Antecedent pre-UFO extraterrestrialism The concept of a Universe decentralized from Earth renaissanced from classical origin by
Nicolas Copernicus (1543) gave impetus to debate on
extraterrestrial life and a
plurality of worlds, to which
Emanuel Swedenborg (1688–1772) contributed.
Introduction Although the modern extraterrestrial hypothesis (ETH) owes much to the flying saucer sightings of the 1940s–1960s, its origins can be traced back to a number of earlier events, such as the now-discredited
Martian canals and ancient Martian civilization promoted by astronomer
Percival Lowell, popular culture including the writings of
H. G. Wells and fellow science fiction pioneers such as
Edgar Rice Burroughs, who likewise wrote of Martian civilizations. In the early part of the twentieth century,
Charles Fort collected accounts of anomalous physical phenomena from newspapers and scientific journals, including many reports of extraordinary aerial objects. These were published in 1919 in
The Book of the Damned. In this and two subsequent books,
New Lands (1923) and
Lo! (1931), Fort theorized that visitors from other worlds were observing Earth. Fort's reports of aerial phenomena were frequently cited in American newspapers when the UFO phenomenon first attracted widespread media attention in June and July 1947. The modern ETH—specifically, the implicit linking of unidentified aircraft and lights in the sky to alien life—took root during the late 1940s and took its current form during the 1950s. It drew on
pseudoscience, as well as popular culture. Unlike earlier speculation of extraterrestrial life, interest in the ETH was also bolstered by many unexplained sightings investigated by the U.S. government and governments of other countries, as well as private civilian groups, such as
NICAP and
APRO.
19th century Historical reports and speculation A news article published November 25, 1896 retells (Colonel H. G. Shaw) of an experience of "strange beings" and "an immense airship" en route from
Lodi, California. Shaw concluded the beings were in fact from Mars. Later, there was a more international airship wave in 1909–1912. An example of an extraterrestrial explanation at the time was a 1909 letter to a New Zealand newspaper suggesting "atomic powered spaceships from Mars".
Early science fiction H. G. Wells,
The War of the Worlds, published April 1897, is a story of alien invasion by craft from Mars.
20th century From the 1920s, the idea of alien visitation in space ships was commonplace in popular comic strips and radio and movie serials, such as
Buck Rogers and
Flash Gordon. In particular, the Flash Gordon serials have the Earth being attacked from space by alien meteors, ray beams, and biological weapons. In 1938, a radio broadcast version of
The War of the Worlds by
Orson Welles, using a contemporary setting for H. G. Wells' Martian invasion, created some public panic in the United States.
The 1947 flying saucer wave in America On June 24, 1947, at about 3:00 p.m. local time, pilot
Kenneth Arnold reported
seeing nine unidentified aircraft flying near
Mount Rainier. When no aircraft emerged that seemed to account for what he had seen, Arnold quickly considered the possibility of the objects being extraterrestrial. On July 7, 1947, two stories came out where Arnold was raising the topic of possible extraterrestrial origins, both as his opinion and those who had written to him. In an Associated Press story, Arnold said he had received quantities of
fan mail eager to help solve the mystery. Some of them "suggested the discs were visitations from another planet." When the 1947 flying saucer wave hit the United States, there was much speculation in the newspapers about what they might be in news stories, columns, editorials, and letters to the editor. For example, on July 10, U.S. Senator
Glen Taylor of Idaho commented, "I almost wish the flying saucers would turn out to be space ships from another planet," because the possibility of hostility "would unify the people of the earth as nothing else could." On July 8,
R. DeWitt Miller was quoted by UP saying that the saucers had been seen since the early nineteenth century. If the present discs weren't secret Army weapons, he suggested they could be vehicles from Mars, or other planets, or maybe even "things out of other dimensions of time and space." Other articles brought up the work of
Charles Fort, who earlier in the twentieth century had documented numerous reports of unidentified flying objects that had been written up in newspapers and scientific journals. Even if people thought the saucers were real, most were generally unwilling to leap to the conclusion that they were extraterrestrial in origin. Various popular theories began to quickly proliferate in press articles and interviews, such as secret military projects, Russian spy devices, hoaxes,
optical illusions, and
mass hysteria. According to journalist
Edward R. Murrow, the ETH as a serious explanation for "flying saucers" did not earn widespread attention until about 18 months after Arnold's sighting. These attitudes seem to be reflected in the results of the first U.S. poll of public UFO perceptions released by
Gallup on August 14, 1947. The term "flying saucer" was familiar to 90% of the respondents. As to what people thought explained them, the poll further showed, that most people either held no opinion or refused to answer the question (33%), or generally believed that there was a mundane explanation. 29% thought they were
optical illusions,
mirages, or imagination; 15% a U.S. secret weapon; 10% a
hoax; 3% a "weather forecasting device"; 1% of Soviet origin, and 9% had "other explanations", including fulfillment of
Biblical prophecy, secret commercial aircraft, or phenomena related to
atomic testing.
