The Mars expedition rover missions will be extended by several months so NASA can gather more evidence backing its belief that water once flowed freely on the planet. The US space agency says the Opportunity rover has demonstrated that rocks on Mars formed as deposits at the bottom of a body of gently flowing salt water.
"We think Opportunity is parked on what was once the shoreline of a salty sea," says principal investigator Steve Squyres. Finely layered rocks examined by the rover appear to have been formed by sediment that was shaped into ripples by water at least 50mm (2in) deep and flowing at 100-500mm/s, NASA says. While some of the ripples could have been formed by wind, "others are reliable evidence of water flow", says rover science team member John Grotzinger.
Source: Flight International
