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Astronomy Picture of the Day (General/Chat)

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  • Astronomy Picture of the Day -- Conjunction Colours

    08/23/2012 4:17:17 AM PDT · by SunkenCiv · 8 replies
    NASA ^ | August 23, 2012 | (see photo credit)
    Explanation: During the past week, nightfall on planet Earth has featured Mars, Saturn, and Spica in a lovely conjunction near the western horizon. Still forming the corners of a distinctive celestial triangle after sunset and recently joined by a crescent Moon, they are all about the same brightness but can exhibit different colors to the discerning eye. This ingenious star trail image was recorded as the trio set on August 12 with a telephoto lens from the shores of Lake Eppalock, in central Victoria, Australia. Focused on foreground eucalyptus trees, the image slightly blurs the trails to show more saturated...
  • Astronomy Picture of the Day -- Clouds Near the Edge of Space

    08/22/2012 7:06:11 PM PDT · by SunkenCiv · 16 replies
    NASA ^ | August 22, 2012 | (see photo credit)
    Explanation: Noctilucent or night-shining clouds lie near the edge of space. From about 80 kilometers above Earth's surface, the icy clouds can still reflect sunlight even though the Sun itself is below the horizon as seen from the ground. Usually occurring at high latitudes in summer months, the diaphanous apparitions are also known as polar mesospheric clouds and may be connected to global change in the lower atmosphere. This serene view features a lovely display of noctilucent clouds over water recorded last month near the coastal town of Vaxholm, Sweden. The picture was taken near local midnight.
  • Astronomy Picture of the Day -- DNA: The Molecule that Defines You

    08/20/2012 9:12:53 PM PDT · by SunkenCiv · 48 replies
    NASA ^ | August 21, 2012 | (see photo credit)
    Explanation: Every living thing on planet Earth is defined by its own molecule -- what's yours? This molecule, called DNA, spans about two meters stretched out but is coiled into every cell in your body. The many copies of DNA that compose you were all copied from one single cell, and your body is continually making new copies. The above ground-breaking animated video depicts the tiny, amazing, bio-molecular machinery that makes these DNA copies. For a fee, it is now possible to find part of all of the code of the DNA molecule that defines you, but lively debates involving...
  • Astronomy Picture of the Day -- A Filament Across the Sun

    08/20/2012 3:56:37 PM PDT · by SunkenCiv · 16 replies
    NASA ^ | August 20, 2012 | (see photo credit)
    Explanation: Is that a cloud hovering over the Sun? Yes, but it is quite different than a cloud hovering over the Earth. The long light feature on the left of the above color-inverted image is actually a solar filament and is composed of mostly charged hydrogen gas held aloft by the Sun's looping magnetic field. By contrast, clouds over the Earth are usually much cooler, composed mostly of tiny water droplets, and are held aloft by upward air motions because they are weigh so little. The above filament was captured on the Sun about two weeks ago near the active...
  • Astronomy Picture of the Day -- A Filament Across the Sun

    08/20/2012 3:56:22 PM PDT · by SunkenCiv · 4 replies
    NASA ^ | August 20, 2012 | (see photo credit)
    Explanation: Is that a cloud hovering over the Sun? Yes, but it is quite different than a cloud hovering over the Earth. The long light feature on the left of the above color-inverted image is actually a solar filament and is composed of mostly charged hydrogen gas held aloft by the Sun's looping magnetic field. By contrast, clouds over the Earth are usually much cooler, composed mostly of tiny water droplets, and are held aloft by upward air motions because they are weigh so little. The above filament was captured on the Sun about two weeks ago near the active...
  • Astronomy Picture of the Day -- M72: A Globular Cluster of Stars

    08/18/2012 10:09:57 PM PDT · by SunkenCiv · 6 replies
    NASA ^ | August 19, 2012 | (see photo credit)
    Explanation: Globular clusters once ruled the Milky Way. Back in the old days, back when our Galaxy first formed, perhaps thousands of globular clusters roamed our Galaxy. Today, there are less than 200 left. Many globular clusters were destroyed over the eons by repeated fateful encounters with each other or the Galactic center. Surviving relics are older than any Earth fossil, older than any other structures in our Galaxy, and limit the universe itself in raw age. There are few, if any, young globular clusters in our Milky Way Galaxy because conditions are not ripe for more to form. Pictured...
  • Astronomy Picture of the Day -- Curiosity on Mars: Still Life with Rover

