The rover Spirit used its rock abrasion tool, or RAT, to scrape a tiny, circular hole, a fraction of an inch deep, into the rock scientists have dubbed Adirondack. The robotic explorer will try to determine the composition of the rock.
"I didn't think that it would cut this deep," said Steve Gorevan, lead scientist for the RAT, according to the Agence France Presse. "In fact, when we saw virtually a complete circle, I was thrilled beyond anything I could have ever dreamed."
After probing the rock, Spirit will drive past the south side of its landing pad and head northwest toward a crater named Bonneville.
Its twin rover, Opportunity, located on the other side of the planet, has been traveling around the 72-foot-wide, 10-foot-deep crater in which it landed, snapping pictures to help scientists choose where to investigate.
An outcropping of what appears to be bedrock is located just below the lip of the crater in the Meridiani Planum. Opportunity took microscopic images of a rock in the outcrop and nearby soil on Sunday, according to NASA's Jet Propulsion Laboratory, which is operating the Mars mission.
The bedrock is important to scientists because it has been there for billions of years and could provide information about how the planet's landscape was shaped -- by wind, lava, or water, the Christian Science Monitor reported.
While sensors have indicated the area around Opportunity is rich in hematite, a mineral that usually forms with water, none seems to be present in the bedrock, according to the Monitor. But the rock appears layered, a process often associated with water.
Opportunity will continue analyzing the rock, and the results will determine how long the rover remains in the crater before moving to the next site.
On Friday, JPL gave Spirit a clean bill of health. The golf cart-sized rover had experienced problems with its memory, which interrupted its transmissions for about two weeks.
Engineers worked remotely, at a distance of about 200 million miles, to delete files from Spirit's flash memory and reformat it, according to The Washington Post. They will continue to monitor both rovers to prevent a recurrence.
The twin six-wheeled rovers are expected to operate until at least April.
In the proposed fiscal year 2005 budget, NASA said future Mars rovers should be able to cover more ground, work nonstop and last longer.
Various missions are planned to launch every two years through 2009, when Earth and Mars are closer together. Scientists expect to have a nuclear-powered rover to operate nonstop and travel hundreds of miles possibly as early as 2009, according to the Post.
The longer-term mission for Mars includes the establishment of permanent robotic outposts similar to some in Antarctica and the retrieval of rock samples from Mars to test in Earth laboratories, NASA scientists said.