Mars rover takes colour picture of three-mile-high mountain

First high-resolution colour image shows geological feature that is the reverse of the Grand Canyon

LAST UPDATED AT 09:40 ON Tue 28 Aug 2012

NASA'S Curiosity rover has beamed back a high-resolution colour image of Mars which may offer clues to the history of the 5.5km-high mountain it was sent to study.

The picture, the first high-resolution colour image to be sent by Curiosity, shows eroded knobs and gulches on a mountainside along with geological layering which is the reverse of that seen in the Grand Canyon, The Guardian reports. Layers of rock towards the summit of Mount Sharp - officially known as Aeolis Mons - are sloped in relation to those below it.

Mount Sharp is at the centre of the Gale Crater, the 154km-wide geological formation in which the Curiosity rover landed earlier this month. The mountain is thought to be all that remains of sediments that once filled the crater.

John Grotzinger, a project scientist with the California Institute of Technology, said there had been a "big change" around Mount Sharp over the aeons and compared it to the Grand Canyon.

"The layers are tilted in the Grand Canyon due to plate tectonics, so it's typical to see older layers be more deformed and more rotated than the ones above them," he said. "In this case you have flat-line layers on Mars overlaid by tilted layers. The science team, of course, is deliberating over what this means.

"This thing just kind of jumped out at us as being something very different from what we ever expected."

Whether Mars has plate tectonics - the geological phenomenon that on Earth causes earthquakes and creates mountains - is a hotly debated topic.

Grotzinger says that, apart from plate tectonics, the most likely explanation for sloping layers is that they were deposited that way by wind or by water. But there is only one way to be sure: "Probably we're going to have to drive up there to see what those strata are made of."

Nasa expects the Curiosity rover will arrive at the foot of Mount Sharp in about a year's time. · 

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