"Mars Rover Makes Discovery While Spinning Its Wheels"
Space.com (December 22, 2009)
"Even though NASA's Mars rover Spirit has been trapped in the sand for months, the robot has still managed to report new facts about the red planet — all by just spinning its wheels.
"These findings shed light on the history of water on Mars, which might once have supported life.
"For nearly six years, Spirit roamed Mars, experiencing a number of close calls. In fact, the solar-powered robot has driven backwards since its right front wheel jammed in 2006...."
And, spun its wheels. Quite a lot. That's when things got a bit more interesting:
"...Spirit broke through a dark reddish-brown crusty surface that was an inch or so thick, exposing loose, sandy material. As the rover tried to break free, its wheels began to churn the soil, uncovering even more sandy material, bearing 'a higher concentration of sulfate that seen anywhere else on Mars,' [Washington University in St. Louis geologist Ray] Arvidson said.
" 'Sulfates are minerals just beneath the surface that shout to us that they were formed in steam vents or hydrothermal pools, since hot water associated with these systems has sulfur in it,' he explained. 'These deposits are evidence of water-charged explosive volcanism. Such areas could have once supported life.'..."
Or, not. Or maybe there still is life on Mars - adapted to its environment, not the soupy heat and humidity we're used to here on Earth.
What's exciting about the new data is the possibility that Mars may have had liquid water during two epochs: a very ancient time of volcanic activity; and during cycles that are still happening, millions of years long.
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