The KREEP-rich circum-Lalande region: a candidate landing area for future lunar crewed missions

The lunar magma ocean hypothesis suggests that urKREEP was the final product of the fractional crystallization. However, urKREEP has never been identified in previous lunar samples or meteorites. The Moon is the focus in many countries and agencies’ space exploration plans, and with the advancement of technology, crewed missions have been proposed. With the primary goal of sampling the speculated primordial urKREEP, two candidate landing sites, located in the northwest (9.5°W, 0.9°S) and southeast (11.1°W, 6.2°S) of the Lalande crater (8.6°W, 4.5°S), are proposed for future crewed missions. Both sites are situated on the Th- (a critical marker of KREEP) and silica-rich Lalande ejecta in the Mare Insularum and Mare Nubium, respectively. Their geolocations at the low-latitude on the lunar nearside, the flat surface and the low rock abundance, suggest the sites are safe for landing and meet the needs of real-time Earth-Moon communication. The astronauts could perform lots of extravehicular activities (EVAs), e.g., collecting KREEP-rich samples, screening clast samples, and drilling regolith cores, to collect a variety of samples, such as Lalande ejecta, basalts, Copernicus ejecta, and regolith. The returned samples are valuable to explore the speculated urKREEP, to reveal the relationship between heat producing elements (HPEs) and volcanism, to refine the lunar cratering chronology function, and to investigate volatiles in the regolith.