Venera 8: Measurements of Solar Illumination Through the Atmosphere of Venus 1

Abstract

Measurements of the flux of downward solar radiation through the atmosphere of Venus and at the planetary surface are reported. These were obtained with the interplanetary spacecraft Venera 8 which landed on the surface of Venus on 22 July 1972 after a 55-min parachute descent through the atmosphere. A significant flux of solar radiation was found to penetrate the entire thickness of the atmosphere, with the amount at the ground ∼1.5% of that incident on the top of the atmosphere. The variation of flux with altitude indicates that the clouds have a lower boundary at an altitude of σ35 km.