PASADENA, Calif. (February 14, 2014) Scientists say they have solved the mystery of the "jelly doughnut" rock on Mars that appeared to have come out of nowhere.
NASA said Friday that a wheel of the rover Opportunity broke the rock off a larger rock and then kicked it into the field of view.
The Internet was abuzz last month after the space agency released side-by-side images of the same patch of ground.
Only one image showed the rock, which was white around the outside and dark red in the middle, and less than 2 inches wide.
Scientists suspected that one of Opportunity's wheels kicked the rock as it drove, and they received confirmation after analyzing recent images of the original piece of rock.
Opportunity recently marked 10 years on Mars.
Its twin, Spirit, stopped communicating in 2010.