Spectral Observations of Venus in the Frequency Interval 18.5-24.0 GHz: 1964 and 1967-68

Abstract

, Venus was observed with a tunable radiometer at eight frequencies in the interval 20.6-24.0 GHz and again at six frequencies in the interval 18.5-24.0 GHz during an eight-month period beginning approximately one month after the inferior conjunction of 1967. Microwave spectra for these frequency intervals were computed using the results from Mariner V and Veneras 4-7 and compared to these data. One block of data suggests a lower percentage of H2O than that reported by the Venera probes, while other blocks may be consistent with the probe data. These data therefore suggest that the distribution of water vapor down to atmospheric levels probed at these frequencies may vary with time or else the Venera probes may have detected localized enhancements in water vapor.

Models for the origin and composition of the earth, and the hypothesis of potassium in the Earth's core

“…Sulfur, H20 , and FeO are predicted to be nearly absent from Venus because its postulated formation temperature is above the condensation temperatures of S (as FeS), H20 (as hydrated silicates), and FeO (in solution in magnesium silicates). These predictions are consistent with the very low abundances of sulfur compounds (Owen, 1968;Cruikshank, 1967;Cruikshank and Kuiper, 1967), and H20 (Belton, 1968;Jones et al, 1972;Fink et al, 1972) in the Venus atmosphere. Rather than being endogenous, the trace amounts of I-I20 and S which are present on Venus may result from the infall of carbonaceous chondrite or cometary material (Lewis, 1974a).…”

“…However, the water content of Venus (Belton, 1968;Jones et al, 1972;Fink et aL, 1972) is about 104 times less than the water content of the Earth. To overcome this discrepancy, Ringwood postulated that the primordial material from which Venus accreted had a much higher C/H ratio than the material from which Earth accreted.…”