Extraterrestrial UFO hypothesis

The extraterrestrial hypothesis (ETH) proposes that some unidentified flying objects (UFOs) are best explained as being physical spacecraft occupied by intelligent extraterrestrial organisms (non-human aliens) from other planets, or probes designed by intelligent extraterrestrials.
Use of the term extraterrestrial hypothesis in printed material on UFOs seems to date to at least the latter half of the 1960s; with French ufologist Jacques Vallée in his 1966 book Challenge to science: the UFO enigma. It was used in a publication by French engineer Aimé Michel in 1967, by James E. McDonald in a symposium in March 1968 and again by McDonald and James Harder while testifying before the Congressional Committee on Science and Astronautics, in July 1968. Skeptic Philip J. Klass used it in his 1968 book UFOs--Identified. In 1969 physicist Edward Condon defined the "extraterrestrial hypothesis" or "ETH" as the "idea that some UFOs may be spacecraft sent to Earth from another civilization or space other than Earth, or on a planet associated with a more distant star," while presenting the findings of the much debated Condon Report. Some UFO historians credit Condon with popularizing the term and its abbreviation "ETH."
Although the extraterrestrial hypothesis (ETH) as a phrase is a comparatively new concept, one which 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, and even to the works of figures such as the Swedish philosopher, mystic and scientist Emanuel Swedenborg, who promoted a variety of unconventional views that linked other worlds to the afterlife.
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.
An early example of speculation over extraterrestrial visitors can be found in the French newspaper Le Pays, which on June 17, 1864, published a story about two American geologists who had allegedly discovered an alien-like creature, a mummified three-foot-tall hairless humanoid with a trunk-like appendage on its forehead, inside a hollow egg-shaped structure.
H. G. Wells, in his 1898 science fiction classic The War of the Worlds, popularized the idea of Martian visitation and invasion. Even before Wells, there was a sudden upsurge in reports in "Mystery airships" in the United States. For example, The Washington Times in 1897 speculated that the airships were "a reconnoitering party from Mars", and the Saint Louis Post-Dispatch wrote: "these may be visitors from Mars, fearful, at the last, of invading the planet they have been seeking." Later, there was a more international airship wave from 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."
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.
On June 24, 1947, at about 3:00 p.m. local time, pilot Kenneth Arnold reported seeing nine unidentified disk-shaped 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, 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.
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." By 1957, 25% of Americans responded that they either believed, or were willing to believe in the ETH, while 53% responded that they were not. 22% reported that they were uncertain.
A Roper poll in 2002 reported that 56% of respondents thought UFOs were real, with 48% believing that UFOs had visited Earth.
Hunt describes the Aetherius Society founded by George King in 1955 as "probably the first and certainly the most enduring UFO cult".
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".
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:
People have had a long-standing curiosity about extraterrestrial life. Aliens are the subject of numerous urban legends, including claims that they have long been present on earth or that they may be able to assist humans in resolving certain issues. Despite these myths, the truth is that there is no scientific proof to back up these assertions, hence we cannot declare with certainty whether or not aliens exist. In spite of ardent believers that various UFO sightings are verifiable evidence for the ET hypothesis, no rigorous analysis has ever concluded as much.
On July 9, Army Air Forces Intelligence began a secret study of the best saucer reports, including that of Arnold's. A follow-up study by the Air Materiel Command intelligence and engineering departments at Wright Field, Ohio led to the formation of the U.S. Air Force's Project Sign at the end of 1947, the first official U.S. military UFO study.
In 1948, Project Sign concluded without endorsing any unified explanation for all UFO reports, and the ETH was rejected by USAF Chief of Staff General Hoyt Vandenberg, citing a lack of physical evidence. Vandenberg dismantled Project Sign, and with this official policy in place, subsequent public Air Force reports concluded, that there was insufficient evidence to warrant further investigation of UFOs.
