Rovers Dig For Clues

Both of America's Martian rovers -- Spirit and Opportunity -- were digging holes on Mars Saturday, trying to scrape up evidence that water once flowed over the surface of the Red Planet.

Scientists at NASA's Jet Propulsion Lab in Pasadena (CA) said Spirit had to work a bit harder to gouge the Martian soil with its robot arm. It spent two hours rocking its wheels back and forth over a patch of the Martian surface, hoping to move aside the most recent soil deposits to get at samples thousands of years older. "The soil at her location was apparently firmer than at Opportunity's site," said Jim Erickson, mission manager for Opportunity.

But once the three-inch trench was dug, Spirit was able to use its thermal emission spectrometer to observe the soil sample. The first rover to land on Mars also looked over toward the horizon and gave itself a visual exam, looking for signs of dust that might block its solar panels.

Spirit will continue studying the trench it dug for the next couple of days, before moving another 445 feet to a crater named by scientists as "Bonneville."

On the other side of Mars, Opportunity finished out the day reviewing samples in the trench it had dug. It then stowed its own robotic arm and made its longest drive yet -- about 50 feet. It's on the way to observe an outcropping dubbed "Stone Tablet" and remotely view another called "El Capitan."

FMI: http://mars.jpl.nasa.gov/mer