约翰·里斯·戴维斯

John Rhys-Davies

饰：Narrator,

Charles Beichman

饰：Himself - NASA Terrestrial Planet Finder

Donald Brownlee

饰：Himself - NASA Stardust Mission

Dennis Danielson

饰：Himself

Kevin R. Grazier

饰：Himself

Robert Jastrow

饰：Himself - Former Director Mt. Wilson Observatory

Bijan Nemati

饰：Himself - Jet Propulsion Laboratory

Guillermo Gonzalez

Guillermo Gonzalez

饰：Himself - Astrobiologist Iowa State University

托姆罗伯茨

Tom Roberts

饰：自己

Jay Richards

饰：Himself - Philosopher Discovery Institute

约翰·里斯·戴维斯

John Rhys-Davies

饰：自己

Seth Shostak

饰：Self - Senior Astronomer SETI Institute