Perched on the rim of an ancient 22,000 meter-wide crater, the Mars rover Opportunity has reached a new type of rock that scientists believe may contain evidence that the planet was once capable of sustaining life.

Washington University professor Raymond E. Arvidson is the mission’s deputy principal coordinator. He works on the project with a team of graduate students and freshman undergraduates from the Pathfinder Program in Environmental Sustainability.

Scientists involved in the program hope that incoming data from the new site, which contains rocks older than anything the rover has yet explored, will reveal an extraterrestrial environment once suitable for life.

“We’re trying to understand what the environment was like when the ancient crater terrain was forming and being modified,” Arvidson said.

The new site, the rim of the crater called Endeavour, is spurring hopes that researchers are getting closer to locating where life may have once been possible.

“What’s really exciting about where opportunity is now is we think we see the signature of clay minerals, [which] form in an environment that has much more neutral waters,” graduate student Abigail Fraeman said.

New data in the coming days will give the team a better idea of whether to continue analyzing the current site for clay minerals or to move to a different location along Endeavour’s rim.

Opportunity stayed in the same area for its entire mission before moving to Endeavour in early August.

The crater formed recently and represents a late geologic period when the planet transitioned from wet to dry.

Although recently developed high-resolution imaging has helped the team locate clay minerals from orbit, locating them with the rover is still painstaking work.

“Opportunity drives much, much slower than a car would—something like a centimeter per second,” graduate student Amy Shaw said.

As a result, the team is meticulous in choosing a site before taking the risk of investigating it.

“The problem is we think the outcrops that contain these minerals are very small, so it’s really hard to get a good signature and figure out exactly where they are,” Fraeman said.

The team also has to keep in mind that Opportunity is operating well past its expiration date—it’s on day 2,725 of what was projected to be a 90-day mission.

“It’s going to take a while because it’s an ancient rover,” Arvidson said. “Some of the instruments aren’t working as well as they used to.”

Arvidson said that although the rover continues to function, the craft now takes almost two weeks to analyze data that could previously be studied in three hours.

An updated model named Curiosity will be launched in November and will join Opportunity next August. At five times the size of its predecessor, the new rover will have the capability of identifying organic molecules, which will allow it to explore ancient lakebeds that have been located by an orbiter.