The Mariner 10 Venus encounter?a review

Abstract

A brief description is given of the Mariner 10 spacecraft, its complement of scientific instruments, and its encounter with Venus. It is noted that the geometry of the Venus encounter was dictated entirely by the necessity to use Venus' gravitational field to deflect the flight path toward Mercury. Results discussed include observations of plasma and magnetic-field perturbations several hundreds of Venus radii downstream of the solar wind which indicated the presence of a well-developed plasma tail and UV observations of H, He, C, and O abundances in the upper atmosphere. The atomic-oxygen abundance was found to be an order of magnitude higher than that observed on Mars. Radio-occultation measurements showed four distinct temperature inversions in the atmosphere and two nightside ionospheric layers. Results of television observations are also discussed which confirmed the hazy model of the visible atmosphere.