Alnitak, Alnilam, MintakaAlnitak (http://www.astro.uiuc.edu/~kaler/sow/alnitak.html),Alnilam (http://www.astro.uiuc.edu/~kaler/sow/alnilam.html),andMintaka (http://www.astro.uiuc.edu/~kaler/sow/mintaka.html),are the bright bluish starsfrom east to west (left to right) along the diagonal inthis gorgeous cosmic vista.Otherwise known as theBelt of Orion (http://www.gb.nrao.edu/~rmaddale/Education/OrionTourCenter/belt.html), thesethree blue supergiant stars are hotter and much moremassive than the Sun.They lie about 1,500 light-years away, bornof Orion's (http://www.gb.nrao.edu/~rmaddale/Education/OrionTourCenter/optical.html) well-studied interstellar clouds.In fact, clouds of gas and dust adrift in this region haveintriguing and some surprisingly familiar shapes, including thedark Horsehead (http://antwrp.gsfc.nasa.gov/apod/ap100513.html) Nebulaand Flame Nebula (http://antwrp.gsfc.nasa.gov/apod/ap101126.html) nearAlnitak at the lower left.The famous Orion (http://antwrp.gsfc.nasa.gov/apod/ap101023.html) Nebulaitself lies off the bottom of this colorful star field.Recorded last December with a modified digital SLR camera and smalltelescope, the well-planned,two frame mosaic (http://astrophoto-sv.com/index.php?p=1_75)spans about 4 degrees on the sky.



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http://antwrp.gsfc.nasa.gov/apod/image/1101/NGC660_LRGB_leshin900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110122.html) Polar Ring Galaxy NGC 660 NGC 660 lies near the center of this intriguing skyscape (http://sleshin.startlogic.com/stargazergallery/ main.php?g2_itemId=391&g2_imageViewsIndex=0), swimming in the boundaries of the constellation Pisces (http://en.wikipedia.org/wiki/Pisces_(constellation)). Over 20 million light-years away, its peculiar appearance marks it as a polar ring galaxy (http://antwrp.gsfc.nasa.gov/apod/ap070216.html). A rare galaxy type, polar ring galaxies have a substantial population of stars, gas, and dust orbiting in rings (http://antwrp.gsfc.nasa.gov/apod/ap990510.html) nearly perpendicular to the plane of the galactic disk. The bizarre configuration (http://arxiv.org/abs/astro-ph/0301391) could have been caused by the chance capture of material from a passing galaxy by the disk galaxy, with the captured debris strung out in a rotating ring. The polar ring component (http://www.obspm.fr/actual/nouvelle/apr03/prg.en.shtml) can be used to explore the shape of the galaxy's otherwise unseen dark matter halo (http://www.solstation.com/x-objects/darkhalo.htm) by calculating the dark matter's (http://chandra.harvard.edu/xray_astro/dark_matter/ index.html) gravitational influence on the rotation of the ring and disk. Broader than the disk, NGC 660's ring spans about 40,000 light-years.



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http://www.astronom.si/forum/ (http://antwrp.gsfc.nasa.gov/apod/ap110123.html)Peekskill Fireball Video: Johnstown



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http://antwrp.gsfc.nasa.gov/apod/image/1101/phobos2_marsexpress.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110124.html)Phobos' South Pole from Mars Express



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http://antwrp.gsfc.nasa.gov/apod/image/1101/snr0509_hubble.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110125.html) The Rippled Red Ribbons of SNR 0509



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http://antwrp.gsfc.nasa.gov/apod/image/1101/m51ir_hubble.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110126.html) The Whirlpool Galaxy in Infrared Dust



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http://www.astronom.si/forum/ (http://antwrp.gsfc.nasa.gov/apod/ap110127.html)



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http://www.astronom.si/forum/ (http://antwrp.gsfc.nasa.gov/apod/ap110128.html)



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http://www.astronom.si/forum/ (http://antwrp.gsfc.nasa.gov/apod/ap110129.html)



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[Astronom.si]

http://apod.nasa.gov/apod/image/1101/OpportunitySol2476_Kremer600hc.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110129.html) Opportunity at Santa Maria Crater Celebrating 7 years (http://www.nasa.gov/mission_pages/mer/news/ mer20110120.html) on the surface of the Red Planet (http://solarsystem.nasa.gov/planets/ profile.cfm?Object=Mars), Mars exploration rover Opportunity now stands near the rim of 90 meter wide Santa Maria crater (http://photojournal.jpl.nasa.gov/catalog/PIA13794). Remarkably, Opportunity and its fellow rover Spirit (http://www.nasa.gov/mission_pages/mer/ spirit-update.html) were initially intended (http://xkcd.com/695/) for a 3 month long primary mission. Still exploring, the golf cart-sized robot and shadow (far right) appear in the foreground of this panoramic view of its current location (http://hirise.lpl.arizona.edu/releases/ oppy-santa-maria.php). The mosaic was constructed using images from the rover's navigation camera. On its 7 year anniversary (http://www.universetoday.com/82784/ 7-years-of-opportunity-on-mars-and-a-science-bonanza/), Opportunity can boast traversing (http://marsrovers.jpl.nasa.gov/mission/ traverse_maps.html) a total of 26.7 kilometers along the martian surface (http://beamartian.jpl.nasa.gov/welcome). After investigating Santa Maria crater, controllers plan to have Opportunity resume a long-term trek toward Endurance crater, a large, 22 kilometer diameter crater about 6 kilometers from Santa Maria. During coming days, communication with the rover will be more difficult as Mars moves close to alignment with the Sun as seen from planet Earth's perspective (http://www.jpl.nasa.gov/missions/mer/ images.cfm?id=2673).



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http://apod.nasa.gov/apod/image/1101/europa_galileo_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110130.html) Gibbous Europa



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http://apod.nasa.gov/apod/image/1101/kountori2_iss_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110131.html)Japan's Kounotori2 Supply Ship Approaches the Space Station



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http://www.astronom.si/forum/ (http://antwrp.gsfc.nasa.gov/apod/ap110201.html)Powers of Ten



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http://apod.nasa.gov/apod/image/1102/moonvenus_kaplan_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110202.html)Moon and Venus Over Switzerland



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http://apod.nasa.gov/apod/image/1102/Kepler11Compare_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110203.html)Six Worlds for Kepler-11Six worlds orbit Kepler-11 (http://www.nasa.gov/mission_pages/kepler/news/new_planetary_system.html),a sunlike star 2,000 light-yearsdistant in the constellation Cygnus.The new discovery, based on data from NASA'splanet hunting Kepler spacecraft (http://www.nasa.gov/mission_pages/kepler/overview/index.html),makes the Kepler-11 systemthe fullest exoplanetary system known.Compared to our Solar System in this illustration,five of Kepler-11's planets orbit closer to their parent star than theMercury-Sun distance, withorbital periods (http://hyperphysics.phy-astr.gsu.edu/hbase/kepler.html) ranging from 10 to 47 days.All six are larger than Earth and are likely composed of mixtures ofrocky material and gas.Their presence, sizes, and masses have been determined by carefullywatching the planets dim the light of Kepler-11 whiletransiting orcrossing (http://www.nasa.gov/multimedia/videogallery/index.html?collection_id=14471&media_id=58022301) in front of the star itself.In fact, in August 2010, Kepler's telescope and camerarecorded a simultaneous transit of three of the planets in the system.As announced yesterday (http://www.nasa.gov/mission_pages/kepler/news/kepler_data_release.html),using the transit techniquethe Kepler mission has now identified over1200 exoplanet candidates in afield of view (http://www.nasa.gov/multimedia/videogallery/index.html?collection_id=14471&media_id=58022301)that covers only about 1/400th of the sky.The tantalizing result suggests there are manyundiscovered (http://www.planethunters.org/)planets orbiting the stars inour galaxy (http://www.nasa.gov/mission_pages/kepler/multimedia/images/kepler-target-in-the-milkyway.html).