    08/17/2012 10:47:17 PM PDT · by SunkenCiv · 21 replies
    NASA ^ | August 18, 2012 | (see photo credit)
    Explanation: What does the Curiosity rover look like on Mars? To help find out, NASA engineers digitally synthesized multiple navigation camera images taken last week into what appears to be the view of a single camera. Besides clods of Martian dirt, many of Curiosity's science instruments are visible and appear in good shape. Near the middle of the rover is an augmented reality tag intended to enable smartphones to provide background information. Far in the distance is a wall of Gale Crater. As Curiosity will begin to roll soon, its first destination has now been chosen: an intriguing intersection of...
  • Astronomy Picture of the Day -- Spiral Galaxy NGC 5033

    08/17/2012 6:01:41 PM PDT · by SunkenCiv · 4 replies
    NASA ^ | August 17, 2012 | (see photo credit)
    Explanation: Magnificent island universe NGC 5033 lies some 40 million light-years away in the well-trained northern constellation Canes Venatici. This telescopic portrait reveals striking details of dust lanes winding near the galaxy's bright core and majestic but relatively faint spiral arms. Speckled with pink star forming regions and massive blue star clusters, the arms span over 100,000 light-years, similar in size to our own spiral Milky Way. A well-studied example of the class of Seyfert active galaxies, NGC 5033 has a core that is very bright and variable. The emission is likely powered by a supermassive black hole. The bright...
  • Astronomy Picture of the Day -- NGC 6888: The Crescent Nebula

    08/16/2012 3:40:44 PM PDT · by SunkenCiv · 16 replies
    NASA ^ | August 16, 2012 | (see photo credit)
    Explanation: NGC 6888, also known as the Crescent Nebula, is a cosmic bubble about 25 light-years across, blown by winds from its central, bright, massive star. This colorful portrait of the nebula uses narrow band image data combined in the Hubble palatte. It shows emission from sulfur, hydrogen, and oxygen atoms in the wind-blown nebula in red, green and blue hues. NGC 6888's central star is classified as a Wolf-Rayet star (WR 136). The star is shedding its outer envelope in a strong stellar wind, ejecting the equivalent of the Sun's mass every 10,000 years. The nebula's complex structures are...
  • Astronomy Picture of the Day -- Curiosity on Mars: A Wall of Gale Crater

    08/15/2012 3:59:37 AM PDT · by SunkenCiv · 7 replies
    NASA ^ | August 15, 2012 | (see photo credit)
    Explanation: If you could stand on Mars, what would you see? The above image is a digitally re-colored approximation of what you might see if the above Martian landscape had occurred on Earth. Images from Mars false-colored in this way are called white balanced and useful for planetary scientists to identify rocks and landforms similar to Earth. The image is a high resolution version of a distant wall of Gale Crater captured by the Curiosity rover that landed on Mars last week. A corresponding true color image exists showing how this scene actually appears on Mars. The robotic Curiosity rover...
  • Astronomy Picture of the Day -- Perseid Meteors and the Milky Way

    08/14/2012 2:29:18 PM PDT · by SunkenCiv · 10 replies
    NASA ^ | August 14, 2012 | (see photo credit)
    Explanation: Where will the next Perseid meteor appear? Sky enthusiasts who trekked outside for the Perseid meteor shower that peaked over the past few days typically had this question on their mind. Six meteors from this past weekend are visible in the above stacked image composite, including one bright fireball streaking along the band of the background Milky Way Galaxy. All Perseid meteors appear to come from the shower radiant in the constellation of Perseus. Early reports about this year's Perseids indicate that as many as 100 meteors per hour were visible from some dark locations during the peak. The...
  • Astronomy Picture of the Day -- A Flight Through the Universe

    08/13/2012 2:33:41 PM PDT · by SunkenCiv · 12 replies
    NASA ^ | August 13, 2012 | (see photo credit)
    Explanation: What would it be like to fly through the universe? Possibly the best simulated video of this yet has been composed from recently-released galaxy data from the Sloan Digital Sky Survey. Every spot in the above video is a galaxy containing billions of stars. Many galaxies are part of huge clusters, long filaments, or small groups, while expansive voids nearly absent of galaxies also exist. The movie starts by flying right through a large nearby cluster of galaxies and later circles the SDSS-captured universe at about 2 billion light years (a redshift of about 0.15) from Earth. Analyses of...
  • Astronomy Picture of the Day -- Spiral Galaxy NGC 4038 in Collision

