^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.

^1,2Elias Wölfer, ^1,2Christoph Burkhardt, ²Gerrit Budde, ²Christian A. Jansen, ²Jonas Pape, ^1,2Thorsten Kleine
Geochimica et Cosmochimica Acta (in Press) Open Access Link to Article [DOI: 10.1016/j.gca.2026.08.021]
¹Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
²Institut für Planetologie, University of Münster, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany
Copyright Elsevier

Nucleosynthetic isotope anomalies allow distinguishing between non-carbonaceous (NC) and carbonaceous (CC) type meteorites, and have revealed correlated isotope variations especially among NC bodies. Understanding the origin of this NC trend is important for identifying the processes that produced the NC isotope heterogeneity, and for using these isotope anomalies to reconstruct the early evolution of the solar protoplanetary disk. We report mass-independent Ti, Cr, and Mo isotope compositions for a comprehensive set of previously not or only poorly investigated meteorites, as well as acid leachates obtained from the sequential digestion of primitive ordinary chondrites. Some of the samples investigated in this study fill previously identified apparent gaps in the NC trend, suggesting these gaps reflect unrepresentative sampling of a more continuous isotopic trend. Bulk meteorites and leachates exhibit distinct isotope systematics, indicating that the NC isotope variability does not reflect selective thermal processing of presolar carriers in the disk. The NC trend also cannot reflect the continuous addition of CC dust from the outer to the inner disk, because early- and late-formed NC meteorites display largely overlapping isotopic compositions. Instead, we find that the NC isotope heterogeneity is best accounted for by fractionation and mixing among chemically and isotopically distinct dust components, similar to the processes that produced the isotopic variability among carbonaceous chondrites. On this basis we argue for the presence of substructures in the inner disk, which facilitated fractionation and mixing among distinct dust components, and helped preserve a long-lived dust reservoir from which NC planetesimals accreted over an extended period of time.

¹Scott J. VanBommel (>10)
Science, 393, 820-825 Link to Article [DOI: 10.1126/science.adu5501]
¹McDonnell Center for the Space Sciences, Department of Earth, Environmental, and Planetary Sciences, Washington University in St. Louis, St. Louis, MO, USA.
Reprinted with permission from AAAS

Martian rocks are known to contain sulfur-bearing species, including sulfates and sulfides. These compounds record a sulfur cycle that operated over the geological evolution of Mars. We used the Curiosity rover to investigate a deposit of light-toned stones in Gediz Vallis within Gale crater on Mars and found that the stones are composed of native sulfur. The sulfur deposit appears to have formed in place, within a sinuous entrenched canyon cut into the floor of Gediz Vallis. The presence of native sulfur implies that a sulfur enrichment pathway involving buoyant subsurface fluids operated on ancient Mars. We propose that the primary source of this sulfur was magmatic vapor, which cooled in the near subsurface cryosphere and was released by decompression during the erosion of Gediz Vallis.

¹Pengfei Zhang (>10)
Journal of Geophysical Research: Planets (in Press) Link to Article [DOI: 10.1029/2026JE009859]
¹Center for Lunar and Planetary Sciences, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, China
Published by arrangement with John Wiley & Sons

