Southwest Research Institute-Boulder
Click for a Live Broadcast.
Recurring slope lineae (RSL) are narrow (0.5-5 m) low-albedo features that incrementally lengthen down steep slopes during warm seasons. All RSL sites have steep slopes (25-40°), outcropping bedrock, and lower albedo than average for Mars. Evidence of surficial material transport and unambiguous spectral signatures of salt have not been detected. Dry and wet origins have been suggested, but water-based hypotheses best match observations that correlate incremental lengthening with higher surface temperatures. Over 165 candidate and confirmed RSL sites have been discovered from 42°N to 52°S. Some RSL sites have more than 1,000 individual RSL and numerous RSL sites are found in the deep canyons of Valles Marineris. In this talk, Dr. Stillman will compare and contrast HiRISE (25 cm/pixel) observations of seasonal, yearly, and latitudinal changes in RSL behavior, present atmospheric, thermal, and hydrological modeling of these features, and describe the mechanism(s) that recharge and source RSL.