Water Ice and the Shallow Regolith Structure of the Shackleton Crater, the Moon: Implications for Future Chang’E-7 In Situ Radar Observation

The unique lighting conditions and environmental characteristics of the lunar polar region create favorable conditions for the accumulation and preservation of water ice, making detecting water ice in the polar permanent shadow regions (PSRs) of significant scientific and practical importance. The Shackleton crater, located near the south pole of the Moon, is believed to be rich in large amounts of water ice deposits within its PSRs, making it a promising potential landing site for the future Chinese Chang’E-7 (CE-7) mission. This paper provides a comprehensive review of water ice detection methods in the Shackleton crater, encompassing Moon-based radars, neutron detectors, spectrometers, etc. The results suggest the probable presence of water ice in the Shackleton crater, particularly within its PSRs, possibly distributed locally from the surface to several meters deep. However, current remote sensing techniques have limitations, necessitating future in situ exploration missions to directly confirm the presence of water ice. This paper aims to contribute to the detection of water ice and the assessment of the regolith structure using the CE-7 ground-penetrating radar, providing a comprehensive reference for future investigations in the Shackleton crater.