Saturday, March 17, 2007

More surprises in soil of Mars

Once thought to be a dead planet with no water,it seems the history of the planet keeps giving new surprises all the time

NASA Mars Rover Churns Up Questions With Sulfur-Rich Soil

Some bright Martian soil containing lots of sulfur and a trace of water intrigues researchers who are
studying information provided by NASA's Spirit rover.

Halfway around Mars, Opportunity is exploring clockwise around "Victoria Crater," a bowl about
800 meters (half a mile) across. Cliff-like promontories alternate with more gradually sloped alcoves
around the scalloped rim. The impact that dug the crater exposed layers that had been buried.

"The images are breathtaking," said Dr. Steve Squyres of Cornell University, principal investigator
for the rovers. "Every promontory we've seen has the kinds of layering expected for ancient wind-
blown sand deposits."

The layers consist of sulfate-rich sandstone similar to other bedrock Opportunity has been finding in
Mars' Meridiani region for more than three years. The minerals come from a wet period in the
region's ancient past. While exploring Victoria's rim with Opportunity, researchers have been on the
lookout for rocks that might have been tossed out from layers deeper and older than the sulfates.

"We found one group of cobbles that were clearly more resistant to erosion than the sulfate blocks
thrown out onto the rim," Squyres said. "We checked the composition of one that we called Santa
Catarina. Our suspicion now is that Santa Catarina is a piece of a meteorite." That would be the fifth
meteorite found by the rovers.

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