Cast: Paul Christian(Tom Nesbitt)
Paula Raymond (Lee Hunter)
Cecil Kellaway (Professor Thurgood Elson)
Kenneth Tobey (Colonel Jack Evans)
Donald Woods (Captain Phil Jackson)
Lee Van Cleef (Corporal Stone)
Steve Brodie (Sergeant Loomis)
Ross Elliott (George Ritchie)
Jack Pennick (Jacob Bowman)
Ray Hyke (Sergeant Willistead)
Mary Hill (Miss Nelson)
Michael Fox (ER Doctor)
Alvin Greenman (1st Radar Man)
James Best (Radar Man)
Frank Ferguson (Dr. Morton)
King Donovan (Dr. Ingersoll)

Crew: Producers: Hal Chester and Jack Dietz
Director: Eugene Lourie
Screenplay: Lou Morheim, Fred Freiberger
(Suggested from THE SATURDAY EVENING POST story by Ray Bradbury)
Technical Effects: Ray Harryhausen
Assistant Art Director: Hal Waler
Director Of Photography: Jack Russell
Photographic Effects: Harold Stine, Bert Willis
Film Editor: Bernard W. Burton
Sound: Max Hutchinson
Musical Score: David Buttolph
Orchestrations: Maurice De Packh
Assistant Director: Horace Hough
Special Effects: Willis Cook
Costumes: Berman's of Hollywood
Makeup Artist: Louis Phillippi
Set Decorator: Edward Boyle
Associate Producer: Bernard W. Burton
Dialogue Director: Michael Fox.