June 25, 2009

Mars rover: Stuck but still reporting

The U.S. space agency's Mars rover Spirit is still stuck in loose Martian soil, but it's providing scientists data on the planet's environmental history.

Spirit became stuck in April in an area composed of layers of soil with differing pastel hues hiding beneath a darker sand blanket, NASA said.

Scientists dubbed the site Troy.

But while Spirit awaits extraction instructions, the rover is keeping busy examining Troy, which is next to a low plateau called Home Plate, approximately 2 miles from where Spirit landed in 2004.

Ray Arvidson of Washington University in St. Louis, deputy principal investigator for the science payloads on Spirit and its twin rover, Opportunity, said Spirit has been using tools on its robotic arm to examine Troy's tan, yellow, white and dark-red sandy soil.

The layers have basaltic sand, sulfate-rich sand and areas with the addition of silica-rich materials, possibly sorted by wind and cemented by the action of thin films of water, Arvidson said. This may be evidence of much more recent processes than the formation of Home Plate -- or is Home Plate being slowly stripped back by wind, and we happened to stir up a deposit from billions of years ago before the wind got to it?

Richard Moddis, a Spirit team scientist, added, If your rover is going to get bogged down, it's nice to have it be at a location so scientifically interesting.