NEW YORK, NEW YORK - APRIL 12:  (L-R) Professor Stephen Hawking, Theoretical physicist and Mathematician Freeman Dyson, Ann Druyan, Theoretical Physicist Avi Loeb, Dr. Mae Jemison and Dr. Pete Worden attend the New Space Exploration Initiative "Breakthrough Starshot" Announcement at One World Observatory on April 12, 2016 in New York City.  (Photo by Jemal Countess/Getty Images)