After reaching the 22 kilometer (13.6 mile) wide crater Endeavour, the exploration vehicle first analyzed a rock and found it contained unusually high levels of zinc and bromine, elements often deposited by water, especially hot water.
The rock, which is called Tisdale 2, “is different from any rock we’ve ever seen on Mars,” said Steve Squyres, a Cornell University scientist, the principal investigator for Opportunity .
“It has a composition similar to some volcanic rocks, but there’s much more zinc and bromine than we’ve typically seen,” he said at a news conference.
“We may be dealing with a situation where water has percolated or flowed, somehow moved through these rocks, maybe as vapor, maybe as liquid, don’t know yet, but has enhanced the zinc concentration in the rock to levels far in excess of anything that we have seen on Mars before,” Squyres said.
NASA researchers also intend to search for other zinc-rich rocks, while Opportunity for bedrock, in particular, which is rock that has not been moved by impacts or other processes.