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Broadband Measurements of the Complex Permittivity of Carbonaceous Asteroid Regolith Analog Materials
Author(s) -
Boivin A. L.,
Hickson D.,
Tsai C.,
Cunje A.,
Ghent R. R.,
Daly M. G.
Publication year - 2018
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
eISSN - 2169-9100
pISSN - 2169-9097
DOI - 10.1029/2018je005662
Subject(s) - regolith , asteroid , meteorite , astrobiology , space weathering , materials science , attenuation , meteoroid , permittivity , wavelength , mineralogy , geology , physics , optics , optoelectronics , dielectric
Abstract We develop a full methodology to measure the complex relative permittivity of planetary regolith analog materials in vacuum and up to 120 °C over a broad range of frequencies (400 MHz to 8.5 GHz or wavelengths 18.8–3.5 cm). We demonstrate our method with measurements of analog regolith materials appropriate for asteroid (101955) Bennu, the target of National Aeronautics and Space Administration's OSIRIS‐REx mission: individual and mixed components of UCF/DSI‐CI‐2, a new carbonaceous asteroid regolith simulant produced by Deep Space Industries based on CI chondrite meteorite mineralogy. We measure, for the first time, the effect of carbonaceous material on the complex relative permittivity of asteroid regolith analogs by measuring the powdered serpentine component of the simulant mixed with varying amounts of carbonaceous material in vacuum at 25 and 40 °C. We find that at a bulk density of 1.60 g/cm 3 and wavelength of 12.6 cm, serpentine with 5 wt% carbonaceous material hasε r ′ = 3.30 ± 0.01 and tan δ = 0.016 ± 0.003 and that carbonaceous material increases the attenuation of electromagnetic energy in our samples. Ground‐based radar (at 12.6‐ and 3.5‐cm wavelengths) has previously been used to investigate carbonaceous asteroid (101955) Bennu. Our measurements provide new constraints on the attenuation of radar energy in granular carbonaceous materials.