Exploring the Jau Crater Cluster, Gale Crater, Mars

Abstract

The Jau crater cluster on the north flank of Mt. Sharp in Gale crater consists of 20 to 30 impact craters formed simultaneously by a fragmenting primary meteorite, are between 2 to 25 m across, and that generally increase in size from the ESE to the WNW. Interpretations are based mostly on Mastcam and Navcam images taken by the Curiosity rover, some of which are used to create orthomosaics and Digital Terrain Models, and that are augmented by orbital images acquired by the HiRISE camera. Comparison of current crater morphology versus expected original post-impact or pristine appearance helped to establish the processes and amount of degradation occurring since formation. We conclude that primarily aeolian degradation has caused ~1-2 m wall back-wasting, 10s of cm of infilling by aeolian transported sediment, and 10s of cm of erosional rim lowering at two of the larger craters. Based on use of prior estimated vertical erosion rate of 0.1 m/Myr and horizontal erosion rate of several m/Myr predicted we estimate the Jau cluster-forming impact occurred less than ~5 Ma.