Carl Sagan's biography, William Poundstone details how a young astronomer, passionate about science and obsessed with the search for life on other worlds, becomes a true media superstar. The immediately recognizable Sagan, an essential guest on television and an extraordinarily successful writer, opened the door to laymen to the mysteries of both the cosmos and science in general. Much of the scientific community saw him, however, as a pariah, a shameless publicity seeker who cared more about his image and his fortune than about the advancement of science. Poundstone rigorously reveals and documents rarely discussed aspects of Sagan's life: the legitimate and important work at the beginning of his scientific career, his almost obsessive ability to embark on infinite projects - such as the search for extraterrestrial life -, through his marital adventures and misadventures, the vicissitudes of his academic ambition and his connections with other famous people such as Isaac Asimov, Arthur C. Clarke or Steven Spielberg.