On the Cover: Lightning strikes during the eruption of the Del Fuego volcano near Antigua, Guatemala. Though the environments of the planets in the solar system may seem vastly different, they are based on common scientific principles. For example, data from experiments on the Soviet Venera 11 and 12 missions indicated that lightning, such as that shown on our cover, is found around possible volcanic mountains on Venus. (See page 8.) Bryan Crader / Tom Stack & Associates
3 Seeding the Galaxy: The Los Alamos Conference on Interstellar Missions: Eric M. Jones and Ben R. Finney look at both the history of human migration, and the future of our expansion into space.
7 Dust Disk Discovered Orbiting Star: Lyndine McAfeepresents an important new discovery in the search for planets beyond our solar system.
8 Lightning, Clouds and Volcanoes: Searching for Lightning on Venus: Leonid V. Ksanfomalititells the story of the search for lightning in the clouds of our nearby neighbor.
14 News & Reviews The September 1984 issue of Sky & Telescope.
15 Society Notes Humans to Mars, international cooperation, and Mars Institute courses.