In the aftermath of World War II, the UFO became all the rage in the media. At first, it was thought that these flying objects were Russian or American secret weapons. Then the public began that they were alien . , these visitors were concerned over the invention of the atomic bomb. in the 1960s, popular authors threw a spin on the timeline of these sightings. They explained that aliens had not landed for the first time in 1947, but rather, several thousand years earlier.