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.