US: Mars orbiter makes find that suggests wet past
19 Dec 2008 10:12 AM
LOS ANGELES, Dec 18 AP - A Mars spacecraft for the first time spotted a key mineral in bedrock on the Martian surface, suggesting parts of the planet might have once had an environment hospitable to life, scientists reported on Thursday.
Previous missions detected carbonate mineral in trace amounts in Martian dust. But earlier this year, the Phoenix lander discovered small amounts of carbonate in soil near its arctic landing site.
The latest find was the first time the mineral has been observed in rock outcrops on the red planet.
Carbonate minerals form in the presence of water. Their presence in bedrock in Nili Fossae, a region of valleys that have cut into the planet's ancient crust, suggests the area was not as harsh as other places on Mars.
The region "would have really been a clement, benign environment for early Martian life," said mission scientist Bethany Ehlmann of Brown University.
Scientists analysed thousands of images taken by the Mars Reconnaissance Orbiter but only found evidence of carbonate in Nili Fossae.
The results were presented on Thursday at an American Geophysical Union meeting in San Francisco and will appear on Friday in the journal Science.
Scientists planning the next Mars landing - the Mars Science Laboratory - initially considered Nili Fossae as a potential landing site, but it did not make the final cut.
The launch of the Mars Science Lab has since been delayed two years to 2011.
On the net:
American Geophysical Union: http://www.agu.org
Mars Reconnaissance Orbiter mission: http://marsprogram.jpl.nasa.gov/mro
