Monday, August 04, 2008

My Way News - Martian soil may contain detrimental substance

My Way News - Martian soil may contain detrimental substance

NASA's Phoenix spacecraft has detected the presence of a chemically reactive salt in the Martian soil, a finding that if confirmed could make it less friendly to potential life than once believed.

Scientists previously reported that the soil near Mars' north pole was similar to backyard gardens on Earth where plants such as asparagus, green beans and turnips could grow. But preliminary results from a second lab test found perchlorate, a highly oxidizing salt, that would create a harsh environment.

The first test "suggested Earth-like soil. Further analysis has revealed un-Earthlike aspects of the soil chemistry," chief scientist Peter Smith of the University of Arizona in Tucson said in a statement Monday.

On Earth, perchlorate is a natural and manmade contaminant sometimes found in soil and groundwater. It is the main ingredient in solid rocket fuel and can be found in fireworks, pyrotechnics and other explosives.

It's unclear how perchlorate forms on Mars or how much there is of it. NASA is investigating whether the substance could have gotten there by contamination before launch. Phoenix used another fuel, hydrazine, to power its thrusters and land on the red planet on May 25.

[...]

Scientists want to confirm their results because another Phoenix instrument that bakes and sniffs soil samples found no evidence of perchlorate during a run on Sunday.

Brown University geologist John Mustard, who has no role in the mission, said judgment about the soil's potential to support life should be reserved until all the data are in.

But at first glance, "it is a reactive compound. It's not usually considered an ingredient for life," Mustard said.

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