Unidentified flying object

From Academic Kids

UFO redirects here. For other uses, see UFO (disambiguation).
A UFO -- posed or genuine?
A UFO -- posed or genuine?

A UFO or unidentified flying object in the original, literal sense is any airborne object or optical phenomenon, detected visually or by radar, whose nature is not readily known. Interest in these objects stems from continued speculation that some of them may be the products of extraterrestrial intelligence.

Perhaps the best scientifically accepted definition of a UFO was provided by the late astronomer Dr. J. Allen Hynek: "A UFO is the reported perception of an object or light seen in the sky or upon the land the appearance, trajectory, and general dynamic and luminescent behaviour of which do not suggest a logical, conventional explanation and which is not only mystifying to the original percipients but remains unidentified after close scrutiny of all available evidence by persons who are technically capable of making a common sense identification, if one is possible."



Strange unidentified apparitions in the sky and on the ground have been reported throughout history. Ancient Roman records occasionally mention "shields" and even "armies" seen in the sky. In 1896-97, unidentified "airships" were reported in the United States, though some of these reports are now known to have been deliberate hoaxes. There were several reports of unidentified aeroplanes in the Scandinavian countries in the 1930s. In Europe during World War II, "Foo-fighters" (luminous balls that followed airplanes) were reported by both allied and axis pilots. In 1946, there was a "wave" of "ghost rockets" seen over Scandinavia.

The modern phase in UFOs started with a claimed sighting by American businessman Kenneth Arnold on June 24 1947, near Mount Rainier, Washington. Arnold said he saw nine bright objects flying at "incredible speed" at 10,000 feet altitude. Though the UFOs Arnold witnessed were not by strict definition saucer-shaped, he described their movements as being similar to that of a saucer skipping over water, hence the origin of the term flying saucer. Arnold's claims subsequently received significant mainstream media and public attention.

UFO sightings of a similar nature were subsequently reported throughout the United States and in other countries. The resulting press publicity given to early UFO sightings undoubtedly helped stimulate further sightings worldwide. In early reports, the objects were observed alone or in formation and were shaped like "discs," "rockets," or "cigars." The objects observed during the day were often described as saucer-shaped and metallic-silver in color. Objects observed during the evening hours were of various colors.

Origins of the terms "flying saucer" and "UFO"

On January, 24, 1878, John Martin, a Texas farmer, is said to have seen a dark flying object in the shape of a disk "flying at wonderful speed," and allegedly used the word "saucer" to describe it. If verifiable, this would be the first known use of the word "saucer" to describe an unidentified flying object. Some seventy years later in 1947, the media used the term "flying saucers" to describe Kenneth Arnold's sighting.

Missing image
Another UFO from Brazil.

The nine objects Kenneth Arnold said he saw were not strictly saucer-shaped. Arnold initially described and drew a picture of eight of the objects as being thin and flat, circular in the front but truncated in the back and coming to a point. (See Kenneth Arnold for drawing and verbal descriptions) Another, later drawing was of a ninth, somewhat larger object with a boomerang or crescent shape, more resembling a flying wing style aircraft. However, several years later, Arnold said he had described their movement as a kind of skipping, like a saucer skimmed over water. He complained that the press misquoted him, picking up the "like a saucer" phrase, and reported it as a "flying saucer".

Another term commonly used by the media to describe the objects in the late 1940s and '50s was "flying disks."

By mid-1950, a Gallup poll revealed that the term "flying saucer" had become so deeply ingrained in the American vernacular, that 94% of those polled were familiar with it, making it the best-known term commonly appearing in the news, easily beating out others like "universal military training" (75%), "bookie" (67%), or "cold war" (58%).

Hollywood science fiction movies in the 1950s, such as The Day the Earth Stood Still (1951), Forbidden Planet (1956), and Earth vs. the Flying Saucers (1956), all depicting flying saucer-like craft, further entrenched the term as a cultural icon. So did popular books on the subject such as Frank Scully's Behind the Flying Saucers (1950), Donald Keyhoe's The Flying Saucers Are Real (1950) and Flying Saucers From Outer Space (1953), and "contactee"-oriented books, such as George Adamski's] Flying Saucers Have Landed (1953).