Evolution of public opinion The early 1950s also saw a number of movies depicting flying saucers and aliens, including
The Day the Earth Stood Still (1951),
The War of the Worlds (1953),
Earth vs. the Flying Saucers (1956), and
Forbidden Planet (1956). A poll published in
Popular Science magazine in August 1951 reported that of the respondents who self-reported as UFO witnesses, 52% believed that they had seen a man-made aircraft, while only 4% believed that they had seen an alien craft; an additional 28% were uncertain, with more than half of these stating they believed they were either man-made aircraft, or "visitors from afar." In 1957, a poll conducted by the
St. Louis Globe Democrat reported that 25% of respondents believed or were willing to believe that flying saucers may be objects from outer space, while 53% responded that they were not and 22% reported that they were uncertain. Many of the respondents who answered in the negative accepted the existence of flying saucers but believed they originated on Earth.
21st century A
Roper poll in 2002 reported that 56% of respondents thought UFOs were real, with 48% believing that UFOs had visited Earth.
NASA In June 2021, NASA Administrator Bill Nelson announced that he had directed NASA scientists to investigate Unidentified Aerial Phenomenon. During an interview at the University of Virginia, Bill Nelson explored the possibility that UAP could represent extraterrestrial technology. NASA scientist Ravi Kopparapu advocates studying UAP. In August 2021, at the American Institute of Aeronautics and Aviation, Kopparapu presented a paper from the American Association for the Advancement of Science, 134th Meeting General Symposium that supported ETH. Kopparapu stated he and his colleagues found the paper "perfectly credible".
Private or government studies Other private or government studies, some secret, have concluded in favor of the ET hypothesis, or have had members who disagreed in contravention with official conclusions reached by the committees and agencies to which they belonged. The following are examples of sources that have focused specifically on the topic: • A 1948 Top Secret USAF Europe document (
at right) states that Swedish air intelligence informed them that at least some of their investigators into the ghost rockets and flying saucers concluded they possibly had extraterrestrial origins. • The
CIA started their own internal scientific review the following day. Some CIA scientists were also seriously considering the ETH. An early memo from August was very skeptical, but also added: "...as long as a series of reports remains 'unexplainable' (interplanetary aspects and alien origin not being thoroughly excluded from consideration) caution requires that intelligence continue coverage of the subject." A report from later that month was similarly skeptical, but nevertheless concluded: "...sightings of UFOs reported at
Los Alamos and
Oak Ridge, at a time when the background
radiation count had risen inexplicably. Here we run out of even 'blue yonder' explanations that might be tenable, and we still are left with numbers of incredible reports from credible observers." A December 1952 memo from the Assistant CIA Director of Scientific Intelligence (O/SI) was much more urgent: "...the reports of incidents convince us that there is something going on that must have immediate attention. Sightings of unexplained objects at great altitudes and traveling at high speeds in the vicinity of U.S. defense installation [
sic] are of such nature that they are not attributable to natural phenomena or known types of aerial vehicles." Some of the memos also made it clear, that CIA interest in the subject was not to be made public, partly in fear of possible public panic. (Good, 331–335) • Extraterrestrial "believers" within Project Blue Book included Major Dewey Fournet, in charge of the engineering analysis of UFO motion, who later became a board member on the civilian UFO organization
NICAP. Blue Book director
Edward J. Ruppelt privately commented on other firm "pro-UFO" members in the USAF investigations, including some Pentagon generals, such as
