Two events at the end of World War II had major impacts on the science fiction genre.
The development of the atomic bomb increased interest in science, as well as anxiety about the possible apocalyptic effects of a nuclear war.
The period also saw the beginning of the Cold War, and widespread Communist paranoia in the United States.
These led to a major increase in the number of sci-fi films being created throughout the 1950s, and creating a Golden Age of Science Fiction that matched the one taking place in literature.
One of the earlier and most important films of the era was 1950's widely publicized Destination Moon. It follows a nuclear-powered rocketship carrying four men to the moon, against a background of competition against the Soviets.
With a script co-written by Robert A. Heinlein and astronomical sets by renowned space artist Chesley Bonestell, the film was a commercial and artistic success, and it brought about more studio financing of science fiction film.
The producer of Destination Moon was notably George Pal who also helped create When Worlds Collide, The Time Machine, The War of the Worlds, and the pseudo-documentary of manned space exploration Conquest of Space.
Although Conquest of Space was a commercial failure that set back Pal's career, the other four each won an Academy Award for Best Visual Effects, which demonstrated the increased technical excellence and critical recognition of the genre.
Alien films saw a huge surge in popularity during the 1950s. Many featured political commentary being mixed with the concept of UFOs, which had become ingrained in the public consciousness after the Kenneth Arnold and Roswell incidents of 1947.
Two of the first were The Day the Earth Stood Still, directed by Robert Wise, and Howard Hawks' The Thing from Another World, with their contrasting views of first contact. While the former had a peaceful race of aliens urging humans to control their use of nuclear weapons, the latter's title creature stalked a crew in Antarctica, with the paranoid final words, "Watch the skies!"
The idea of alien invasions as an allegory recurred with Don Siegel's 1956 film, Invasion of the Body Snatchers. Critically acclaimed as a classic, it has been viewed as both a veiled criticism of McCarthyism, or a cautionary story of Communist infiltration.
Another important UFO film, Earth vs. the Flying Saucers, had special effects created by Ray Harryhausen, a master of stop-motion animation that had previously worked with King Kong animator, Willis O'Brien. His work also appeared in such films as 20 Million Miles to Earth, and 1953's hit film, The Beast From 20,000 Fathoms.
That film, based on a short story by Ray Bradbury, featured the fictional Rhedosaurus, which is thawed out of the Arctic by atomic testing and begins to ravage sections of the United States. Its massive success set off a new wave of science-fiction monster films.
Like the 1930s, these movies demonstrated a mix of horror and sci-fi, now often mixed with anxiety of nuclear technology or the dangers of outer space. Them!, It Came from Beneath the Sea, and Tarantula, released within two years of The Beast from 20,000 Fathoms, all featured over-sized animals created by nuclear testing.
It! The Terror from Beyond Space, The Blob, The Angry Red Planet, and Kronos, on the other hand, featured alien monsters. Still others, like The Fly, The Amazing Colossal Man, and The Incredible Shrinking Man, focused on human mutation.
This trend was not limited to the United States; perhaps the most successful monster movies were the kaiju films released by Japanese film studio Toho.
The 1954 film Godzilla, with the title monster attacking Tokyo, gained immense popularity, spawned multiple sequels, led to other kaiju films like Rodan, and created one of the most recognizable monsters in cinema history.
The financial success of these films relied on studios drawing in large teenage audiences, taking advantage of popular techniques such as drive-in theaters and 3D, notably used by movies like The Creature from the Black Lagoon and Gog.
In addition to increasing the audience size, many sci-fi films of the time were created with minuscule budgets; the phrase "B-movie" came to signify a formulaic genre film made with low production costs (usually for less than $400,000).
This concept was exemplified in a studio memo about the movie Them! that stated, "We want a picture with the same exploitation possibilities as we had in The Beast from 20,000 Fathoms. We all know this will not be a 'class production' but it has all the ingredients of being a successful box office attraction.
The idea of low-quality, low-cost films were taken to an extreme by directors such as Roger Corman, Coleman Francis, and Ed Wood, and the latter's Plan 9 from Outer Space has been hailed as one of the worst films of all time.
However, in the second half of the decade, the steady success of the genre led to some studios attempting serious films with large budgets, including the coldly realistic depiction of a post-nuclear war world, On the Beach, and Forbidden Planet, a sci-fi re-imagining of Shakespeare's The Tempest.
The second film would have an impact on the genre for years to come; it included the first all-electronic music score, introduced the character Robby the Robot, and served as the inspiration for Gene Roddenberry's Star Trek.
The success of science fiction films also saw the genre grow internationally.
In Britain, there was a period of notable production, with Hammer Films adaptations of Nigel Kneale's Quatermass series. The success of the television versions inspired the company to commission a series of film adaptations .
At the climax of the movie "The Creauture From Another World" Scotty, the Reporter, files his "story of a lifetime" by radio to a roomful of reporters in Anchorage. During his report, Scotty broadcasts a warning to the reporters: "Tell the world. Tell this to everybody, wherever they are. Watch the skies everywhere. Keep looking. Keep watching the skies."