Dr. Cynthia Phillips

December 21, 2006

“Dark Slope Streaks on Mars:  Formation, Changes and Fading"


Dark slope streaks on Mars are associated with particular temperate locations, in regions of low thermal inertia. They begin at a point source, and proceed downslope in either simple wedge-shaped or branching patterns, or in complex braided formations. Two major classes of models have been proposed. The dry models suggest that streaks form through dust movement, while the wet models suggest that water, ice, and/or brine are present to lubricate or stain the surface. New slope streaks have been observed forming during the Mars Global Surveyor mission, on timescales as short as about 100 days. We propose to search the database of MOC images for overlapping image pairs that contain slope streaks, and document changes with an iterative coregistration and ratioing technique. We hope to find various details of how slope streaks form, change, or fade over time that could support one of the two major classes of models. If slope streaks are found to require the presence of liquid water, such features could have major astrobiological significance and be important targets for future missions.