Mike Rowe Narrator Erik Dellums Narrator Michio Kaku Self Stephen Hawking Self Steve Squyres Self Alex Filippenko Self Lawrence Krauss Self Phil Plait Self Michelle Thaller Self Stan Love Self Janna Levin Self Richard Lintern Narrator Geoff Marcy Self Andrea Ghez Self Michael Strauss Self Shaun Trevisick Director Lorne Townend Director Peter Chinn Director Louise Say Director Alex Hearle Director Stuart Carter Executive Producer Paul Gasek Executive Producer Adam Warner Producer Martin Mortimore Producer