Differential VLBI Measurements of the Venus Atmosphere Dynamics by Balloons - VEGA Project

Abstract

Results are reported of the measurements of balloon motion in the upper layers of the Venus atmosphere. The measurement of the balloon trajectories was carried out by differential VLBI observations of the balloons relative to the fly-by spacecrafts (VEGA-1 and VEGA-2). Balloon-2, launched in the southern hemisphere of the planet led to the discovary of gas motion with average velocities of 65.3 m/s and 3.4 m/s in longitude and latitude, respectively. Balloon-1, launched in the southern hemisphere, showed that gas motions occur with an average velocity of 68.7 m/s in the longitudinal direction, but no wind was detected in the latitudinal direction