NASA's Mars Exploration Rover Spirit's rock abrasion tool is shown covered in reddish dust during a recent soil-brushing experiment. An abundance of iron oxide minerals in the dust gave the device a reddish-brown veneer. Investigators were using the rock abrasion tool to uncover successive layers of soil in an attempt to reveal near-surface sedimentary rock. Afterward, remnant dirt clods were visible on both the bit and the brush of the tool.

The rock abrasion tool was designed to run the rock abrasion tool's brush in reverse to dislodge the dirt and return the tool to normal operation. Communications with the rover revealed that the procedure is working and the rock abrasion tool remains healthy.

--SPACE.com staff

Credit: NASA/JPL-Caltech/Cornell