March 2, 2007 - NASA has released new detailed images that provide further evidence that water once flowed beneath the martian surface. Photos taken by Mars Reconnaissance Orbiter of Candor Chasma, one of several large canyons on Mars, have revealed rock that appears to have been chemically altered by the long-term presence of flowing water.

Previous NASA probes have found evidence of water on Mars, but the new findings bolster the theory that water may have existed long enough to sustain simple forms of life. This is because the exposed rock of the canyon, which in the past had been underground, shows that water had once pooled beneath the surface where it would have sheltered any primitive life from Mars's harsh surface environment. The findings were presented in the journal Science.

The National Academies' Space Studies Board has done a number of reports dealing with the scientific study of Mars and the investigation of present or past life on that planet. Assessment of NASA's Mars Architecture 2007-2016 identifies and prioritizes Mars research opportunities in the near future. Preventing the Forward Contamination of Mars examines the problems associated with space missions possibly bringing microorganisms to Mars, thereby complicating investigations to detect any native life.

Also, a project currently under way and scheduled for completion this spring, Astrobiology Strategy for the Exploration of Mars, will further define a scientific strategy for the search for life on Mars.

• Assessment of NASA's Mars Architecture 2007-2016 (2003)
• Preventing the Forward Contamination of Mars (2006)
• Astrobiology Strategy for the Exploration of Mars (2007)

• Mars Exploration Rover Mission Homepage
• Mars Reconnaissance Orbiter Homepage