    08/12/2012 9:22:01 AM PDT · by SunkenCiv · 9 replies
    NASA ^ | August 12, 2012 | (see photo credit)
    Explanation: This galaxy is having a bad millennium. In fact, the past 100 million years haven't been so good, and probably the next billion or so will be quite tumultuous. Visible on the upper left, NGC 4038 used to be a normal spiral galaxy, minding its own business, until NGC 4039, toward its right, crashed into it. The evolving wreckage, known famously as the Antennae, is pictured above. As gravity restructures each galaxy, clouds of gas slam into each other, bright blue knots of stars form, massive stars form and explode, and brown filaments of dust are strewn about. Eventually...
  • Astronomy Picture of the Day -- The First Color Panorama from Mars by Curiosity

    08/11/2012 2:09:57 AM PDT · by SunkenCiv · 38 replies
    NASA ^ | August 11, 2012 | (see photo credit)
    Explanation: You've just landed on Mars and opened your eyes -- what do you see? If you're the Curiosity rover, you see a strange gravelly place with a large mountain in the distance. You've landed on target near the edge of 150-km wide Gale Crater, with Mount Sharp on the horizon being the rise in the crater's center. As a car-sized rover with six wheels and a laser, you prepare yourself to go on a two-year mission of exploration, climbing Mt. Sharp, and looking for signs that Mars once harbored life. Currently you sit motionless, check yourself over, and receive...
  • Astronomy Picture of the Day -- Perseid Below

    08/10/2012 3:55:27 AM PDT · by SunkenCiv · 2 replies
    NASA ^ | August 10, 2012 | (see photo credit)
    Explanation: Denizens of planet Earth watched last year's Perseid meteor shower by looking up into the bright moonlit night sky. But this remarkable view captured on August 13, 2011 by astronaut Ron Garan looks down on a Perseid meteor. From Garan's perspective onboard the International Space Station orbiting at an altitude of about 380 kilometers, the Perseid meteors streak below, swept up dust left from comet Swift-Tuttle heated to incandescence. The glowing comet dust grains are traveling at about 60 kilometers per second through the denser atmosphere around 100 kilometers above Earth's surface. In this case, the foreshortened meteor flash...
  • Astronomy Picture of the Day -- Mars in the Loop

    08/09/2012 5:26:03 PM PDT · by SunkenCiv · 17 replies
    NASA ^ | August 09, 2012 | (see photo credit)
    Explanation: This composite of images spaced some 5 to 7 days apart from late October 2011 (top right) through early July 2012 (bottom left), traces the retrograde motion of ruddy-colored Mars through planet Earth's night sky. To connect the dots in Mars' retrograde loop, just slide your cursor over the picture (and check out this animation). But Mars didn't actually reverse the direction of its orbit. Instead, the apparent backwards motion with respect to the background stars is a reflection of the motion of the Earth itself. Retrograde motion can be seen each time Earth overtakes and laps planets orbiting...
  • Astronomy Picture of the Day -- Curiosity Drops In

    08/08/2012 6:32:09 PM PDT · by SunkenCiv · 14 replies
    NASA ^ | August 08, 2012 | (see photo credit)
    Explanation: Just as it captured the Phoenix lander parachuting to Mars in 2008, the HiRise camera onboard the Mars Reconnaissance Orbiter (MRO) snapped this picture of the Curiosity rover's spectacular descent toward its landing site on August 5 (PDT). The nearly 16 meter (51 foot) wide parachute and its payload are caught dropping through the thin martian atmosphere above plains just north of the sand dune field that that borders the 5 kilometer high Mt. Sharp in Gale Crater. The MRO spacecraft was about 340 kilometers away when the image was made. From MRO's perspective the parachute is flying at...
  • Astronomy Picture of the Day -- A Wheel on Mars

    08/07/2012 2:31:57 PM PDT · by SunkenCiv · 28 replies
    NASA ^ | August 07, 2012 | (see photo credit)
    Explanation: A wheel attached to NASA's Curiosity rover is firmly on the martian surface in this early picture from the Mars Science Laboratory mission, captured after a successful landing on August 5, 2012 at 10:32pm (PDT). Seen at the lower right of a Hazard Avoidance Camera fisheye wide-angle image, the rover's left rear wheel is 50 centimeters (about 20 inches) in diameter. Part of a spring hinge for the camera's dust cover is just visible in the right corner, while at the upper left is part of the rover's RTG power source. Looking into the Sun across the rock stewn...
  • Astronomy Picture of the Day -- Nocturnal: Scenes from the Southern Night

    08/06/2012 6:19:19 PM PDT · by SunkenCiv · 6 replies
    NASA ^ | August 06, 2012 | (see photo credit)
    Explanation: Have you ever seen the night sky change? It does -- sometimes in beautiful and unexpected ways. To see it, though, usually requires patience. The above award winning video shows several of the possible changes in dramatic fashion with a time lapse video. Visible are sunset-illuminated clouds moving, stars of vivid colors rising, the long tail of a Comet Lovejoy rising, bright satellites crossing, a meteor exploding, a distant lightning storm approaching, skyscapes including the Magellanic Clouds rotating, and a fisheye sky rotating while the foreground becomes illuminated by moonlight. Frequently featuring an artistic human sculpture in the foreground...
  • Astronomy Picture of the Day -- IC 1396: Emission Nebula in Cepheus

