PIA05502: Rock Dusting Leaves "Mickey Mouse" Mar

This image taken by the navigation camera on the Mars Exploration Rover Spirit shows the rock dubbed "Humphrey" and the circular areas on the rock that were wiped off by the rover. The rover used a brush on its rock abrasion tool to clean these spots before examining them with its miniature thermal emission spectrometer. Later, the rover drilled into the rock with its rock abrasion tool, exposing fresh rock underneath.

PIA05499: A Hole in Humphrey

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."