The study of life in our universe has been given the name 'astrobiology'. It is a relatively new subject, but not a new discipline since it brings together several mature fields of science including astronomy, geology, biology, and climatology. An understanding of the singular conditions that allowed the only example of life that we know exists to emerge and survive on our turbulent planet is essential if we are to seek answers to two fundamental questions facing humanity: will life (and especially human life) continue on Earth, and does life exist elsewhere in the universe?...