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Night Launch of the Space Shuttle Endeavour Credit: NASA Explanation: Sometimes, the space shuttle launches at night. Pictured above, the space shuttle Endeavour lifted off in yesterday's early morning hours from Launch Pad 39A in Kennedy Space Center, Florida, USA, bound for the International Space Station (ISS). A night launch, useful for reaching the space station easily during some times of the year, frequently creates vivid launch imagery. The shuttle, as pictured above, is framed by an enormous but typical exhaust plume ejected as the shuttle's powerful rockets began lifting the two million kilogram space bus into Earth orbit....

A Sun Halo Over Cambodia Credit & Copyright: Nagy Attila Explanation: Have you ever seen a halo around the Sun? This fairly common sight occurs when high thin clouds containing millions of tiny ice crystals cover much of the sky. Each ice crystal acts like a miniature lens. Because most of the crystals have a similar elongated hexagonal shape, light entering one crystal face and exiting through the opposing face refracts 22 degrees, which corresponds to the radius of the Sun halo. A similar Moon halo may be visible during the night. Pictured above, a nearly complete sun halo...

The Einstein Cross Gravitational Lens Credit & Copyright: J. Rhoads (ASU) et al., WIYN, AURA, NOAO, NSF Explanation: Most galaxies have a single nucleus -- does this galaxy have four? The strange answer leads astronomers to conclude that the nucleus of the surrounding galaxy is not even visible in this image. The central cloverleaf is rather light emitted from a background quasar. The gravitational field of the visible foreground galaxy breaks light from this distant quasar into four distinct images. The quasar must be properly aligned behind the center of a massive galaxy for a mirage like this to...

Dust Storm on Mars Credit & Copyright: Jean-Luc Dauvergne, Francois Colas, IMCCE/S2P, Obs. Midi-Pyrénées Explanation: It's spring for the northern hemisphere of Mars and spring on Mars usually means dust storms. So the dramatic brown swath of dust (top) marking the otherwise white north polar cap in this picture of the Red Planet is not really surprising. Taking advantage of the good views of Mars currently possible near opposition and its closest approach to planet Earth in 2010, this sharp image shows the evolving dust storm extending from the large dark region known as Mare Acidalium below the polar...

Stardust in Perseus Credit & Copyright: Máximo Ruiz Explanation: This cosmic expanse of dust, gas, and stars covers close to 3 degrees on the sky in the heroic constellation Perseus. Right of center in the gorgeous skyscape is the dusty blue reflection nebula NGC 1333, about 1,000 light-years away. At that estimated distance, the field of view is about 50 light-years across. Next to NGC 1333 is the reddish glow of shocked hydrogen gas created by energetic jets and winds from stars in the process of formation. Other reflection nebulae are scattered around, along with remarkable dark dust nebulae....

P/2010 A2: Unusual Asteroid Tail Implies Powerful Collision Credit: NASA, ESA, D. Jewitt (UCLA) Explanation: What is this strange object? First discovered on ground based LINEAR images on January 6, the object appeared unusual enough to investigate further with the Hubble Space Telescope last week. Pictured above, what Hubble saw indicates that P/2010 A2 is unlike any object ever seen before. At first glance, the object appears to have the tail of a comet. Close inspection, however, shows a 140-meter nucleus offset from the tail center, very unusual structure near the nucleus, and no discernable gas in the tail....

Mars and a Colorful Lunar Fog Bow Credit & Copyright: Wally Pacholka (AstroPics.com, TWAN) Explanation: Even from the top of a volcanic crater, this vista was unusual. For one reason, Mars was dazzlingly bright two weeks ago, when this picture was taken, as it was nearing its brightest time of the entire year. Mars, on the far upper left, is the brightest object in the above picture. The brightness of the red planet peaked last week near when Mars reached opposition, the time when Earth and Mars are closest together in their orbits. Arching across the lower part of...

