NASA’s Mars probe spots evidence of ancient lake

NASA’s Opportunity Mars rover is examining the edge of a crater on the red planet that may once have been a lake of liquid water. The Opportunity rover found rocks at the edge of Endeavour Crater that were either transported by a flood or eroded in place by wind.

The features were seen just outside the crater rim’s crest above “Perseverance Valley,” which is carved into the inner slope of the rim. Researchers plan to drive Opportunity down Perseverance Valley after completing a “walkabout” survey of the area above it. The Opportunity mission has been investigating sites on and near the western rim of Endeavour Crater since 2011. The crater is about 22 kilometres across.

“The walkabout is designed to look at what’s just above Perseverance Valley,” said Ray Arvidson, from Washington University in St Louis. “We see a pattern of striations running east-west outside the crest of the rim,” said Arvidson, Deputy Principal Investigator of the Opportunity mission. A portion of the crest at the top of Perseverance Valley has a broad notch. Just west of that, elongated patches of rocks line the sides of a slightly depressed, east-west swath of ground, which might have been a drainage channel billions …read more