No. 20: Mar-Apr 1982
(1) Lightning on Venus, as detected by electromagnetic sensors on Pioneer Venus, seems to be concentrated over two major surface features. (2) Venus has 10,000 to 100,000 times less water than the earth, which is so much like it in size and other parameters.
(Beatty, J. Kelly; "Venus: The Mystery Continues," Sky and Telescope, 63:134, 1982.)