The U.S. mechanical rover on Mars has taken its first close-up pictures of the red planet's surface. The activity took place one day after it rolled onto Martian dirt from its landing platform.

Ground controllers at the Jet Propulsion Laboratory in California extended the robot arm of the Spirit rover for the first time.

Mission manager Mark Adler says scientists pointed the microscope-camera at the end of the arm toward the Martian ground. "Today, Spirit began its mission. We made our first use of the arm. We put the arm out in front of the rover, down, hovering over the soil with the microscopic imager and we took the first microscopic images of the surface of another planet," he said.

The new black and white pictures show a patch of Martian soil at the landing site that intrigues scientists because it seems to stick together like mud, but without liquid. They call it the "magic carpet." Researchers first noticed it soon after the Spirit spacecraft landed almost two weeks ago. The unusual soil clung together and folded over itself when airbags that cushioned the landing were being retracted over it.

Geologist Ken Herkenhoff says the camera saw details as small as a grain of sand. "This is the highest resolution by far we have ever seen Mars at. This is really an exciting picture. This is brand new, so we're still trying to understand what we're seeing here, but my personal view is that this is an agglomerate of dust particles on the surface of Mars, perhaps cemented," he said.

Scientists are planning detailed analysis of this and other Martian soil and rock. Their goal is to seek signs that water once flowed there, perhaps supporting life.

But before the rover moves away from the lander in a few days, the researchers are trying to determine how easy or hard it might be for its six wheels to push through the soil.

Images of the rover's track marks show a powdery soil finer than sand, but apparently cohesive. Cornell University scientist Rob Sullivan says the track marks are shallow, a good sign. "We don't anticipate any problems if the terrain continues to hold up like this. The rover really didn't sink in very much at all," he said.

Spirit's twin, named Opportunity, is hurtling toward a January 25 landing on a flat plain on the opposite side of Mars, where the terrain is different. If successful, it will conduct the same type of soil and rock analysis as Spirit.