    08/05/2012 10:01:09 AM PDT · by SunkenCiv · 5 replies
    NASA ^ | August 05, 2012 | (see photo credit)
    Explanation: Stunning emission nebula IC 1396 mixes glowing cosmic gas and dark dust clouds in the high and far off constellation of Cepheus. Energized by the bright, bluish central star seen here, this star forming region sprawls across hundreds of light-years -- spanning over three degrees on the sky while nearly 3,000 light-years from planet Earth. Among the intriguing dark shapes within IC 1396, the winding Elephant's Trunk nebula lies just below center. The gorgeous color view is a composition of digitized black and white photographic plates recorded through red and blue astronomical filters. The plates were taken using the...
  • Astronomy Picture of the Day -- The Bubble Nebula

    08/05/2012 10:01:09 AM PDT · by SunkenCiv · 3 replies
    NASA ^ | August 04, 2012 | (see photo credit)
    Explanation: Blown by the wind from a massive star, this interstellar apparition has a surprisingly familiar shape. Cataloged as NGC 7635, it is also known simply as The Bubble Nebula. Although it looks delicate, the 10 light-year diameter bubble offers evidence of violent processes at work. Above and right of the Bubble's center is a hot, O star, several hundred thousand times more luminous and around 45 times more massive than the Sun. A fierce stellar wind and intense radiation from that star has blasted out the structure of glowing gas against denser material in a surrounding molecular cloud. The...
  • Astronomy Picture of the Day -- Messier 5

    08/03/2012 5:12:10 AM PDT · by SunkenCiv · 9 replies
    NASA ^ | August 03, 2012 | (see photo credit)
    Explanation: "Beautiful Nebula discovered between the Balance [Libra] & the Serpent [Serpens] ..." begins the description of the 5th entry in 18th century astronomer Charles Messier's famous catalog of nebulae and star clusters. Though it appeared to Messier to be fuzzy and round and without stars, Messier 5 (M5) is now known to be a globular star cluster, 100,000 stars or more, bound by gravity and packed into a region around 165 light-years in diameter. It lies some 25,000 light-years away. Roaming the halo of our galaxy, globular star clusters are ancient members of the Milky Way. M5 is one...
  • Astronomy Picture of the Day -- South Pole Star Trails

    08/02/2012 4:09:49 AM PDT · by SunkenCiv · 11 replies
    NASA ^ | August 02, 2012 | (see photo credit)
    Explanation: No star dips below the horizon and the Sun never climbs above it in this remarkable image of 24 hour long star trails. Showing all the trails as complete circles, such an image could be achieved only from two places on planet Earth. This example was recorded during the course of May 1, 2012, the digital camera in a heated box on the roof of MAPO, the Martin A. Pomerantz Observatory at the South Pole. Directly overhead in the faint constellation Octans is the projection of Earth's rotational axis, the South Celestial Pole, at the center of all the...
  • Astronomy Picture of the Day -- The Milky Way Over Monument Valley

    08/01/2012 2:07:49 PM PDT · by SunkenCiv · 18 replies
    NASA ^ | August 01, 2012 | (see photo credit)
    Explanation: You don't have to be at Monument Valley to see the Milky Way arch across the sky like this -- but it helps. Only at Monument Valley USA would you see a picturesque foreground that includes these iconic rock peaks called buttes. Buttes are composed of hard rock left behind after water has eroded away the surrounding soft rock. In the above image taken about two months ago, the closest butte on the left and the butte to its right are known as the Mittens, while Merrick Butte can be seen just further to the right. High overhead stretches...
  • Astronomy Picture of the Day -- Curiosity Before Mars: Seven Minutes of Terror

    07/31/2012 4:57:46 PM PDT · by SunkenCiv · 27 replies
    NASA ^ | July 31, 2012 | (see photo credit)
    Explanation: Next week at this time, there may be an amazing new robotic explorer on Mars. Or there may be a new pile of junk. It all likely depends on many things going correctly in the minutes after the Mars Science Laboratory mission arrives at Mars and attempts to deploy the Curiosity rover from orbit. Arguably the most sophisticated landing yet attempted on the red planet, consecutive precision events will involve a heat shield, a parachute, several rocket maneuvers, and the automatic operation of an unusual device called a Sky Crane. These "Seven Minutes of Terror" -- depicted in the...
  • Astronomy Picture of the Day -- Ash and Lightning Above an Icelandic Volcano

