An anonymous reader writes in with this bit of news about the Mars rover Curiosity. "NASA's Curiosity Mars rover is using several tools this weekend to take a closer look at a sandstone slab being assessed as a possible drilling target. If it fits the bill, the target could become Curiosity's third drilled rock. 'Windjana,' named after a gorge in Western Australia, would be the mission's first drilled rock that is not mudstone. To determine whether Curiosity should drill at Windjana, engineers have asked the rover to perform a number of tasks, including observations with the camera and X-ray spectrometer located at the end of the its arm and interpretations of composition at different points on the rock with a device that fires laser shots from the rover's mast."