September 27, 2012: The path on Mars of NASA's Curiosity rover toward Glenelg, an area where three terrains of scientific interest converge, is seen in this undated NASA handout image taken by the High Resolution Imaging Science Experiment (HiRISE) instrument on NASA's Mars Reconnaissance Orbiter. Arrows mark geological features encountered so far that led to the discovery of what appears to be an ancient Martian streambed. (NASA/JPL-Caltech/Univ. of Arizona/Handout/Reuters)