麦克·罗维

Mike Rowe

饰：Narrator

Phil Plait

饰：Himself - Phd., Astronomer

Michelle Thaller

饰：Herself - Phd., astronomer, NASA Goddard Space Flight Center

Hakeem Oluseyi

饰：Himself, Astrophysicist

加来道雄

Michio Kaku

饰：自己 Self

劳伦斯·M.克劳斯

Lawrence M. Krauss

饰：自己

Moogega Cooper

饰：Herself - Planetary Protection Engineer

Dan Durda

Alex Filippenko

饰：Self - Astrophysicist

Lewis Dartnell

饰：Self - Astrobiologist

Konstantin Batygin

饰：Self - Planetary Astrophysicist

David Spergel

饰：Self - Theoretical Physicist

Caleb Scharf

饰：Self - Astrobiologist

Claudia Alexander

饰：Self - Planetary Science

Carey Lisse

饰：Self - Astronomer

Carlos Frenk

饰：Self - Cosmologist

Heidi Hammel

饰：Self - Astronomer

Steve Squyres

饰：Self - Astronomer

Monica Dunford

饰：Self - ATLAS Engineer

William Hartmann

饰：Self - Planetary Scientist

Dante Lauretta

饰：Self - Cosmochemist, University of Arizona

Saul Perlmutter

饰：Self - Astrophysicist

Robert Zubrin

饰：Self - Aerospace Engineer

Dougal Jerram

饰：Self - Volcanologist

Seth Shostak

饰：Self - Astronomer

Linda Spilker

饰：Self - Cassini Mission Project Scientist

Peter Galison

James S. Bullock

饰：Self - Astrophysicist

理查德·林特恩

Richard Lintern

饰：Self - Narrator

麦克斯·泰格马克

Max Tegmark

饰：Self - Theoretical Physicist

埃里克·德拉姆斯

Erik Dellums

饰：Narrator

Geoff Marcy

饰：Self - Astronomer, University of California, Berkeley

Amy Mainzer

Russell Schweickart

饰：Self - Apollo 9 Astronaut, B612 Foundation

Janna Levin

饰：Self - Theoretical Physicist

Michael Rampino

Michael Rampino

饰：Self - Geologist

史蒂芬·霍金

Stephen Hawking

饰：Self - Theoretical Physicist

Gentry Lee

饰：Self - Space Flight Engineer

Adam Showman

饰：Self - Planetary Scientist, University of Arizona

阿兰·古斯

Alan Guth

饰：Self - Theoretical Physicist

焦立中

Leroy Chiao

饰：Self - Astronaut

Tara Shears

饰：Self - Particle Physicist