This image of a U.S. penny on a calibration target was taken by the Mars Hand Lens Imager (MAHLI) aboard NASA's Curiosity rover in Gale Crater on Mars. At 14 micrometers per pixel, this is the highest-resolution image that MAHLI can acquire.
This image was obtained as part of a test on the 411th Martian day, or sol, of the mission (Oct. 2, 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 has accumulated Martian dust and clumps of dust, despite its vertical mounting position on the calibration target for MAHLI.
The previous highest-resolution MAHLI images, which were pictures of Martian rocks, were at 16 to 17 micrometers per pixel. A micrometer, also known as a micron, is about 0.000039 inch.
The penny is a 1909 VDB penny minted in Philadelphia during the first year that Lincoln cents became available. More information about its inclusion on the MAHLI calibration target is available at http://www.jpl.nasa.gov/news/news.php?release=2012-033.
The gold medal for highest resolution photographs on Mars goes to NASA's Phoenix Mars Lander's optical microscope. As a microscope, though, fine-grained samples had to be delivered to it, whereas MAHLI can be deployed to look at geologic materials in their natural setting.
Malin Space Science Systems, San Diego, developed, built and operates MAHLI. NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Mars Science Laboratory Project and the mission's Curiosity rover for NASA's Science Mission Directorate in Washington. The rover was designed and assembled at JPL, a division of the California Institute of Technology in Pasadena.