Phoenix lander leaves its mark on Mars

TUCSON, Ariz. — NASA's new robot on Mars has reached out and touched the soil for the first time, leaving behind a striking impression that looks like a footprint.

The Phoenix Mars Lander's robotic arm was making a test run, just one week after its landing. The spacecraft, which is also its own laboratory, will soon start scooping up soil and ice and running tests on it.

"This first touch allows us to utilize the robotic arm accurately," said David Spencer, Phoenix's surface mission manager at the Jet Propulsion Laboratory in Pasadena, Calif.

"We are in a good situation" for the future testing, he said Sunday.

The camera on Phoenix's robotic arm also took a number of images of what appears to be exposed ice under the lander.

Phoenix, which touched down on Mars on May 25 after a 10-month, 420 million-mile (676 million-kilometer) journey from Earth, will bore into the ground and study water and soil samples to determine if conditions were ever suitable to support life.

"What we see in the images is in agreement with the notion that it may be ice, and we suspect we will see the same thing in the digging area," said Uwe Keller of the Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany.

"We could very well be seeing rock, or we could be seeing exposed ice in the retrorocket blast zone," agreed Ray Arvidson of Washington University in St. Louis.

"We'll test the two ideas by getting more data, including color data, from the robotic arm camera. We think that if the hard features are ice, they will become brighter because atmospheric water vapor will collect as new frost on the ice," Arvidson added in a statement.

The Viking landers in the 1970s and early 1980s conducted similar tests on surface soils. The detection of subsurface frozen water in 2002 by Mars Odyssey prompted scientists to propose the Phoenix mission.

This report includes information from The Associated Press and Reuters.