Outside of religion, no human pursuit deals with deeper questions of existence than astronomy, and few areas of science compare in capturing the public imagination. Today, however, the pace of discovery is so rapid that even professional astronomers have difficulty staying current. In this book, an astronomer and award-winning, highly acclaimed teacher shares the ten deepest mysteries that motivate astronomy today -- from the quest for life outside Earth, to the ultimate fate of the universe. It's an awesome collection of mysteries, and Jeffrey Bennett explains each one with remarkable clarity, enabling any educated citizen to share in the wonder, no matter how little scientific or mathematics background they may have. Is there life elsewhere in our solar system? Where are the Sun's missing neutrinos? What does the universe look like? How do galaxies evolve? Are Earth-like planets common? What makes gamma-ray bursts? Is the inflationary big bang theory true? What is the universe made out of -- and what is its fate? Every mystery is framed with a story that draws upon history or an especially resonant metaphor, then explained in detail, but simply enough for those coming to astronomy for the first time.