Shepherd Moon Prometheus from Cassini Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA Explanation: Another moon of Saturn has been imaged in detail by the Cassini spacecraft. Orbiting Saturn since 2004, the robotic Cassini got its closest look yet at Saturn's small moon Prometheus last week. Visible above in an unprocessed image from 36,000 kilometers away, Prometheus' 100-km long surface was revealed to have an interesting system of bulges, ridges, and craters. These features, together with the moon's oblong shape and high reflectivity, are now being studied to help better understand the history of Prometheus and Saturn's rings. Prometheus...

The Mysterious Voynich Manuscript Credit: Yale University ; Digital Copyright: B. E. Schaefer (LSU) Explanation: The ancient text has no known title, no known author, and is written in no known language: what does it say and why does it have many astronomy illustrations? The mysterious book was once bought by an emperor, forgotten on a library shelf, sold for thousands of dollars, and later donated to Yale. Possibly written in the 15th century, the over 200-page volume is known most recently as the Voynich Manuscript, after its (re-)discoverer in 1912. Pictured above is an illustration from the book...

Messier 88>br> Credit & Copyright: Adam Block, Mt. Lemmon SkyCenter, U. Arizona Explanation: Charles Messier described the 88th entry in his 18th century catalog of Nebulae and Star Clusters as a spiral nebula without stars. Of course the gorgeous M88 is now understood to be a galaxy full of stars, gas, and dust, not unlike our own Milky Way. In fact, M88 is one of the brightest galaxies in the Virgo Galaxy Cluster some 50 million light-years away. M88's beautiful spiral arms are easy to trace in this colorful cosmic portait. The arms are lined with young blue star...

Kemble's Cascade Credit & Copyright: Processing - Noel Carboni, Imaging - Greg Parker, New Forest Observatory Explanation: An asterism is just a recognized pattern of stars that is not one the 88 official constellations. For example, one of the most famous (and largest) asterisms is the Big Dipper within the constellation Ursa Major. But this pretty chain of stars, visible with binoculars towards the long-necked constellation of Camelopardalis, is also a recognized asterism. Known as Kemble's Cascade, it contains about 20 stars nearly in a row, stretching over five times the width of a full moon. Tumbling from the...

Tethys Behind Titan Credit: Cassini Imaging Team, ISS, JPL, ESA, NASA Explanation: What's that behind Titan? It's another of Saturn's moons: Tethys. The robotic Cassini spacecraft orbiting Saturn captured the heavily cratered Tethys slipping behind Saturn's atmosphere-shrouded Titan late last year. The largest crater on Tethys, Odysseus, is easily visible on the distant moon. Titan shows not only its thick and opaque orange lower atmosphere, but also an unusual upper layer of blue-tinted haze. Tethys, at about 2 million kilometers distant, was twice as far from Cassini as was Titan when the above image was taken. In 2004, Cassini...

Annular Eclipse Over Myanmar Credit & Copyright: Wei Loon Chin Explanation: A hole crossed the Sun for a few minutes this month, as seen across a thin swath of planet Earth. The event on January 15 was actually an annular solar eclipse, and the hole was really Earth's Moon, an object whose dark half may appear even darker when compared to the tremendously bright Sun. The Moon was too far from Earth to create a total solar eclipse, but instead left well placed observers with a bright surrounding circle called the ring of fire. Pictured above was a complete...

The Magellanic Stream Credit: David L. Nidever et al., NRAO/AUI/NSF & A. Mellinger, LAB Survey, Parkes Obs., Westerbork Obs., Arecibo Obs. Explanation: Spanning the sky toward the majestic Clouds of Magellan is an unusual stream of gas: the Magellanic Stream. The origin of this gas remains unknown but likely holds a clue to the origin and fate of our Milky Way's most famous satellite galaxies: the LMC and the SMC. Until recently, two leading genesis hypotheses have been considered: that the stream was created by gas stripped off these galaxies as they passed through the halo of our Milky...

Eclipses in the Shade Credit & Copyright: Stephan Heinsius Explanation: Eclipses are everywhere in this shady scene. The picture was taken on the Indian Ocean atoll island of Ellaidhoo, Maldives, on January 15, during the longest annular solar eclipse for the next 1,000 years. Tall palm trees provided the shade. Their many crossed leaves created gaps that acted like pinhole cameras, scattering recognizable eclipse images across the white sands of a tropical garden near the beach. From this idyllic location near the centerline of the Moon's shadow track, the ring of fire or annular phase of the eclipse lasted...

