^1,2Jean Charlier,¹Alice Aléon-Toppani,¹Rosario Brunetto,²Jérôme Aléon,³Ferenc Borondics
Meteoritics & Planetary Science (in Press) Open Access Link to Article [https://doi.org/10.1111/maps.14314]
¹Institut d’Astrophysique Spatiale, CNRS, Université Paris-Saclay, Orsay, France
²Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Sorbonne Université, Museum National d’Histoire Naturelle, CNRS UMR 7590, IRD, Paris, France
³SOLEIL Synchrotron, L’Orme des Merisiers, RD 128, Saint Aubin, France
Published by arrangement with John Wiley & Sons

Refractory inclusions (RIs) in chondrites are widely used as tracers of early solar system formation conditions. In the context of sample-return missions, a non-destructive and non-invasive analytical tool that can rapidly detect and characterize RIs in space samples during their early phase of study is highly needed. Here, we performed mid-infrared (MIR) fine-scale hyperspectral imaging over large fields of view to detect RIs in CM and CO chondrites. A database of MIR spectra of typical RIs minerals was built (1) to support future remote sensing observations in astronomical environments and (2) to develop a detection method based on machine-learning algorithms and spectral distance between sample and reference minerals. With this method, up to 96.5% of the RI content is detected in a meteorite section. Further comparison between scanning electron microscopy and spot analysis acquired in reflectance in the full MIR range shows that RIs can be classified following their mineralogy based on infrared (IR) properties. Finally, we show that the relative OH content of several RIs in CM chondrites determined from IR spectroscopy can be used to infer the extent of modification caused by aqueous alteration on the asteroidal parent body.