Mars photos baffle scientists, present new mystery

Opportunity is knocking with mysterious new photos from Mars, but scientists aren’t sure what they’re looking at.

The roving explorer sent photos back from the Red Planet’s surface of spherical objects concentrated at an outcrop Opportunity reached last week.

The spheres measure as much as one-eighth of an inch in diameter.

These new blobs aren’t what NASA calls “blueberries,” iron-rich spherules that Opportunity first spotted in 2004.

They don’t contain as much iron as blueberries, which are in many locations on Mars.

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The new spheres are concentrated at an outcrop called Kirkwood in the Cape York segment of the western rim of Endeavour Crater, NASA said in a news release.

“This is one of the most extraordinary pictures from the whole mission,” said Opportunity’s principal investigator, Steve Squyres of Cornell University. “Kirkwood is chock full of a dense accumulation of these small spherical objects. Of course, we immediately thought of the blueberries, but this is something different. We never have seen such a dense accumulation of spherules in a rock outcrop on Mars."

Opportunity’s microscopic imager on its arm and an instrument called an Alpha Particle X-Ray Spectrometer help NASA analyze the new formations.

“They seem to be crunchy on the outside and softer in the middle,” Squyres said. “We have a wonderful geological puzzle in front of us. We have multiple working hypotheses, and we have no favorite hypothesis at this time. It's going to take a while to work this out, so the thing to do now is keep an open mind and let the rocks do the talking.”

Mars is getting renewed attention.

The rovers Spirit and Opportunity landed on Mars in 2004 and survived years longer than NASA expected them to.

The rover Curiosity landed August 5 to study Gale Crater to determine if Mars ever supported life.

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