Paydirt at Mars Rover Site
A report in the May 4 edition of the journal Science details discoveries Opportunity made in its first four months at the rim of Endeavour Crater, including key findings reported at a geophysics conference in late 2011.
Opportunity completed its original three-month mission on Mars eight years ago. It reached Endeavour last summer, three years after the rover’s science team chose Endeavour as a long-term destination. This crater is about 4 billion years old and 14 miles (22 kilometers) in diameter.
The impact that excavated the crater left a jumble of fused-together rock fragments around the rim. In a chunk brought to the surface by a later, much smaller impact into the rim, Opportunity found evidence that the original impact released heated, underground water that deposited zinc in that rock. Later after the impact, cool water flowed through cracks in the ground near the edge of the crater and deposited veins of the mineral gypsum.
“These bright mineral veins are different from anything seen previously on Mars, and they tell a clear story of water flowing through cracks in the rocks,” said Steve Squyres of Cornell University, Ithaca, N.Y. He is the principal investigator for Opportunity and lead author of the new report by 27 researchers. “From landing until just before reaching the Endeavour rim, Opportunity was driving over sandstone made of sulfate grains that had been deposited by water and later blown around by the wind. These gypsum veins tell us about water that flowed through the rocks at this exact spot. It’s the strongest evidence for water that we’ve ever seen with Opportunity.”