¹Victoria E.Hamilton,²Hannah H.Kaplan,^3,4Harold C.ConnollyJr,⁵Cyrena A.Goodrich,⁶Neyda M.Abreu,²Amy A.Simon
Icarus (in Press) Link to Article [https://doi.org/10.1016/j.icarus.2022.115054]
¹Southwest Research Institute, Boulder, CO, United States of America
²NASA Goddard SpaceFlight Center, Greenbelt, MD, United States of America
³Rowan University, Glassboro, NJ, United States of America
⁴American Museum of Natural History, New York, NY, United States of America
⁵Lunar and Planetary Institute, USRA, Houston, TX, United States of America
⁶NASA Langley Research Center, Hampton, VA, United States of America
Copyright Elsevier

Orbital spectra collected of asteroid (101955) Bennu by NASA’s Origins, Spectral Interpretation, Resource Identification, Security–Regolith Explorer (OSIRIS–REx) spacecraft have identified ungrouped C, CI, and CM meteorites having petrologic types 1, 1/2, and 2 as the best mineralogical analogues to Bennu to date. Here we present spectral evidence that Grosvenor Mountains (GRO) 95,577, a CR1, is a better analogue for Bennu’s bulk surface mineralogy. CR-like parent bodies are targets of interest because they contain some of the most pristine materials from the solar nebula and can contain substantial amounts of H2O and OH− in addition to exotic organics. Unfortunately, terrestrial weathering makes constraining their indigenous mineralogy and organics challenging. Analysis of samples retrieved directly from an asteroid would help us disentangle the effects of terrestrial weathering and asteroidal aqueous alteration and hence whether some of the exotic organics and large populations of presolar grains were affected by terrestrial processes in meteorites. If Bennu is comprised of CR1(−like) material, in whole or in part, the OSIRIS–REx returned sample represents a tremendous opportunity to explore in depth what is currently a unique material among carbonaceous chondrites.