Interpretation of Mariner 5 and Venera 4 Data on the Upper Atmosphere of Venus

Abstract

Abstract Calculations have been completed on the structure of the ionosphere of Venus. Comparisons between these calculations and the results of the Mariner 5 and Venera 4 flights yield the following information on the structure of the Venus upper atmosphere: the ionosphere of Venus is of the F1 type; no more than 2% of the CO2 in the Venus ionosphere is dissociated; the relative abundance of N2 is ≤10%, in rough agreement with the Venus 4 limit of 7%; the exospheric temperature is 700±100K, the uncertainty in this result reflecting uncertainties in the CO2 vibrational deactivation coefficient and beating efficiency.