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http://apod.nasa.gov/apod/image/1102/zetaoph_wise_900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110204.html) Zeta Oph: Runaway Star Like a ship plowing through cosmic seas, runaway star (http://apod.nasa.gov/apod/ap061124.html) Zeta Ophiuchi produces the arcing interstellar bow wave or bow shock seen in this stunning infrared portrait (http://wise.ssl.berkeley.edu/ gallery_zeta_ophiuchi.html) from the WISE spacecraft. In the false-color view, bluish Zeta Oph, a star about 20 times more massive than the Sun, lies near the center of the frame, moving toward the top at 24 kilometers per second. Its strong stellar wind precedes it, compressing and heating the dusty interstellar material (http://espg.sr.unh.edu/ism/what1.html) and shaping the curved shock front. Around it are clouds of relatively undisturbed material. What set this star in motion? Zeta Oph was likely once a member of a binary star system (http://apod.nasa.gov/apod/ap970219.html), its companion star was more massive and hence shorter lived (http://imagine.gsfc.nasa.gov/docs/teachers/lessons/ xray_spectra/background-lifecycles.html). When the companion exploded as a supernova (http://en.wikipedia.org/wiki/Type_II_supernova) catastrophically losing mass, Zeta Oph was flung out of the system. About 460 light-years away, Zeta Oph is 65,000 times more luminous than the Sun and would be one of the brighter stars in the sky if it weren't surrounded by obscuring dust. The WISE (http://wise.ssl.berkeley.edu/education_class.html) image spans about 1.5 degrees or 12 light-years at the estimated distance of Zeta Ophiuchi (http://stars.astro.illinois.edu/sow/zetaoph.html).



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[Astronom.si]

http://apod.nasa.gov/apod/image/1102/a14pan9335-43emj_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110205.html) Apollo 14: A View from Antares Forty years ago (http://www.nasa.gov/externalflash/apollo40/), while looking out the window of Apollo 14's Lunar Module Antares (http://nssdc.gsfc.nasa.gov/nmc/ spacecraftDisplay.do?id=1971-008C), astronaut Ed Mitchell (http://history.nasa.gov/alsj/a14/ A14Mitchell-FlownSuit.html) snapped a series of photos (http://history.nasa.gov/alsj/a14/images14.html#9335) of the lunar surface, assembled (http://history.nasa.gov/alsj/a14/images14.html#Pans) into this detailed mosaic by Apollo Lunar Surface Journal (http://history.nasa.gov/alsj/frame.html) editor Eric Jones. The view looks across the Fra Mauro highlands (http://www.lpi.usra.edu/lunar/missions/apollo/apollo_14/ landing_site/) to the northwest of the landing site after the Apollo 14 astronauts had completed their second and final walk on the Moon (http://history.nasa.gov/alsj/a14/a14.clsout2.html). Prominent in the foreground is their Modular Equipment Transporter (MET (http://www.nasm.si.edu/collections/imagery/apollo/as14/ a14met.htm)), a two-wheeled, rickshaw-like device used to carry tools and samples. Near the horizon at top center is a 1.5 meter wide boulder dubbed Turtle rock. In the shallow crater below Turtle rock is the long white handle of a sampling instrument, thrown there javelin-style by Mitchell. Mitchell's fellow moonwalker and first American in space, Alan Shepard (http://apod.nasa.gov/apod/ap010505.html), also used a makeshift six iron to hit two golf balls (http://history.nasa.gov/alsj/a14/ a14.clsout2.html#1350811). One of Shepard's golf balls is just visible as a white spot below Mitchell's javelin (http://history.nasa.gov/alsj/a14/a14det9337.jpg).



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http://apod.nasa.gov/apod/image/1102/unknownseti_cavan_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110206.html)An Anomalous SETI Signal



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http://apod.nasa.gov/apod/image/1102/sun360_stereo_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110207.html)Sun 360: STEREO Captures Views of the Entire Sun



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http://apod.nasa.gov/apod/image/1102/iridescent_stankievech_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110208.html) Iridescent Clouds from the Top of the World Highway



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http://apod.nasa.gov/apod/image/1102/ngc2174_hst_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110209.html) NGC 2174: Stars Versus Mountains



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http://apod.nasa.gov/apod/image/1102/hannyVWRP_hst_900h.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110210.html) Hanny's Voorwerp Hanny's Voorwerp (http://apod.nasa.gov/apod/ap080625.html), Dutch for "Hanny's Object", is enormous, about the size (http://hubblesite.org/newscenter/archive/releases/2011/01/ image/c/format/web/) of our own Milky Way Galaxy. Glowing strongly in the greenish light produced by ionized oxygen atoms, the mysterious voorwerp (http://hannysvoorwerp.zooniverse.org/the-story-so-far/) is below spiral galaxy IC 2497 in this view from the Hubble Space Telescope (http://hubblesite.org/newscenter/archive/releases/ 2011/01/). Both lie at a distance of some 650 million light-years in the faint constellation Leo Minor. In fact, the enormous green cloud is now suspected to be part of a tidal tail (http://apod.nasa.gov/apod/ap100926.html) of material illuminated by a quasar (http://hubblesite.org/newscenter/archive/releases/2011/01/ image/d/format/web_print/) inhabiting the center of IC 2497. Powered by a massive black hole, the quasar suddenly turned off (http://arxiv.org/abs/1011.0427), leaving only galaxy and glowing voorwerp visible in telescopes at optical wavelengths. The sharp Hubble image also resolves a star forming region in the voorwerp, seen in yellow on the side near IC 2497. That region was likely compressed by an outflow of gas driven from the galaxy's core. The remarkable mystery object was discovered by Dutch schoolteacher Hanny van Arkel (http://www.hannysvoorwerp.com/) in 2007 while participating online in the Galaxy Zoo project. Galaxy Zoo enlists (http://www.galaxyzoo.org/story) the public to help classify galaxies found in the Sloan Digital Sky Survey, and more recently in deep Hubble imagery.



