Characteristics of the lunar samples returned by the Chang'E-5 mission.

Forty-five years after the Apollo and Luna missions returned lunar samples, China's Chang'E-5 (CE-5) mission collected new samples from the mid-latitude region in the northeastern Oceanus Procellarum of the Moon. Our study shows that 95% of CE-5 lunar soil sizes are found to be within the range of 1.40-9.35 μm, while 95% of the soils by mass are within the size range of 4.84-432.27 μm. The bulk density, true density and specific surface area of CE-5 soils are 1.2387 g/cm3, 3.1952 g/cm3 and 0.56 m2/g, respectively. Fragments from the CE-5 regolith are classified into igneous clasts (mostly basalt), agglutinate and glass. A few breccias were also found. The minerals and compositions of CE-5 soils are consistent with mare basalts and can be classified as low-Ti/low-Al/low-K type with lower rare-earth-element contents than materials rich in potassium, rare earth element and phosphorus. CE-5 soils have high FeO and low Mg index, which could represent a new class of basalt.

Li C ，Hu H ，Yang MF ，Pei ZY ，Zhou Q ，Ren X ，Liu B ，Liu D ，Zeng X ，Zhang G ，Zhang H ，Liu J ，Wang Q ，Deng X ，Xiao C ，Yao Y ，Xue D ，Zuo W ，Su Y ，Wen W ，Ouyang Z ... -  《-》

Mineral chemistry and 3D tomography of a Chang'E 5 high-Ti basalt: implication for the lunar thermal evolution history.

In December 2020, Chang'E-5 (CE-5), China's first lunar sample return mission, successfully collected samples totaling 1731 g from the northern Oceanus Procellarum. The landing site was located in a young mare plain, a great distance from those of Apollo and Luna missions. These young mare basalts bear critical scientific significance as they could shed light on the nature of the lunar interior (composition and structure) as well as the recent volcanism on the Moon. In this article, we investigated a CE-5 basalt sample (CE5C0000YJYX065) using a combination of state-of-art techniques, including high resolution X-ray tomographic microscopy (HR-XTM), energy dispersive X-ray spectroscopy (EDS)-based scanning electron microscope (SEM), and electron probe microanalysis (EPMA) to reveal its 3D petrology and minerology. Our results show that this sample has a fine- to medium-grained subophitic texture, with sparse olivine phenocrysts setting in the groundmass of pyroxene, plagioclase, ilmenite and trace amounts of other phases. It has an extremely high ilmenite modal abundance (17.8 vol%) and contains a significant amount (0.5 vol%) of Ca-phosphate grains. The mineral chemistry is in excellent agreement with that of Apollo and Luna high-Ti basalts. The major phase pyroxenes also display strong chemical zoning with compositions following the trends observed in Apollo high-Ti basalts. Based on current data, we came to the conclusion that CE5C0000YJYX065 is a high-Ti mare basalt with a rare earth element (REE) enriched signature. This provides a rigid ground-truth for the geological context at the CE-5 landing site and clarifies the ambiguity inferred from remote sensing surveys.

Jiang Y ，Li Y ，Liao S ，Yin Z ，Hsu W ... -  《-》

Non-KREEP origin for Chang'e-5 basalts in the Procellarum KREEP Terrane.

Mare volcanics on the Moon are the key record of thermo-chemical evolution throughout most of lunar history1-3. Young mare basalts-mainly distributed in a region rich in potassium, rare-earth elements and phosphorus (KREEP) in Oceanus Procellarum, called the Procellarum KREEP Terrane (PKT)4-were thought to be formed from KREEP-rich sources at depth5-7. However, this hypothesis has not been tested with young basalts from the PKT. Here we present a petrological and geochemical study of the basalt clasts from the PKT returned by the Chang'e-5 mission8. These two-billion-year-old basalts are the youngest lunar samples reported so far9. Bulk rock compositions have moderate titanium and high iron contents  with KREEP-like rare-earth-element and high thorium concentrations. However, strontium-neodymium isotopes indicate that these basalts were derived from a non-KREEP mantle source. To produce the high abundances of rare-earth elements and thorium, low-degree partial melting and extensive fractional crystallization are required. Our results indicate that the KREEP association may not be a prerequisite for young mare volcanism. Absolving the need to invoke heat-producing elements in their source implies a more sustained cooling history of the lunar interior to generate the Moon's youngest melts.

Tian HC ，Wang H ，Chen Y ，Yang W ，Zhou Q ，Zhang C ，Lin HL ，Huang C ，Wu ST ，Jia LH ，Xu L ，Zhang D ，Li XG ，Chang R ，Yang YH ，Xie LW ，Zhang DP ，Zhang GL ，Yang SH ，Wu FY ... -  《-》

Comprehensive mapping of lunar surface chemistry by adding Chang'e-5 samples with deep learning.

Lunar surface chemistry is essential for revealing petrological characteristics to understand the evolution of the Moon. Existing chemistry mapping from Apollo and Luna returned samples could only calibrate chemical features before 3.0 Gyr, missing the critical late period of the Moon. Here we present major oxides chemistry maps by adding distinctive 2.0 Gyr Chang'e-5 lunar soil samples in combination with a deep learning-based inversion model. The inferred chemical contents are more precise than the Lunar Prospector Gamma-Ray Spectrometer (GRS) maps and are closest to returned samples abundances compared to existing literature. The verification of in situ measurement data acquired by Chang'e 3 and Chang'e 4 lunar rover demonstrated that Chang'e-5 samples are indispensable ground truth in mapping lunar surface chemistry. From these maps, young mare basalt units are determined which can be potential sites in future sample return mission to constrain the late lunar magmatic and thermal history.

Yang C ，Zhang X ，Bruzzone L ，Liu B ，Liu D ，Ren X ，Benediktsson JA ，Liang Y ，Yang B ，Yin M ，Zhao H ，Guan R ，Li C ，Ouyang Z ... -  《Nature Communications》

Age and composition of young basalts on the Moon, measured from samples returned by Chang'e-5.

Che X ，Nemchin A ，Liu D ，Long T ，Wang C ，Norman MD ，Joy KH ，Tartese R ，Head J ，Jolliff B ，Snape JF ，Neal CR ，Whitehouse MJ ，Crow C ，Benedix G ，Jourdan F ，Yang Z ，Yang C ，Liu J ，Xie S ，Bao Z ，Fan R ，Li D ，Li Z ，Webb SG ... -  《-》