A mysterious rock has suddenly appeared in front of the Mars rover Opportunity, but where could it possibly have come from?
On Sol 3528, the Mars rover Opportunity captured an image of a small segment of the Martian surface. Twelve days later, on Sol 3540, a second image of the same area was taken - and this one was different. A rock, about the size of a jelly donut, had suddenly appeared in front of the rover.
"It was a total surprise, we were like, 'Wait a second, that wasn't there before, it can't be right'," Mars Exploration Rover Lead Scientist Steve Squyres of Cornell University told Discovery. "'Oh my god! It wasn't there before!' We were absolutely startled."
There are currently two theories about the origin of the rock, dubbed "Pinnacle Island" by scientists: That it was knocked or flipped there by Opportunity, or that it was cast off from a nearby meteorite strike. The former is considered the more likely of the two, since Opportunity's front right steering actuator is no longer working, making it likely to disturb the ground during maneuvers.
"So my best guess for this rock ... is that it's something that was nearby," Squyres said. "I must stress that I'm guessing now, but I think it happened when the rover did a turn in place a meter or two from where this rock now lies."
There is of course a third theory that daring minds are willing to consider: Martians! Seriously, think about it: What better way to mess with those boneheaded humans who keep running across your lawn with their stupid RC toy than booting a rock in front of its camera and then running away while they try to figure out where it came from? It's like an interplanetary ring-and-run!
Mission scientists hope to study the rock, which Squyres said is "obligingly turned upside-down, so we're seeing a side that hasn't seen the Martian atmosphere in billions of years," and the investigation into its actual origin is also ongoing and expected to be complete within a few days.