"Flying Saucer" was the preferred term for most unidentified aerial sightings through the late 1940s to 1960's, even for those that were not actually saucer-shaped. By the late 1960s, the term "UFO" was more commonly used. Use of "UFO" instead of "flying saucer" was first suggested in 1952 by Capt. Edward J. Ruppelt, the first director of the U. S. Air Force's Project Blue Book, who felt that "flying saucer" failed to capture the diversity of the sightings. His suggestion was quickly adopted by the Air Force, who also briefly used "UFOB" through about 1954. Ruppelt recounted his experiences with Project Blue Book in his memoir, The Report on Unidentified Flying Objects (1956) online (http://www.nicap.dabsol.co.uk/Rufo.htm).

An unforseen difficulty with the term "UFO" is that it often leads to semantic debates between skeptics and advocates. Skeptics often argue that "UFO" simply means that the object was "unidentified" by those making the sighting and doesn't mean the object is unexplainable, much less extraterrestrial. In contrast, researchers like Hynek have argued that the term should be strictly limited to those sightings that have been intensively investigated and still defy conventional explanation, which was the actual definition adopted by the Air Force in official directives in the 1950s.

E.g., Air Force Regulation 200-2, issued in 1954, defined a "UFOB" as "any airborne object which by performance, aerodynamic characteristics, or unusual features, does not conform to any presently known aircraft or missile type, or which cannot be positively identified as a familiar object." Furthermore, investigation of "UFOBs" was stated to be for the purposes of national security and to ascertain "technical aspects." Obviously such concerns would not apply to the usual explanations for most UFO sightings, such as natural phenomena or man-made conventional objects, except, perhaps, previously unknown foreign aircraft.

Thus the "U" in "UFO," instead of standing for "Unidentified," would more aptly stand for "Unexplained" or "Unconventional." Along these lines, Paul Hill, an early NACA/NASA aerospace engineer, titled his 1970s book on the subject, Unconventional Flying Objects.

The acronym equivalent of UFO in Spanish, Portuguese, and French is OVNI, which literally translated in English would be "Object flying of no identification" (e.g., in Spanish, Objeto Volador No Identificado). See UFO.

UFOs and popular culture

Regardless of any ultimate explanation, UFOs constitute an international cultural phenomenon of the last half-century. Since the mid-1900's, UFOs have been the subject of a very large number of books, motion pictures, songs, documentaries and other media. UFO topics were amongst the most popular on early computer Bulletin board systems, and millions of people have some degree of interest in the subject. There have also been notable hoaxes involving UFO reports, some which have received substantial press attention.

A 1996 Gallup poll reported that 71% of the United States' population believed that the government was covering up some information about UFOs.

Typical reported characteristics of UFOs

  • Saucer, toy-top, or disk-shaped "craft" without visible or audible propulsion. (day and night)
  • Rapidly-moving lights or lights with apparent ability to rapidly change direction — the earliest mention of their motion was given as "saucers skipping on water"
  • Large triangular "craft" or triangular light pattern
  • Cigar-shaped "craft" with lighted windows (Meteor fireballs are sometimes reported this way).

The number of different shapes, sizes, and configurations of claimed UFOs has been large, with descriptions of chevrons, equilateral triangles, spheres, domes, diamonds, shapeless black masses, eggs, and cylinders. Skeptics argue this diversity of shapes, size and configurations points to a socio-psychological explanation. Other researchers argue that the large diversity of UFO shapes points to a possible paraphysical origin. Still others argue that there is a large diversity in the shapes and sizes of human flying craft, reflecting different origins, propulsion systems, and purposes, so such diversity in UFOs is not necessarily unexpected or inexplicable.

Another argument is that the true underlying shape may, in some cases, be concealed or distorted by the ionization of air around the objects, believed by some researcher advocates, such as NASA engineers Paul Hill and James McCampbell, to be a characteristic of the propulsion system. Air ionization could also partly explain the diversity of colors reported, as different air molecules are excited at different energy levels, as well as the electric, neon-like glow around the objects often reported, similar to what happens with polar auroras. However, some feel that such speculation is overly premature because the very actuality of UFOs as alien craft is itself problematic.

Other advocates, arguing for the non-conventional interpretation, reply that the volume of impressive sightings reported by witnesses, from commercial airline pilots to United States presidents, and occasionally captured on film and radar, possesses strong consistency and cannot be explained away simply as mundane phenomena (weather balloons, aircraft, Venus, etc.).

