THE ASTRONOMY PICTURE OF THE DAY FOR 2011 MAY 22
2011 May 22
Io: The Prometheus Plume
Credit: Galileo Project, JPL, NASA
Explanation: What's happening on Jupiter's moon Io? Two sulfurous eruptions are visible on Jupiter's volcanic moon Io in this color composite image from the robotic Galileo spacecraft
that orbited Jupiter from 1995 to 2003. At the image top, over Io's limb, a bluish plume rises about 140 kilometers above the surface of a volcanic caldera known as Pillan Patera.
In the image middle, near the night/day shadow line, the ring shaped Prometheus plume is seen rising about 75 kilometers above Io while casting a shadow below the volcanic vent.
Named for the Greek god who gave mortals fire, the Prometheus plume is visible in every image ever made of the region dating back to the Voyager flybys of 1979 - presenting the
possibility that this plume has been continuously active for at least 18 years. The above digitally sharpened image of Io was originally recorded in 1997 from a distance of about 600,000 kilometers
. Recent analyses of Galileo data has uncovered evidence of a magma ocean beneath Io's surface.
THE ASTRONOMY PICTURE OF THE DAY FOR 2011 February 27
Saturn's Hyperion: A Moon with Odd Craters
Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA
Explanation: What lies at the bottom of Hyperion's strange craters? Nobody's sure. To help find out, the robot Cassini spacecraft now orbiting Saturn swooped past the sponge-textured moon in 2005 and 2010 and took images of unprecedented detail. An image from the 2005 pass, shown above in false color, shows a remarkable world strewn with strange craters and a generally odd surface. The slight differences in color likely show differences in surface composition. At the bottom of most craters lies some type of unknown dark material. Inspection of the image shows bright features indicating that the dark material might be only tens of meters thick in some places. Hyperion is about 250 kilometers across, rotates chaotically, and has a density so low that it might house a vast system of caverns inside.
THE ASTRONOMY PICTURE OF THE DAY FOR 2010 September 15
Clouds, Birds, Moon, Venus
Credit & Copyright: Isaac Gutiérrez Pascual (Spain)
Explanation: Sometimes the sky above can become quite a show. Last week, for example, the Moon and Venus converged, creating quite a sight by itself for sky enthusiasts around the globe. From some locations, though, the sky was even more picturesque. In the above image taken last week from Spain, a crescent Moon and the planet Venus, on the far right, were captured during sunset posing against a deep blue sky. In the foreground, dark storm clouds loom across the image bottom, while a white anvil cloud shape appears above. Black specks dot the frame, caused by a flock of birds taking flight. Very soon after this picture was taken, however, the birds passed by, the storm ended, and Venus and the Moon set. The Moon and Venus have now separated, although Venus will remain visible at sunset for the rest of this month of September.
ASTRONOMY PICTURE OF THE DAY for 2009 January 21
A Lenticular Cloud Over New Zealand
Credit & Copyright: Chris Picking (Starry Night Skies Photography)
Explanation: What's happening above those mountains? Several clouds are stacked up into one striking lenticular cloud. Normally, air moves much more horizontally than it does vertically. Sometimes, however, such as when wind comes off of a mountain or a hill, relatively strong vertical oscillations take place as the air stabilizes. The dry air at the top of an oscillation may be quite stratified in moisture content, and hence forms clouds at each layer where the air saturates with moisture. The result can be a lenticular cloud with a strongly layered appearance. The above picture was taken in 2002 looking southwest over the Tarurua Range mountains from North Island, New Zealand.
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THE ASTRONOMY PICTURE OF THE DAY FOR 2010 August 24
Galaxy Cluster Abell 1689 Magnifies the Dark Universe
Credit: NASA, ESA, E. Jullo (JPL), P. Natarajan (Yale), & J.-P. Kneib (LAM, CNRS)
Acknowledgment: H. Ford and N. Benetiz (JHU), & T. Broadhurst (Tel Aviv)
Explanation: What's the matter with this cluster of galaxies? To find out what forms matter takes in the Abell 1689 cluster requires not only deep images from telescopes like the Hubble Space Telescope, but detailed computer modeling as well. To start, almost every fuzzy yellow patch in the above image is an entire galaxy. A close inspection, however, shows that many background galaxies are strangely magnified and distorted into long curving arcs by the gravitational lens deflections of the cluster. Computer analyses of the placement and smoothness of these arcs indicate that in addition to the matter in the galaxies you can see, the cluster must also contain a significant amount of dark matter such as the model digitally superposed in purple. Now Abell 1689 remains enigmatic because the arcs are so numerous and diverse that no single dark matter model has emerged that can explain them all and still remain consistent with dark matter models needed to constrain their motion. Still, the detailed information available from clusters of galaxies like Abell 1689 gives hope that one day full solutions will be found that will not only fully reveal the dark matter in clusters, but also reveal the amounts of dark energy in the universe needed to lie along the line of sight to the distant arcs.
