Marc Flemming
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Registered: Jan 2003
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A new ground-based image of Mars is being touted as one of the sharpest ever taken from Earth.
Astronomers took advantage of Mars' historic close approach, the nearest in about 60,000 years, to photograph the red planet with the United Kingdom Infrared Telescope (UKIRT) in Hawaii.
The result is "perhaps the sharpest image of Mars ever made from the ground," said Jeremy Bailey of the Anglo-Australian Observatory and the Australian Center for Astrobiology at Macquarie University in Sydney.
The picture shows Mars' Hellas Basin, caused by an ancient impact, as well as Isidis Planitia, the planned landing site for the European Space Agency's Beagle 2, now on its way to the red planet aboard the Mars Express.
The picture is not red, but green, reflecting the infrared photography involved.
The image, and more important other data behind it, will be used to search for signs of minerals that might indicate the presence of water on Mars, the researcher said. Minerals absorb some wavelengths of sunshine and reflect others. Each mineral has a characteristic spectral signature -- the set of wavelengths it reflects.
"We’re looking particularly for the signatures of minerals, such as hydrated clay minerals, that would indicate the past presence of liquid water," Bailey said.
Mars is loaded with water ice. But the search for liquid water has so far come up dry. Biologists generally agree that life needs liquid water -- at least a trickle every few millennia -- to survive.
Recent studies have hinted at liquid water on the dusty planet. Most scientists do not expect conclusive evidence at least until thorough surveys are conducted by three spacecraft currently en route to Mars. And, they say, it could take much longer. Meanwhile, ground-based observations are likely to expand the base of knowledge about our mysterious planetary neighbor.
"While spacecraft can get up close, ground-based observations still have a role, as they allow us to use larger and more powerful instruments," Bailey said.
UKIRT, with a 3.8-meter aperture, is the world’s largest telescope devoted specifically to infrared observations, according to a statement released today.
The Hubble Space Telescope is scheduled to photograph Mars Tuesday night and Wednesday morning. The first of two Hubble pictures will be available via the SPACE.com home page shortly after 6 a.m. ET (1100 GMT) Wednesday.
Source: Space.com
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08-27-2003 04:17 PM