China plans to return samples from the near-Earth asteroid (469219) Kamoʻoalewa, which we previously identified as an LL-chondrite-compositional, highly space-weathered object with fine-grained regolith. In this study, we developed 10 mL of Kamoʻoalewa regolith simulant, designated “IGCAS-AST01,” by irradiating LL5/6 chondrite (Kheneg Ljouâd) powder with a high-energy pulsed laser. We then analyzed the composition, grain size distribution, density, porosity, visible to near-infrared reflectance spectrum, emission spectrum (approximated as 1–Reflectance), thermal diffusivity, specific heat capacity, and microstructural features of both the fresh (unirradiated) powder and IGCAS-AST01. IGCAS-AST01 is composed of 57.8 vol.% olivine, 19.9 vol.% orthopyroxene, 5.6 vol.% diopside, 12.2 vol.% plagioclase, 2.6 vol.% troilite, and minor amounts of other phases. It has a mean size of 26.99 μm, a median size of 23.19 μm, a density of 1196.8 kg m⁻³, and a porosity of 64.3%. Additionally, IGCAS-AST01 exhibits a low reflectance of 0.1 at 0.55 μm and an extremely steep spectral slope. In the temperature range of 253.15–473.15 K, its thermal diffusivity and specific heat capacity range from 3.6–4.7 × 10⁻⁶  m² s⁻¹ and 718.43–890.20 J kg⁻¹ K⁻¹, respectively. Furthermore, thick amorphous rims and abundant nanophase metallic iron particles are observed in olivine and pyroxene grains of IGCAS-AST01. These results could support the Tianwen-2 mission’s payload calibration, sampling operations, on-orbit scientific data interpretation, and future sample analysis.

^1,2M. Kołodziej, ³B. Pieterek, ⁴G. Zieliński, ¹K. Załęski, ¹E. Coy
Journal of Geophysical Research: Planets (in Press) Open Source Link to Article [DOI: 10.1029/2026JE009937]
¹NanoBioMedical Centre, Adam Mickiewicz University in Poznan, Poznan, Poland
²Institute of Molecular Physics, Polish Academy of Sciences, Poznan, Poland
³Geohazard Research Unit, Institute of Geology, Adam Mickiewicz University in Poznan, Poznan, Poland
⁴Micro-area Analysis Laboratory, Polish Geological Institute—National Research Institute, Warsaw, Poland
Published by arrangement with John Wiley & Sons

Meteorites serve as an exceptional source of insight into our planet and the Solar System. Most meteorite fragments were recovered hundreds to thousands of years after their fall, and therefore exhibit varying degrees of terrestrial weathering, which has altered or completely removed weather-sensitive mineral phases. This study focuses on two aubrites—NWA 14582 and Ribbeck—examining the differences in their mineral composition. The NWA 14582 was collected in a desert long after its fall and has undergone significantly greater shock metamorphic alteration than the Ribbeck meteorite. The alterations are evidenced by the structural changes in its enstatite and diopside, along with the absence of feldspars, which have transformed into maskelynite. The Ribbeck meteorite, recovered shortly after its descent, revealed several mineral phases not present in NWA 14582. Electron microprobe investigations confirmed that minerals such as troilite, daubréelite, schreibersite, and kamacite exhibit resistance to weathering. Conversely, the observed minerals, such as heideite, caswellsilverite, oldhamite, pentlandite, and alabandite, appear to be particularly susceptible to terrestrial weathering processes. Our observations further indicate that the climate at the fall site can have a substantial impact on the preservation of primary mineral phases and the formation of secondary weathering products. We additionally report a Cu-based iodide in an early sample preparation that was not preserved in subsequently prepared mounts, as well as a rare Al–Cu–Zn alloy in Ribbeck. Further microchemical and isotopic analyses are required to determine the provenance of these phases.

¹Zhichen Zhao (>10)
Journal of Geophysical Research: Planets (in Press), Link to Article [DOI: 10.1029/2026JE009684]
¹MOE Key Laboratory of Advanced Micro‐Structured Materials, Shanghai Frontiers Science Center of Digital Optics, Institute of Precision Optical Engineering, and School of Physics Science and Engineering, Tongji University, Shanghai, China
Published by arrangement with John Wiley & Sons

Nanophase iron (np-Fe0$$), as one of the key products of space weathering, is widely observed in the near-surface layer of lunar materials, providing crucial evidence for their geological evolution. Here we report the discovery of np-Fe0$$ with a rare lamellar morphology, embedded in Fe-Ti-Cr oxide solid solutions within the interior of the lunar meteorite NWA 4734, characterized by nanometer-scale thicknesses and micrometer-scale lateral dimensions. Notably, these lamellae exhibit a unique three-layer core-shell structure, consisting of np-Fe0$$ core, Fe3+$$-bearing shell, and ilmenite-dominated outer layer. This finding offers new insights into the formation process of np-Fe0$$ in lunar materials through thermal decomposition and disproportionation associated with impact events and space weathering, and reveals a novel pathway for nanomaterial synthesis under extreme conditions.

