You can't take a spin on Mars without getting dirty.
The photo mosaic above shows three of the six wheels on NASA's Curiosity rover, already dusted with Mars dirt after just a month on the Red Planet. Curiosity snapped the shots of its wheels and underbelly using the Mars Hand Lens Imager (MAHLI) on the end of the rover’s 2.1-meter robotic arm. MAHLI took the mosaic photos September 9, during a weeklong checkout of the robotic arm's functions.
Source: Scientific American. Read full article. (link)