Icarus (in Press) Link to Article [https://doi.org/10.1016/j.icarus.2021.114328]
1Institute for Planetary Materials, Okayama University – Misasa, 827 Yamada, Misasa, Tottori 682-0122, Japan
2Research School of Earth Sciences, Australian National University Canberra, ACT 2601, Australia
3Inst. Meteoritics, Univ. New Mexico, Albuquerque, NM 87131, USA
4Lab. d’Astrophys. de Marseille, Pôle de l’Etoile Site de Château-Gombert 38, Marseille cedex 13, France
5NASA Johnson Space Center, 2101 E NASA Pkwy, Houston, TX 77058, United States
Salt-rich deposits may be more widespread on planetary surfaces than is generally appreciated. Remote observations, laboratory studies of meteorites, and cosmochemical constraints all point towards widespread occurrences of salts (including halides, sulfates, and (bi)carbonates) on asteroids, icy bodies, Mars, and elsewhere. We have investigated the mid-infrared (1.8–25 μm) reflectance spectral properties of mixtures of chondritic (ordinary, enstatite and carbonaceous) meteorites with potassium bromide; a mid-infrared transmissive salt like all halides. Our results demonstrate that halide-chondrite mixtures provide spectral signatures that either reveal the presence of transmissive materials or provide evidence for highly porous regolith. Previously, the nature of the surfaces of the asteroids 624 Hektor and 21 Lutetia was inferred using a limited range of spectra from halide-chondrite mixtures. Here, we provide an extensive dataset of halide-chondrite mixtures to encompass a wider set of possible surface compositions.