Scientists Solve Mystery of Mars 'Doughnut Rock'
Scientists Solve Mystery of Mars 'Doughnut Rock'NASA/JPL-Caltech/Cornell Univ.

Scientists have solved the mystery of the strange "jelly doughnut" rock that appeared out of nowhere on the planet Mars in January 2014.

NASA's Mars Exploration Rover Opportunity's spectrometer revealed that the rock had some sort of composition, which is quite different from anything seen ever before. The rock is white in color with dark red spot in the middle. The width of the rock is 1.5 inches as described by Steve Squyres, the lead researcher in this study. Squyres named the rock Pinnacle Island.

Scientists have determined that the Pinnacle Island is actually a small piece of larger rock, broken and moved by the rover wheel.

"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. We drove over it. We can see the track. That's where Pinnacle Island came from." said Ray Arvidson from Washington University, deputy principal directory of Opportunity, in a statement.

The rock is composed of high level of sulfur and manganese, which the researcher claim must have been concentrated in the rock due of water.

"This may have happened just beneath the surface relatively recently 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", added Arvidson.

Opportunity, the space exploration vehicle has been exploring Mars since 2004 and weighs 384 pounds and measures about 5 feet in length and height.