Watch The Universe Season 4 Episode 4 online free

Erik Thompson
Self - Narrator

Alex Filippenko
Self - Univ. of California, Berkeley

Laura Danly
Self - Griffith Observatory

Clifford V. Johnson
Self - Univ. of Southern California

Michio Kaku
Self - Author, 'Physics of the Impossible'

Amy Mainzer
JPL

Greg Laughlin
Self - Univ. of California, Santa Cruz

Neil deGrasse Tyson
Self - American Museum of Natural History

Michael Mischna
JPL

Rob Roy Britt
Self - Livescience.com

Michelle Thaller
Self - Caltech

Travis Taylor
Self - Physicist

Chris McKay
Self - NASA Ames Research Center

Kevin R. Grazier
Self - Planetary Scientist

Lucianne Walkowicz
Self - Princeton University

Don Yeomans
JPL

Holly Gilbert
Self - NASA

Sean Carroll
Self - Caltech