MARS: Great Lakes? – investigation of evidence for life on mars

MARS: Great Lakes? – investigation of evidence for life on mars – Brief Article

Sean Price

In NASA scientists’ hunt for life on Mars, they don’t expect to find billboards advertising “Welcome to the Red Planet!” But every new piece of evidence edges them closer to an extraordinary revelation: Life existed–and might still exist–on Mars.

The latest images captured by Mars Global Surveyor detail layered rock formations like swirled cake frosting in canyons and craters –some more than 3,219 meters (2 miles) deep. The formations could be remnants of lake beds in which liquid water once gushed on the now-frigid, barren planet. “We think these thin rock layers formed underwater,” says NASA researcher Michael Malin. “It’s hard to come up with an alternative.”

What’s so special about dried-up lake beds? Scientists say they’re strikingly similar to those on Earth–which teem with fossils, preserved living remains. If Mars once harbored water, it could conceal a trove of fossils. But the fossil hunt won’t begin until 2013, when a NASA robot probe should blast off and return with rock samples two or three years later. While no one expects to behold a Martian T. rex, scientists do hope to discover fossils–or living!–microbes (single-celled life forms).

Surveyor’s latest photos suggest water could have flowed for millions of years on early Mars. If sand and dust eventually settled into lakes, water (or ice) may have cemented the particles into rocks. New water could have created more bands of rock over many millennia, later carved or eroded by savage winds. Could water still bubble deep beneath Mars’ surface (see SW 9/4/2000)? If ancient waters hosted Martian life forms, says Michael Carr at the U.S. Geological Survey, it’s possible: “Life can adapt to changing conditions so well, it could survive today,” Carr says. “Perhaps it’s deep below the surface, in liquid water.”

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