3-micron Reflectance Spectroscopy of Carbonaceous Chondrites under Asteroid-like Conditions

Abstract: We measured 3-micron reflectance spectra of 21 meteorites that represent all carbonaceous chondrite types available in terrestrial meteorite collections. The measurements were conducted at the Laboratory for Spectroscopy under Planetary Environmental Conditions (LabSPEC) at the Johns Hopkins University Applied Physics Laboratory (JHU APL) under vacuum and thermally-desiccated conditions (asteroid-like conditions). This is the most comprehensive 3-micron dataset of carbonaceous chondrites ever acquired in environments similar to the ones experienced by asteroids. The 3-micron reflectance spectra are extremely important for direct comparisons with and appropriate interpretations of reflectance data from ground-based telescopic and spacecraft observations of asteroids. We found good agreement between 3-{\mu}m spectral characteristics of carbonaceous chondrites and carbonaceous chondrite classifications. The 3-{\mu}m band is diverse, indicative of varying composition, thus suggesting that these carbonaceous chondrites experienced distinct parent body aqueous alteration and metamorphism environments.