Researchers have determined the now-infamous Martian rock resembling a jelly doughnut, dubbed Pinnacle Island, is a piece of a larger rock broken and moved by the wheel of NASA’s Mars Exploration Rover Opportunity in early January.
This image from the panoramic camera (Pancam) on NASA’s Mars Exploration Rover Opportunity shows where a rock called “Pinnacle Island” had been before it appeared in front of the rover in early January 2014. Image Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.
Only about 1.5 inches wide (4 centimeters), the white-rimmed, red-centered rock caused a stir last month when it appeared in an image the rover took Jan. 8 at a location where it was not present four days earlier.
More recent images show the original piece of rock struck by the rover’s wheel, slightly uphill from where Pinnacle Island came to rest.
“Once we moved Opportunity a short distance, after inspecting Pinnacle Island, we could see directly uphill an overturned rock that has the same unusual appearance,” said Opportunity Deputy Principal Investigator Ray Arvidson of Washington University in St. Louis. “We drove over it. We can see the track. That’s where Pinnacle Island came from.”
Examination of Pinnacle Island revealed high levels of elements such as manganese and sulfur, suggesting these water-soluble ingredients were concentrated in the rock by the action of water. “This may have happened just beneath the surface relatively recently,” Arvidson said, “or it may have happened deeper below ground longer ago and then, by serendipity, erosion stripped away material above it and made it accessible to our wheels.”
Now that the rover is finished inspecting this rock, the team plans to drive Opportunity south and uphill to investigate exposed rock layers on the slope.
The boulder-studded ridge in this scene recorded by NASA’s Mars Exploration Rover Opportunity is “McClure-Beverlin Escarpment,” informally named for Jack Beverlin and Bill McClure, engineers who on Feb. 14, 1969, risked their lives to save NASA’s second successful Mars mission, Mariner 6, on its launch pad. Image Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.