David H. Levy is the co-discoverer of Comet Shoemaker-Levy, which slammed into Jupiter in 1994 in a series of spectacular explosions with a force equal to several million tons of TNT. He is the author of More Things in Heaven and Earth, the Man Who Sold the Milky Way, The Ultimate Universe and Impact Jupiter. Levy was asked by Parade Magazine to take over the science column after the death of Carl Sagan. Levy is also the editor of The Scientific American Book of the Cosmos.