NASA's Mars Rover Spirit has been analyzing sulfur-rich rocks and surface materials in the "Columbia Hills" in Gusev Crater on Mars. This image of a very soft, nodular, layered rock nicknamed "Peace" in honor of Martin Luther King Jr. shows a 4.5-centimeter-wide (1.8-inch-wide) hole Spirit ground into the surface with the rover's rock abrasion tool. The high sulfur content of the rock measured by Spirit's alpha particle X-ray spectrometer and its softness measured by the abrasion tool are probably evidence of past alteration by water. Spirit's panoramic camera took this false-color image on martian day, or sol, 381 (Jan. 27, 2005), using Pancam filters at wavelengths of 750, 530, and 430 nanometers. Darker red hues in the image correspond to greater concentrations of oxidized soil and dust. Bluer hues correspond to sulfur-rich rock excavated or exposed by the abrasion tool and not as heavily coated with soils or not as highly oxidized.