This book provides an introduction, from the astronomical point of view of the author, to the exciting search for extra-terrestrial life, and an overview of the current status of research into 'alien' life in the Solar System and beyond. It also explores the potential future human exploration of the Moon and Mars. Up-to-date with the latest developments in the field and accompanied by key references for further study, it is a fantastic introduction to the field of astrobiology for non-science majors taking an elective module, in addition to undergraduates studying physics with an interest in this area. Features: Contains the latest groundbreaking research in the hunt for life outside of Earth Discusses the identification of biosignatures in exo-planets Reviews future options for human outposts on the Moon and Mars