Martin Rees (Lord Rees of Ludlow, OM, FRS) is the UK’s Astronomer Royal. He is based at Cambridge University where he is a Fellow (and Former Master) of Trinity College, and was Director of the Institute of Astronomy. He is a former President of the Royal Society and a member of many foreign academies. His research interests include space exploration, high energy astrophysics, cosmology and extraterrestrial life. He is co-founder of the Centre for the Study of Existential Risks at Cambridge University (CSER), and has served on many bodies connected with education, space research, arms control and international collaboration in science. In addition to his research publications he has written many general articles and ten books, including, most recently ‘On the Future: Prospects for Humanity’ , ‘The End of Astronauts’, and ‘If Science is to Save Us’.