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Astronomy (General/Chat)

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  • 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....
  • Earth once had hazy methane atmosphere like ice-moon Titan--Microbial flatulence dominated ---

    07/30/2012 9:53:01 AM PDT · by Ernest_at_the_Beach · 14 replies
    The Register ^ | 19th March 2012 15:00 GMT | Lewis Page
    Billions of years ago, before Earth's atmosphere had oxygen, it periodically possessed a "haze" of organic chemicals including methane, boffins have discovered. During these periods the planet's air was more like that of Titan, ice moon of Saturn, than the stuff we breathe today. "Models have previously suggested that the Earth's early atmosphere could have been warmed by a layer of organic haze," says Dr Aubrey Zerkle of Newcastle uni. "Our geochemical analyses of marine sediments from this time period provide the first evidence for such an atmosphere." According to Zerkle and his colleagues, during the period 2.5 to 2.65...
  • Enceladus: home of alien lifeforms?

    07/29/2012 12:36:42 PM PDT · by LibWhacker · 13 replies
    Guaradian ^ | 7/28/12 | Robin McKie
    Mars dominates the search for extraterrestrial life in our solar system, but a growing number of scientists believe Enceladus, an icy moon of Saturn, is a much better betEnceladus is little bigger than a lump of rock and has appeared, until recently, as a mere pinprick of light in astronomers' telescopes. Yet Saturn's tiny moon has suddenly become a major attraction for scientists. Many now believe it offers the best hope we have of discovering life on another world inside our solar system. The idea that a moon a mere 310 miles in diameter, orbiting in deep, cold space, 1bn...
  • 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,...
  • How Black Holes Shape the Galaxies, Stars and Planets around Them

    07/26/2012 7:17:56 PM PDT · by LibWhacker · 13 replies
    Scientific American ^ | 7/17/12 | Caleb Scharf
    The matter-eating beast at the center of the Milky Way may actually account for Earth's existence and habitabilityAdapted from Gravity’s Engines: How Bubble-Blowing Black Holes Rule Galaxies, Stars, and Life in the Cosmos, by Caleb ScharfOur existence in this place, this microscopic corner of the cosmos, is fleeting. with utter disregard for our wants and needs, nature plays out its grand acts on scales of space and time that are truly hard to grasp. Perhaps all that we can look to for real solace is our endless capacity to ask questions and seek answers about the place we find ourselves...
  • 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....
  • Behind the Higgs: A primer on a long-sought boson

    07/25/2012 4:14:10 PM PDT · by SunkenCiv · 9 replies
    Science News ^ | July 28th, 2012 | Tom Siegfried
    In 1964, physicist Peter Higgs of the University of Edinburgh proposed that the infant universe (as in, perhaps a trillionth of a second old) experienced... a phase transition. In much the way an iron bar can suddenly become a magnet when cooled below a certain temperature, space itself acquired a new feature. Instead of a magnetic field, space was filled with a new forcelike field -- since named for Higgs. Other physicists worked out similar scenarios at about the same time, and later work showed how the Higgs phase transition could explain the distinct identities of two of nature's basic...
  • String theorists squeeze nine dimensions into three

    07/25/2012 3:36:54 PM PDT · by SunkenCiv · 22 replies
    Science News ^ | Friday, January 13th, 2012 | Devin Powell
    A simulation of the early universe using string theory may explain why space has three observable spatial dimensions instead of nine. The leading mathematical explanation of physics goes beyond modern particle theory by positing tiny bits of vibrating string as the fundamental basis of matter and forces. String theory also requires that the universe have six or more spatial dimensions in addition to the ones observed in everyday life. Explaining how those extra dimensions are hidden is a central challenge for string theorists... In the simulation, the universe starts off as a tiny blob of strings that is symmetric in...
  • 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...
  • How Big is the Entire Universe?

    07/21/2012 12:57:15 AM PDT · by LibWhacker · 61 replies
    Starts with a Bang ^ | 7/18/12 | Ethan Siegel
    (25) Millenium simulation from Volker Springel et al., from the Max Planck Institute for Astrophysics. “The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge.” -Stephen Hawking The Universe is a vast, seemingly unending marvel of existence. Over the past century, we’ve learned that the Universe stretches out beyond the billions of stars in our Milky Way, out across billions of light years, containing close to a trillion galaxies all told.Image credit: NASA, ESA, S. Beckwith (STScI) and the HUDF Team. And yet, that’s just the observable Universe! There are good reasons to believe that the...
  • Within Two Worlds

    07/20/2012 7:48:29 PM PDT · by iceskater · 4 replies
    Vimeo ^ | 7/20/12 | Goldpaint photography
    Take a few minutes and enjoy. A reminder of how beautiful the world can be is order after today's horror. http://vimeo.com/goldpaintphotography/withintwoworlds