Frank Drake

饰：自己

Nick Sagan

饰：自己

Fran Bagenal

饰：自己 Self

Heidi Hammel

饰：自己

John Casani

饰：Self

Timothy Ferris

Timothy Ferris

饰：Self

Andrew Ingersoll

饰：Self

约翰·本杰明·海基

John Benjamin Hickey

饰：Self - Narrator

Brad Smith

Brad Smith

饰：Self

劳伦斯·M.克劳斯

Lawrence M. Krauss

饰：Self

Edward Stone

Edward Stone

饰：Self

Larry Soderblom

Larry Soderblom

饰：Self

Jon Lomberg

饰：Self

Linda Spilker

饰：Self

Dr. Don Gurnett

Dr. Don Gurnett

饰：Self

卡尔·萨根

Carl Sagan

饰：Self,(archive footage)