    07/30/2012 2:22:27 PM PDT · by SunkenCiv · 18 replies
    NASA ^ | July 30, 2012 | (see photo credit)
    Explanation: Why did the picturesque 2010 volcanic eruption in Iceland create so much ash? Although the large ash plume was not unparalleled in its abundance, its location was particularly noticeable because it drifted across such well-populated areas. The Eyjafjallajökull volcano in southern Iceland began erupting on 2010 March 20, with a second eruption starting under the center of a small glacier on 2010 April 14. Neither eruption was unusually powerful. The second eruption, however, melted a large amount of glacial ice which then cooled and fragmented lava into gritty glass particles that were carried up with the rising volcanic plume....
  • Astronomy Picture of the Day -- Star Cluster R136 Bursts Out

    07/30/2012 2:09:08 PM PDT · by SunkenCiv · 6 replies
    NASA ^ | July 29, 2012 | (see photo credit)
    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 Wide Field Camera peering through the 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 these hot cluster stars. The 30 Doradus Nebula lies within a neighboring galaxy known as the Large Magellanic Cloud and is located a mere 170,000 light-years away....
  • Astronomy Picture of the Day -- Trails in the Morning Sky

    07/28/2012 7:09:36 AM PDT · by SunkenCiv · 5 replies
    NASA ^ | July 28, 2012 | (see photo credit)
    Explanation: Brilliant Venus and bright Jupiter still rise together before dawn. The peaceful waters by a small lakeside house near Stuttgart, Germany reflect their graceful arcing trails in this composited series of exposures, recorded on the morning of July 26. A reflection of planet Earth's rotation on its axis, the concentric trails of these celestial beacons along with trails of stars are punctuated at their ends by a separate final frame in the morning skyview. Easy to pick out, Venus is brightest and near the trees close to the horizon. Jupiter arcs above it, toward the center of the image...
  • Astronomy Picture of the Day -- High Energy Stereoscopic System II

    07/27/2012 5:27:05 PM PDT · by SunkenCiv · 5 replies
    NASA ^ | July 27, 2012 | (see photo credit)
    Explanation: The largest of its kind, the High Energy Stereoscopic System (H.E.S.S.) II telescope stands in the foreground of this photo. Tilted horizontally it reflects the inverted landscape of the Namibian desert in a segmented mirror 24 meters wide and 32 meters tall, equal in area to two tennis courts. Now beginning an exploration of the Universe at extreme energies, H.E.S.S. II saw first light on July 26. Most ground-based telescopes with lenses and mirrors are hindered by the Earth's nurturing, protective atmosphere that blurs images and scatters and absorbs light. But the H.E.S.S. II telescope is a cherenkov telescope,...
  • Astronomy Picture of the Day -- The Tulip in the Swan

    07/26/2012 2:23:23 PM PDT · by SunkenCiv · 9 replies
    NASA ^ | July 26, 2012 | (see photo credit)
    Explanation: Framing a bright emission region this telescopic view looks out along the plane of our Milky Way Galaxy toward the nebula rich constellation Cygnus the Swan. Popularly called the Tulip Nebula the glowing cloud of interstellar gas and dust is also found in the 1959 catalog by astronomer Stewart Sharpless as Sh2-101. About 8,000 light-years distant the nebula is understandably not the only cosmic cloud to evoke the imagery of flowers. The complex and beautiful nebula is shown here in a composite image that maps emission from ionized sulfur, hydrogen, and oxygen atoms into red, green, and blue colors....
  • Astronomy Picture of the Day -- Pink Aurora Over Crater Lake

    07/25/2012 4:39:07 PM PDT · by SunkenCiv · 12 replies
    NASA ^ | July 25, 2012 | (see photo credit)
    Explanation: Why is this aurora strikingly pink? When photographing picturesque Crater Lake in Oregon, USA last month, the background sky lit up with auroras of unusual colors. Although much is known about the physical mechanisms that create auroras, accurately predicting the occurrence and colors of auroras remains a topic of investigation. Typically, it is known, the lowest auroras appear green. These occur at about 100 kilometers high and involve atmospheric oxygen atoms excited by fast moving plasma from space. The next highest auroras -- at about 200 kilometers up -- appear red, and are also emitted by resettling atmospheric oxygen....
  • Astronomy Picture of the Day -- South Polar Vortex Discovered on Titan

