Ian Crawford is Professor of Planetary Science and Astrobiology in the Department of Earth and Planetary Sciences, Birkbeck College, University of London, UK. His current research interests focus on lunar science, the search for life in the universe, and the future of space exploration. He has been at Birkbeck since 2003, where he was responsible for establishing the B.Sc. Degree in Planetary Science with Astronomy. Prior to his appointment at Birkbeck, Professor Crawford had a fifteen-year career as an observational astronomer at University College London, specialising is studies of the interstellar medium.  He was President of the Society for Popular Astronomy for 2006-2008, and a Vice-President of the Royal Astronomical Society for 2017-2019. Professor Crawford also has strong interests in the social and cultural implications of astrobiology and space exploration. In 2018, he was awarded a Visiting Fellowship at the Humanities Research Centreof the Australian National University to further explore these topics. This book is partly a result of that activity. Professor Crawford was awarded the 2021 Service Award for Geophysics by the Royal Astronomical Society for his long-standing promotion of lunar science and human space exploration, his role as a mentor for young planetary scientists, and other contributions to the planetary science community over the last twenty years.