File:PIA16158-Mars Curiosity Rover-Water-AlluvialFan.jpg
An alluvial fan, or fan-shaped deposit where debris spreads out downslope, has been highlighted in lighter colors for better viewing. On Earth, alluvial fans often are formed by water flowing downslope. New observations from Curiosity of rounded pebbles embedded with rocky outcrops provide concrete evidence that water did flow in this region on Mars, creating the alluvial fan. Water carrying the pebbly material is thought to have streamed downslope extending the alluvial fan, at least occasionally, to where the rover now sits studying its ancient history. Elevation data were obtained from stereo processing of images from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter.
Image Credit: NASA/JPL-Caltech/UofA