The glimpse given of the spacecraft reveals it to be from another Columbia release, Invasión de discos voladores (1956). The scene was also used in Flying Saucer Daffy (1958) and an episode of The Twilight Zone (1985).
This was based on a novel by John Mantley, a highly regarded writer who also wrote the screenplay. This may explain why this film is regarded as more intelligent than most low-budget science-fiction films of that period.
The beach scene at which Eve Wingate is out with her original boyfriend, and later where she throws away the capsules, is the same location used by Columbia for the famous love scene between Burt Lancaster and Deborah Kerr inDe aquí a la eternidad (1953).
The unusual-looking sports car that Eve's boyfriend is seen standing near in the opening scenes on the beach is a 1954 Arnolt Bristol Competition.
The role of the newscaster was an on-screen role for voice specialist Paul Frees. The voices on the radio heard throughout the film were performed by Frees.