Dust and the NGC 7771 Group Credit & Copyright: Ken Crawford (Rancho Del Sol Observatory) Explanation: Galaxies of the NGC 7771 Group are featured in this intriguing skyscape. Some 200 million light-years distant toward the constellation Pegasus, NGC 7771 is the large, edge-on spiral near center, about 75,000 light-years across, with two smaller galaxies just below it. Large spiral NGC 7769 is seen face-on to the right. Galaxies of the NGC 7771 group are interacting, making repeated close passages that will ultimately result in galaxy-galaxy mergers on a cosmic timescale. The interactions can be traced by galaxy distortions and...

Today's apod is The Known Universe video by The American Museum of Natural History. My understanding of embedding video is that it consumes large amounts of bandwidth, so I'm just posting a link. The video has been shown on Free Republic before, but it's worth watching. Enjoy.The Known UniverseCredit & Copyright: American Museum of Natural History Explanation: What would it look like to travel across the known universe? To help humanity visualize this, the American Museum of Natural History has produced a modern movie featuring many visual highlights of such a trip. The video starts in Earth's Himalayan Mountains and...

Dark Sand Cascades on Mars Credit: HiRISE, MRO, LPL (U. Arizona), NASA Explanation: They might look like trees on Mars, but they're not. Groups of dark brown streaks have been photographed by the Mars Reconnaissance Orbiter on melting pinkish sand dunes covered with light frost. The above image was taken in 2008 April near the North Pole of Mars. At that time, dark sand on the interior of Martian sand dunes became more and more visible as the spring Sun melted the lighter carbon dioxide ice. When occurring near the top of a dune, dark sand may cascade down...

New Year Sungrazer Credit: LASCO, SOHO Consortium, NRL, ESA, NASA Explanation: Intense and overwhelming, the direct glare of the Sun is blocked by the smooth occulting disk in this image from the sun-staring SOHO spacecraft. Taken on January 3rd, an extreme ultraviolet image of the Sun to scale, is superimposed at the center of the disk. Beyond the disk's outer boundary is a sungrazer comet, one of the brightest yet seen by SOHO. The comet was discovered (movie link) by Australian amateur astronomer Alan Watson, while examining earlier images from another sun-watching spacecraft, STEREO-A. Based on their orbits, sungrazers...

Scenes from Two Hemispheres Credit & Copyright: Babak Tafreshi (TWAN) Explanation: The stars of a summer night on the left and the winter night sky on the right are the same stars. In fact, both pictures were taken in late December and have similar fields of view. The left panel shows a scene from a beach on Bruny Island off the coast of Tasmania, Australia, while the right panel features the sky over the snowy Alborz Mountains of northern Iran. But if the sky on one side still looks unfamiliar to you, just put your cursor over the image...

M94: A New Perspective Image Credit & Copyright: R Jay Gabany (Blackbird Obs.) Collaboration: I. Trujillo, I. Martinez-Valpuesta, D. Martinez-Delgado ( IAC); J. Penarrubia (IoA Cambridge); M. Pohlen (Cardiff) Explanation: Beautiful island universe M94 lies a mere 15 million light-years distant in the northern constellation of the hunting dogs, Canes Venatici. A popular target for astronomers the brighter inner part of the face-on spiral galaxy is about 30,000 light-years across. Traditionally, deep images have been interpreted as showing M94's inner spiral region surrounded by a faint, broad ring of stars. But a new multi-wavelength investigation has revealed previously undetected...

The Flame Nebula in Infrared Credit & Copyright: ESO/J. Emerson/VISTA; Acknowledgment: Cambridge Astronomical Survey Unit Explanation: What lights up the Flame Nebula? Fifteen hundred light years away towards the constellation of Orion lies a nebula which, from its glow and dark dust lanes, appears, on the left, like a billowing fire. But fire, the rapid acquisition of oxygen, is not what makes this Flame glow. Rather the bright star Alnitak, the easternmost star in the Belt of Orion visible just above the nebula, shines energetic light into the Flame that knocks electrons away from the great clouds of hydrogen...

