Carl Sagan

Self (archive footage)

John Casani

Self

Lawrence Krauss

Self

Carolyn Porco

Self

Timothy Ferris

Self

Edward Stone

Self

Nick Sagan

Self

Larry Soderblom

Self

Charley Kohlhase

Self

Fran Bagenal

Self

James F. Bell

Self

Frank Locatell

Self

Suzanne Dodd

Self

Jon Lomberg

Self

Heidi Hammel

Self

Candy Hansen

Herself

Andrew Ingersoll

Himself

Dave Linick

Himself