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http://apod.nasa.gov/apod/image/1102/OrionColors_hackmann900h.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110211.html) Star Colors in Orion What determines a star's color (http://outreach.atnf.csiro.au/education/senior/ astrophysics/photometry_colour.html)? Its temperature. Red stars are cool, with surface temperatures of around 3,000 kelvins (K) (http://lamar.colostate.edu/~hillger/temps.htm), while blue stars are hotter and can have temperatures over 30,000 K. Our own lovely "yellow" Sun's (http://casa.colorado.edu/~ajsh/colour/ Tspectrum.html) temperature is a comforting 6,000 K. Differences in star colors are particularly easy to see in this intriguing composite view of the constellation Orion, made while experimenting with a star trail step-focus technique (http://www.aao.gov.au/images/captions/ misc011.html). In it, a series of 35 consecutive exposures were combined to produce trails of stars moving left to right through the frame, while changing focus in steps. Beginning and ending with the camera out of focus produced a sharply focused exposure near the middle of the series and blurs the star trails into a bow tie shape. For the brighter stars, blurring produces more saturated colors in the images. At the upper left, Orion's cool red supergiant Betelgeuse (http://apod.nasa.gov/apod/ap100106.html) stands out from the other, hotter, bluish stars composing the body of the constellation (http://apod.nasa.gov/apod/ap030207.html). Not a star at all, the Orion Nebula (http://apod.nasa.gov/apod/ap081023.html) contributes a pinkish tint below center. Also remarkable in the field, the fainter step focus trail of cool, deep red carbon star W Orionis (http://stars.astro.illinois.edu/sow/wori.html) is near the center right edge, its red hue enhanced by a carbon-rich composition (http://apod.nasa.gov/apod/ap081218.html).



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http://apod.nasa.gov/apod/image/1102/SH2_240_NobuhikoMiki.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110212.html) Simeis 147: Supernova Remnant It's easy to get lost following the intricate filaments in this detailed mosaic image (http://www.miki-hosp.or.jp/BIND/pg147.html) of faint supernova remnant (http://chandra.harvard.edu/xray_sources/ supernovas.html) Simeis 147. Also cataloged as Sh2-240 and seen towards (http://apod.nasa.gov/apod/ap101220.html) the constellation Taurus (http://www.allthesky.com/constellations/taurus/), it covers nearly 3 degrees (6 full moons) on the sky. That corresponds to a width of 150 light-years at the stellar debris cloud's estimated distance of 3,000 light-years. The remarkable composite includes image data taken through narrow-band filters to highlight emission from hydrogen and oxygen atoms tracing regions of shocked, glowing gas (http://apod.nasa.gov/apod/ap090108.html). This supernova remnant has an estimated age of about 40,000 years - meaning light from the massive stellar explosion first reached Earth 40,000 years ago. But this expanding remnant is not the only aftermath (http://apod.nasa.gov/apod/ap011026.html). The cosmic catastrophe also left behind (http://arxiv.org/abs/astro-ph/0611068) a spinning neutron star or pulsar, all that remains (http://hubblesite.org/newscenter/newsdesk/archive/releases/ 1996/22/astrofile/#2) of the original star's core.



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http://apod.nasa.gov/apod/image/1102/deephole_icecube_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110213.html)Ice Fishing for Cosmic Neutrinos



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http://apod.nasa.gov/apod/image/1102/rosette_lula_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110214.html) The Rosette Nebula



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http://apod.nasa.gov/apod/image/1102/northamerica_ir_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110215.html) The North America Nebula in Infrared



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http://apod.nasa.gov/apod/image/1102/tempel1_stardust_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110216.html)Comet Tempel 1 from Stardust-NeXT Spacecraft



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http://apod.nasa.gov/apod/image/1102/SDO20110215_015332_900c_0193.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110217.html) X-Class Flare On Valentine's Day (ET) the Sun unleased (http://sdoisgo.blogspot.com/2011/02/ enormous-flare-in-progress-in-ar-1158.html) one of its most powerful explosions, an X-class flare (http://www.spaceweather.com/glossary/ flareclasses.html). The blast was the largest so far in the new solar cycle. Erupting from active region (http://apod.nasa.gov/apod/ap020801.html) AR1158 in the Sun's southern hemisphere, the flare is captured here (http://www.nasa.gov/mission_pages/sunearth/news/ News021411-xclass.html) in this extreme ultraviolet image from the Solar Dynamics Observatory (http://www.nasa.gov/mission_pages/sdo/main/ index.html) (SDO). The intense burst of electromagnetic radiation momentarily overwhelmed pixels in SDO's detectors causing the bright vertical blemish. This X-class flare was also accompanied by a coronal mass ejection (http://apod.nasa.gov/apod/ap070206.html) (CME), a massive cloud of charged particles traveling outward (http://apod.nasa.gov/apod/ap100806.html) at nearly 900 kilometers per second. Skywatchers at high latitudes should be alert for aurorae (http://www.spaceweather.com/) tonight.



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http://apod.nasa.gov/apod/image/1102/pn912035927_metsavainio900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110218.html)Planetary Nebula ProjectCast off by dying sunlike stars,planetary nebulae (http://seds.org/messier/planetar.html)are a brief but glorious final phase of stellar evolution.The gaseous shrouds are ionized by an extremely hot central source,the shrinking core of a star running out offuel for nuclear fusion (http://fusedweb.pppl.gov/cpep/chart_pages/5.plasmas/Nebula.html).Shining in the cosmic night, their simplesymmetries (http://www.eecs.harvard.edu/~keith/poems/tyger.html)are fascinating and have inspired thisplanetary nebula poster project (http://astroanarchy.blogspot.com/2011/02/planetary-nebula-poster.html).In it, nine planetaries are displayed for comparison in a 3x3 grid.Of course, planetary nebula fans should be able topick out (http://astroanarchy.blogspot.com/2011/02/planetary-nebula-poster.html) the brightMessier objectsM27 (http://apod.nasa.gov/apod/ap100826.html) - the Dumbbell Nebula,M76 (http://apod.nasa.gov/apod/ap100723.html) - the Little Dumbbell, andM57 (http://apod.nasa.gov/apod/ap080918.html) - the Ring Nebula, as well asNGC 6543 (http://apod.nasa.gov/apod/ap070629.html), aka the Cat's Eye Nebula.Lesser known nebulae include theMedusa (http://apod.nasa.gov/apod/ap071123.html) and theBug (http://apod.nasa.gov/apod/ap070429.html).All the images were made with detailed narrow band data andare shown at the sameangular scale (http://chandra.harvard.edu/photo/scale.html),spanning 20 arc minutes (1/3 degree).At that scale, the grey circle represents the apparent size ofthe Full Moon.These planetary nebulaehint (http://arxiv.org/abs/1010.3802) at the fate of our ownSun as its core runs out of nuclear fuel in another5 billion years (http://hubblesite.org/newscenter/archive/releases/1997/38/background/#background-info-2).



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[Astronom.si]

http://apod.nasa.gov/apod/image/1102/ngc2841c_hst_sm.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110219.html)Spiral Galaxy NGC 2841 Close UpA mere 46 million light-years distant, spiral galaxy NGC 2841can be found in the northern constellation ofUrsa Major (http://apod.nasa.gov/apod/ap070108.html).This sharp view of the gorgeousisland universe (http://cass.ucsd.edu/public/tutorial/Galaxies.html)shows off a striking yellow nucleus and galactic disk.Dust lanes, small, pink star-forming regions, and young blue star clustersare embedded in the patchy, tightlywound (http://casa.colorado.edu/~danforth/science/spiral/)spiral (http://apod.nasa.gov/apod/ap030925.html) arms.In contrast (http://apod.nasa.gov/apod/ap091017.html), many other spiralsexhibit grand, sweepingarms with large star-forming regions. NGC 2841 has a diameter of over 150,000 light-years, even larger thanour own (http://www.atlasoftheuniverse.com/galaxy.html)Milky Way, but thisclose-up Hubble image (http://hubblesite.org/newscenter/archive/releases/2011/06/) spans about34,000 light-years along the the galaxy's inner region.X-ray images (http://chandra.harvard.edu/photo/2006/n2841/)suggest that resulting winds and stellar explosions createplumes of hot gas extending into a halo around NGC 2841.



