Dielectric and Polarimetric Radar Properties of Suspected Surficial Ice Exposures at the Lunar South Pole
Tanish Himani (Johns Hopkins University)
Kevin Lewis (Johns Hopkins University)
G. Wesley Patterson (Johns Hopkins University)
Edgard G. Rivera-Valentín (Johns Hopkins University)
Shashwat Shukla (TU Delft - Physical and Space Geodesy)
Nicholas Dutton (Johns Hopkins University)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
Various active and passive orbital measurements have provided evidence for surficial water ice within some lunar permanently shadowed regions (PSRs), especially from near-infrared observations by the M3 instrument. However, radar identification of lunar ice has so far remained ambiguous. Here, we examine the radar-inferred dielectric properties of lunar PSRs and illuminated craters to investigate the potential for ice. We show that the dielectric permittivity of proposed surficial ice-bearing PSRs is lower and has a different distribution than illuminated crater floors of the same diameter range. This difference is confirmed via polarimetric analysis. However, we find that regions with fewer or greater numbers of M3 detections do not have meaningfully different dielectric properties. The lack of correlation with M3 detections suggests the differences in radar properties are likely due to a smoother surface at the wavelength scale, perhaps as a consequence of the presence of deeper ice, as suggested by prior studies.
help_outline