Caleb Scharf is director of Astrobiology at Columbia University. He is also a Global Science Coordinator for the Earth-Life Science Institute’s Origins Network at the Tokyo Institute for Technology and a co-founder of YHouse, Inc. He received his PhD in Astronomy from the University of Cambridge. His Life, Unbounded blog at Scientific American has an annual readership of over 500,000. His book, The Copernicus Complex, was The Times of London’s ‘Science Book of the Year’, and long-listed for the 2015 PEN/E.O. Wilson award. Together with ‘Gravity’s Engines’, his works have been widely praised and listed as ‘top reads’ by Barnes and Noble, New Scientist, NBC News, and more. He has written for The New York Times, LA Times, Nature, WIRED, The New Yorker, Nautilus, and many other publications.