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Keyword: astronomy

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  • Astronomy Picture of the Day -- NGC 922: Collisional Ring Galaxy

    12/18/2012 6:58:33 PM PST · by SunkenCiv · 6 replies
    NASA ^ | December 17, 2012 | (see photo credit)
    Explanation: Why does this galaxy have so many big black holes? No one is sure. What is sure is that NGC 922 is a ring galaxy created by the collision of a large and small galaxy about 300 million years ago. Like a rock thrown into a pond, the ancient collision sent ripples of high density gas out from the impact point near the center that partly condensed into stars. Pictured above is NGC 922 with its beautifully complex ring along the left side, as imaged recently by the Hubble Space Telescope. Observations of NGC 922 with the Chandra X-ray...
  • Astronomy Picture of the Day -- MWC 922: The Red Square Nebula

    12/16/2012 1:01:56 AM PST · by SunkenCiv · 7 replies
    NASA ^ | December 16, 2012 | (see photo credit)
    Explanation: What could cause a nebula to appear square? No one is quite sure. The hot star system known as MWC 922, however, appears to be embedded in a nebula with just such a shape. The above image combines infrared exposures from the Hale Telescope on Mt. Palomar in California, and the Keck-2 Telescope on Mauna Kea in Hawaii. A leading progenitor hypothesis for the square nebula is that the central star or stars somehow expelled cones of gas during a late developmental stage. For MWC 922, these cones happen to incorporate nearly right angles and be visible from the...
  • Astronomy Picture of the Day -- When Gemini Sends Stars to Paranal

    12/14/2012 9:40:15 PM PST · by SunkenCiv · 1 replies
    NASA ^ | December 15, 2012 | (see photo credit)
    Explanation: From a radiant point in the constellation of the Twins, the annual Geminid meteor shower rained down on planet Earth this week. Recorded near the shower's peak in the early hours of December 14, this skyscape captures Gemini's lovely shooting stars in a careful composite of 30 exposures, each 20 seconds long, from the dark of the Chilean Atacama Desert over ESO's Paranal Observatory. In the foreground Paranal's four Very Large Telescopes, four Auxillary Telescopes, and the VLT Survey telescope are all open and observing. The skies above are shared with bright Jupiter (left), Orion, (top left), and the...
  • Astronomy Picture of the Day -- Umbra World

    12/14/2012 9:35:39 PM PST · by SunkenCiv · 11 replies
    NASA ^ | December 14, 2012 | (see photo credit)
    Explanation: On the morning of November 14, sky gazers from around the world gathered on this little planet to stand in the dark umbral shadow of the Moon. Of course, the Moon cast the shadow during last month's total solar eclipse, and the little planet is actually a beach on Green Island off the coast of Queensland, Australia. The picture itself, the first little planet projection of a total solar eclipse, is a digitally warped and stitched wrap-around of 8 images covering 360x180 degrees. To make it, the intrepid photographer had to remember to shoot both toward and away(!) from...
  • Geminids Rain Down Shooting Stars

    12/14/2012 5:24:29 AM PST · by Mozilla · 12 replies
    Slate ^ | 12/14/12 | Phil Plait
    As I wrote a couple of days ago, the annual Geminid meteor shower peaked last night, raining down a magnificent display of shooting stars. Did you go out and watch? A lot of photographers did. One was John Chumack, an accomplished astrophotographer, who captured this amazing shot of three meteors: Chumack was in Yellow Springs, Ohio on the evening of the 12th (the day before the peak!) using a simple DSLR camera and a fisheye lens. This was a 25-second exposure, enough to see Orion, Jupiter (the bright “star” above Orion), Gemini—the direction from which the eponymous meteors appear to...
  • Astronomy Picture of the Day -- Apollo 17: A Stereo View from Lunar Orbit [3D]

    12/13/2012 8:55:00 PM PST · by SunkenCiv · 6 replies
    NASA ^ | December 13, 2012 | (see photo credit)
    Explanation: Get out your red/blue glasses and check out this awesome stereo view of another world. The scene was recorded by Apollo 17 mission commander Eugene Cernan on December 11, 1972, one orbit before descending to land on the Moon. The stereo anaglyph was assembled from two photographs (AS17-147-22465, AS17-147-22466) captured from his vantage point on board the Lunar Module Challenger as he and Dr. Harrison Schmitt flew over Apollo 17's landing site in the Taurus-Littrow Valley. The broad, sunlit face of the mountain dubbed South Massif rises near the center of the frame, above the dark floor of Taurus-Littrow...
  • Astronomy Picture of the Day -- Milky Way Over Quiver Tree Forest