The Astronaut Who Captured a Satellite Credit: STS-51A, NASA Explanation: In 1984, high above the Earth's surface, an astronaut captured a satellite. It was the second satellite captured that mission. Pictured above, astronaut Dale A. Gardner flies free using the Manned Maneuvering Unit and begins to attach a control device dubbed the Stinger to the rotating Westar 6 satellite. Communications satellite Westar 6 had suffered a rocket malfunction that left it unable to reach its intended high geosynchronous orbit. Both the previously caught Palapa B-2 satellite and the Westar 6 satellite were guided into the cargo bay of the...

Andromeda Island Universe Credit & Copyright: Martin Pugh Explanation: The most distant object easily visible to the eye is M31, the great Andromeda Galaxy some two and a half million light-years away. But without a telescope, even this immense spiral galaxy - spanning over 200,000 light years - appears as a faint, nebulous cloud in the constellation Andromeda. In contrast, details of a bright yellow nucleus and dark winding dust lanes, are revealed in this digital telescopic image. Narrow band image data, recording emission from hydrogen atoms, shows off the reddish star-forming regions dotting gorgeous blue spiral arms and...

The Mystery of the Fading Star Image Credit & Copyright: Alson Wong and Citizen Sky Explanation: Every 27 years Epsilon Aurigae fades, remaining dim for roughly two years before growing bright again. Since the 19th century, astronomers have studied the mystery star, eventually arguing that Epsilon Aur, centered in this telescopic skyview, was actually undergoing a long eclipse by a dark companion object. But the nature of the companion and even the state of bright star itself could not be pinned down by observations. Continuing to collect evidence, Citizen Sky, a team of professional and amateur astronomers, is studying...

The Tail of the Small Magellanic Cloud Credit: NASA / JPL-Caltech / STScI Explanation: A satellite galaxy of our Milky Way, the Small Magellanic Cloud is wonder of the southern sky, named for 16th century Portuguese circumnavigator Ferdinand Magellan. Some 200,000 light-years distant in the constellation Tucana, the small irregular galaxy's stars, gas, and dust that lie along a bar and extended "wing", are familiar in images from optical telescopes. But the galaxy also has a tail. Explored in this false-color, infrared mosaic from the Spitzer Space Telescope, the tail extends to the right of the more familiar bar...

The Spotty Surface of Betelgeuse Credit: Xavier Haubois (Observatoire de Paris) et al. Explanation: Betelgeuse really is a big star. If placed at the center of our Solar System it would extend to the orbit of Jupiter. But like all stars except the Sun, Betelgeuse is so distant it usually appears as a single point of light, even in large telescopes. Still, astronomers using interferometry at infrared wavelengths can resolve the surface of Betelgeuse and reconstructed this image of the red supergiant. The intriguing picture shows two, large, bright, star spots. The spots potentially represent enormous convective cells rising...

Comet Halley's Nucleus: An Orbiting Iceberg Credit & Copyright: Halley Multicolor Camera Team, Giotto Project, ESA Explanation: What does a comet nucleus look like? Formed from the primordial stuff of the Solar System, comet nuclei were thought to resemble very dirty icebergs. But ground-based telescopes revealed only the surrounding cloud of gas and dust of active comets nearing the Sun, clearly resolving only the comet's coma, and the characteristic cometary tails. In 1986, however, the European spacecraft Giotto became one of the first group of spacecraft ever to encounter and photograph the nucleus of a comet, passing and imaging...

A Force from Empty Space: The Casimir Effect Credit & Copyright: Umar Mohideen (U. California at Riverside) Explanation: This tiny ball provides evidence that the universe will expand forever. Measuring slightly over one tenth of a millimeter, the ball moves toward a smooth plate in response to energy fluctuations in the vacuum of empty space. The attraction is known as the Casimir Effect, named for its discoverer, who, 50 years ago, was trying to understand why fluids like mayonnaise move so slowly. Today, evidence is accumulating that most of the energy density in the universe is in an unknown...

