Photo credit: NASA/JPL-Caltech/University of Arizona/Texas A&M University

This mosaic of images from the Surface Stereo Imager camera on NASA's Phoenix Mars Lander shows several trenches dug by Phoenix, plus a corner of the spacecraft's deck and the Martian arctic plain stretching to the horizon.

The footpad at the bottom center is about 1 meter (3 feet) below the spacecraft deck seen at the lower left. Overlaid images show trenches dug to either nearly pure water ice or ice-cemented soil. Analyses of samples taken from these trenches give clues to the history of the region.

This approximately true color view combines images taken on several dates during the five months Phoenix studied its surroundings after landing on May 25, 2008.

NASA Phoenix Results Point To Martian Climate Cycles

July 02, 2009 -- Favorable chemistry and episodes with thin films of liquid water during ongoing, long-term climate cycles may sometimes make the area where NASA's Phoenix Mars mission landed last year a favorable environment for microbes.

Interpretations of data that Phoenix returned during its five months of operation on a Martian arctic plain fill four papers in this week's edition of the journal Science, the first major peer-reviewed reports on the mission's findings. Phoenix ended communications in November 2008 as the approach of Martian winter depleted energy from the lander's solar panels.

"Not only did we find water ice, as expected, but the soil chemistry and minerals we observed lead us to believe this site had a wetter and warmer climate in the recent past -- the last few million years -- and could again in the future," said Phoenix Principal Investigator Peter Smith of the University of Arizona, Tucson. Read More