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The Martian rock’s a mystery—but it’s just a rock

Ellen Stofan says the “Pinnacle Island” Martian mystery rock remains unexplained—but it’s not a fungus.

Joel Levine, a research professor in the William & Mary Department of Applied Science, asked Stofan about the rock during the Q&A segment of her Feb. 6 presentation to the Department of Geology.

Levine, a 41-year NASA veteran and contributor to several Mars missions himself, asked Stofan to comment “as a geologist, and not as NASA’s chief scientist” on the strange piece of Mars discovered by the Opportunity rover. Stofan gave some background on the rock, which first appeared in an image sent on Jan. 8.

“For those of you who aren’t familiar, there was a thing that looks more or less like a jelly donut that showed up at the foot of Opportunity that had not been there a week before,” she said.

The rock has prompted head-scratching among scientists, provoked conjecture in the press, stimulated conspiracy theorists and generated a lawsuit against NASA. Even William Shatner has weighed in.

Stofan said she brought up the mystery rock with some scientists at the Goddard Space Center: “They were giving me a nice presentation and I was like, ‘What the heck is with that rock?’”

She said the rock appears to have been flipped over, as it is showing an unweathered side that’s considerably lighter than the rest of the Martian terrain.

Stofan outlined two theories accounting for the rock—and pointed out problems with each theory. She said the first explanation was that during a maneuver Opportunity kicked up the rock and flipped it over. Stofan said that while it’s the most plausible explanation, the flipped-by-rover hypothesis isn’t without problems.

“My question is—and I’m not trying to be a conspiracy theorist here, but I spent some time—the nerd that I am—looking at the two images,” she said. “Because to me, if you throw up one rock, you’re going to throw up more than one rock. So you’d expect kind of a spray of rocks. The only thing that seems to be different is the one rock.”

The second possible explanation is that the mystery rock landed near Opportunity from some sort of impact on the nearby Martian surface. Stofan isn’t completely buying that idea either.

 “We don’t know that there wasn’t an impact, but if there was an impact nearby that was throwing up big rocks, we would probably know about it,” she said. “So it wasn’t an impact.”

NASA is paying attention to Pinnacle Island, she said, which appears to be mostly manganese. Stofan said that all the observations on the rock find their way to the NASA web site, even as conspiracy theorists accuse NASA of covering up the discovery of life on Mars.

“Somebody is actually suing NASA under the Freedom of Information Act, claiming it’s some sort of fungus or something,” she said. “You know, if it were a fungus, we would be the first person out there saying it. Can you imagine how our budget would grow?”