Blue Moon Eclipse Credit & Copyright: Jean Paul Roux Explanation: The International Year of Astronomy 2009 ended with a Blue Moon and a partial lunar eclipse, as the second Full Moon of December grazed the Earth's shadow on December 31st. The New Year's Eve Blue Moon eclipse was visible throughout Europe, Asia, Africa and parts of Alaska, captured in this two exposure composite in cloudy skies over Saint Bonnet de Mure, France. Playing across the Moon's southern reaches, the edge of Earth's umbra, or dark central shadow, appears on the right side along with the prominent ray crater Tycho....

No, I'm not obsessed with Saturn. OK, I am obsessed with Saturn. But so is Time, who picked this deliciously crispy photo as one of the images of the year, revealing ring bumps as high as the Rocky Mountains. I'm not surprised, because it's a truly unique moment, one that happens at Saturn's equinox, which is an event that only happens twice in 10,179 Earth days. And this time, we had Cassini there to take this amazing photo, just when the sun illuminates the rings edge-on. As Carolyn Porco—Cassini imaging team leader—puts it: The geometry revealed structures and phenomena in...

Dust and the Helix Nebula NASA, JPL-Caltech, Kate Su (Steward Obs, U. Arizona) et al. Explanation: Dust makes this cosmic eye look red. The eerie Spitzer Space Telescope image shows infrared radiation from the well-studied Helix Nebula (NGC 7293) a mere 700 light-years away in the constellation Aquarius. The two light-year diameter shroud of dust and gas around a central white dwarf has long been considered an excellent example of a planetary nebula, representing the final stages in the evolution of a sun-like star. But the Spitzer data show the nebula's central star itself is immersed in a surprisingly...

Spitzer's M101 NASA, JPL-Caltech, K. Gordon (STScI) et al. Explanation: Big, beautiful spiral galaxy M101 is one of the last entries in Charles Messier's famous catalog, but definitely not one of the least. About 170,000 light-years across, this galaxy is enormous, almost twice the size of our own Milky Way Galaxy. M101 was also one of the original spiral nebulae observed by Lord Rosse's large 19th century telescope, the Leviathan of Parsontown. Recorded at infrared wavelengths by the Spitzer Space telescope, this 21st century view shows starlight in blue hues while the galaxy's dust clouds are in red. Examining...

Rigel and the Witch Head Nebula Credit & Copyright: Rogelio Bernal Andreo (Deep Sky Colors) Explanation: Double, double toil and trouble; Fire burn, and cauldron bubble -- maybe Macbeth should have consulted the Witch Head Nebula. This suggestively shaped reflection nebula on the lower left is associated with the bright star Rigel, to its right, in the constellation Orion. More formally known as IC 2118, the Witch Head Nebula glows primarily by light reflected from Rigel. Fine dust in the nebula reflects the light. Pictured above, the blue color of the Witch Head Nebula and of the dust surrounding...

Barred Spiral Galaxy NGC 6217 Credit: NASA, ESA, and the Hubble SM4 ERO Team Explanation: Many spiral galaxies have bars across their centers. Even our own Milky Way Galaxy is thought to have a modest central bar. Prominently barred spiral galaxy NGC 6217, pictured above, was captured in spectacular detail in this recently released image taken by the newly repaired Advanced Camera for Surveys on the orbiting Hubble Space Telescope. Visible are dark filamentary dust lanes, young clusters of bright blue stars, red emission nebulas of glowing hydrogen gas, a long bright bar of stars across the center, and...

The Cat's Eye Nebula Credit: J. P. Harrington (U. Maryland) & K. J. Borkowski (NCSU) HST, NASA Explanation: Three thousand light-years away, a dying star throws off shells of glowing gas. This image from the Hubble Space Telescope reveals the Cat's Eye Nebula to be one of the most complex planetary nebulae known. In fact, the features seen in the Cat's Eye are so complex that astronomers suspect the bright central object may actually be a binary star system. The term planetary nebula, used to describe this general class of objects, is misleading. Although these objects may appear round...

