Kenneth Arnold

Flying objects, not easily identifiable by the human eye, have been spotted all around the world for centuries. Those who reported seeing such mysterious objects often attributed them to spirits, angels, phantoms, ghosts or other supernatural phenomena. In 1938, with the specter of war looming in Europe, Orson Welles caused mass hysteria in America when his radio broadcast based on H.G. Wells’ science-fiction novel War of the Worlds suggested that meteor-like rocket ships carrying aliens were invading Earth.

World War II and the accompanying development of rocket science marked a new level of interest in strange flying objects. Numerous Allied pilots flying at night over German reported seeing balls of light following their aircraft. Nicknamed “foo fighters,” these ghostly flyers were said to be one of Germany’s secret weapons; varying explanations for the flares claimed they were optical illusions or results of the electrical phenomenon known as “St. Elmo’s Fire.”

On June 24, 1947, the civilian pilot Kenneth Arnold reported seeing nine objects, glowing bright blue-white, flying in a “V” formation over Washington’s Mount Rainier. He estimated the objects’ flight speed at 1700 mph and compared their motion to “a saucer if you skip it across water.” (In newspaper reports of Arnold’s sighting, this description was mistakenly taken to mean that the objects were shaped like saucers, leading to the popularization of the term “flying saucer” as a synonym for UFO.)

Though Arnold said he initially thought what he had seen were test flights of military aircraft, the military later said they had been conducting no test flights during the time of the incident. A prospector on Mt. Adams saw the objects at around the same time as Arnold, bolstering his story.

After news of Arnold’s sightings hit the media, similar sightings began to be reported in increasing numbers across the United States. Also in July 1947, a Roswell, New Mexico newspaper claimed that personnel of the nearby U.S. Army airfield had recovered a crashed flying saucer. The Army, in turn, explained that the crash was that of a wrecked weather balloon. (Though the Roswell incident was mostly forgotten until the late 1970s, around that time several eyewitnesses began to come forward claiming the “weather balloon” was in fact an alien craft; conspiracy theories regarding Roswell still abound among ufologists.)

In response to the increasing number of UFO sightings that followed Arnold’s report, the U.S. Air Force began an investigation of these reports, called Operation Sign, in 1948. Among the initial theories of the project’s participants was that the UFOs were actually types of sophisticated Soviet aircraft, although there was also a hypothesis that they might be extraterrestrial spacecraft. Regarding the June 1947 sighting over Mount Rainier, Air Force investigators deemed both Arnold and the prospector to be credible witnesses, but concluded that what they had seen was a mirage, not actual flying ships.

Project Sign was succeeded in 1949 by Project Grudge, which in 1952 became Project Blue Book, the longest running of the U.S. government’s official inquiries into UFOs. Project Blue Book compiled reports of more than 12,000 UFO sightings or related events from 1952 to 1969. Of these, more than 90 percent were eventually classified as “identified,” meaning they were caused by a known astronomical, atmospheric or artificial (man-made) phenomenon. The remaining number, approximately 6 percent, were “unidentified,” and included cases in which there was insufficient information to assign the event a known cause.

In 1969, the Condon Report on the results of a two-year study of UFO files collected by Project Blue Book found that the project was not scientifically useful, and the Air Force shut it down. By then, however, the U.S. government’s official investigation of UFO sightings had inspired an increasing number of movies and other forms of pop culture depicting UFOs and alien invasions. Particularly memorable examples included The Day the Earth Stood Still (1951) and The War of the Worlds (1953). These movies undoubtedly reflected America’s involvement in the Cold War, and the wave of anti-communist hysteria sweeping the country at the time, stirred up by Senator Joseph McCarthy and his House Un-American Activities Committee (HUAAC). The “aliens” portrayed on film during the 1950s were often thinly veiled stand-ins for communists, bent on destroying the capitalist world.

By the mid-1970s, UFOs and the surrounding subculture had not lost their momentum as a popular distraction; even President Jimmy Carter, elected in 1976, claimed to have seen a UFO. In 1977, Steven Spielberg’s Close Encounters of the Third Kind drew on The UFO Experience by Dr. J. Allen Hynek, the scientific adviser to three UFO studies conducted by the U.S. Air Force. The film depicts many aspects of actual UFO incidents reported to Hynek, though many details and circumstances were manipulated for maximum dramatic effect. Government conspiracies surrounding UFOs and alien invasions–fueled by the enduring Roswell controversy–remained a popular culture touchstone in the following decades, as evidenced by the success of “The X-Files” TV series and movies such as Independence Day (1996), Men in Black (1997), and early 21st century remakes of the ’50s films War of the Worlds (2005) and The Day the Earth Stood Still (2008).