Whoa – wait a minute. The first picture taken by the Opportunity Rover shows no rock. The second, taken of the exact same spot 12 Mars days later, shows a very real rock. How’d that get there?
The discovery was revealed by Mars Exploration Rover (MER) lead scientist Steve Squyres in a 10 years of Roving Mars keynote address at NASA’s Jet Propulsion Laboratory last night. MER scientists immediately named the new rock “Pinnacle Island”.
Scientists are still scratching their heads as to how that rock could move, but there are two intriguing possibilities, one of them unlikely and another so ordinary, it almost has to be true.
Squyres thinks it’s either a stone blown out from a meteorite impact that happened to land in front of the rover or, more likely, a rock flicked like a tiddlywink when the rover performed a turn in place not far from where the rock now lies. Or the rock got stuck earlier in a rover wheel and dropped out during the maneuver.
Not ones to miss a scientific opportunity, Opportunity scientists hope to study the bright rock. “It obligingly turned upside down, so we’re seeing a side that hasn’t seen the Martian atmosphere in billions of years, and there it is for us to investigate. It’s just a stroke of luck,” Squyres said.
Opportunity’s front right steering actuator or motor has stopped working, so Squyres identified that as the possible culprit behind the whole mystery. Each wheel has its own actuator; the jam in the one wheel prevents it from turning left or right.
As the rover did a turn in place on the bedrock, the faulty wheel may have shot out the rock something like your car’s wheels blasting ice chunks out when you gun the engine to get out of a snow drift.
Still, no one knows for sure how it got there. A pal of mine suggested a blast of Martian wind. We’re lucky Opportunity found the intruder. The rover’s been parked at the same spot for weeks as it waits for better weather and a higher sun to help power it along its way. Sticking around the same spot allowed for nearly identical images to be taken on widely-separated Sols. Maybe a closer study of the rock in the coming days will tell us more about how it got there.
Despite being designed for a 90-day mission, the robot-that-could is still kicking 10 years later with more than 23 miles on its odometer. To check out the high resolution, raw images yourself, here are the links: Sol 3528 and Sol 3540.