In January, scientists scratched their heads trying to solve the case of a new rock found on Mars. It simply appeared out of nowhere. A white rock with a dark red low spot in the middle was lying where the rover was situated, said Steve Squyres, lead scientist of the Mars Exploration Rover mission.
According to CNN, in recent weeks prior to the rock discovery, Opportunity took photos of the same spot on Mars, 12 days apart. The rover’s panoramic camera showed only barren bedrock on mission day 3528 (in Mars time), but on day 3540, a photo of the same scene revealed the mysterious, doughnut-shaped rock.
About a month later, scientists believe they have solved the mystery of the dougnut rock. Either: Opportunity flicked the rock with one of its wheels or it could be a piece of crater ejecta, or piece of matter spewn from the impact of a meteorite. Researchers now say Pinnacle Island (the location where the rock was found) is a piece of a larger rock, which Opportunity broke and moved with its wheel in early January.
Researchers also say the rock has high levels of manganese and sulfur, which may have been concentrated in the rock because of water.
Aside from the mystery rock, Opportunity has encountered plenty of scientifically helpful discoveries. The rover found clay minerals that form in watery conditions, and indicate that water with a neutral pH could have once been there, which would be conducive to microbial life if there had been any.
NASA is planning another rover mission in 2020.