One might have wondered what the Opportunity rover would do as an encore to its discovery of “blueberries” near its landing site during its first year on Mars as it celebrated its 10th anniversary. The veteran rover delivered in a big way with the discovery of a mysterious “jelly doughnut rock.”
“It’s white around the outside, in the middle there’s kind of a low spot that’s dark red: It looks like a jelly doughnut,” said Cornell University astronomer Steven Squyres, the principal investigator of the Mars Exploration Rover Mission. He announced the finding last week at a celebratory event at the California Institute of Technology in Pasadena to honor the rover’s 10th anniversary.
What makes this rock so mysterious is that it seems to have just showed up a few weeks ago in a spot where there was nothing before. Further, it is unlike anything scientists have seen on Mars before.
“It appeared — it just plain appeared at that spot,” Squyres said. NASA has dubbed it Pinnacle Island.
Squyres has two theories about how the rock got there. One possibility is that a nearby impact could have flung a piece of debris Opportunity’s way. Or, in what Squyres believes more likely happened, one of Opportunity’s six wheels flicked it up out of the ground.
Scientists believe that Pinnacle Island landed upside down, giving them a serendipitous glimpse of the underside of a Martian rock that may not have been exposed to the atmosphere for billions of years. The NASA team is closely inspecting its composition, but so far, this rock is nothing like others they have seen.
“We’ve taken pictures of both the doughnut part and the jelly part,” he said at the event. “We got our first data on the composition of the jelly yesterday.”
The dark-red portion has lots of sulfur and magnesium, as well as twice as much manganese as anything previously measured on Mars. The results have deeply confused NASA scientists, Squyres said, and have inspired heated debates about what all this might mean.
Originally set for a mission of 90 days, Opportunity on Saturday will celebrate the 10-year anniversary of its arrival on the planet. In that decade, the rover has trekked almost 25 miles along the Martian soil. However, it is starting to show its age.
“The front steering actuator is jammed, and the robotic arm has some arthritis to it,” said Mars Exploration Rovers project manager John Callas at a news conference Thursday. He also described Opportunity as “having a senior moment” due to problems with its flash memory. But all in all, the team has been pleasantly surprised at its long lifetime and numerous contributions to our understanding of Mars.