NASA’s Mars rover Curiosity has taken the first photographs of a camera calibration target that actually includes a classic United States coin. Found in the target is a 1909 V.D.B. Lincoln cent.
The century old coin and other calibration devices are used by Curiosity’s Mars Hand Lens Imager ( MAHLI) to test its performance. MAHLI is capable of focusing on objects as close as 2.1 centimeters up to infinity.
The choice to include the Lincoln cent was the recommendation of MAHLI’s principal investigator, Ken Edgett.
"The penny is on the MAHLI calibration target as a tip of the hat to geologists’ informal practice of placing a coin or other object of known scale in their photographs. A more formal practice is to use an object with scale marked in millimeters, centimeters or meters," Edgett said. "Of course, this penny can’t be moved around and placed in MAHLI images; it stays affixed to the rover."
This specific coin was actually purchased by Edgett for use on Mars rover Curiosity. He chose the 1909 V.D.B. Lincoln Cent originally because the rover was due to launch in 2009, the centennial of the Lincoln Cent. Delays would force the launch back to 2011, but the choice to still use the same coin remained as its specifications had already been committed to.
Lincoln Cents made their first appearance in 1909 as part of a 100th anniversary celebration of the birth of the 16th President of the United States, Abraham Lincoln. The original Lincoln cent design was the work of artist Victor David Brenner whose initials (V.D.B.) originally appear on the reverse of the coin.
"Everyone in the United States can recognize the penny and immediately know how big it is, and can compare that with the rover hardware and Mars materials in the same image," stated Edgett. "The public can watch for changes in the penny over the long term on Mars. Will it change color? Will it corrode? Will it get pitted by windblown sand?"
Coins have been used previously on NASA missions as part of other instrument packages. However, this marks the first time that one will be monitored for changes as it is subjected to the conditions of the surface of another planet.
Mars rover Curiosity launched at 7:02 a.m. PST on November 26, 2011. The ten-foot long rover was designed to "search areas of Mars for past or present conditions favorable for life, and conditions capable of preserving a record of life," according to NASA.
For the latest news about NASA’s Mars rover Curiosity and the Mars mission, visit: http://www.nasa.gov/mission_pages/msl/index.html