    07/24/2012 5:18:07 AM PDT · by SunkenCiv · 6 replies
    NASA ^ | July 24, 2012 | (see photo credit)
    Explanation: What's happening over the south pole of Titan? A vortex of haze appears to be forming, although no one is sure why. The above natural-color image shows the light-colored feature. The vortex was found on images taken last month when the robotic Cassini spacecraft flew by the unusual atmosphere-shrouded moon of Saturn. Cassini was only able to see the southern vortex because its orbit around Saturn was recently boosted out of the plane where the rings and moons move. Clues as to what created the enigmatic feature are accumulating, including that Titan's air appears to be sinking in the...
  • Astronomy Picture of the Day -- Lightning Captured at 7,207 Images per Second

    07/23/2012 5:29:08 PM PDT · by SunkenCiv · 24 replies
    NASA ^ | July 23, 2012 | (see photo credit)
    Explanation: How fast is lightning? Lightning, in fact, moves not only too fast for humans to see, but so fast that humans can't even tell which direction it is moving. The above lightning stroke did not move too fast, however, for this extremely high time resolution video to resolve. Tracking at an incredible 7,207 frames per second, actual time can be seen progressing at the video bottom. The above lightning bolt starts with many simultaneously creating ionized channels branching out from an negatively charged pool of electrons and ions that has somehow been created by drafts and collisions in a...
  • Astronomy Picture of the Day -- M16: Pillars of Creation

    07/22/2012 7:18:25 AM PDT · by SunkenCiv · 12 replies
    NASA ^ | July 22, 2012 | (see photo credit)
    Explanation: It was one of the most famous images of the 1990s. This image, taken with the Hubble Space Telescope in 1995, shows evaporating gaseous globules (EGGs) emerging from pillars of molecular hydrogen gas and dust. The giant pillars are light years in length and are so dense that interior gas contracts gravitationally to form stars. At each pillars' end, the intense radiation of bright young stars causes low density material to boil away, leaving stellar nurseries of dense EGGs exposed. The Eagle Nebula, associated with the open star cluster M16, lies about 7000 light years away. The pillars of...
  • Astronomy Picture of the Day -- The Eagle Rises

    07/21/2012 5:42:43 AM PDT · by SunkenCiv · 8 replies
    NASA ^ | July 21, 2012 | (see photo credit)
    Explanation: Get out your red/blue glasses and check out this remarkable stereo view from lunar orbit. Created from two photographs (AS11-44-6633, AS11-44-6634) taken by astronaut Michael Collins during the 1969 Apollo 11 mission, the 3D anaglyph features the lunar module ascent stage, dubbed The Eagle, as it rises to meet the command module in lunar orbit on July 21. Aboard the ascent stage are Neil Armstrong and Buzz Aldrin, the first to walk on the Moon. The smooth, dark area on the lunar surface is Mare Smythii located just below the equator on the extreme eastern edge of the Moon's...
  • Astronomy Picture of the Day -- Moon Meets Jupiter

    07/19/2012 11:27:02 PM PDT · by SunkenCiv · 16 replies
    NASA ^ | July 20, 2012 | (see photo credit)
    Explanation: Skygazers around planet Earth enjoyed the close encounter of planets and Moon in July 15's predawn skies. And while many saw bright Jupiter next to the slender, waning crescent, Europeans also had the opportunity to watch the ruling gas giant pass behind the lunar disk, occulted by the Moon as it slid through the night. Clouds threaten in this telescopic view from Montecassiano, Italy, but the frame still captures Jupiter after it emerged from the occultation along with all four of its large Galilean moons. The sunlit crescent is overexposed with the Moon's night side faintly illuminated by Earthshine....
  • Astronomy Picture of the Day -- Dawn of the Dish

    07/19/2012 9:09:30 PM PDT · by SunkenCiv · 8 replies
    NASA ^ | July 19, 2012 | (see photo credit)
    Explanation: Wandering planets Venus and Jupiter were joined by an old crescent Moon near the eastern horizon on July 15. This serene southern skyview of the much anticipated predawn conjunction includes the lovely Pleiades star cluster and bright stars Aldebaran and Betelgeuse in the celestial lineup. For help identifying the stars and constellations, just slide your cursor over the image. Of course, the radio telescope in the foreground is the Parkes 64 meter dish of New South Wales, Australia. Known for its exploration of the distant Universe at radio wavelengths, the large, steerable antenna is also famous for its superior...
  • Astronomy Picture of the Day -- A Hole in Mars