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[Astronom.si]

http://apod.nasa.gov/apod/image/1102/mammatus_saal_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110220.html) Mammatus Clouds Over Olympic Valley What's happened to these clouds? Normal cloud bottoms are flat (http://www.newton.dep.anl.gov/askasci/wea00/wea00041.htm) because moist warm air that rises and cools will condense into water droplets at a very specific temperature, which usually corresponds to a very specific height. After water droplets form (http://earthobservatory.nasa.gov/Library/GlobalClouds/) that air becomes an opaque cloud. Under some conditions, however, cloud (http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/cld/cldtyp/home.rxml) pockets can develop that contain large drop (http://www.youtube.com/watch?v=zaHLwla2WiI)lets of water or ice that fall into clear air as they evaporate. Such pockets (http://en.wikipedia.org/wiki/Pocket) may occur in turbulent (http://en.wikipedia.org/wiki/Turbulence) air near a thunderstorm (http://apod.nasa.gov/apod/ap101130.html), being seen near the top of an anvil cloud (http://apod.nasa.gov/apod/ap040218.html), for example. Resulting mammatus clouds can appear especially dramatic (http://www.youtube.com/watch?v=sdvcXcTpX1w) if sunlit from the side. These mammatus clouds (http://en.wikipedia.org/wiki/Mammatus_clouds) were photographed last August over Olympic Valley (http://en.wikipedia.org/wiki/Olympic_Valley,_California), California (http://en.wikipedia.org/wiki/California), USA (http://www.yourchildlearns.com/mappuzzle/us-puzzle.html).



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[Astronom.si]

http://apod.nasa.gov/apod/image/1102/mwcliffs_vetter_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110221.html)Milky Way Over SwitzerlandWhat's visible in the night sky during this time of year?To help illustrate the answer, a beautiful land, cloud, and skyscape was captured earlier this month overNeuchâtel (http://en.wikipedia.org/wiki/Neuchatel),Switzerland (http://en.wikipedia.org/wiki/Switzerland).Visible in the foreground were the snow covered cliffs of the amphitheater shapedCreux du Van (http://en.wikipedia.org/wiki/Creux_du_Van), as well as distant trees, and town-lit clouds.Visible in the night sky (at midnight) were galaxies including thelong arch (http://apod.nasa.gov/apod/ap080713.html) of the central band of ourMilky Way Galaxy (http://bb.nightskylive.net/asterisk/viewtopic.php?f=24&t=18006), theAndromeda galaxy (http://apod.nasa.gov/apod/ap090510.html) (M31), and theTriangulum (http://www.youtube.com/watch?v=p5QPRez-hyU) galaxy(M33 (http://apod.nasa.gov/apod/ap101203.html).Star clusters visible included NGC 752,M34 (http://apod.nasa.gov/apod/ap100211.html),M35 (http://apod.nasa.gov/apod/ap031215.html),M41 (http://en.wikipedia.org/wiki/Messier_41),the double cluster (http://apod.nasa.gov/apod/ap091204.html), andthe Beehive (M44 (http://apod.nasa.gov/apod/ap040617.html)).Nebulas visible included the Orion Nebula(M42 (http://apod.nasa.gov/apod/ap090222.html)),NGC 7822 (http://apod.nasa.gov/apod/ap101022.html),IC 1396 (http://apod.nasa.gov/apod/ap090819.html), theRosette Nebula (http://apod.nasa.gov/apod/ap070214.html),the Flaming Star Nebula (http://apod.nasa.gov/apod/ap090126.html), theCalifornia Nebula (http://apod.nasa.gov/apod/ap060924.html), theHeart (http://apod.nasa.gov/apod/ap090214.html) andSoul Nebulas (http://apod.nasa.gov/apod/ap080914.html), and thePacman Nebula (http://apod.nasa.gov/apod/ap050823.html).Rolling your cursor over theabove image (http://www.nuitsacrees.fr/DP/CV_apod2000.jpg) will bring up labels for all of these (http://www.nuitsacrees.fr/DP/CV_apod2000_comments.jpg).But the abovewide angle sky image (http://www.sergebrunier.com/gallerie/pleinciel/360.swf) captured even more sky wonders.What other nebulas

[Astronom.si]

http://www.astronom.si/forum/ (http://antwrp.gsfc.nasa.gov/apod/ap110222.html)Star Size ComparisonsHow big is our Sun compared to other stars?In a dramatic andpopular video (http://www.youtube.com/watch?v=HEheh1BH34Q) featured onYouTube (http://en.wikipedia.org/wiki/YouTube),the relative sizes of planets and stars are shown from smallest to largest.Theabove video (http://www.youtube.com/watch?v=fKTu6B4Rgek) starts withEarth's Moon (http://apod.nasa.gov/apod/ap051113.html) and progresses through increasingly larger planets in ourSolar System (http://science.nationalgeographic.com/science/space/solar-system). Next, theSun (http://apod.nasa.gov/apod/sun.html) is shown along as compared to many of thebrighter stars in our neighborhood of theMilky Way Galaxy (http://bb.nightskylive.net/asterisk/viewtopic.php?f=24&t=18006).Finally, some of the largest stars known spin into view.Note that the true sizes of most stars outside of the Sun andBetelgeuse (http://apod.nasa.gov/apod/ap100106.html) are not known by direct observation, but rather inferred by measurements of their perceivedbrightness (http://en.wikipedia.org/wiki/Luminosity),temperature (http://www.youtube.com/watch?v=s9eE2jFoioM), and distance.Although an inspiring learning tool that is mostly accurate,APOD readers (http://www.ny3d.org/Audience.jpg) are encouraged to complete the learning experience -- and possibly help make future versions more accurate -- bypointing out slight inaccuracies (http://bb.nightskylive.net/asterisk/discuss_apod.php?date=110222) in the video.