M51 Hubble Remix S. Beckwith (STScI), Hubble Heritage Team, (STScI/AURA), ESA, NASA Additional Processing: Robert Gendler Explanation: The 51st entry in Charles Messier's famous catalog is perhaps the original spiral nebula - a large galaxy with a well defined spiral structure also cataloged as NGC 5194. Over 60,000 light-years across, M51's spiral arms and dust lanes clearly sweep in front of its companion galaxy (right), NGC 5195. Image data from the Hubble's Advanced Camera for Surveys has been reprocessed to produce this alternative portrait of the well-known interacting galaxy pair. The processing has further sharpened details and enhanced color...

A Graceful Arc Credit & Copyright: Tony Hallas Explanation: The graceful arc of the Milky Way begins and ends at two mountain peaks in this solemn night sky panorama. Created from a 24 frame mosaic, exposures tracking Earth and sky were made separately, with northern California's Mount Lassen at the left and Mount Shasta at the far right, just below the star and dust clouds of the galactic center. Lassen and Shasta are volcanoes in the Cascade Mountain Range of North America, an arc of the volcanic Pacific Ring of Fire. In the dim, snow-capped peaks, planet Earth seems...

Gamma Cas and Friends Credit & Copyright: Processing - Noel Carboni, Imaging - Greg Parker, New Forest Observatory Explanation: Gamma Cassiopeiae shines high in northern autumn evening skies. The brightest spiky star in this rich and colorful Milky Way starfield, bluish Gamma Cas marks the central peak in the W-shaped constellation Cassiopeia. A hot, variable, and rapidly rotating star about 600 light-years distant, Gamma Cas also ionizes surrounding interstellar material, including the wispy IC 63 (left) and IC 59 emission and reflection nebulae. The two faint nebulae are physically close to Gamma Cas, separated from the star by only...

December Sunrise, Cape Sounion Credit & Copyright: Anthony Ayiomamitis (TWAN) Explanation: The Sun is a moving target. Its annual motion through planet Earth's sky tracks north and south, from solstice to solstice, as the seasons change. On December 21st, the solstice marking the first day of winter in the northern hemisphere and summer in the south, the Sun rose at its southernmost point along the eastern horizon. Earlier this month, looking toward the Aegean Sea from a well-chosen vantage point at Cape Sounion, Greece, it also rose in this dramatic scene. In the foreground lies the twenty-four hundred year...

Star Cluster R136 Bursts Out Credit: NASA, ESA, & F. Paresce (INAF-IASF), R. O'Connell (U. Virginia), & the HST WFC3 Science Oversight Committee Explanation: In the center of star-forming region 30 Doradus lies a huge cluster of the largest, hottest, most massive stars known. These stars, known collectively as star cluster R136, were captured above in visible light by the newly installed Wide Field Camera peering though the recently refurbished Hubble Space Telescope. Gas and dust clouds in 30 Doradus, also known as the Tarantula Nebula, have been sculpted into elongated shapes by powerful winds and ultraviolet radiation from...

Aurora Shimmer, Meteor Flash Credit & Copyright: Bjørnar G. Hansen Explanation: Northern Lights, or aurora borealis, haunted skies over the island of Kvaløya, near Tromsø Norway on December 13. This 30 second long exposure records their shimmering glow gently lighting the wintery coastal scene. A study in contrasts, it also captures the sudden flash of a fireball meteor from December's excellent Geminid meteor shower. Streaking past familiar stars in the handle of the Big Dipper, the trail points back toward the constellation Gemini, off the top of the view. Both aurora and meteors occur in Earth's upper atmosphere at...

Mojave Desert Fireball Credit & Copyright: Wally Pacholka (AstroPics.com, TWAN) Explanation: Monstrously bright, this fireball meteor lit up the Mojave Desert sky Monday morning, part of this year's impressive Geminid meteor shower. Seen toward the southwest over rock formations near Victorville, California, a more familiar celestial background was momentarily washed out by the meteor's flash. The background includes bright star Sirius at the left, and Aldebaran and the Pleaides star cluster at the right side of the image. The meteor itself blazes through the constellation Orion. Its greenish trail begins just left of a yellow-tinted Betelgeuse and points back...

