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Lunar and Venusian radar bright ringsTwenty-one lunar craters have radar bright ring appearances which are analogous to eleven complete ring features in the earth-based 12.5 cm observations of Venus. Radar ring diameters and widths for the lunar and Venusian features overlap for sizes from 45 to 100 km. Radar bright areas for the lunar craters are associated with the slopes of the inner and outer rim walls, while level crater floors and level ejecta fields beyond the raised portion of the rim have average radar backscatter. It is proposed that the radar bright areas of the Venusian rings are also associated with the slopes on the rims of craters. The lunar craters have evolved to radar bright rings via mass wasting of crater rim walls and via post-impact flooding of crater floors. Aeolian deposits of fine-grained material on Venusian crater floors may produce radar scattering effects similar to lunar crater floor flooding. These Venusian aeolian deposits may preferentially cover blocky crater floors producing a radar bright ring appearance. It is proposed that the Venusian features with complete bright ring appearances and sizes less than 100 km are impact craters. They have the same sizes as lunar craters and could have evolved to radar bright rings via analogous surface processes.
Document ID
Document Type
Reprint (Version printed in journal)
External Source(s)
Thompson, T. W. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Saunders, R. S. (California Institute of Technology Jet Propulsion Laboratory, Pasadena, United States)
Weissman, D. E. (Hofstra University Hempstead, NY, United States)
Date Acquired
August 13, 2013
Publication Date
October 1, 1986
Publication Information
Publication: Earth, Moon, and Planets
Volume: 36
ISSN: 0167-9295
Subject Category
Distribution Limits