    12/11/2012 9:40:55 PM PST · by SunkenCiv · 8 replies
    NASA ^ | December 12, 2012 | (see photo credit)
    Explanation: In front of a famous background of stars and galaxies lies some of Earth's more unusual trees. Known as quiver trees, they are actually succulent aloe plants that can grow to tree-like proportions. The quiver tree name is derived from the historical usefulness of their hollowed branches as dart holders. Occurring primarily in southern Africa, the trees pictured in the above 16-exposure composite are in Quiver Tree Forest located in southern Namibia. Some of the tallest quiver trees in the park are estimated to be about 300 years old. Behind the trees is light from the small town of...
  • Astronomy Picture of the Day -- NGC 604: Giant Stellar Nursery

    12/11/2012 4:15:16 AM PST · by SunkenCiv · 4 replies
    NASA ^ | December 11, 2012 | (see photo credit)
    Explanation: Stars are sometimes born in the midst of chaos. About 3 million years ago in the nearby galaxy M33, a large cloud of gas spawned dense internal knots which gravitationally collapsed to form stars. NGC 604 was so large, however, it could form enough stars to make a globular cluster. Many young stars from this cloud are visible in the above image from the Hubble Space Telescope, along with what is left of the initial gas cloud. Some stars were so massive they have already evolved and exploded in a supernova. The brightest stars that are left emit light...
  • Astronomy Picture of the Day -- Time-Lapse: A Total Solar Eclipse

    12/10/2012 7:17:29 PM PST · by SunkenCiv · 5 replies
    NASA ^ | December 10, 2012 | (see photo credit)
    Explanation: Have you ever experienced a total eclipse of the Sun? The above time-lapse movie depicts such an eclipse in dramatic detail as visible from Australia last month. As the video begins, a slight dimming of the Sun and the surrounding Earth is barely perceptible. Suddenly, as the Moon moves to cover nearly the entire Sun, darkness sweeps in from the left -- the fully blocked part of the Sun. At totality, only the bright solar corona extends past the edges of the Moon, and darkness surrounds you. Distant horizons are still bright, though, as they are not in the...
  • Astronomy Picture of the Day -- The Astronaut Who Captured a Satellite [from 1984]

    12/08/2012 9:19:40 PM PST · by SunkenCiv · 16 replies
    NASA ^ | December 09, 2012 | (see photo credit)
    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 Space Shuttle Discovery and returned to Earth. Westar 6 was...
  • Astronomy Picture of the Day -- Baku Moonrise

    12/08/2012 10:58:48 AM PST · by SunkenCiv · 6 replies
    NASA ^ | December 08, 2012 | (see photo credit)
    Explanation: A Full Moon rises in this waterfront scene. Its colorful, watery reflection is joined by harbor lights and a windowed skyscraper's echo of the western horizon just after sunset. The tantalizing image is a composite of frames recorded at 2 minute intervals on November 28 from the Caspian Sea port city of Baku, Azerbaijan. Still, this Full Moon was not really as big or as bright as others, though it might be hard to tell. In fact, November 28's Full Moon was near apogee, making it the smallest Full Moon of 2012. As it rose over the Baku boardwalk...
  • Astronomy Picture of the Day -- Earth at Night

    12/07/2012 9:13:19 PM PST · by SunkenCiv · 35 replies
    NASA ^ | December 07, 2012 | (see photo credit)
    Explanation: This remarkably complete view of Earth at night is a composite of cloud-free, nighttime images. The images were collected during April and October 2012 by the Suomi-NPP satellite from polar orbit about 824 kilometers (512 miles) above the surface using its Visible Infrared Imaging Radiometer Suite (VIIRS). VIIRS offers greatly improved resolution and sensitivity compared to past global nightlight detecting instrumentation on DMSP satellites. It also has advantages compared to cameras on the International Space Station. While the space station passes over the same point on Earth every two or three days, Suomi-NPP passes over the same point twice...
  • Astronomy Picture of the Day -- 47 Tuc Near the Small Magellanic Cloud

    12/05/2012 9:44:29 PM PST · by SunkenCiv · 3 replies
    NASA ^ | December 06, 2012 | (see photo credit)
    Explanation: Globular star cluster 47 Tucanae is a jewel of the southern sky. Also known as NGC 104, it roams the halo of our Milky Way Galaxy along with around 200 other globular star clusters. The second brightest globular cluster (after Omega Centauri) as seen from planet Earth, it lies about 13,000 light-years away and can be spotted naked-eye near the Small Magellanic Cloud (SMC) in the constellation of the Toucan. Of course, the SMC is some 210,000 light-years distant, a satellite galaxy of our Milky Way and not physically close to 47 Tuc. Stars on the outskirts of the...
  • Astronomy Picture of the Day -- Plasma Jets from Radio Galaxy Hercules A

