Astrobiology is an interdisciplinary field that asks profound scientific questions. How did life originate on the Earth? How has life persisted on the Earth for over three billion years? Is there life elsewhere in the Universe? What is the future of life on Earth? Astrobiology: Understanding Life in the Universe is an introductory text which explores the structure of living things, the formation of the elements for life in the Universe, the biological and geological history of the Earth and the habitability of other planets in our own Solar System and beyond. The book is designed to convey some of the major conceptual foundations in astrobiology that cut across a diversity of traditional fields including chemistry, biology, geosciences, physics and astronomy. It can be used to complement existing courses in these fields or as a stand-alone text for astrobiology courses. Readership: Undergraduates studying for degrees in earth or life sciences, physics, astronomy and related disciplines, as well as anyone with an interest in grasping some of the major concepts and ideas in astrobiology.