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http://apod.nasa.gov/apod/image/1102/solarsystem_messenger_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110223.html) The Solar System from MESSENGER If you looked out from the center of the Solar System, what would you see? Nearly such a view was taken recently from the MESSENGER spacecraft (http://en.wikipedia.org/wiki/MESSENGER) currently orbiting the Sun from the distance of Mercury (http://apod.nasa.gov/apod/ap081008.html). The Sun's planets all appear as points of light, with the closest and largest planets appearing the brightest. The planets (http://planetary.org/blog/article/00002923/) all appear to orbit in the same direction and are (nearly) confined to the same great circle (http://v-flyer.com/the-toolbox/blue-marble-mapper) around the sky -- the ecliptic (http://en.wikipedia.org/wiki/Plane_of_the_ecliptic) plane. Mercury, Venus (http://photojournal.jpl.nasa.gov/catalog/PIA10124), Earth (http://messenger.jhuapl.edu/flyby/index.html), Mars, Jupiter, and Saturn are all visible in the above horizontally compressed (http://turbocycling.files.wordpress.com/2011/01/crushed.jpg) image, while the positions of Uranus and Neptune are labeled even though they are too faint to make out. Pluto, which has had its planetary status (http://www.iau.org/public/pluto/) recently called into question, is much too faint to see. Earth's Moon (http://apod.nasa.gov/apod/ap100901.html) is visible, however, as are the Galilean moons (http://apod.nasa.gov/apod/ap001118.html) of Jupiter. The above image (http://messenger.jhuapl.edu/news_room/details.php?id=155) is the reverse of one taken (http://apod.nasa.gov/apod/ap020214.html) from the outside of the Solar System in 1990 by Voyager (http://en.wikipedia.org/wiki/Voyager_program) 1. MESSENGER, which has flown by Mercury three times now, is on schedule to enter orbit (http://www.youtube.com/watch?v=otF2FjpCyZk) around the Solar System's innermost planet next month.



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http://apod.nasa.gov/apod/image/1102/n1999_block900c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110224.html)NGC 1999: South of OrionSouth of the large star-forming region known as theOrion Nebula, lies bright blue reflection nebulaNGC 1999 (http://apod.nasa.gov/apod/ap000302.html).Also at the edge of theOrion molecularcloud (http://www.seds.org/messier/more/oricloud.html) complex some 1,500 light-years distant, NGC 1999'sillumination is provided by theembedded variable star V380 Orionis.The nebula is marked with a dark sideways T-shape near center in thisbroadcosmic vista (http://www.caelumobservatory.com/gallery/n1999.shtml) that spans over 10 light-years.The dark shape was once assumed to be an obscuring dust cloudseen in silhouette against the bright reflection nebula.But recentinfrared images (http://www.esa.int/esaCP/SEMFEAKPO8G_index_0.html)indicate the shape is likely a hole blown through the nebulaitself by energetic young stars.In fact,thisregion abounds (http://www.noao.edu/outreach/latest/ngc1999about.html) with energetic young starsproducing jets and outflows that create luminous shock waves.Cataloged as Herbig-Haro (HH) objects, named for astronomersGeorge Herbig and Guillermo Haro,the shocks appear bright red inthis view (http://skycenter.arizona.edu/news/109) that includesHH1 and HH2 just below NGC 1999.The stellar jets (http://hubblesite.org/newscenter/newsdesk/archive/releases/1995/24/astrofile/) andoutflows push through the surroundingmaterial at speeds of hundreds of kilometers per second.



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http://apod.nasa.gov/apod/image/1102/NGC4449_hlaGendler900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110225.html) NGC 4449: Close-up of a Small Galaxy Grand spiral galaxies (http://apod.nasa.gov/apod/ap071201.html) often seem to get all the glory. Their young, blue star clusters and pink star forming regions along sweeping spiral arms (http://casa.colorado.edu/~danforth/science/spiral/) are guaranteed to attract attention. But small irregular galaxies form stars too, like NGC 4449 (http://www.seds.org/~spider/spider/Misc/n4449.html), about 12 million light-years distant. Less than 20,000 light-years across, the small island universe is similar in size, and often compared (http://heritage.stsci.edu/2007/26/supplemental.html) to our Milky Way's satellite galaxy, the Large Magellanic Cloud (http://apod.nasa.gov/apod/ap101016.html) (LMC). This remarkable Hubble (http://www.robgendlerastropics.com/ NGC4449-HST-Gendler.html) Space Telescope close-up of the well-studied (http://arxiv.org/abs/astro-ph/0010515) galaxy was reprocessed to highlight the telltale reddish glow of hydrogen gas. The glow traces NGC 4449's widespread star forming regions, some even larger than those in the LMC (http://apod.nasa.gov/apod/ap060518.html), with enormous interstellar arcs and bubbles blown by short-lived, massive stars (http://apod.nasa.gov/apod/ap991130.html). NGC 4449 is a member of a group of galaxies (http://www.atlasoftheuniverse.com/galgrps/cvni.html) found in the constellation Canes Venatici. Interactions with the nearby galaxies (http://seds.org/MESSIER/galaxy.html) are thought to have influenced star formation in NGC 4449.



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http://apod.nasa.gov/apod/image/1102/Arp227friends_leshin900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110226.html) Shell Galaxies in Pisces This colorful cosmic skyscape (http://sleshin.startlogic.com/stargazergallery/ main.php?g2_itemId=415) features a peculiar system of galaxies cataloged as (http://nedwww.ipac.caltech.edu/level5/Arp/ frames.html) Arp 227 some 100 million light-years distant. Swimming within (http://pixinsight.com/forum/index.php?topic=2623.0) the boundaries of the constellation Pisces (http://www.pa.msu.edu/people/horvatin/Astronomy_Facts/ constellation_pages/pisces.htm), Arp 227 consists of the two galaxies prominent (http://apod.nasa.gov/apod/image/1102/arp227field_leshin600.jpg) on the left; the curious shell galaxy NGC 474 and its blue, spiral-armed neighbor NGC 470. The faint, wide arcs or shells of NGC 474 (http://adsabs.harvard.edu/abs/1999IAUS..186..191T) could have been formed by a gravitational encounter with neighbor NGC 470. Alternately the shells could be caused by a merger (http://apod.nasa.gov/apod/ap021111.html) with a smaller galaxy producing an effect analogous to ripples across the surface of a pond. Remarkably, the large galaxy on the right hand side of the deep image, NGC 467, appears to be surrounded by faint shells too, evidence of another interacting (http://burro.cwru.edu/JavaLab/GalCrashWeb/) galaxy system. Intriguing background galaxies are scattered around the field that also includes spiky (http://spider.ipac.caltech.edu/staff/kaspar/obs_mishaps/ images/int_reflection2.html) foreground stars. Of course, those stars lie well within our own Milky Way Galaxy (http://apod.nasa.gov/apod/ap080104.html). The field of view spans 25 arc minutes or about 1/2 degree on the sky (http://chandra.harvard.edu/photo/scale.html).



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http://apod.nasa.gov/apod/image/1102/hyperion3_cassini_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110227.html)Saturn's Hyperion: A Moon with Odd CratersWhat lies at the bottom ofHyperion (http://en.wikipedia.org/wiki/Hyperion_(moon))'s strange craters? Nobody's sure. To help find out, therobot Cassini spacecraft (http://www.nasa.gov/mission_pages/cassini/spacecraft/index.html) now orbitingSaturn (http://en.wikipedia.org/wiki/Saturn_(planet)) swooped past thesponge-textured moon (http://www.oceanicresearch.org/education/wonders/sponges.html) in 2005 and2010 (http://www.youtube.com/watch?v=U5VfYDYL3rA) and took images of unprecedented detail. An image from the 2005 pass,shown above (http://photojournal.jpl.nasa.gov/catalog/PIA07740) in false color, shows a remarkable world strewn withstrange craters and agenerally odd surface (http://www.youtube.com/watch?v=30pH8Xn41Os). The slight differences (http://www.johnmunsch.com/images/FiveDifferences.png) in color likely show differences in surface composition. At the bottom of most craters lies some type ofunknown dark material (http://www.lpi.usra.edu/meetings/lpsc2010/pdf/1541.pdf). Inspection of the image shows (http://saturn.jpl.nasa.gov/science/moons/hyperion/) bright features indicating that the dark material might be only tens of meters thick in some places. Hyperionis about 250 kilometers across, rotates chaotically (http://apod.nasa.gov/apod/ap050726.html),and has a density so low that itmight house (http://adsabs.harvard.edu/abs/2010DPS....42.0603H)a vast system ofcaverns (http://en.wikipedia.org/wiki/Cavern) inside.