In 1952, Life Magazine published "Have We Visitors From Space?" which popularized the Extraterrestrial Hypothesis and is thought to have triggered the 1952 UFO flap. Immediately following the great UFO wave of 1952 and the military debunking of radar and visual sightings, plus jet interceptions over Washington, D.C. in August, the CIA's Office of Scientific Investigation took particular interest in UFOs. Though the ETH was mentioned, it was generally given little credence. However, others within the CIA, such as the Psychological Strategy Board, were more concerned about how an unfriendly power such as the Soviet Union might use UFOs for psychological warfare purposes, exploit the gullibility of the public for the sensational, and clog intelligence channels. Under a directive from the National Security Council to review the problem, in January 1953, the CIA organized the Robertson Panel, a group of scientists who quickly reviewed the Blue Book's best evidence, including motion pictures and an engineering report that concluded that the performance characteristics were beyond that of earthly craft. After two days' review, all cases were claimed to have conventional explanations. An official policy of public debunkery was recommended using the mass media and authority figures in order to influence public opinion and reduce the number of UFO reports.
The scientific community has shown very little support for the ETH, and has largely accepted the explanation that reports of UFOs are the result of people misinterpreting common objects or phenomena, or are the work of hoaxers. Professor Stephen Hawking has expressed skepticism about the ETH. In a 1969 lecture, U.S. astrophysicist Carl Sagan said:
Similarly, British astrophysicist Peter A. Sturrock wrote
An informal poll done by Sturrock in 1973 of American Institute of Aeronautics and Astronautics members found that about 10% of them believed that UFOs were vehicles from outer space. In another poll conducted in 1977, Sturrock asked members of the American Astronomical Society to assign probabilities to eight possible explanations for UFOs. The results were:
The primary scientific arguments against ETH were summarized by astronomer and UFO researcher J. Allen Hynek during a presentation at the 1983 MUFON Symposium, where he outlined seven key reasons why he could not accept the ETH.
Hynek argued that:
According to the personal assessment of Hynek at the time, points 1 through 6 could be argued, but point 7 represented an "insurmountable" barrier to the validity of the ETH.
As the proliferation of smartphone camera technology across the population has not led to a significant increase in recorded UFO sightings, the claimed phenomenology of UFOs has been called into question. This goes counter to the predictions of supporters of the extraterrestrial hypothesis, even causing a crisis of confidence among some within the informal UFO research community.
NASA frequently fields questions in regard to the ETH and UFOs. As of 2006, its official standpoint was that ETH has a lack of empirical evidence.
Despite public interest, up until 2021, NASA had considered the study of ETH to be irrelevant to its work because of the number of false leads that a study would provide, and the limited amount of usable scientific data that it would yield.
The CIA organized the January 1953 Robertson Panel of scientists to debunk the data collected by the Air Force's Project Blue Book. This included an engineering analysis of UFO maneuvers by Blue Book (including a motion picture film analysis by Naval scientists) that had concluded UFOs were under intelligent control and likely extraterrestrial.
In November 2011, the White House released an official response to two petitions asking the U.S. government to acknowledge formally that aliens have visited Earth and to disclose any intentional withholding of government interactions with extraterrestrial beings. According to the response, "The U.S. government has no evidence that any life exists outside our planet, or that an extraterrestrial presence has contacted or engaged any member of the human race." Also, according to the response, there is "no credible information to suggest that any evidence is being hidden from the public's eye." The response further noted that efforts, like SETI, the Kepler space telescope and the NASA Mars rover, continue looking for signs of life. The response noted "the odds are pretty high" that there may be life on other planets but "the odds of us making contact with any of them—especially any intelligent ones—are extremely small, given the distances involved."
A frequent concept in ufology and popular culture is that the true extent of information about UFOs is being suppressed by some form of conspiracy of silence, or by an official cover-up that is acting to conceal information.
In 1968, American engineer James Harder argued that significant evidence existed to prove UFOs "beyond reasonable doubt," but that the evidence had been suppressed and largely neglected by scientists and the general public, thus preventing sound conclusions from being reached on the ETH.
A survey carried out by Industrial Research magazine in 1971 showed that more Americans believed the government was concealing information about UFOs (76%) than believed in the existence of UFOs (54%), or in ETH itself (32%).
On the History Channel UFO Hunters episode "The NASA Files" (2008), Former NASA astronauts have commented; Gordon Cooper wrote that NASA and the government "swept these and other sightings under the rug". Brian O'Leary stated "some of my fellow astronauts and scientists astronauts that did go up and who have observed things, very clearly, they were told - not to report it".