One writer contends that UFO mass sightings--sometimes called "flaps"--are "a hard core of genuinely unusual sightings ... surrounded by a great deal more misidentification, wishful thinking and general flakiness." [1] (http://www.strangemag.com/invadersfromelsewhere1.html)

Other researchers, such as Jacques Vallee, argue that if UFO sightings are motivated by some mechanism through which the public can release hidden fears and satisfy a psychological need for fantasies, why did "UFO waves" not coincide with such science-fiction feats such as Orson Welles' radio adaptation of The War of the Worlds in 1938, or the motion-picture versions of Flash Gordon (1936-37)? Vallee points out that the theory regarding how the general public generates and propagates UFO reports as a way of releasing psychological tensions, is denied by the absence of correlation between notable periods of interest in science fiction and major peaks of UFO activity. It should also be noted that no single, comprehensive "psychological" theory to explain the generation of all UFO reports has yet been proposed. A notable attempt on the basis of his theory of archetypes was made by the Swiss psychiatrist Carl Jung in his book _Flying Saucers_ (1959). Jung, however, also felt that at least some UFOs were "nuts and bolts" craft, based on physical evidence such as simultaneous radar contact.


Ufology is the study of UFO reports and associated evidence.

UFOs have been subject to various investigations over the years, varying widely in scope and scientific rigor. Governments or military agencies of the United States, Canada, the United Kingdom, France, Belgium, Sweden, Brazil, Mexico, Spain, and the Soviet Union, are known to have carried out the investigation of UFO reports at various times. Despite a strong residue of extremely puzzling cases, no national government has ever publicly suggested that UFOs represent any form of alien intelligence. However, this may be changing. As recently as May 2005, the Brazilian Air Force disclosed highly classified case files to civilian investigators, including over 100 photographs taken by Air Force investigators during mass Amazon River sightings in 1977 (called "Operation Saucer"). [2] (http://www.ufo.com.br/materiaespecial/operacaoPrato.htm) Classified documents released over the years in the U.S. also indicate that at least some segments within the U.S. Air Force and agencies such as the CIA favored the extraterrestrial hypothesis, despite public denials to the contrary. E.g., the U.S. Air Force's first public UFO investigation, Project Sign, is said to have secretly come to the conclusion that some of the most puzzling cases studied were best explained as extraterrestrial. (See "Official Government Studies--United States" below)

Perhaps the best known study was Project Blue Book, conducted by the United States Air Force from 1952. Even before Blue Book was shut down in 1969, however, it became clear that its investigations, particularly after the departure of Edward J. Ruppelt, were often (though not in every case) little more than public relations exercises designed to debunk widely publicized "sightings." Still, even though Blue Book had directives to reduce the number of unidentifieds to a minimum, 6% of over 12,000 cases remained unexplained. Other studies commissioned by the Air Force, such as the one conducted by the Battelle Memorial Institute from 1952-1954, had much higher percentages of unknowns. The Battelle Institute found, e.g., that 22% of some 3200 Air Force cases they studied remained unexplained, and for the very best cases, the percentage of unknowns was as high as 35%.

Despite these unexplained cases, the general opinion of the mainstream scientific community is probably that all UFO sightings ultimately result from ordinary misidentification of natural and man-made phenomena, deliberate hoaxes, or psychological phenomena such as optical illusions or lucid dreaming/sleep paralysis (often given as an explanation for purported alien abductions). Statistics compiled by U.S. Air Force studies found that the strong preponderance of identified sightings were due to misidentifications, with hoaxes and psychological aberrations accounting for only a few percent of all cases. Still many academics feel that the subject is a waste of time, due to a number of factors. Unreliability of witness testimony is often cited.

It has been suggested, however, that rather few academics have actually researched the topic themselves or become personally familiar with the literature. Some academics have argued that this constitutes unacceptable bias, and that while current evidence may be lacking, new evidence should be evaluated objectively as it arises. Some in the scientific community feel there is enough evidence to warrant further investigation efforts, comparing it to the period in the history of meteorite research or atmospheric electrical phenomena such as sprites or ball lightning when there was only witness testimony available. In such examples, the eyewitness accounts of such phenomena eventually proved correct despite initial skepticism, denial, and sometimes hostility from many scientists. Others point out that it is erroneous to claim the evidence is only observational and that a number of recorded physical effects also exist that are amenable to research by the physical sciences. These include simultaneous radar contact, photographs/movies/videos, radiation increases, electromagnetic interference, and physiological/biological effects. (See Science and UFOs section below)

While most academics prefer to ignore the subject, others, including mostly amateur and some professional scientific researchers, continue to investigate. Unfortunately, quality of investigations by amateur researchers can vary enormously.

