Mars mystery of the white rock leaves Nasa scientists puzzled

[Reefa]

Specimen pictured by planet rover Opportunity could have been deposited by meteorite

This composite image shows before and-after images taken by the Opportunity rover of the same spot on Mars two weeks apart Photograph: Nasa/AP

Scientists are stumped as to how a rock mysteriously appeared in images of the same spot taken two weeks apart by Nasa's Mars rover Opportunity.

The rover, which landed in an area known as Meridiani Planum a decade ago, is exploring the rim of a crater for signs of past water.

On January 8, while preparing to use its robotic arm for science investigation, Opportunity sent back a picture of its work area.

It showed a bright white rock, about the size of a doughnut, where only barren bedrock had appeared in a picture it had sent back two weeks earlier. Scientists suspect the rock was flipped over by one of the rover's wheels.

It also may have been deposited after a meteorite landed nearby.

Either way, the rock, dubbed "Pinnacle Island", is providing an unexpected science bonus.

"Much of the rock is bright-toned, nearly white," Nasa said in a statement on Tuesday. "A portion is deep red in colour. Pinnacle Island may have been flipped upside-down when a wheel dislodged it, providing an unusual circumstance for examining the underside of a Martian rock."

The Huffington post quoted Steve Squyres, the rover's lead scientist at Cornell University in Ithaca, New York, as saying: "It's like nothing we ever seen before. It's very high in sulphur, very high in magnesium; it has twice as much manganese than anything we've seen on Mars. I don't know what any of this means. We're completely confused, we're having a wonderful time."

He added: "Mars keeps throwing new things at us."

Another rover, Curiosity, touched down on the opposite side of the planet in 2012 for a more ambitious mission to look for past habitable environments.

Source

[Beamslider]

Ice that evaporated perhaps