On this image of the rock target "Knorr," color coding maps the amount of mineral hydration indicated by a ratio of near-infrared reflectance intensities measured by the Mast Camera (Mastcam) on NASA's Mars rover Curiosity. The color scale on the right shows the assignment of colors for relative strength of the calculated signal for hydration. The map shows that the stronger signals for hydration are associated with pale veins and light-toned nodules in the rock. This image and the data for assessing hydration come from a Mastcam observation of Knorr during the 133rd Martian day, or sol, of Curiosity's work on Mars (Dec. 20, 2012). The width of the area shown in the image is about 10 inches (25 centimeters).
Image credit: NASA/JPL-Caltech/MSSS/ASU