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A Shocking Surprise in Stephan's Quintet This false-color composite image of the Stephan's Quintet galaxy cluster clearly shows one of the largest shock waves ever seen (green arc), produced by one galaxy falling toward another at over a million miles per hour. It is made up of data from NASA's Spitzer Space Telescope and a ground-based telescope in Spain. Four of the five galaxies in this image are involved in a violent collision, which has already stripped most of the hydrogen gas from the interiors of the galaxies. The centers of the galaxies appear as bright yellow-pink knots inside...

Young Star Cluster Westerlund 2 Credit: X-ray; Y.Nazé, G.Rauw, J.Manfroid (Université de Liège), CXC, NASA Infrared; E.Churchwell (University of Wisconsin), JPL, Caltech, NASA Explanation: Dusty stellar nursery RCW 49 surrounds young star cluster Westerlund 2 in this remarkable composite skyscape from beyond the visible spectrum of light. Infrared data from the Spitzer Space Telescope is shown in black and white, complimenting the Chandra X-ray image data (in false color) of the hot energetic stars within the cluster's central region. Looking toward the grand southern constellation Centaurus, both views reveal stars and structures hidden from optical telescopes by obscuring dust. Westerlund...

WASHINGTON - The latest act of senseless violence caught on tape is cosmic in scope: A black hole in a "death star galaxy" blasting a neighboring galaxy with a deadly jet of radiation and energy. A fleet of space and ground telescopes have captured images of this cosmic violence, which people have never witnessed before, according to a new study released Monday by NASA. "It's like a bully, a black-hole bully punching the nose of a passing galaxy," said astrophysicist Neil deGrasse Tyson, director of the Hayden Planetarium in New York, who wasn't involved in the research. But ultimately, this...

Did a giant impact create the two faces of Mars? 16:29 15 March 2007 NewScientist.com news service David Shiga, Houston Mars's northern hemisphere is lower in elevation – by about 5 kilometres – than its southern hemisphere (see image below). This coloured topographical map shows low elevations in blue and high elevations in yellow and red. The map is centred on a latitude of 55° north (Illustration: Mike Caplinger/MSSS) Mars's southern hemisphere is higher and more heavily cratered than the northern hemisphere, suggesting it is older terrain. The two low elevations (blue) in this map, which is centred on the...

The Cassini radar image (left) shows one of Titan's seas is larger than Lake Superior (right) Nasa's Cassini probe has found evidence for seas, probably filled with liquid hydrocarbons, at the high northern latitudes of Saturn's moon Titan.The dark features, detected by Cassini's radar, are much bigger than any lakes already detected on Titan. The largest is some 100,000 sq km (39,000 sq miles) - greater in extent than North America's Lake Superior. It covers a greater fraction of Titan than the proportion of Earth covered by the Black Sea. The Black Sea is the Earth's largest inland sea...

Rumors of a Strange Universe Credit: High-Z Supernova Search Team, HST, NASA Explanation: Eight years ago results were first presented indicating that most of the energy in our universe is not in stars or galaxies but is tied to space itself. In the language of cosmologists, a large cosmological constant is directly implied by new distant supernovae observations. Suggestions of a cosmological constant (lambda) are not new -- they have existed since the advent of modern relativistic cosmology. Such claims were not usually popular with astronomers, though, because lambda is so unlike known universe components, because lambda's value appeared...

In the Shadow of Saturn Credit: SSI, JPL, ESA, NASA Explanation: In the shadow of Saturn, unexpected wonders appear. The robotic Cassini spacecraft now orbiting Saturn recently drifted in giant planet's shadow for about 12 hours and looked back toward the eclipsed Sun. Cassini saw a view unlike any other. First, the night side of Saturn is seen to be partly lit by light reflected from its own majestic ring system. Next, the rings themselves appear dark when silhouetted against Saturn, but quite bright when viewed away from Saturn and slightly scattering sunlight, in the above exaggerated color image....

Photo shows the area in which Opportunity landed, the track outlined path it took over two years to negotiate 6 miles of desert to Victoria Crater Victoria Crater. The Mars-orbiting NASA satellite took a picture as it passed Victoria Crater and actually captured the Rover sitting on the edge of the crater.........A blow-up of the satellite photo showing Opportunity sitting on the crater's rim False color looking North to Cape Verde; great rock layers to explore. Looking Southeast across Duck Bay.

A new view of the Eagle Nebula, one of the two largest and sharpest images Hubble Space Telescope has ever taken, is released by NASA for Hubble's 15th anniversary April 25, 2005. The new Eagle Nebula image reveals a tall, dense tower of gas being sculpted by ultraviolet light from a group of massive, hot stars. During the 15 years Hubble has orbited the Earth, it has taken more than 700,000 photos of the cosmos.

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 September 4 Halo of the Cat's Eye Credit: R. Corradi (Isaac Newton Group), D. Goncalves (Inst. Astrofisica de Canarias) Explanation: The Cat's Eye Nebula (NGC 6543) is one of the best known planetary nebulae in the sky. Its haunting symmetries are seen in the very central region of this stunning false-color picture, processed to reveal the enormous but extremely faint halo of gaseous material, over three light-years...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 July 25 NGC 1569: Heavy Elements from a Small Galaxy Credit: C.Martin (UCSB / Caltech), et al., CXC, NASA Explanation: For astronomers, elements other than hydrogen and helium are sometimes considered to be simply "heavy elements". It's understandable really, because even lumped all together heavy elements make up an exceedingly small fraction of the Universe. Still, heavy elements can profoundly influence galaxy and star formation ... not...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 July 12 Recycling Cassiopeia A Credit: R. Fesen (Dartmouth) and J. Morse (CASA, U. Colorado), Hubble Heritage Team, NASA Explanation: For billions of years, massive stars in our Milky Way Galaxy have lived spectacular lives. Collapsing from vast cosmic clouds, their nuclear furnaces ignite and create heavy elements in their cores. After a few million years, the enriched material is blasted back into interstellar space where star...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 June 26 In the Center of the Trifid Nebula Credit: GMOS, Gemini Observatory Explanation: Clouds of glowing gas mingle with lanes of dark dust in the Trifid Nebula, a star forming region toward the constellation of Sagittarius. In the center, the three huge dark dust lanes that give the Trifid its name all come together. Mountains of opaque dust appear on the lower left, while filaments of...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 May 31 In Chandor Chasma on Mars Credit: THEMIS, Mars Odyssey Team, JPL, NASA Explanation: Scroll right and dive into a spectacular canyon on Mars. This daytime infrared view, recently recorded by the THEMIS camera on board the orbiting Mars Odyssey spacecraft, covers a 30 by 175 kilometer swath running along the canyon floor. The north (left) end of the scene is poised at the edge of...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 March 16 The Colorful Moon Credit: Galileo Project, JPL, NASA Explanation: Do you recognize the Earth's Moon when you see it? The crazy, patchwork appearance of the false-color image makes this almost full view of the Moon's familiar near side look very strange. The Sea of Tranquillity (Mare Tranquillitatis) is the bright blue area at right, the Ocean of Storms (Oceanus Procellarum) is the extensive blue and...