An outstanding popularizer of science, a wonderful storyteller, a passionate promoter of space, a visionary, Carl Sagan believes that the desire to wander and expand the boundaries of knowledge is inherent in human nature and is associated with our survival as a species. His candid, engrossing book interweaves philosophical musings with enthusiastic descriptions of triumphant exploration of planets and moons, both by humans visiting the Moon and by robotic missions. By introducing us to our neighbors in space, Sagan not only enlightens and delights the reader, he also helps us understand how to protect the Earth.