'A thorough tour of the possible abodes of life elsewhere in the cosmos, Life Beyond Earth unifies the study of planets in a way that should be more common but is still rare. Coustenis and Encrenaz provide a clear and engaging exposition of planetary habitability, giving an authoritative picture of the wealth of information that we have on planets and the engaging mysteries that remain unsolved.' Jonathan I. Lunine, Director, Center for Radiophysics and Space Research, Cornell University, and author of Earth: Evolution of a Habitable Planet