¹S. A. Parra,¹R. N. Greenberger,¹B. L. Ehlmann
Journal of Geophysical Research: Planets (In Press) Open Access Link to Article [https://doi.org/10.1029/2025JE009048]
¹Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
Published by arrangement with John Wiley & Sons

Primitive asteroids and carbonaceous chondrites (CCs) record the history of processes in theearly solar system. Visible and shortwave infrared (VSWIR) spectroscopy of primitive asteroids and bulk‐powdered CCs has identified shared spectral features suggestive of shared parent body origins. However, bulkpowder CC spectra are spatially unresolved and destroy textures, which hinders tying shared spectral featuresto particular phases, petrologic contexts, and alteration histories. This study analyzes 20 CCs measured usingmicroimaging hyperspectral VSWIR spectroscopy, recording over 700,000 individual spectra at the ∼80 μm/pixel scale. We compare CC spectral features with asteroids using the Expanded Bus‐DeMeo taxonomy. Weintroduce a spectral processing pipeline using Savitzky‐Golay filtering to better capture subtle spectralfeatures, reduce noise and enhance comparisons between asteroid classes and CC subgroups and constituentphases. Key findings include a close spectral match between CM chondrites and Cgh‐class asteroids, as wellas between CV3 chondrites and L‐class asteroids. Unaltered, iron‐bearing silicate CC components are similarto “stony” asteroid spectral classes. Furthermore, taxonomy‐based separation of CC spectra also identifiesfeatures unique to CCs, for example, oxidized iron signatures in CR2 chondrite NWA 7502 and other samplesindicative of terrestrial weathering. Together these CC data show that primary and secondary Fe‐bearingminerals drive the separations in the asteroid classes expressed in the Expanded Bus‐DeMeo taxonomy. Thesefindings also underscore the value of microimaging spectroscopy and statistically motivated frameworks inconducting larger surveys to interrogate the shared record of alteration in the early solar system. The data setis released for further study.

^1,2,3,4Jiaxin Xi,^1,2,3,4Shan Li,^1,2,3Haiyang Xian,^1,2,3Yiping Yang,⁵Dongsheng He,^1,2,3,4Jianxi Zhu,^1,2,3Xiaoju Lin,^1,2,3,4Hongmei Yang,^1,2,3,4Hongping He
Journal of Geophysical Research: Planets (in Press) Link to Article [https://doi.org/10.1029/2025JE009174]
¹State Key Laboratory of Deep Earth Processes and Resources, Guangzhou Institute of Geochemistry, Chinese Academy ofSciences, Guangzhou, P.R. China
²Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, P.R. China
³Center for Advanced Planetary Science(CAPS), Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, P.R. China
⁴University of Chinese Academy of Sciences, Beijing, P.R. China
⁵Pico Center and Department of Physics, Southern University of Science and Technology, Shenzhen, China
Published by arrangement with John Wiley & Sons

Recent studies challenge the classical view of the Moon as lacking ferric iron (Fe3+). Laboratoryinvestigations and remote sensing data confirm the presence of Fe3+, but its evolutionary mechanisms are notfully understood. We propose a temperature‐dependent mechanism for the evolution of iron content and valencein the assembly of clinopyroxene‐glass from Chang’e 5 lunar regolith samples. In situ heating experimentsusing transmission electron microscopy coupled with electron energy loss spectroscopy showed that heatingfrom 23°C to 1,000°C reduced clinopyroxene’s Fe concentration from 7.73% to 5.59%, while its Fe3+/∑Fe(∑Fe = Fe3+ + Fe2+) ratio increased from 30.17% to 59.74%. Concurrently, the Fe content in adjacent glassdecreased at higher temperatures, with a significant drop in its Fe3+/∑Fe ratio from 22.81% at 700°C to 3.93% at900°C. These findings indicate a heating‐induced co‐evolution of iron in lunar glass and clinopyroxene,suggesting that the impact‐induced thermal evolution of Fe3+ may influence the lunar surface’s local redox state.