DISTRIBUTION OF BOULDERS AROUND DE GERLACHE CRATER AND LUNAR SOUTH POLE CANDIDATE LANDING REGIONS

De Gerlache crater and the surrounding Lunar South Pole (LSP) highlands host numerous boulder fields of scientific interest. NASA has identified two potential landing regions for the Artemis 3 mission that fall within this province, and boulder fields on de Gerlache Rim (site 005) and de Gerlache Rim 2 (site 006) provide a unique opportunity to sample rock that may have originated from steeper slopes or been emplaced during regional impact events.

Here, we present a map of >10,000 boulders occurring as: (1) distal isolated blocks as well as (2) boulder fields. Our mapping is based on data returned from the Lunar Reconnaissance Orbiter (LRO) mission. Where possible and practical, we used Narrow Angle Camera (NAC) photomosaics to identify geologic units and boulders. In areas with significant shadow, we relied on Lunar Orbiter Laser Altimeter (LOLA) high-resolution digital elevation models and hillshades to estimate the boundaries of boulder fields or individual clusters. Approximately 94.91% of boulders in the de Gerlache area rest on slopes less than the angle of repose, 30 degrees; 57.02% rest on slopes accessible by humans or robotic rovers, 20 degrees. It is likely that many of these boulders are older than 3.85 Ga, and thus represent some of the oldest crustal material accessible in the Solar System. As a result of this work, we document areas where boulder fields occur on very old crust adjacent to known volatiles or permanently shadowed regions, areas that thus meet many of the high priority objectives of upcoming Artemis missions.