    07/18/2012 3:21:59 AM PDT · by SunkenCiv · 52 replies
    NASA ^ | July 18, 2012 | (see photo credit)
    Explanation: What created this unusual hole in Mars? The hole was discovered by chance on images of the dusty slopes of Mars' Pavonis Mons volcano taken by the HiRISE instrument aboard the robotic Mars Reconnaissance Orbiter currently circling Mars. The hole appears to be an opening to an underground cavern, partly illuminated on the image right. Analysis of this and follow-up images revealed the opening to be about 35 meters across, while the interior shadow angle indicates that the underlying cavern is roughly 20 meters deep. Why there is a circular crater surrounding this hole remains a topic of speculation,...
  • Astronomy Picture of the Day -- Simulation: A Disk Galaxy Forms

    07/17/2012 3:24:36 AM PDT · by SunkenCiv · 7 replies
    NASA ^ | July 17, 2012 | (see photo credit)
    Explanation: How do galaxies like our Milky Way form? Since our universe moves too slowly to watch, faster-moving computer simulations are created to help find out. Green depicts (mostly) hydrogen gas in the above movie, while time is shown in billions of years since the Big Bang on the lower right. Pervasive dark matter is present but not shown. As the simulation begins, ambient gas falls into and accumulates in regions of relatively high gravity. Soon numerous proto-galaxies form, spin, and begin to merge. After about four billion years, a well-defined center materializes that dominates a region about 100,000 light-years...
  • Astronomy Picture of the Day -- Fifth Moon Discovered Orbiting Pluto

    07/16/2012 3:14:30 PM PDT · by SunkenCiv · 29 replies
    NASA ^ | July 16, 2012 | (see photo credit)
    Explanation: A fifth moon has been discovered orbiting Pluto. The moon was discovered earlier this month in images taken by the Hubble Space Telescope in preparation for the New Horizons mission's scheduled flyby of Pluto in 2015. Pictured above, the moon is currently seen as only a small blip that moves around the dwarf planet as the entire system slowly orbits the Sun. The moon, given a temporary designation of S/2012 (134340) 1 or just P5 (as labeled), is estimated to span about 15 kilometers and is likely composed mostly of water-ice. Pluto remains the only famous Solar System body...
  • Astronomy Picture of the Day -- Orion Nebula: The Hubble View

    07/15/2012 2:41:20 PM PDT · by SunkenCiv · 12 replies
    NASA ^ | July 15, 2012 | (see photo credit)
    Explanation: Few cosmic vistas excite the imagination like the Orion Nebula. Also known as M42, the nebula's glowing gas surrounds hot young stars at the edge of an immense interstellar molecular cloud only 1,500 light-years away. The Orion Nebula offers one of the best opportunities to study how stars are born partly because it is the nearest large star-forming region, but also because the nebula's energetic stars have blown away obscuring gas and dust clouds that would otherwise block our view - providing an intimate look at a range of ongoing stages of starbirth and evolution. This detailed image of...
  • Astronomy Picture of the Day -- AR1520: Islands in the Photosphere

    07/14/2012 6:04:54 AM PDT · by SunkenCiv · 7 replies
    NASA ^ | July 14, 2012 | (see photo credit)
    Explanation: Awash in a sea of plasma and anchored in magnetic fields, sunspots are planet-sized, dark islands in the solar photosphere, the bright surface of the Sun. Dark because they are slightly cooler than the surrounding surface, this group of sunspots is captured in a close-up telescopic snapshot from July 11. The field of view spans nearly 100,000 miles. They lie in the center of active region AR1520, now crossing the Sun's visible face. In fact, an X-class solar flare and coronal mass ejection erupted from AR1520 on July 12, releasing some of the energy stored in the region's twisted...
  • Astronomy Picture of the Day -- 21st Century M101

    07/13/2012 4:12:38 AM PDT · by SunkenCiv · 3 replies
    NASA ^ | July 13, 2012 | (see photo credit)
    Explanation: One of the last entries in Charles Messier's famous catalog, big, beautiful spiral galaxy M101 is 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 with Lord Rosse's large 19th century telescope, the Leviathan of Parsontown. In contrast, this mulitwavelength view of the large island universe is a composite of images recorded by space-based telescopes in the 21st century. Color coded From X-rays to infrared wavelengths (high to low energies), the image data was...
  • Astronomy Picture of the Day -- Teimareh Petroglyphs and Star Trails

    07/12/2012 3:09:43 AM PDT · by SunkenCiv · 18 replies
    NASA ^ | July 12, 2012 | (see photo credit)
    Explanation: Engraved in rock, these ancient petroglyphs are abundant in the Teimareh valley, located in the Zagros Mountains of central Iran. They likely tell a tale of hunters and animals found in the middle eastern valley 6,000 years ago or more, etched by artists in a prehistoric age. In the night sky above are star trails etched by the rotation of planet Earth during the long composite exposure made with a modern digital camera. On the left, the center of the star trail arcs is the North Celestial Pole (NCP), the extension of Earth's axis into space, with Polaris, the...
  • Astronomy Picture of the Day -- A Morning Line of Stars and Planets

