US penny. Image of a 1909 VDB US penny on a calibration target, taken by the Mars Hand Lens Imager (MAHLI) onboard NASA's Curiosity rover in Gale Crater on Mars. This image was obtained as part of a test on the 411th Martian day, or sol, of the mission (2nd October 2013), the first time the rover's robotic arm placed MAHLI close enough to a target to obtain the camera's highest-possible resolution. It shows that, during the penny's 14 months (so far) on Mars, it had accumulated Martian dust, despite its vertical mounting position on the calibration target for MAHLI.