Signs of erchlorates and sulfur-containing compounds

NASA's Mars rover Curiosity has detected sulfur, chlorine, and oxygen compounds in fine grains scooped by the rover at a wind drift site called "Rocknest." The grains were heated and analyzed using the rover's Sample Analysis at Mars, or SAM, instrument suite. Scientists indicate the oxygen and chlorine may come from perchlorate or similar compounds, which contain chlorine and oxygen. Perchlorates were also found by NASA's Phoenix Lander at a different location on Mars. The sulfur compounds suggest the presence of sulfides or sulfates in the grains.