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http://apod.nasa.gov/apod/image/1102/mooncity_vanzella_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110228.html) Red Snow Moon Over Edmonton What's hovering between those buildings? The Moon. The above image was taken two weeks ago as the full Snow Moon (http://www.farmersalmanac.com/astronomy/2009/02/09/full-snow-moon/) started to rise above Edmonton (http://en.wikipedia.org/wiki/Edmonton), Alberta (http://en.wikipedia.org/wiki/Alberta), Canada (http://en.wikipedia.org/wiki/Canada). The odd coincidence between the angular size (http://www.1728.com/angsize.htm) of the far distant Moon (http://apod.nasa.gov/apod/ap071025.html) and the angular width of nearby buildings created a striking juxtaposition. Backing away from the buildings so to reduce their angular size was a key to planning the image. The temperature was so low, -25 C (http://www.sizes.com/units/temperature_centigrade.htm), that plumes of steam rose from neighboring oil refineries. The above image was taken during a momentary break in the plumes. The rising Moon (http://www.youtube.com/watch?v=-ifTCa97G6Q) appears red here for the same reason that a setting Sun appears red (http://apod.nasa.gov/apod/ap980526.html) -- because blue light is preferentially scattered away by intervening air. In this case, the shimmering (http://apod.nasa.gov/apod/ap101019.html) steam plumes likely also caused the Moon to appear slightly compressed (http://apod.nasa.gov/apod/ap090223.html). The next full moon, the full Worm Moon (http://www.farmersalmanac.com/full-moon-names/), will occur in mid-March.



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http://apod.nasa.gov/apod/image/1103/discovery_iss_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110301.html) Discovery Visits the Space Station What's happening outside the space station? A space shuttle has docked. Five days ago, the space shuttle Discovery (http://en.wikipedia.org/wiki/Space_Shuttle_Discovery) was launched (http://www.youtube.com/watch?v=GE_USPTmYXM) to the International Space Station (http://www.nasa.gov/mission_pages/station/main/index.html), carrying six crew members and the large Leonardo Multi Purpose Logistics Module (http://en.wikipedia.org/wiki/Leonardo_MPLM). Three days ago, as pictured above (http://spaceflight.nasa.gov/gallery/images/shuttle/sts-133/html/s133e006561.html), the docked shuttle was prepared to be unloaded by the space stations Dextre (http://apod.nasa.gov/apod/ap080401.html) robot and Canadarm2 (http://science.nasa.gov/science-news/science-at-nasa/2001/ast18apr_1/). The above expansive photo captures much more, however, including Japan's Kibo Experiment Module (http://www.nasa.gov/mission_pages/station/structure/elements/jem.html) on the lower right, Earth across the top of the frame, and a seemingly starless (http://www.badastronomy.com/bad/tv/foxapollo.html#stars) backdrop of space in the distance. During the next week, the shuttle and ISS (http://apod.nasa.gov/apod/ap100303.html) crews are scheduled to permanently attach Leonardo as well as fix and upgrade (http://cache.gawkerassets.com/assets/images/4/2011/02/mc-escher-waterfall.jpg) parts of the ISS. After 38 previous voyages, this is expected to be the last space mission (http://en.wikipedia.org/wiki/STS-133) for the Space Shuttle (http://apod.nasa.gov/apod/ap100907.html) Discovery (http://www-pao.ksc.nasa.gov/kscpao/images/large/2010-4453.jpg).



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http://apod.nasa.gov/apod/image/1103/california_noller_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110302.html)NGC 1499: The California NebulaWhat's California doing in space? Drifting through the Orion Arm of the spiral Milky Way Galaxy,this cosmic cloud (http://www.atlasoftheuniverse.com/nebulae/ngc1499.html)by chance echoes the outline of California (http://en.wikipedia.org/wiki/California) on the west coast of the United States (https://www.cia.gov/library/publications/the-world-factbook/geos/us.html).Our own Sun also lies within the Milky Way'sOrionArm (http://www.atlasoftheuniverse.com/5000lys.html), only about 1,500 light-years from the California Nebula (http://en.wikipedia.org/wiki/California_Nebula).Also known as NGC 1499 (http://www.seds.org/~spider/spider/Misc/n1499.html), the classic emission nebula is around 100 light-years long.On many images, the most prominent glow of the California Nebula isthe red light characteristic of hydrogen (http://periodic.lanl.gov/1.shtml) atoms recombining with longlost (http://apod.nasa.gov/apod/lib/lament.html) electrons, stripped away (ionized (http://csep10.phys.utk.edu/astr162/lect/light/ionization.html))by energetic starlight.In the above image (http://www.deep-sky-images.de/displayimage.php?album=lastup&cat=0&pid=239#top_display_media), however, hydrogen is colored green, while sulfur is mapped (http://bf-astro.com/hubbleP.htm) to red and oxygen mapped to blue. The star most likely providing the energeticstarlight that ionizes much of the nebular gas is the bright, hot, bluish Xi Persei (http://en.wikipedia.org/wiki/Xi_Persei),just outside the right image edge.A regular target for astrophotographers, the California Nebula can be spotted (http://apod.nasa.gov/apod/ap090411.html) with a wide-field telescope under a dark skytoward the constellation of Perseus (http://en.wikipedia.org/wiki/Perseus_%28constellation%29), not far from the Pleiades (http://apod.nasa.gov/apod/ap091103.html).



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http://apod.nasa.gov/apod/image/1103/lroc_wac_nearside800.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110303.html)Lunar NearsideAbout 1,300 images from the Lunar Reconnaissance Orbiterspacecraft's wide angle camera were used to compose thisspectacular view of afamiliar face -the lunar nearside (http://lroc.sese.asu.edu/news/index.php?/archives/341-Nearside-Spectacular!.html).But why is there a lunar nearside?TheMoon rotates (http://lunarscience.arc.nasa.gov/kids/lunar_day) on its axis andorbitsthe Earth (http://en.wikipedia.org/wiki/Orbit_of_the_Moon) at the same rate, about once every 28 days.Tidally locked (http://www.astronomycafe.net/qadir/q277.html)in this configuration, thesynchronous rotation always keeps one side, the nearside,facing Earth (http://geosteph-adventuresinearthandspace.blogspot.com/2008/02/other-side-of-moon-synchronous-rotation.html).As a result, featured in remarkable detail in thefull resolution mosaic (http://wms.lroc.asu.edu/lroc_browse/view/wac_nearside),the smooth, dark (http://apod.nasa.gov/apod/ap080208.html),lunar mare (actually lava-flooded impact basins),and rugged highlands, are well-knownto earthbound skygazers.To find your favoritemare or large crater, just slide your cursor overthe picture.The LRO images (http://lroc.sese.asu.edu/images/)used to construct the mosaic were recorded overa two week period last December.