Probably the most favored theory among advocates is the more conventional extraterrestrial hypothesis, though the Interdimensional hypothesis and the Paranormal/Occult Hypothesis for UFOs are sometimes given as possibilities by some.

It is erroneous to assume that the only question of interest provided by the subject is whether UFOs represent alien intelligence. There have been studies of UFOs and UFO enthusiast subcultures from a folklore or anthropological perspective, and some feel the subject, at the very least, may provide new insights in the fields of psychology (both individual and social), sociology, and communications.

Scientific UFO Field Studies


One established non-military station, which has seriously monitored UFOs, including anomalous lights, is project Hessdalen AMS in Norway.

United States

Challenged to explain sightings of unidentified lights and luminous phenomena in the hills around Piedmont, Missouri, Dr. Harley Rutledge established Project Identification in 1973 to gather scientific data.

Official Governmental Studies


In the early 1950s, Project Magnet was created to investigate the possibility of discs powered by magnetic propulsion. The equipment was designed to detect gamma rays, magnetic fluctuations, radio noises and gravity or mass changes in the atmosphere. One of these monitoring stations was located at Shirley Bay, Canada.

United States

In response to the June/July 1947 wave of UFO sightings and resulting publicity, the U.S. government began a number of formal studies of UFOs:

  • From July 9 to July 30, 1947, Army Air Force Intelligence studied the 16 best UFO sightings of the previous months, mostly those reported by military and civilian pilots, and concluded that the "flying saucer situation" was neither imaginary nor adequately explained as natural phenomena: "something is really flying around."
  • In response to the earlier study, the engineering and intelligence divisions of the Air Force Materiel Command at Wright-Patterson Air Force Base, under the direction of General Nathan Twining, further reviewed the data. Twining's memo of September 23, 1947, likewise concluded the craft were real, further defined their described characteristics, and urged that the subject should be treated seriously, including a formal investigation by multiple government agencies besides the Air Force. Both the Air Intelligence and Material Command studies concluding saucer reality were classified and not publicly acknowledged for many years.
  • Twining's memo resulted in the United States Air Force founding Project Sign in late 1947, the first publicly acknowledged government UFO study. In late summer, 1948, Project Sign issued an intelligence estimate that UFOs were real craft and extraterrestrial in origin. USAF Chief of Staff General Hoyt S. Vandenberg ordered the report destroyed citing lack of physical proof. In late 1948 Project Sign was renamed Project Grudge allegedly with a high-level mandate to debunk UFO sightings. Grudge was active until early 1952, when it too was renamed and upgraded in status by the Pentagon, becoming Project Blue Book, which lasted until 1969. Since Project Blue Book was dissolved, the United States government reports that they have had no formal study of UFO reports.
  • In December 1948, mysterious Green Fireballs were sighted over sensitive military and government research facilities in New Mexico, such as Los Alamos National Laboratory. Dr. Lincoln LaPaz, astronomer and noted meteor expert, was requested by the Air Force to investigate, with extensive help from military intelligence and the FBI. Based on the objects' many anomalous characteristics, La Paz quickly concluded the objects were artificial, perhaps secret Russian spy devices. However, scientists at Los Alamos privately told Project Blue Book head, Capt. Edward J. Ruppelt, they thought the green fireballs were extraterrestrial probes. But the green fireballs were seen by so many people of high repute, including LaPaz and scientists at Los Alamos, that everybody agreed they were real. Secret conferences were convened at Los Alamos to study the phenomenon and in Washington by the Air Force Scientific Advisory Board. In December 1949, Project Twinkle, a network of observation and photographic stations was established but never fully implemented. It was discontinued two years later, with the official conclusion that the phenomenon was probably natural in origin. LaPaz and others never agreed.
