Mars rover finds intriguing rock

Washington Post : After 10 years roaming Mars’s surface, the Opportunity rover is still making new discoveries. Just a few weeks ago, a mysterious rock suddenly appeared next to the rover, which was parked on the rim of Endeavour Crater. Dubbed the “jelly doughnut” because of its appearance—white around the outside with a low red spot in the center—the rock has puzzled NASA scientists because it is unlike any others seen on the planet’s surface. While the red part appears to contain sulfur, magnesium, and manganese, the white part is still being analyzed. Scientists believe either the rock landed near the rover from a nearby impact or the rover itself churned it up from the ground with one of its wheels.