^1,2N. Imae
Journal of Geophysical Research: Planets, 131, e2026JE009763 Open Access Link to Article [DOI: 10.1029/2026JE009763]
¹National Institute of Polar Research (NIPR), Tokyo, Japan
²The Graduate University for Advanced Studies (SOKEDAI), Tokyo, Japan
Published by arrangement with John Wiley & Sons

Enstatite chondrites record highly reducing conditions in the early solar nebula, yet the origin of their abundant sulfides remains unclear. Niningerite (MgS) and oldhamite (CaS) are ubiquitous in EH3 enstatite chondrites and distinguish them from other chondrite groups. To investigate sulfide formation, we conducted sulfidation experiments under ultra-reducing conditions using evacuated silica-glass tubes to reproduce extremely low oxygen pressure environments. Experiments at 1,200–1,420°C and IW−5 to −6 with pyrrhotite–troilite buffers examined reactions of Mg- and Ca-bearing silicates with sulfur-rich gas. Niningerite formed from forsterite–enstatite, and oldhamite from diopside, producing granular niningerite surrounding olivine and enstatite and granular oldhamite associated with diopside, coexisting with cristobalite and enstatite. Mg–Fe compositions of synthetic niningerite are included in those in EH3 chondrites. In the experiments, niningerite and oldhamite did not form within the coexisting Fe-S reservoir, whereas natural EH3 meteorites show enrichment of these sulfides in metal-sulfide nodules, a key discrepancy with natural EH3 textures. This suggests that the precursors of chondrules and metal nodules—aggregates of chondrules and metal nodules—underwent melting and segregation events, during which niningerite and oldhamite preferentially partitioned into the metal nodules. These multi-stage high-temperature processes provide new constraints on the physicochemical environment of sulfide formation in the inner solar nebula.

¹M. C. Rojas, ¹M. Mantegazza, ²J. L. Bishop, ¹M. G. Spagnuolo
The Planetary Science Journal, 7, 130 Open Source Link to Article [DOI: 10.3847/PSJ/ae5dcb]
¹IDEAN-UBA CONICET Instituto De Estudios Andinos “Don Pablo Groeber,” Argentina
²SETI Institute and NASA Ames Research Center, Mountain View, CA 94043, USA

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^1,2Victoria Muñoz-Iglesias, ³Elodie Gloesener, ⁴Carolina Gil-Lozano, ⁵Mathieu Choukroun, ¹Olga Prieto-Ballesteros, ¹Oscar Ercilla Herrero, ¹Maite Fernández Sampedro, ⁶Valentín García Baonza, ²Gabriel Tobie
The Planetary Science Journal, 7, 106 Open Access Link to Article [DOI: 10.3847/PSJ/ae63c1]
¹Centro de Astrobiología (CAB), CSIC-INTA, Carretera de Ajalvir km 4, 28850 Torrejón de Ardoz, Madrid, Spain
²Nantes Université, Univ Angers, Le Mans Université, CNRS, Laboratoire de Planétologie et Géosciences, LPG, UMR 6112, France
³Univ. Lille, CNRS, UMR 8523—PhLAM—Physique des Lasers Atomes et Molécules, F-59000 Lille, France
⁴Centro de Investigación Mariñas, XM1, Universidade de Vigo, Vigo, Spain
⁵Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
⁶Malta-Consolider Team and Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Plz. Ciencias 2, E-28040 Madrid, Spain

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