Mars rover finds telltale signs of water in crater

CORNELL (US)—The two-year exploration of Victoria Crater by the Mars rover Opportunity points to the red planet’s windy past and supports previous findings that water once flowed there.

Goldwin Smith, professor of astronomy at Cornell University, and Steve Squyres, principal investigator for NASA’s Mars Exploration Rover Mission, say many of the observations—of hematite spheres (blueberries), sulfate-rich sandstone, and small chunks of rock containing kamacite, troilite, and other minerals commonly found in meteorites—are consistent with Opportunity’s findings across Meridiani Planum, the rocky plateau the size of Oklahoma where the rover landed Jan. 24, 2004.

“It shows that the processes that we investigated in detail for the first time at Endurance Crater, (where Opportunity spent six months in 2004)  are regional in scale, [indicating that] the kinds of conclusions that we first reached at Endurance apply perhaps across Meridiani,” says Squyres.

Still, there are a few key differences. The rim of Victoria Crater is higher than the rim of Endurance, says Squyres, and as the rover drove south toward Victoria the hematite blueberries in the soil became fewer and smaller. Rocks deep inside the crater, however, contained big blueberries—indicating that the rocks higher up had less interaction with water—and thus the water’s source was likely underground.

Jim Bell, Cornell professor of astronomy and leader of the Pancam color camera team for the mission, says analysis of the Victoria data will occupy researchers for years to come.

On the other side of the planet in Gusev Crater, meanwhile, Opportunity’s twin rover Spirit is stuck, possibly belly-deep, in a patch of fine Martian soil.

“The vehicle seems to be in a unique combination of soft, sandy material, and slopes that we haven’t encountered yet,” says Bell. “Neither one has been particularly problematic in the past, but the combination of the two has us bogged down.”

In 2005 Opportunity faced a similar quandary when it found itself mired down for a month in a sand trap named Purgatory Dune.

“We’re not calling this purgatory for Spirit yet, but it has that potential,” Bell says.

Rover team members, including Cornell senior research associate Rob Sullivan, who played a leading role in freeing Opportunity from Purgatory Dune, are using data from the rover and from NASA’s Mars Odyssey orbiter and Mars Reconnaissance Orbiter to plan Spirit’s escape.

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