The post-terminator ionosphere of Venus

► We study photoionization and downward ion fluxes in the nightside Venus ionosphere. ► We find that the ionosphere is sunlit to 95° SZA or slightly more. ► We find that the downward ion flux over the 90-125° range is 1.2E8 cm−2 s−1. ► We find that the nightside ne peaks are systematically higher than the RO profiles. ► We suggest that the VTS3 neutral densities are too large over the entire nightside.