The lunar magma ocean hypothesis suggests that the primordial KREEP(an acronym of potassium(K),rare earth element(REE),and phosphorus(P))was the final product of fractional crystallization.However,the primordial KREEP...The lunar magma ocean hypothesis suggests that the primordial KREEP(an acronym of potassium(K),rare earth element(REE),and phosphorus(P))was the final product of fractional crystallization.However,the primordial KREEP(a.k.a.urKREEP)has never been identified in previous lunar samples or meteorites.The Moon is the focus of many countries’and agencies’space exploration plans,and with the advancement of technology,crewed missions have been proposed.We propose two candidate landing sites,located respectively in the northwest(9.5°W,0.9°S)and southeast(11.1°W,6.2°S)of Lalande crater(8.6°W,4.5°S),for future crewed missions,with the primary goal of sampling the speculated urKREEP.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 many extravehicular activities,such as collecting KREEP-rich samples,screening clast samples,and drilling regolith cores,to gather 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 and volcanism,to refine the lunar cratering chronology function,and to investigate volatiles in the regolith.展开更多
Water has been detected in lunar regolith,with multiple sources identified through the analysis of individual grains.However,the primary origin of water in the bulk lunar regolith remains uncertain.This study presents...Water has been detected in lunar regolith,with multiple sources identified through the analysis of individual grains.However,the primary origin of water in the bulk lunar regolith remains uncertain.This study presents spectroscopic analyses of water content in sealed Chang’e-5 samples.These samples were sieved into various size fractions(bulk,<45μm,and 45–355μm)inside a glovebox filled with high-purity nitrogen.Results indicate a higher water content in the fine fractions(~87±11.9 ppm)than in bulk soil(~37±4.8 ppm)and coarse fractions(~11±1.5 ppm).This suggests that water is predominantly concentrated in the outermost rims of the regolith grains,and thus exhibits dependence on the surface volume ratio(also known as surface correlation),indicating solar wind is a primary source of lunar surface water.Laboratory,in-situ,and orbital results bridge sample analysis and remote sensing,offering a cohesive understanding of lunar surface water characteristics as represented by Chang’e-5.The discovery provides statistical evidence for the origin of water in lunar soil and can be considered representative of the lunar surface conditions.The water enrichment of the finest fraction suggests the feasibility of employing size sorting of lunar soils as a potential technological approach for water resource extraction in future lunar research stations.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2022YFF0503104)the National Natural Science Foundation of China(Grant Nos.42241111,62227901,and 42441826)+1 种基金the Macao Young Scholars Program(Grant No.AM201902)the Key Research Program of the Institute of Geology and Geophysics,Chinese Academy of Sciences(Grant No.IGGCAS-202401).
文摘The lunar magma ocean hypothesis suggests that the primordial KREEP(an acronym of potassium(K),rare earth element(REE),and phosphorus(P))was the final product of fractional crystallization.However,the primordial KREEP(a.k.a.urKREEP)has never been identified in previous lunar samples or meteorites.The Moon is the focus of many countries’and agencies’space exploration plans,and with the advancement of technology,crewed missions have been proposed.We propose two candidate landing sites,located respectively in the northwest(9.5°W,0.9°S)and southeast(11.1°W,6.2°S)of Lalande crater(8.6°W,4.5°S),for future crewed missions,with the primary goal of sampling the speculated urKREEP.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 many extravehicular activities,such as collecting KREEP-rich samples,screening clast samples,and drilling regolith cores,to gather 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 and volcanism,to refine the lunar cratering chronology function,and to investigate volatiles in the regolith.
基金supported by the National Natural Science Foundation of China(42241106,42230206)the Key Research Program of the Institute of Geology and Geophysics+2 种基金Chinese Academy of Sciences(IGGCAS-202101)the Young Elite Scientists Sponsorship Program by China Association for Science and Technology(2021QNRC001)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2023071)。
文摘Water has been detected in lunar regolith,with multiple sources identified through the analysis of individual grains.However,the primary origin of water in the bulk lunar regolith remains uncertain.This study presents spectroscopic analyses of water content in sealed Chang’e-5 samples.These samples were sieved into various size fractions(bulk,<45μm,and 45–355μm)inside a glovebox filled with high-purity nitrogen.Results indicate a higher water content in the fine fractions(~87±11.9 ppm)than in bulk soil(~37±4.8 ppm)and coarse fractions(~11±1.5 ppm).This suggests that water is predominantly concentrated in the outermost rims of the regolith grains,and thus exhibits dependence on the surface volume ratio(also known as surface correlation),indicating solar wind is a primary source of lunar surface water.Laboratory,in-situ,and orbital results bridge sample analysis and remote sensing,offering a cohesive understanding of lunar surface water characteristics as represented by Chang’e-5.The discovery provides statistical evidence for the origin of water in lunar soil and can be considered representative of the lunar surface conditions.The water enrichment of the finest fraction suggests the feasibility of employing size sorting of lunar soils as a potential technological approach for water resource extraction in future lunar research stations.
