Selected models of the Venus night-time ionosphere

Venus is a slowly rotating planet with a measured night-time ionosphere. The mechanism by which the ionosphere is maintained is still largely unexplained. Previous models and the reduction of the experimental data have all assumed spherical symmetry in the electron concentration profile. We have dispensed with this assumption and here give detailed models based on the flow of He ions from the dayside to the nightside. Further, a preliminary examination of implications of these models for the reinterpretation of the original data from Mariner V and a means for doing this are presented