This image taken by the navigation camera onboard the Mars Exploration Rover Spirit shows a hole drilled by the rover in the rock dubbed "Humphrey." Spirit ground into the rock with the rock abrasion tool located on its robotic arm on the 60th martian day, or sol, of its mission. Scientists are investigating the freshly exposed rock with the rover's suite of scientific instruments, also located on the rover's arm. Spirit is on its way to a large crater nicknamed "Bonneville."
Image credit: NASA/JPL