New Geological Maps of the Amundsen and Rubin Crater Regions Near the Lunar South Pole.

The lunar south pole region is a high-priority exploration target due to its unique geological history, potential resources in permanently shadowed regions (PSRs), and regions of nearly continuous sunlight [e.g., 1-5]. In this context, the Amundsen crater region offers significant opportunities to investigate impact processes, lunar evolution, and volatile distribution, which we have presented through geologic mapping at a regional scale of 1:100,000 for the Amundsen crater region [1] and at a local scale of 1:30,000 for Rubin crater [2].We produced a 1:100,000 scale geomorphologic map delineating basin materials, crater materials, and modified surface units, allowing a comprehensive reconstruction of the geologic history of the region [1]. Amundsen’s proximity to the proposed outer rim of the South Pole-Aitken (SPA) basin suggests that its ejecta may have reworked ancient lunar rocks, making it an invaluable site for sampling and understanding south polar impact history. Crater size-frequency distribution (CSFD) measurements yield an Amundsen crater formation age of ~4.04 Ga [1].Within the Amundsen crater region, we have identified five Areas of Interest (AoIs), which are scientifically valuable regions such as the plains near Idel’son L and Rubin crater on the Amundsen rim [1]. These AoIs meet critical technical criteria, including gentle slopes, sufficient solar illumination, and Earth visibility to ensure safe landings and operational feasibility. Because Rubin crater (~4 km diameter), located on the northwestern rim of Amundsen, offers perfect conditions for a safe landing and may have direct access to the SPA material, we present a higher-resolution (1:30,000) map of this region [2].The high-resolution mapping shows that Rubin crater’s terrain hosts boulders, PSRs, and fresh craters, serving as prime sampling targets for robotic and human exploration. To minimize risk and optimize science return, we evaluated candidate landing sites and traverse options near Rubin crater, considering engineering constraints such as slope limits and energy requirements. Detailed geologic mapping of the Rubin ejecta and surrounding terrain [2] provides insight into its potential as a science- and resource-rich site and its role as a testbed for operations in more challenging polar terrain.Our mapping and analysis of the Amundsen region highlight its ability to address key lunar science objectives [3,4]. Sampling of Amundsen and Rubin ejecta can refine the lunar chronology and improve our understanding of lunar differentiation and early Solar System dynamics. Additionally, the study of PSRs can reveal the composition, distribution, and stability of lunar volatiles, which is critical for resource utilization [4,6]. By integrating regional and site-specific geologic data, we provide a framework for mission planning that maximizes scientific return while ensuring safety. These efforts confirm the Amundsen region’s status as a key location for advancing lunar science and exploration.  [1] Wueller et al. (2024) PSJ 5(6).[2] Wueller et al. (2025) submitted to Adv. In Space Res.[3] National Research Council (2007) The Scientific Context for Exploration of the Moon, National Academic Press.[4] Artemis Science Definition Team (2020) Artemis Science Definition team Report.[5] Krasilnikov et al. (2023) Icarus, 394.[6] Crawford et al. (2023) Reviews in Mineralogy and Geochemistry, 89(1), 829-868.