Chang’e-5 lunar samples shed new light on the Moon

Abstract

<p>The Chang��e-5 (CE-5) mission, the first return of lunar samples to Earth since the Apollo and Luna missions more than 44 years ago, landed on one of the youngest mare basalt units (1.0-3.0 Ga, based on superposed crater counts), located at middle latitude (~43��N) far from previous landing sites. On December 17, 2020, the sample capsule returned to Earth with 1731 grams of lunar soil collected from the upper few centimeters of the surface and from an ~1 meter-long core drilled into the lunar regolith. This paper summarizes the main discoveries of the CE-5 samples allocated since July 12, 2021, and measured with state-of-the-art analytical techniques. Physical property studies indicate that the CE-5 soil is mature, with a peak particle size of ~50 ?m (in volume), and a particle size distribution similar to the sub-mature and mature Apollo lunar soils (<1 cm). The soil sample contains basalt and mineral fragments, impact melt breccia, agglutinates, and glasses. The basalt fragments can be divided into several petrographic types, likely crystallized from the same lava flow at different depths and cooling rates. The CE-5 basalt Pb/Pb SIMS analyses yielded a crystallization age of 2.030 �� 0.004 Ga, extending the duration of lunar volcanic activity by ~1.0~0.8 Ga. This age, in turn, has helped to calibrate the widely applied lunar crater chronology model. The isotopic ratios of Pb, Nd and Sr indicate that the contribution of a KREEP component in forming CE-5 basalt is limited (<0.5%), excluding high concentrations of heat-producing radioactive elements in their mantle source. The isotope analyses of H, Cl, and S reveal that the mantle source is dry, which cannot account for the prolonged volcanism observed in the CE-5 landing region. A possible explanation is that the CE-5 mantle source contains enhanced clinopyroxene-ilmenite cumulate (~20%), which reduces the melting temperature by ~80��C. The REE-, FeO-enrichment of the CE-5 basalt can be attributed to a low degree of partial melting followed by extensive fractional crystallization. The CE-5 soil has also recorded a two-billion-year history of meteorite impact and solar wind irradiation. A few exotic fragments have been recognized (some with high-pressure silica phases) and are likely ejected from distant lunar highlands. The U-Pb dating of impact glass beads reveals at least 17 main impact events. New space weathering effects, especially the formation of Fe<sup>3+</sup>, have been found. <i>In situ</i> reflectance spectra and laboratory analyses of CE-5 soil show the presence of water (in the form of H, OH, and/or H<sub>2</sub>O). The solar wind hydrogen was implanted and concentrated in the outermost rims (<100 nm) of soil grains, with a temperature (hence latitude)-dependent maximum water concentration of up to ~2 wt%.</p>

Chang'E‐5 In Situ Spectra Reveal Photometric Properties of the Lunar Surface

“…The CE‐5 soils are dominated by basaltic composition (C. Li et al., 2022). As the same as Apollo samples, the CE‐5 sample has been classified as mature lunar soil based on its particle size distribution (C. Li et al., 2022; Chen et al., 2023). Furthermore, based on the analysis of the maturity of CE‐5 regolith from the LMS data, X. Wu et al.…”

Energy system and resource utilization in space: A state-of-the-art review

“…The future development of ECLSS will be comprehensively planned according to the transportation capacity, equipment operating environment, physiological and psychological changes of the crew, water ice, lunar soil and other in-situ resources. It is also necessary to carry out ecosystem experiments in special extraterrestrial environments including gravity, magnetic field, radiation, etc., and to establish a large-scale manned base technology system and model 100 and photothermal catalysis (H) 101 with the catalysts from lunar soil.…”

“…In order to reduce reliance on Earth supplies, Yao et al studied the crystal composition of the lunar soil collected by the Chang'e-5 mission and verified the potential of lunar soil as a catalyst for water electrolysis. 101 Extraterrestrial artificial photosynthesis (EAP) is a biomimetic conversion to extract O 2 from H 2 O and CO 2 driven by solar energy, along with generation of fuels (e.g., H 2 , C x H y O z ), to achieve long-term extraterrestrial residence and long-term space flight. Compared to the mature space station Sabatier technology to convert CO 2 exhaled by astronauts and electrolytic water byproduct H 2 into O 2 and methane, this approach has mild reaction conditions and low system power consumption.…”

“…The illustration of EAP is given in Figure 3C, which contains photocatalysis Figure 3D, photo electrocatalysis Figure 3E and F, photovoltaic electrocatalysis Figure 3G, and photothermal catalysis Figure 3H. Zou et al proposed an extraterrestrial life support system by the research of EAP via Chang'E-5 lunar soil, 101 and they also systematically summarized the related materials for EAP. 100 Feng et al 102,103 developed a system design and ground-based experimental validation for extraterrestrial experiments, showing that electrocatalytic CO 2 reduction to ethylene based on microfluidic membrane reactors can achieve the highest Faraday efficiencies of 72.7%.…”

“…In addition, new insights into the space resources can be obtained by analyzing the various extraretinal materials (meteorites) in the solar system. For examples: (1) the extraterrestrial photosynthesis pathway on the moon has been proposed by evaluating the extraterrestrial photosynthesis performance of the Chang'e-5 lunar sample; 101 (2) In ureilite meteorite, the diamond grains have been widely observed; 240,241 (3) The abundance of copper grains have been identified in H chondrites as a potential space resource for asteroid ISRU (Figure 9D); 239 (4) The abundance of metallic resources (e.g., Fe, Ni, Co, and Au) on parent bodies of S-type chondrites have been confirmed. 242,243…”