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.

A paper about Phoenix water studies, for which Smith is the lead author with 36 coauthors from six nations, cites clues supporting an interpretation that the soil has had films of liquid water in the recent past. The evidence for water and potential nutrients "implies that this region could have previously met the criteria for habitability" during portions of continuing climate cycles, these authors conclude.

More at phoenix.lpl.arizona.edu