Nutrients and episodes with thin films of water during long-term climate cycles may sometimes make arctic Mars a favorable environment for microbes.
NASA's activities in social networking media will be recognized Wednesday in New York, when the agency receives an award for its presence on the popular Web site Twitter.
After a picture-perfect landing, the Phoenix Mars Lander returned unprecedented views and new findings from Mars’ north polar region.
› View This VideoThe Mars Lander surpassed its original three-month mission, lasting five months in the Martian northern plains, digging up scientific "firsts" along the way.
› View This VideoAn audio recording and images from the August 5, 2008, media telecon.