A high-power camera on the Mars Curiosity rover snapped a picture of a 1909 American penny featuring Abraham Lincoln. The coin is used as a calibration target for the Mars Hand Lens Imager (MAHLI) that is at the end of Curiosity’s robotic arm. In just over an Earth year on the Red Planet, you can see the bright copper is muted by lots of Mars dust.
Although the image has public relations appeal, there are scientific reasons behind picking that particular calibration target. It is supposed to measure how well the camera is performing, which is important as it zooms in on interesting features on Mars.
“The image 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,” the Planetary Science Institute stated.
“At 14 micrometers per pixel, this is the highest resolution image that the MAHLI can acquire,” the statement added.
“This image was obtained as part of a test; it was the first time that the rover’s robotic arm placed the MAHLI close enough to a target to obtain MAHLI’s highest-possible resolution. The previous highest-resolution MAHLI images, which were pictures of Martian rocks, were at 16-17 micrometers per pixel. A micrometer, also known as a micron, is about 0.000039 inches.”
Check out more about the history of this penny in Ken Kremer’s past article for Universe Today. Curiosity has a two-year prime mission on the Red Planet. Since landing in August 2012, it has already uncovered evidence of past water and gone on a search (in vain) for Mars methane.
Source: Planetary Science Institute