Eureka!

Science World, April 26, 2004 by Britt Norlander

This March, one of NASA's twin Mars rovers found what it was searching for: evidence that a lot of liquid water--an ingredient thought to be necessary for life to form--once existed on the Red Planet.

While exploring Meridiani Planum, an Oklahoma-size plain on Mars, the rover named Opportunity discovered bedrock (solid rock beneath soil) at the edge of a crater. The rover sent data to Earth showing that the rocks contain jarosite, an iron-bearing mineral that forms in acidic water. The rocks also contain minerals rich in sulfur. Scientists believe these minerals precipitated (separated a solid from a liquid) when large amounts of salty water evaporated.

"It looks like [the area] was a water-rich environment at some time in Mars' history," says Jeffrey R. Johnson, a planetary geologist at NASA. Scientists don't know yet if the water formed a lake or if it soaked the rocks as groundwater (water trapped in holes in subsurface rocks).

With evidence of water, will scientists discover that life existed on Mars? "On Earth, life can thrive in some pretty inhospitable places," says Johnson. "Long ago, life may have found a niche on Mars."

Lesson Plans

Follow the Mars rovers and other late-breaking news about the Red Planet at Mars TV: www.mars.tv/

Find out more about the minerals recently discovered on Mars: www.jpl.nasa.gov/releases/2004/88.cfm

Keep track of the latest news on Mars rovers Spirit and Opportunity at this NASA Web site: http://marsrovers.jpl.nasa.gov/home/index.html