    12/05/2012 9:30:09 PM PST · by SunkenCiv · 19 replies
    NASA ^ | December 05, 2012 | (see photo credit)
    Explanation: Why does this galaxy emit such spectacular jets? No one is sure, but it is likely related to an active supermassive black hole at its center. The galaxy at the image center, Hercules A, appears to be a relatively normal elliptical galaxy in visible light. When imaged in radio waves, however, tremendous plasma jets over one million light years long appear. Detailed analyses indicate that the central galaxy, also known as 3C 348, is actually over 1,000 times more massive than our Milky Way Galaxy, and the central black hole is nearly 1,000 times more massive than the black...
  • Astronomy Picture of the Day -- In the Center of Saturn's North Polar Vortex

    12/04/2012 8:30:49 PM PST · by SunkenCiv · 6 replies
    NASA ^ | December 04, 2012 | (see photo credit)
    Explanation: What's happening at the north pole of Saturn? A vortex of strange and complex swirling clouds. The center of this vortex was imaged in unprecedented detail last week by the robotic Cassini spacecraft orbiting Saturn. These clouds lie at the center of the unusual hexagonal cloud system that surrounds the north pole of Saturn. Saturn's north pole precessed into sunlight just a few years ago, with Cassini taking only infrared images of the shadowed region previously. The above image is raw and unprocessed and is being prepared for release in 2013. Several similar images of the region have recently...
  • Astronomy Picture of the Day -- A Quadruple Lunar Halo Over Spain

    12/02/2012 9:17:35 PM PST · by SunkenCiv · 7 replies
    NASA ^ | December 03, 2012 | (see photo credit)
    Explanation: Sometimes falling ice crystals make the atmosphere into a giant lens causing arcs and halos to appear around the Sun or Moon. This past Saturday night was just such a time near Madrid, Spain, where a winter sky displayed not only a bright Moon but as many as four rare lunar halos. The brightest object, near the top of the above image, is the Moon. Light from the Moon refracts through tumbling hexagonal ice crystals into a 22 degree halo seen surrounding the Moon. Elongating the 22 degree arc horizontally is a circumscribed halo caused by column ice crystals....
  • Astronomy Picture of the Day -- The Gegenschein Over Chile

    12/01/2012 9:56:19 PM PST · by SunkenCiv · 6 replies
    NASA ^ | December 02, 2012 | (see photo credit)
    Explanation: Is the night sky darkest in the direction opposite the Sun? No. In fact, a rarely discernable faint glow known as the gegenschein (German for "counter glow") can be seen 180 degrees around from the Sun in an extremely dark sky. The gegenschein is sunlight back-scattered off small interplanetary dust particles. These dust particles are millimeter sized splinters from asteroids and orbit in the ecliptic plane of the planets. Pictured above from 2008 October is one of the more spectacular pictures of the gegenschein yet taken. Here a deep exposure of an extremely dark sky over Paranal Observatory in...
  • Astronomy Picture of the Day -- Northern Mercury

    12/01/2012 10:10:52 AM PST · by SunkenCiv · 13 replies
    NASA ^ | December 01, 2012 | (see photo credit)
    Explanation: Innermost planet Mercurywould probably not be a good location for an interplanetary winter olympics. But new results based on data from the Mercury orbitingMESSENGER spacecraft indicate that it does have substantial water icein permanently shadowed regions within craters near its north pole. The possibility of ice on Mercury has been entertained for years, inspired by the discovery of radar bright, hence highly reflective, regions near the north pole. Highlighted in yellow in this map based on projected MESSENGER images, radar bright regions are seen to correspond with floors and walls of north polar impact craters. Farther from the pole...
  • Astronomy Picture of the Day -- Clouds in Cygnus

    11/30/2012 7:47:55 PM PST · by SunkenCiv · 5 replies
    NASA ^ | November 30, 2012 | (see photo credit)
    Explanation: Cosmic clouds of gas and dust drift across this magnificent mosaic covering a 12x12 degree field within the high flying constellation Cygnus. The collaborative skyscape, a combination of broad and narrow band image data presented in the Hubble palette, is anchored by bright, hot, supergiant star Deneb, below center near the left edge. Alpha star of Cygnus, Deneb, is the top of the Northern Cross asterism and is seen here next to the dark void known as the Northern Coal Sack. Below Deneb are the recognizable North America and Pelican nebulae (NGC 7000 and IC 5070). Another supergiant star,...
  • Astronomy Picture of the Day — Super Moon vs. Micro Moon

    11/30/2012 7:40:02 PM PST · by SunkenCiv · 8 replies
    NASA ^ | November 29, 2012 | (see photo credit)
    Explanation: Did you see the big, bright, beautiful Full Moon Wednesday night? That was actually a Micro Moon! On that night, the smallest Full Moon of 2012 reached its full phase only about 4 hours before apogee, the most distant point from Earth in the Moon's elliptical orbit. Of course, earlier this year on May 6, a Full Super Moon was near perigee, the closest point in its orbit. The relative apparent size of November 28's Micro Moon (right) is compared to the famous May 6 Super Moon in these two panels, matching telescopic images from Bucharest, Romania. The difference...