Charles P. Cabell, USAF Chief of Air Intelligence, who, angry at the inaction and debunkery of
Project Grudge, dissolved it in 1951, established Project Blue Book in its place, and made Ruppelt director. In 1953, Cabell became deputy director of the CIA. Another defector from the official Air Force party line was consultant
J. Allen Hynek, who started out as a staunch skeptic. After 20 years of investigation, he changed positions and generally supported the ETH. He became the most publicly known UFO advocate scientist in the 1970s and 1980s. • The first CIA Director, Vice Admiral
Roscoe H. Hillenkoetter, stated in a signed statement to Congress, also reported in
The New York Times (February 28, 1960): "It is time for the truth to be brought out... Behind the scenes high-ranking Air Force officers are soberly concerned about the UFOs. However, through official secrecy and ridicule, many citizens are led to believe the unknown flying objects are nonsense... I urge immediate Congressional action to reduce the dangers from secrecy about unidentified flying objects." In 1962, in his letter of resignation from
NICAP, he told director
Donald Keyhoe, "I know the UFOs are not U.S. or Soviet devices. All we can do now is wait for some actions by the UFOs." • In 1967, Greek physicist
Paul Santorini, a
Manhattan Project scientist, publicly stated that a 1947 Greek government investigation into the European
Ghost rockets of 1946 under his lead quickly concluded that they were not missiles. Santorini claimed the investigation was then quashed by military officials from the U.S., who knew them to be extraterrestrial, because there was no defense against the advanced technology and they feared widespread panic should the results become public. • Although the 1968
Condon Report came to a negative conclusion (written by
Condon), it is known that many members of the study strongly disagreed with Condon's methods and biases. Most quit the project in disgust, or were fired for insubordination. A few became ETH supporters. Perhaps the best known example is David Saunders, who in his 1968 book
UFOs? Yes lambasted Condon for extreme bias, and for ignoring or misrepresenting critical evidence. Saunders wrote: "It is clear... that the sightings have been going on for too long to explain in terms of straightforward terrestrial intelligence. It's in this sense that ETI (Extra Terrestrial Intelligence) stands as the 'least implausible' explanation of 'real UFOs'." • In 1999, the private French
COMETA report (written primarily by military defense analysts) stated the conclusion regarding UFO phenomena, that a "single hypothesis sufficiently takes into account the facts and, for the most part, only calls for present-day science. It is the hypothesis of extraterrestrial visitors." The report noted issues with formulating the extraterrestrial hypothesis, likening its study to the study of meteorites, but concluded, that although it was far from the best scientific hypothesis, "strong presumptions exist in its favour". The report also concludes, that the studies it presents, "demonstrate the almost certain physical reality of completely unknown flying objects with remarkable flight performances and noiselessness, apparently operated by intelligent [beings] ... Secret craft definitely of earthly origins (drones, stealth aircraft, etc.) can only explain a minority of cases. If we go back far enough in time, we clearly perceive the limits of this explanation." •
Jean-Jacques Velasco, the head of the official French UFO investigation
SEPRA, wrote a book in 2005, saying, that 14% of the 5800 cases studied by SEPRA were 'utterly inexplicable and extraterrestrial' in origin. However, the CNES own report says 28% of sightings remain unidentified.
Yves Sillard, the head of the new official French UFO investigation
GEIPAN and former head of French space agency
CNES, echoes Velasco's comments and adds, that the United States 'is guilty of covering up this information.' However, this is not the official public posture of SEPRA, CNES, or the French government. (The CNES placed their 5,800 case files on the Internet starting March 2007.) ==Critical responses and positions of the ETH==