    07/11/2012 3:19:14 AM PDT · by SunkenCiv · 4 replies
    NASA ^ | July 11, 2012 | (see photo credit)
    Explanation: Early morning dog walkers got a visual treat last week as bright stars and planets appeared to line up. Pictured above, easily visible from left to right, were the Pleiades open star cluster, Jupiter, Venus, and the "Follower" star Aldebaran, all seen before a starry background. The image was taken from the Atacama desert in western South America. The glow of the rising Sun can be seen over the eastern horizon. Jupiter and Venus will continue to dazzle pre-dawn strollers all over planet Earth for the rest of the month, although even now the morning planets are seen projected...
  • Astronomy Picture of the Day -- Happy People Dancing on Planet Earth

    07/10/2012 4:41:29 PM PDT · by SunkenCiv · 31 replies
    NASA ^ | July 10, 2012 | (see photo credit)
    Explanation: What are these humans doing? Dancing. Many humans on Earth exhibit periods of happiness, and one method of displaying happiness is dancing. Happiness and dancing transcend political boundaries and occur in practically every human society. Above, Matt Harding traveled through many nations on Earth, planned on dancing, and filmed the result. The above video, the latest in a series of similar videos, is perhaps a dramatic example that humans from all over planet Earth feel a common bond as part of a single species. Happiness is frequently contagious -- few people are able to watch the above video without...
  • Astronomy Picture of the Day -- Greeley Panorama on Mars

    07/09/2012 7:43:46 PM PDT · by SunkenCiv · 5 replies
    NASA ^ | July 09, 2012 | (see photo credit)
    Explanation: What did you do over your winter vacation? If you were the Opportunity rover on Mars, you spent four months of it stationary and perched on the northern slope of Greeley Haven -- and tilted so that your solar panels could absorb as much sunlight as possible. During its winter stopover, the usually rolling robot undertook several science activities including snapping over 800 images of its surroundings, many of which have been combined into this 360-degree digitally-compressed panorama and shown in exaggerated colors to highlight different surface features. Past tracks of Opportunity can be seen toward the left, while...
  • Astronomy Picture of the Day -- Volcano and Aurora in Iceland

    07/08/2012 7:59:25 AM PDT · by SunkenCiv · 14 replies
    NASA ^ | July 08, 2012 | (see photo credit)
    Explanation: Sometimes both heaven and Earth erupt. In Iceland in 1991, the volcano Hekla erupted at the same time that auroras were visible overhead. Hekla, one of the most famous volcanoes in the world, has erupted at least 20 times over the past millennium, sometimes causing great destruction. The last eruption occurred only twelve years ago but caused only minor damage. The green auroral band occurred fortuitously about 100 kilometers above the erupting lava. Is Earth the Solar System's only planet with both auroras and volcanos?
  • Astronomy Picture of the Day -- The Tidal Tail of NGC 3628

    07/06/2012 9:26:10 PM PDT · by SunkenCiv · 7 replies
    NASA ^ | July 06, 2012 | (see photo credit)
    Explanation: A mere 30 million light-years away, large spiral galaxy NGC 3628 (center left) shares its neighborhood in the local Universe with two other large spirals, in a magnificent grouping otherwise known as the Leo Triplet. In fact, fellow trio member M65 is near the center right edge of this deep cosmic group portrait, with M66 just above it and to the left. But, perhaps most intriguing is the spectacular tail stretching up and to the left for about 300,000 light-years from NGC 3628's warped, edge-on disk. Know as a tidal tail, the structure has been drawn out of the...
  • Astronomy Picture of the Day -- Gravitational Tractor

    07/06/2012 9:26:10 PM PDT · by SunkenCiv · 17 replies
    NASA ^ | July 07, 2012 | (see photo credit)
    Explanation: How would you change the course of an Earth-threatening asteroid? One idea - a massive spacecraft that uses gravity as a towline - is illustrated in this dramatic artist's view of a gravitational tractor in action. In the hypothetical scenario worked out in 2005 by Edward Lu and Stanley Love at NASA's Johnson Space Center, a 20 ton nuclear-electric spacecraft tows a 200 meter diameter asteroid by simply hovering near the asteroid. The spacecraft's ion drive thrusters are canted away from the surface. The steady thrust would gradually and predictably alter the course of the tug and asteroid, coupled...