Students and Teachers: Free video online Astro 101 course
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THE ASTRONOMY PICTURE OF THE DAY FOR 2010 July 1
Above Aurora Australis
Credit: ISS Expedition 23 Crew, ISAL, NASA
Explanation: On May 29, looking southward from a vantage point about 350 kilometers above the southern Indian Ocean, astronauts onboard the International Space Station watched this enormous, green ribbon shimmering below. Known as aurora australis or southern lights, the shifting, luminous bands are commonly seen at high northern latitudes as well, there known as the aurora borealis or northern lights. North or south their cause is the same though, as energetic charged particles from the magnetosphere pile into the atmosphere near the Earth's poles. To produce the characteristic greenish glow, the energetic particles excite oxygen atoms at altitudes of 100 kilometers or more. Aurora on May 29 were likely triggered by the interaction of the magnetosphere with a coronal mass ejection erupting from the Sun on 2010 May 24.
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The Full Moon and The Shuttle Discovery on the Launchpad - March 11 Credit: NASA/Bill Ingalls
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While attending the Texas Star Party in Fort Davis Texas, We were not only treated to clear skies, but also a beautiful show by Venus and the Moon. Image was taken through a Celestron 14 telescope at F/7 with a (Occultation occurred on 2009 April 22nd ) - Nikon D200 at ISO 400
from Spaceweather.com
AMAZING PHOTO OF COMET LULIN ON FEB 22 FROM CLIFTON, TX BY PHILIP JONES
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LOOK AT ALL THESE GALAXIES !!!
ASTRONOMY PICTURE OF THE DAY FOR 2009 February 9
Anemic Galaxy NGC 4921 at the Edge
Credit: NASA, ESA, K. Cook (LLNL)
Explanation: How far away is spiral galaxy NGC 4921? Although presently estimated to be about 320 million light years distant, a more precise determination could be coupled with its known recession speed to help humanity better calibrate the expansion rate of the entire visible universe. Toward this goal, this image was taken by the Hubble Space Telescope in order to help identify key stellar distance markers know as Cepheid variable stars. Since NGC 4921 is a member of the Coma Cluster of Galaxies, refining its distance would also allow a better distance determination to one of the largest NGC 4921 has been informally dubbed anemic because of its low rate of star formation and low surface brightness. The remarkably sharp image was made with Hubble's Advanced Camera for Surveys, currently in need of repair. Visible in the image are, from the center, a bright nucleus, a bright central bar, a prominent ring of dark dust, blue clusters of recently formed stars, several smaller companion galaxies, unrelated galaxies in the far distant universe, and unrelated stars in our Milky Way Galaxy.
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THE ASTRONOMY PICTURE OF THE DAY FOR 2009 February 12
Zodiacal Light (Left) and the Milky Way (Right)
Credit & Copyright: Daniel López, IAC
Explanation: Two fundamental planes of planet Earth's sky compete for attention in this remarkable wide-angle vista, recorded on January 23rd. Arcing above the horizon and into the night at the left is a beautiful band of Zodiacal Light - sunlight scattered by dust in the solar system's ecliptic plane. Its opponent on the right is composed of the faint stars, dust clouds, and nebulae along the plane of our Milky Way Galaxy. Both celestial bands stand above the domes and towers of the Teide Observatory on the island of Tenerife. Also out to play in the pristine, dark skies over the Canary Islands, are brilliant Venus (lower left), the distant Andromeda Galaxy (near center), and the lovely Pleiades star cluster (top center). Of course, seasoned skygazers might even spot M33, the California Nebula, IC1805, and the double star cluster of Perseus. (Need some help? Just slide your cursor over the picture.)
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On Friday 2009 Jan 30 the evening the public Observatory Philippus Lansbergen in Middelburg, The Netherlands had more than 60 visitors admiring the crescent Moon and Venus. In this building from 1607, 1 year older than the first telescope invented in our town, we have organized a space-expo at the moment.
PHOTO BY Jan Koeman in Middelburg, Netherlands
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SPACE SHUTTLE ENDEAVOUR LANDED AT EDWARDS AIR FORCE BASE AT 4:25 PM EST ON NOVEMBER 30. NOTE THE CRESCENT MOON OVER THE WING WITH VENUS THEN JUPITER ABOVE.