We are in a golden age in astronomy, living on the cusp of breakthroughs that will revolutionize our understanding of our place in the cosmos in. Yet a profound question remains: Are we alone in the universe? We have never been closer to answering this question. In , astrobiologist and the director of the Carl Sagan Center at the SETI Institute Nathalie A. Cabrol takes us to the frontiers of the search for life. The book’s odyssey begins by exploring how life began on Earth in order to understand what’s necessary for its existence elsewhere. What role did our Moon play? And could life on Mars have seeded life on Earth? Cabrol continues this dazzling interplanetary tour, illuminating the likeliest places for life in our neighborhood: While Mars and the icy moons of Jupiter and Saturn are among the top contenders, recent missions are redefining the limits of habitability to include unexpected worlds. Finally, we seek life beyond our Solar System, becoming witness to a revolution in the night sky: the realization that there are as many planets as stars in our galaxy. With more than 300 million exoplanets in the habitable zone of their stars in the Milky Way alone, to think we are alone, or the only advanced intelligent civilization, may be little more than nonsense. is a comprehensive and authoritative guide to the search for life. This is an exhilarating journey for anyone who has ever looked up at the stars and wondered what might be out there.