O⁺⁺ in the Venusian ionosphere

It is shown that the revised photochemical theory for O ++ in the earth's ionopshere, where double photoionization of O is the dominant source, is consistent with recent O ++ measurements on Venus. A rate coefficient of 1.5 × 10 −10 cm³ s −1 for O ++ + O is obtained, and the possible importance of O ++ chemistry on minor atomic ions and airglow emissions is explored.