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MRO early images
Some of the initial pictures and data from NASA's Mars Reconnaissance Orbiter since the craft entered its mapping orbit around the Red Planet are presented in this news briefing held October 16 from the Jet Propulsion Laboratory.

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Soyuz moves ports
The three-man Expedition 14 crew of the International Space Station complete a short trip, flying their Soyuz capsule to another docking port in preparation for receiving a resupply ship.

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STS-39: Military maneuvers
Space shuttle Discovery's STS-39 flight, launched in April 1991, served as a research mission for the U.S. Department of Defense. An instrument-laden spacecraft for the Strategic Defense Initiative Organization was released to watch Discovery perform countless rocket firings and maneuvers, as well as canisters releasing clouds of gas. The crew tells the story of the mission in this post-flight film presentation.

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STS-37: Spacewalkers help Gamma Ray Observatory
Seeking to study explosive forces across the universe, the Gamma Ray Observatory was launched aboard shuttle Atlantis in April 1991. But when the craft's communications antenna failed to unfold, spacewalking astronauts ventured outside the shuttle to save the day. The rescue EVA was followed by a planned spacewalk to test new equipment and techniques. The crew of STS-37 narrate this post-flight mission film.

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Mars rover seen by orbiter
Dazzling images from Mars are revealed by scientists. The robotic rover Opportunity has reached the massive Victoria crater with its steep cliffs and layers of rock exposing the planet's geologic history. Meanwhile, the new Mars Reconnaissance Orbiter has photographed the rover and its surroundings from high above.

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Hubble discovery
n this news conference from NASA Headquarters, scientists announce the Hubble Space Telescope's discovery of 16 extrasolar planet candidates orbiting a variety of distant stars in the central region of our Milky Way galaxy. Five of the newly found planets represent a new extreme type of planet not found in any nearby searches.

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Researchers find no evidence of ice reserves on the moon
CORNELL UNIVERSITY NEWS RELEASE
Posted: October 18, 2006

Alas, the moon is not for winter sports. Never mind the difficulty of a triple axel in a bulky spacesuit (though the diminished gravity might help) -- ice, it turns out, is hard to come by up there.


Shackleton crater (A) is 19 km in diameter. The Lunar Prospector orbiter impacted Shoemaker crater (B), 51 km in diameter. The south pole is about on the center of the left rim of Shackleton. Image courtesy of D. Campbell (Cornell), B. Campbell (Smithsonian) and L. Carter (Smithsonian)
 
That's the latest word from astronomers at Cornell and the Smithsonian Institution, who used high-resolution radar-mapping techniques to look for ice deposits at the lunar poles. Their research appears in the Oct. 19 issue of the journal Nature.

The researchers, led by Donald Campbell, professor of astronomy at Cornell, analyzed radar transmitted to the moon from the Arecibo Observatory in Puerto Rico and received 2.5 seconds later at the Robert C. Byrd Green Bank Telescope in West Virginia. Using 20-meter resolution, 13-centimeter wavelength radar, they looked at areas around the lunar south pole where earlier low-resolution images had indicated a high circular polarization ratio (CPR) -- a possible signature of low-temperature water ice.

They found similar high CPR values. But they also found that those values are not confined to areas that stay cold enough to sustain ice; they occurred in sunlit areas as well, where temperatures can reach 243 degrees Fahrenheit (117 degrees Celsius) and ice would evaporate rapidly. That indicates that scattered rocks associated with young impact craters are more likely the causes of the high CPR.

Accessible ice would be a valuable resource for any long-term human presence on the moon, but reserves could only exist in deep, permanently shaded craters at the poles, where the temperature doesn't rise above about -280 F (-173 C), Campbell said.

Previous data had given the search for lunar ice a boost, including 1992 radar data indicating ice deep in craters at the poles of Mercury, 1996 radio data from the moon taken by the Clementine orbiter and the Lunar Prospector Orbiter's 1998 discovery of an elevated amount of hydrogen at the lunar poles.

But the elevated hydrogen level could come from other sources -- solar wind, perhaps -- and subsequent radar data has failed to show any evidence of ice deposits.

Campbell says the new data should close the door on the debate.

"This is much higher resolution than we've ever done before," said Campbell. "We put the nail in the coffin in terms of the fact that these high CPRs are correlated with presence of rocky, blocky material around young impact craters. The assumption of many people is that high CPRs must indicate the presence of water ice. What we're saying is, that might not be the case.

"There is always the possibility that concentrated deposits exist in a few of the shadowed locations not visible to radars on Earth," he added. "But any current planning for landers or bases at the lunar poles should not count on this."

The Arecibo Observatory is operated by the National Astronomy and Ionosphere Center at Cornell for the National Science Foundation (NSF). The Green Bank Telescope is part of the National Radio Astronomy Observatory, which is operated by Associated Universities for the NSF.




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