Astronomer, planetary scientist, astrophysicist, exobiologist, educator, public figure, skeptic-all these hats represent important parts of Carl Sagan's complex, multifaceted career. Perhaps best known as the host of the popular television series Cosmos, Sagan offered to the world his extraordinary gift for cross-disciplinary research, his deep well of integrated visions and fruitful ideas, his vivid imagination, and his wealth of nonstop enthusiasm...