Why is NASA sending a penny to Mars?
A US penny is on-board NASA's Curiosity rover that is scheduled to land on Mars in August. The 1909 penny commemorating the centennial of President Lincoln's birth will act as a calibration target to help scientists and the public to gauge the size of objects on Mars.
A penny in today's economy does not go very far, but that has not stopped NASA from making a 1-cent piece stretch all the way to another planet: Mars.
The copper coin is attached to a smartphone-size plaque at the end of the robotic arm on Curiosity, NASA's Mars Science Laboratory car-size rover. The plaque, which was added to the vehicle as a calibration target, looks like an eye chart supplemented with color chips and the attached penny.
Targeted for a landing inside the Red Planet's Gale Crater, Curiosity will then begin its two-year mission to determine whether the area's environment has ever been favorable to support microbial life.
Researchers will use Curiosity's calibration plaque to test one of the six-wheeled rover's five science cameras, the Mars Hand Lens Imager (MAHLI).
The "hand lens" in MAHLI's name refers to Earth-bound field geologists' practice of carrying a hand lens for close inspection of rocks they find. When shooting photos in the field, geologists use various calibration methods.
"When a geologist takes pictures of rock outcrops she is studying, she wants an object of [a] known scale in the photographs," said principal investigator Ken Edgett with Malin Space Science Systems in San Diego, Calif. "If it is a whole cliff face, she'll ask a person to stand in the shot. If it is a view from a meter or so away, she might use a rock hammer." [Photos: NASA's New Mars Rover Curiosity]