Comet Hyakutake Passes the Earth Credit & Copyright: Doug Zubenel (TWAN) Explanation: In 1996, an unexpectedly bright comet passed by planet Earth. Discovered less than two months before, Comet C/1996 B2 Hyakutake came within only 1/10th of the Earth-Sun distance from the Earth in late March. At that time, Comet Hyakutake, dubbed the Great Comet of 1996, became the brightest comet to grace the skies of Earth in 20 years. During its previous visit, Comet Hyakutake may well have been seen by the stone age Magdalenian culture, who 17,000 years ago were possibly among the first humans to live...

Saturns Hexagon Comes to Light Cassini Imaging Team, SSI, JPL, ESA, NASA Explanation: Believe it or not, this is the North Pole of Saturn. It is unclear how an unusual hexagonal cloud system that surrounds Saturn's north pole was created, keeps its shape, or how long it will last. Originally discovered during the Voyager flybys of Saturn in the 1980s, nobody has ever seen anything like it elsewhere in the Solar System. Although its infrared glow was visible previously to the Cassini spacecraft now orbiting Saturn, over the past year the mysterious hexagonal vortex became fully illuminated by sunlight...

Crescent Neptune and Triton Credit: Voyager 2, NASA Explanation: Gliding silently through the outer Solar System, the Voyager 2 spacecraft camera captured Neptune and Triton together in crescent phase in 1989. The above picture of the gas giant planet and its cloudy moon was taken from behind just after closest approach. It could not have been taken from Earth because Neptune never shows a crescent phase to sunward Earth. The unusual vantage point also robs Neptune of its familiar blue hue, as sunlight seen from here is scattered forward, and so is reddened like the setting Sun. Neptune is...

Geminid Meteor over Monument Valley Credit & Copyright: Wally Pacholka (AstroPics.com, TWAN) Explanation: The Geminids are expected to put on a good show this year. Created as planet Earth sweeps through dusty debris from extinct comet Phaethon, the annual Geminid meteor shower is predicted to peak on December 14th, around 0510 UT (12:10am EST). With better viewing for northern hemisphere observers, pictures of Geminids streaking through the night could include wintery landscapes, like this snow-tinged image of a 2007 Geminid meteor over buttes of the Monument Valley region in the southwestern US. The meteor streak points back to the...

The Colors of IC 1795 Credit & Copyright: Don Goldman Explanation: This colorful cosmic portrait features glowing gas and dark dust clouds in IC 1795, a star forming region in the northern constellation Cassiopeia. The nebula's colors were created by adopting the Hubble false-color palette for mapping narrow emission from oxygen, hydrogen, and sulfur atoms to blue, green and red colors, and further blending the data with images of the region recorded through broadband filters. Not far on the sky from the famous Double Star Cluster in Perseus, IC 1795 is itself located next to IC 1805, the Heart...

HUDF Infrared: Dawn of the Galaxies Credit: NASA, ESA, G. Illingworth (UCO/Lick & UCSC), R. Bouwens (UCO/Lick & Leiden U.), & the HUDF09 Team Explanation: When did galaxies form? To help find out, the deepest near-infrared image of the sky ever has been taken of the same field as the optical-light Hubble Ultra Deep Field (HUDF) in 2004. The new image was taken this summer by the newly installed Wide Field Camera 3 on the refurbished Hubble Space Telescope. Faint red smudges identified on the above image likely surpass redshift 8 in distance. These galaxies therefore likely existed when...

The International Space Station Over the Horizon Credit: STS-129 Crew, Expedition 21 Crew, NASA Explanation: This was home. Just over a week ago, the STS-129 crew of the Space Shuttle Atlantis undocked from the International Space Station (ISS) and returned to Earth. As the shuttle departed the space station, they took the above image. Visible on the ISS are numerous modules, trusses, and long wing-like solar panels. The space shuttle crew spent almost 12 days calling the space station home. The shuttle crew resupplied the space station and delivered valuable spare parts. The ISS continues to be home for...