Neil deGrasse Tyson discusses his new book, Letters from an Astrophysicist, with Radiolab host Robert Krulwich. Every year, Tyson receives thousands of letters from people across the globe who have sought him out in search of answers to questions about science, faith, philosophy, life and, of course, Pluto. His replies are by turns wise, funny and mind-blowing. The conversation was recorded on October 11, 2019 in front of a live audience at New York's 92nd Street Y.