This image of terrain inside Mars' Gale Crater and the inset of the calibration target for the Mast Camera (Mastcam) on NASA's Mars rover Curiosity illustrate how the calibration target aids researchers in adjusting images to estimate "natural" color, or approximately what the colors would look like if we were to view the scene ourselves on Mars, using the known colors of materials on the target. This scene includes a layered outcrop called "Shaler." The Mastcam took this image during the 71st Martian day, or sol, of Curiosity's work on Mars (Oct. 17, 2012).
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.
More information about Curiosity is online at http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl/.