Radio and Radar Studies of Venus and Mercury

Abstract

Recent radio and radar studies of Mercury and Venus conducted since the last Symposium on Planetary Surfaces and Atmospheres are reviewed briefly.

The surfaces of solar‐system bodies

“…Three topographical prominences (a, j3, and 7) on the surface of Venus were detected by radar [Goldstein, 1967a] and identified as mountains [Goldstein, 1961b[Goldstein, , 1969. Feature a is in the southeast, and j3 and 7 are composed of three separate rounded features, each about 150 miles across [Goldstein, 1970]. There is a small dark area below the center of the disk and a dark area with a central peak near feature a Rogers and Ingalls, 1970].…”

Asteroid Characteristics by Radar

“…Hence the surface is relatively smooth, to a scale somewhat larger than the wavelength used (12.5 cm for the Goldstone radar). Under the assumption of a uniform surface, the spectrum can be converted uniquely to a backscattering function (Goldstein, 1964), which shows how the radar cross section of an average surface element varies with the angle of incidence. This backscattering function can be considered directly as the distribution of surface slopes.…”

“…Further, the more distant and difficult targets, Mercury and Mars, have also yielded up secrets to radar probing. Finally, during the close approach of June 1968 Icarus itself was observed by radar from two different observatories (Goldstein, 1969;Pettengill et al, 1969). Review articles on radar studies of the planets are given in Shapiro (1968) and Goldstein (1970).…”