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Infrared Astronomy
Image courtesy Infrared Processing and Analysis Center, California Institute of Technology
December 23, 2009--Four pictures of the Rho Ophiuchi star-forming region illustrate the "evolution" of infrared astronomy over the past quarter century.
Each image, seen above in chronological order, was made by a past or present infrared observatory run with U.S. participation: the InfraRed Astronomical Satellite (IRAS), the Infrared Space Observatory (ISO), the Two Micron All-Sky Survey (2MASS), and the Spitzer Space Telescope.
Infrared light is invisible to human eyes, so the Infrared Processing and Analysis Center assigned false colors to all four images to help astronomers visualize how stars are born in Rho Ophiuchi. Different colors represent the temperature and composition of dust, as well as the ages of the hundreds of stars forming in the dense molecular cloud.December 30, 2009
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Terra Meridiani
Photograph courtesy NASA/JPL/University of Arizona
December 23, 2009--Looking like a row of jagged Antarctic icebergs, a recently released false-color picture actually depicts dark sand covering bright bedrock in the Terra Meridiani region of Mars.
The Mars Reconnaissance Orbiter snapped the shot in November 2006, as the Mars rover Opportunity (not pictured) explored Meridiani.
The regular spacing of dark ridges suggests sand was blown over the bright bedrock to form dunes and ripples. Data from Opportunity shows that the dark sand is mostly made of volcanic basalt, unlike most Earthly sand, which is primarily made of quartz.December 30, 2009
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Dusty Disk
Image courtesy David A. Hardy
December 23, 2009--Planets take shape in the dusty disk around a young star in an artist's conception. The scene is an example of what things might be like around MWC 419, a blue star about 2,100 light-years from Earth that astronomers recently probed using the W. M. Keck Observatory in Hawaii.
Using a device that reads near-infrared light, the team was able to measure the dust disk's temperature to within about 50 million miles of the star--about half the distance from Earth to the sun.
Temperature differences in the disk might be linked to chemical composition and other properties, which may affect how planets form around the star.December 30, 2009
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Viti Levu
Image courtesy NASA
December 26, 2009--Dark green mangrove forests surround the Ba River Delta (lower right) on Viti Levu, Fiji's main island, in a true-color image captured December 18 by NASA's Earth-Observer 1 satellite.
Mangroves help protect and nurture the vast but vulnerable coral reefs nearby, seen as pale blue structures. Rooted in shallow seafloors, the tangled trees often shelter young fish until they're hardy enough for reef life. The roots also trap water-clouding river sediments, which would otherwise deprive reefs of needed sunlight, as well as agricultural runoff, which could encourage harmful algae blooms.
In turn, the reefs slow waves as they speed toward the shore, protecting the mangroves' roots from excessive turbulence.December 30, 2009
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Solar Activity
Photograph courtesy SOHO/ESA/NASA
December 25, 2009--Five regions of magnetic activity create bright blemishes on the sun on December 22 as seen in an ultraviolet image from the Solar and Heliospheric Observatory (SOHO). Two of the regions correspond to dark sunspots when the sun is seen in visible light.
This is the first time in 2009 that the orbiting probe has captured so much concurrent action on the sun. It's possible that the upswing will signal an end to the sun's unusually long quiet period, SOHO scientists say.December 30, 2009
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