To many people, the main question about extraterrestrial life is whether it exists. But to the scientific community, that question has already been answered: it does, and within our solar system. The new science of astrobiology is already being practiced at NASA's Astrobiology Institute and the University of Washington's new Department of Astrobiology. Life Everywhere is the first book to lay out what the new science of astrobiology is all about. It asks the fascinating questions researchers in astrobiology are asking themselves: What is life? How does it originate? How often does life survive once it arises? How does evolution work? And what determines whether complex or intelligent life will emerge from more primitive forms? Informed by interviews with most of the top people in this nascent field, this book introduces readers to one of the most important scientific developments of the next century.