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[Astronom.si]

http://apod.nasa.gov/apod/image/1103/NGC6914_peris_600h.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110304.html) NGC 6914 Nebulae A dramatic study in contrasts, this colorful skyscape (http://pixinsight.com/gallery/NGC6914-CAHA/ en.html) features stars, dust, and glowing gas in NGC 6914. The complex of nebulae lies some 6,000 light-years away, toward the high-flying northern constellation Cygnus and the plane (http://apod.nasa.gov/apod/ap070920.html) of our Milky Way Galaxy. With foreground dust clouds in silhouette, both reddish hydrogen emission nebulae (http://fusedweb.pppl.gov/cpep/chart_pages/5.plasmas/ nebula/emission.html) and dusty blue reflection nebulae (http://fusedweb.pppl.gov/cpep/chart_pages/5.plasmas/ nebula/reflection.html) fill the 1/2 degree wide field of view that spans nearly 50 light-years at the esitmated distance of NGC 6914. Ultraviolet radiation from the massive, hot, young stars of the extensive (http://arxiv.org/abs/1003.2463) Cygnus OB2 (http://stardate.org/radio/program/2009-08-26) association ionize the region's atomic hydrogen gas (http://apod.nasa.gov/apod/ap051223.html), producing the characteristic red glow as protons and electrons recombine. Embedded Cygnus OB2 stars also provide the blue starlight strongly reflected by the dusty clouds. Constructed as a two-panel mosaic, the image was processed to bring out (http://pixinsight.com/examples/NGC6914-CAHA/en.html) both bright and dim colors and detailed structures.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap110304.html)

[Astronom.si]

http://apod.nasa.gov/apod/image/1103/casa_main.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110305.html) Cooling Neutron Star Supernova remnant (http://chandra.harvard.edu/xray_sources/ supernovas.html) Cassiopeia A (Cass A) is a comfortable (http://www.nasa.gov/centers/goddard/news/topstory/2003/ 0108supernova.html) 11,000 light-years away. Light from the Cass A supernova, the death explosion of a massive star, first reached Earth just 330 years ago. The expanding debris cloud spans about 15 light-years in this composite X-ray (http://apod.nasa.gov/apod/ap040826.html)/optical image, while the bright source near the center is a neutron star (http://www.astro.umd.edu/~miller/nstar.html) (inset illustration (http://chandra.harvard.edu/photo/2011/casa/ more.html#casa1)) the incredibly dense, collapsed remains of the stellar core. Still hot enough to emit X-rays, Cass A's neutron star is cooling. In fact, 10 years of observations with the orbiting Chandra X-ray observatory find that the neutron star is cooling rapidly (http://chandra.harvard.edu/photo/2011/casa/), so rapidly that researchers suspect a large part of the neutron star's core is forming a frictionless neutron superfluid (http://chandra.harvard.edu/photo/2011/casa/ more.html#casa3). The Chandra results represent the first observational evidence for this bizarre state (http://www.sciencedaily.com/releases/2011/02/ 110223151943.htm) of matter.



Več... (http://antwrp.gsfc.nasa.gov/apod/ap110305.html)

[Astronom.si]

http://apod.nasa.gov/apod/image/1103/asteroidstreak_hst_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110306.html)Asteroids in the DistanceRocks from space hit Earth every day. The larger the rock, though, the less often Earth is struck. Many kilograms of space dust pitter to Earth daily.Larger bits appear initially as a bright meteor. Baseball-sized rocks and ice-ballsstreak through our atmosphere daily,most evaporating quickly to nothing. Significant threats (http://neo.jpl.nasa.gov/risk/) do exist for rocks near100 meters in diameter, whichstrike the Earth (http://apod.nasa.gov/apod/ap990711.html)roughly every 1000 years. An object this size could cause significanttsunamis were it to strike an ocean,potentially devastating even distant shores.A collision with a massive asteroid (http://apod.nasa.gov/apod/ap040619.html),over 1 km across, is more rare (http://apod.nasa.gov/apod/ap980313.html),occurring typically millions of years apart, butcould have truly global consequences (http://neo.jpl.nasa.gov/risk/doc/sentry.html).Many asteroids remainundiscovered (http://spacewatch.lpl.arizona.edu/). In fact, one was discovered in 1998 as the long blue streak in theabove archival image (http://hubblesite.org/newscenter/newsdesk/archive/releases/1998/10/) taken by the Hubble Space Telescope.In 2002 June,the small 100-meter asteroid2002 MN (http://www.skyandtelescope.com/news/3306216.html) was discovered only after itwhizzed by the Earth,passing (http://www.youtube.com/watch?v=0WgBWyiLD0I)well within the orbit of the Moon.2002 MN (http://neo.jpl.nasa.gov/risk/2002mn.html) passed closer than any asteroid since1994 XM1 (http://astrowww.phys.uvic.ca/media/press/1.htm), but not as close as2004 MN4 (http://neo.jpl.nasa.gov/news/news149.html) will pass in 2029.A collision (http://apod.nasa.gov/apod/ap050308.html) with a large asteroid would not affect Earth's orbit so much asraise dust (http://www.youtube.com/watch?v=95tmYmeHf84)that would affect Earth's climate. One likely result is a global extinction of many species of life,possibly dwarfing the ongoingextinction occurring now (http://www.pbs.org/wgbh/evolution/library/03/2/l_032_04.html).



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[Astronom.si]

http://www.astronom.si/forum/ (http://antwrp.gsfc.nasa.gov/apod/ap110307.html)A Solar Prominence Eruption from SDOOne of the most spectacular solar sights is an erupting prominence.Two weeks ago, NASA's Sun-orbitingSolar Dynamic Observatory (http://www.nasa.gov/mission_pages/sdo/main/index.html) spacecraft imaged animpressively large prominence (http://apod.nasa.gov/apod/ap030223.html)erupting from the surface.The dramatic explosion (http://www.youtube.com/watch?v=_N2PXdq_bWE) was captured in ultraviolet light in theabove time lapse video (http://www.nasa.gov/mission_pages/sunearth/news/News022411-monsterprom.html) covering 90 minutes,where a new frame was taken every 24 seconds. The scale of the prominence is huge -- the entire Earth would easily fit under the flowing curtain (http://apod.nasa.gov/apod/ap011203.html) of hot gas. A solar prominence (http://solar.physics.montana.edu/YPOP/Program/hfilament.html) is channeled and sometimes held above theSun's surface by the Sun'smagnetic field (http://solarscience.msfc.nasa.gov/the_key.shtml).A quiescent prominence typically lasts about a month, and may erupt in aCoronal Mass Ejection (http://lheawww.gsfc.nasa.gov/~reames/DARK7.HTML) (CME)expelling hot gas (http://apod.nasa.gov/apod/ap010924.html) into theSolar System (http://en.wikipedia.org/wiki/Sweden_Solar_System). The energy mechanism that creates asolar prominence (http://apod.nasa.gov/apod/ap030707.html) is still a topic ofresearch (http://adsabs.harvard.edu/abs/2004ApJ...600.1043Z). As the Sun progresses towardSolar Maximum (http://en.wikipedia.org/wiki/Solar_maximum)in the next few years,solar activity (http://apod.nasa.gov/apod/ap071203.html) likeeruptive prominences (http://apod.nasa.gov/apod/ap100510.html) are expected to become more common.



