¹I. Spring, ²T. Erickson, ¹A. Mallik, ¹A. Roy, ³A. Treiman
Journal of Geophysical Research: Planets, 131, e2026JE009689 Link to Article [DOI: 10.1029/2026JE009689]
¹Department of Geosciences, University of Arizona, Tucson, AZ, USA
²NASA Johnson Space Center’s Astromaterials Curation and Research Laboratory, Houston, TX, USA
³Lunar and Planetary Institute (USRA), Houston, TX, USA
Published by arrangement with John Wiley & Sons

Lunar dunite clast, D1, from lunar meteorite NWA 11421 represents the first lunar sample thatpotentially traces back to the lunar mantle and may provide insights into the Moon’s interior structure andchemistry. We conducted electron backscatter diffraction (EBSD) analysis of the clast to characterize its olivinemicrostructures and preferred orientations and to quantify its shock history. The EBSD data indicate that D1olivine grains are generally elongate with a moderate shape preferred orientation and a weak B‐typecrystallographic preferred orientation. Intragrain misorientations indicate that D1 experienced a high‐pressure,low‐temperature shock event. Grain orientation spread (GOS) indicates a weighted shock stage of 4.1 ± 1.3,corresponding to shock pressures of 15–20 GPa. Crystallographic rotation axes associated with low‐angle(2–10°) misorientations demonstrate preferential activation of C‐type slip, consistent with the relatively lowshock temperatures of 720 ± 99°C that were estimated using previously published linear relationships ofexperimentally shocked olivine. Notably, this shock temperature is below the sample’s equilibrium temperatureof 980 ± 20°C, as determined by two‐pyroxene thermometry. This contrast suggests that the thermal stateachieved during shock was conducive to preserving the primary mantle chemistry. The olivine fabric within D1displays J‐ and M‐indices consistent with other shocked meteorites; notably, the M‐index of these meteorites islower than that of terrestrial mantle xenoliths. Combined with the sample’s depth of origin, these characteristicssuggest D1 was excavated from either the Imbrium or Serenitatis basins and may provide the first chemicalconstraints on nearside lunar mantle.

^1,2Shixin Zhang, ^1,3,4Yachen Xie, ^4,5Yifei Liu, ^1,3,4Dongzhan Wu, ^1,2Bowen Liu, ⁴Wei Liu, ⁴Hongtao Wang, ⁴Yanyan Li, ^4,5Cunbao Li, ^4,5Heping Xie
Journal of Geophysical Research: Planets, 131, e2026JE009932 Link to Article [DOI: 10.1029/2026JE009932]
¹State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering, Sichuan University, Chengdu, China
²College of Architecture and Environment, Sichuan University, Chengdu, China
³College of Water Resource and Hydropower, Sichuan University, Chengdu, China
⁴State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering, Shenzhen University, Shenzhen, China
⁵Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization, College of Civil and Transportation Engineering, Institute of Deep Earth Sciences and Green Energy, Shenzhen University, Shenzhen, China
Published by arrangement with John Wiley & Sons

Deep-space exploration requires reliable mechanical constraints for lunar materials; however, the scarcity of samples limits destructive macroscale testing. Here, we combine automated mineralogical analysis and nanoindentation to investigate the mineral-scale mechanical behavior of two Chang’e-5 regolith particles and a Laâyoune 002 feldspathic breccia comparison sample. Rather than treating these materials as bulk proxies for all mare and highland regolith regions, we compare analogous mineral domains using an identical testing protocol. Minerals in the Chang’e-5 particles generally show lower elastic modulus and hardness, greater indentation depth and creep displacement, and higher plastic work ratios than analogous minerals measured in the interior polished section of Laâyoune 002. The strongest contrast occurs in ilmenite, where more plastic, energy-dissipative deformation is observed. These measured contrasts document micromechanical differences among analogous minerals in the analyzed lunar samples. Their interpretation considers lithology, mineral chemistry, local microstructure, and impact history, with regolith processes and space-weathering overprint as plausible contributors to the Chang’e-5 response. First-order homogenization of the analyzed particle-scale assemblages yields equivalent elastic moduli of about 54 GPa for the Chang’e-5 assemblage and about 78 GPa for the Laâyoune 002 assemblage. These results provide mineral-resolved mechanical constraints for interpreting lunar material evolution and for designing better simulants, experiments, and multiscale engineering assessments.

¹Ziyan Han (>10)
Earth and Planetary Science Letters, 693, 120294 Link to Article [DOI: 10.1016/j.epsl.2026.120294]
¹State Key Laboratory of Critical Earth Material Cycling and Mineral Deposits & Lunar and Planetary Science Institute, School of Earth Sciences and Engineering, Nanjing University, Nanjing, Jiangsu, 210023, China
Copyright Elsevier

The Moon is currently airless, but intense impact bombardments in its history may have resulted in transient atmospheres on the early Moon. However, the existence and scale of the impact-induced atmosphere have remained speculative. Here, we identified pervasive Na and K in-gassing profiles in Chang’e 6 impact glass beads that were produced from formation of craters with diameters larger than 10 m. These profiles were generated in the impact plumes where both Na and K partial pressures were larger than 10^–6 to 10^–4 bar. Using mass balance calculations, the total vapor pressures in the impact plumes containing H, N, S, C, Cl, and F could have been larger than 10^–5 to 10^–3 bar. Combined with lunar impact-flux models, our results imply that impact bombardments could have provided an important mechanism capable of generating a global transient atmosphere on the Moon with high impact flux at ≥4.4 Ga, and younger impacts alone likely only sustained local transient atmospheres as impact flux decreased after 4.4 Ga.