Lincoln Cent on Mars Rover
The Lincoln penny in this photograph is part of a camera calibration target attached to NASA's Mars rover Curiosity, which is on track for a landing on Mars the night of Aug. 5 to Aug. 6, 2012.
The calibration target for the Mars Hand Lens Imager (MAHLI) instrument also includes color references, a metric bar graphic, and a stair-step pattern for depth calibration. The MAHLI adjustable-focus, color camera at the end of Curiosity's robotic arm can be used for taking extreme close-ups of rocks and soil on Mars, as well as images from greater distances.
The penny is a nod to geologists' tradition of placing a coin or other object of known scale as a size reference in close-up photographs of rocks, and it gives the public a familiar object for perceiving size easily when it will be viewed by MAHLI on Mars. The specific coin, provided by MAHLI's principal investigator, Ken Edgett, is a 1909 "VDB" penny.