But this was also the era of big, colorful cars with enormous tail fins, situation comedies and growing prosperity, ever-bigger houses in the suburbs, and rock & roll on the transistor radio. There were few psychological studies of public feelings about nuclear war. Eventually, the government quietly sponsored research into why the public wasn't reacting. The theories ranged from "cognitive dissonance" to a kind of apathy later identified as "learned helplessness," to the simple but powerful psychological defense mechanism known as denial.

But the Cold War had clearly intensified, and along with Sputnik, provided new nuclear themes for the drive-in and Saturday matinee outlets for suppressed anxieties. Besides the mutation monsters (a number of them hitting the screens in 1957), the instantly deadly bolt from the blue came in the form of invasion from outer space, usually by technologically superior aliens with no conscience or aim other than destruction.

Many of these films predated Sputnik, for the fear of the Soviet threat was cultivated from the beginning of the atomic era. "In order to make the country bear the burden, " said President Eisenhower's Secretary of State, John Foster Dulles, referring to the arms race of the Cold War, "we have to create an emotional atmosphere akin to a wartime psychology. We must create the idea of a threat from without." But the fear that had been subsumed in early alien invasion films became more potent when that satellite beeping overhead added its alarm.

The aliens were technologically superior but otherwise mindless and implacable: instead of monsters created by radiation, they were monsters with ray guns and death rays as radiation weapons. Most rose or fell on how convincing their effects were, while their plots were all in their titles: Earth v. the Flying Saucers, Phantom from Space, Invaders from Mars, Killers from Space, Target Earth, It Conquered the World, It! The Terror From Beyond Space.
The best of the alien invasion films, and the one with the most visceral Cold War themes, was producer George Pal’s 1953 “War of the Worlds,” adapted from the H.G. Wells story. Set this time in contemporary California, it updates the technology and Americanizes the characters, and the protagonist is a credentialed scientist—a physicist, like the fearsome geniuses behind the Bomb.

It remains a remarkable film for its bright technicolor humbling of humanity. Neither our technology, our innocence (up to and including the atomic bomb) nor our religious faith could stop the mute Martian invaders and their death machines that floated in the air. The first victims of the Martian death ray were turned into piles of cinders on the ground with human outline, a clear reference to Hiroshima. The scientists who in most alien invasion and monster movies would figure out the enemy’s weakness, are in this film savagely beaten by a mob on their way to their laboratory with promising research. There is heroism, love and a happy ending, but once again this story has the power to tap into the solemn fears of the moment.

Some movies showed the aliens invading not by overwhelming force but by stealth; not by killing humans but by inhabiting them, “taking them over.” “Red Planet Mars” (1952) and “I Married a Monster from Outer Space” (1958), for example, were fairly explicit parables of alien subversion. The classic of the genre, Jack Arnold’s “Invasion of the Body Snatchers” (1955), showed the slow horror of alien plants turning a town’s population into pod people. The danger of being “taken over” by Communist subversion was a relentless theme of FBI chief J. Edgar Hoover, who was an important public figure in the 1950s.