Possible water lubricated grain movement in the circumpolar region of Mars

摘要

In this work we evaluate a new model on the possibility, could microscopic liquid water supported grain movement on Mars happen at the circumpolar region (in Richardson crater) today, combined with the analysis of new HiRISE ESP images. We confirmed earlier (PSP images based) findings on the morphology, sequential growth and two separate phased formation method of flow features emanate from Dark Dune Spots (1: gas jet driven streaks toward different directions, 2: flow-like streaks downward). We also identified that the gas jet ejected and back fallen grains surrounded by water ice produce local enrichment of H2O, forming local water ice layer.