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[Astronom.si]

http://apod.nasa.gov/apod/image/1103/titansaturn_cassini_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110308.html) Titan, Rings, and Saturn from Cassini How thin are the rings of Saturn? Brightness measurements (http://adsabs.harvard.edu/abs/1997Icar..129..555B) from different angles have shown Saturn's rings (http://www.planetary.org/saturn/rings.html) to be about one kilometer thick, making them many times thinner, in relative proportion, than a razor blade (http://en.wikipedia.org/wiki/Razor). This thinness sometimes appears (http://apod.nasa.gov/apod/ap051021.html) in dramatic fashion (http://apod.nasa.gov/apod/ap950801.html) during an image taken nearly along the ring plane. The robot Cassini spacecraft (http://www.nasa.gov/mission_pages/cassini/spacecraft/index.html) now orbiting Saturn has now captured another shot that dramatically highlights the ring's thinness. The above image (http://photojournal.jpl.nasa.gov/catalog/PIA12756) was taken in mid January in infrared (http://en.wikipedia.org/wiki/Infrared) and polarized (http://www.youtube.com/watch?v=8uS4e1teka8) light. Titan (http://apod.nasa.gov/apod/ap060508.html) looms just over the thin rings, while dark ring shadows (http://apod.nasa.gov/apod/ap100215.html) on Saturn show the Sun to be above the ring (http://www.youtube.com/watch?v=3p-AOsb4bdA) plane. Close inspection (http://charleykanesfunhouse.com/wp-content/uploads/2009/08/funny-cat-picture-regrets-latest-garbage-raid.jpg) of the image will show the smaller moon Enceladus (http://apod.nasa.gov/apod/ap090628.html) on the far right. Cassini, humanity's first mission to orbit Saturn (http://asterisk.apod.com/viewtopic.php?f=24&t=18015), currently has operations planned (http://saturn.jpl.nasa.gov/news/newsreleases/newsrelease20100203/) until 2017.



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[Astronom.si]

http://apod.nasa.gov/apod/image/1103/iss_sts133_900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110309.html)The International Space Station Expands AgainThe developingInternational Space Station (http://www.shuttlepresskit.com/ISS_OVR/index.htm) (ISS) has changed its appearance again. In a recently completed rendezvous, theSpace Shuttle (http://apod.nasa.gov/apod/ap010412.html) orbiterDiscovery (http://science.ksc.nasa.gov/shuttle/resources/orbiters/discovery.html), in its final flight (http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts133/discovery_final_flight.html), visited the ISS and added components that included theLeonardo Multi Purpose Logistics Module (http://en.wikipedia.org/wiki/Leonardo_MPLM).The ISS and many of its modules and expansive solar panels are visible inthe above picture (http://spaceflight.nasa.gov/gallery/images/shuttle/sts-133/html/s133e010480.html) taken by the Discovery Crew (http://en.wikipedia.org/wiki/STS-133#Crew) after leaving theISS (http://www.youtube.com/watch?v=0t5--gUbMCg)to return to Earth. The world's foremostspace outpost (http://spaceflight.nasa.gov/station/) can be seen developing over the past several yearsby comparing the above imageto (http://apod.nasa.gov/apod/ap090406.html)other (http://apod.nasa.gov/apod/ap080623.html) past (http://apod.nasa.gov/apod/ap060920.html)images (http://apod.nasa.gov/apod/ap020102.html). Also visible above are manydifferent types of modules (http://spaceflight.nasa.gov/gallery/images/station/assembly/ndxpage1.html) and supply ships (http://apod.nasa.gov/apod/ap080514.html). Construction began on the ISS in 1998.



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[Astronom.si]

http://apod.nasa.gov/apod/image/1103/discovery_110307_ladanyi_c.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110310.html) Discovery in Twilight As evening twilight faded (http://apod.nasa.gov/apod/ap071227.html) on March 7, sky gazers (http://www.pa.msu.edu/abrams/nightskynotes/) around planet Earth enjoyed a beautiful pairing of young crescent Moon and brilliant planet Jupiter. Along with stars setting in the west, the two bright celestial beacons, Moon above and Jupiter below, leave short trails in this well-planned time exposure, a composite of 54 individual frames each 4 seconds long. On its final flight (http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/ sts133/discovery_final_flight.html), the Space Shuttle Discovery (http://apod.nasa.gov/apod/ap050727.html) and International Space Station form the second close pairing in the night skyscape. Still glinting (http://apod.nasa.gov/apod/ap080604.html) in the sunlight (http://apod.nasa.gov/apod/ap010320.html) in low Earth orbit (http://apod.nasa.gov/apod/ap030517.html), they gracefully trace overlapping arcs (http://apod.nasa.gov/apod/ap090902.html) from lower right to upper left. Moon, Jupiter, Discovery (http://apod.nasa.gov/apod/ap100409.html), and ISS are reflected (http://apod.nasa.gov/apod/ap060719.html) in the calm waters of Lake Bakonyb&eacute;l, Hungary. Want to see the sequence of frames as a short youtube video? Check it out here (http://www.youtube.com/watch?v=_rOMRnlVTjk). In the video, the trails of the ISS and Discovery (http://apod.nasa.gov/apod/ap100408.html) are seen to separate as the pair passes above the Moon.



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[Astronom.si]

http://apod.nasa.gov/apod/image/1103/IC405FlamingstarDetail_geissinger900.jpg (http://antwrp.gsfc.nasa.gov/apod/ap110311.html)AE Aurigae and the Flaming Star NebulaAE Aurigae (http://stars.astro.illinois.edu/sow/aeaur.html)is the bright star below and left of center in thisevocative portrait of IC 405 (http://www.stern-fan.de/Seiten/galerie_Bild_IC405-Flamingstar.html),also known as the Flaming Star Nebula.Embedded in the cosmic cloud, the hot, variableO-type star (http://apod.nasa.gov/apod/ap070726.html) energizesthe glow of hydrogen along convoluted filaments of atomic gas, its blue starlight scattered byinterstellar (http://espg.sr.unh.edu/ism/what1.html) dust.But AE Aurigae wasn't formed in the nebula it illuminates.Retracing the star's motion through space, astronomersconclude that AE Aurigae was probably born in theOrion Nebula (http://apod.nasa.gov/apod/ap090222.html).Close gravitational encounters with other starsejected it from the region, along with another O star,Mu Columbae (http://stars.astro.illinois.edu/sow/mucol.html),over two million years ago.Therunaway stars (http://wise.ssl.berkeley.edu/gallery_IC405.html) have drifted in opposite directionsever since, separating at about 200 kilometers per second.This sharp, detailed image of IC 405spans over 5 light-years at thenebula's estimated distance of 1,500 light-yearsin the northern constellationAuriga (http://apod.nasa.gov/apod/ap100305.html), the Charioteer.



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