  • The Robertson Panel was organized by the Central Intelligence Agency in late 1952, in response to a wave of UFO sightings, especially in the Washington DC area, which included highly-publicized radar contacts and jet intercepts. So many persons tried to contact authorities (primarily the Air Force) regarding UFO reports that day-to-day duties were adversely impacted. The CIA feared that this level of publicity (described by Hoyt S. Vandenberg as “mass hysteria”) could be utilized by enemies of the United States. The Robertson Panel convened for 12 hours to study this problem and offer solutions. Among their proffered solutions was a campaign of official public ridicule using the mass media, authoritative figures, and celebrities to decrease public interest in the subject and thus reduce the strain on intelligence channels. Further, they recommended that civilian UFO groups be spied upon because of their influence on the public and the possibility that they might be used by enemies of the U.S. Many ufologists believe the Robertson Panel recommendations were put into effect and the resulting official debunkery relegated the subject matter permanently to the fringe, both in the mainstream media and scientific communities. Also after the Robertson Panel, Project Blue Book was reduced in status and stripped of most of duties of investigating serious UFO cases, which were instead secretly turned over to a newly-formed division of the Air Defense Command. Directives were also issued not to discuss the unexplainable cases with the public and to reduce the percentage of unknowns to a minimum.
  • Project Blue Book Special Report #14 (1951-1954) was a scientific statistical study of all collected Air Force UFO cases (3200) commissioned by Project Blue Book and carried out by the Battelle Memorial Institute. Chief conclusions were that unexplained cases constituted 22% of the total and the highest quality cases (such as from airline pilots or simultaneous radar/visual sightings) were nearly twice as likely to remain unexplained as the poorest reports. They also compared physical properties of the explained and unexplained sightings, such as reported speed, brightness, duration, and number, and found they differed at a highly statistically significant level, strongly indicating that the difference in the two categories was quite real. Nonetheless, when the Air Force publicly revealed the study in 1955, they instead claimed it scientifically proved that UFOs did not exist and that only 3% of reports were unexplained.
  • The Condon Committee (1966 to 1969), commissioned by Project Blue Book while under pressure from a Congressional inquiry after a new wave of sightings in 1965 and 1966, was a landmark but still controversial study which supported the misidentification-delusion-hoax explanation for UFO reports, and furthermore argued that no available evidence warranted further scientific study. The conclusions were quickly endorsed by the National Academy of Science (NAS), but a more detailed review by the American Institute of Aeronautics and Astronautics (AIAA) criticized the NAS position and the Condon Report conclusions, which they noted did not match the actual data. About 30% of the cases examined by the Condon Committee itself were "well-documented but unexplainable" and formed the "hard core of the UFO controversy." They recommended a moderate level, ongoing scientific study of UFOs.

Ultimately, the official U.S. Air Force public position was that UFO reports were due almost entirely to misidentification of ordinary aerial phenomena, delusion, or hoaxes. Both contemporary and modern critics, however, argue that some of the listed studies harbored an unacceptable degree of bias, were involved in sloppy science of dubious validity, or even perpetrating a cover up. Furthermore, the official Air Force position was frequently at odds with internal, classified documents, many later released under the Freedom of Information Act, which proved that the subject was treated far more seriously by the Air Force and other government agencies, like the CIA and FBI, than the public had been led to believe. In addition, many documents still remain classified or are heavily censored even when released, such as those of the CIA. Sometimes lawsuits have had to be filed to get even the censored documents released to the public.

Besides the listed studies, others are believed to have unofficially existed, but details are generally not known. E.g., Generals Douglas MacArthur and George Marshall are believed by some to have started an Interplanetary Phenomenon Unit (IPU) at the end of World War II. In a 1987 query to the U.S. Army Director of Counterintelligence, it was acknowledged that the IPU did indeed exist, but was disbanded in the late 1950s. It was then stated, "All records pertaining to this unit were surrendered to the U.S. Air Force Office of Special Investigations [AFOSI] in conjunction with operation BLUEBOOK." The IPU records supposedly retained by AFOSI remain classified and have never been released.

Civilian UFO Investigation groups

There have been a number of civilian groups formed to study UFO’s and/or to promulgate their opinions on the subject. Some have achieved fair degrees of mainstream visibility while others remain obscure.

The groups listed below have embraced a broad variety of approaches, and have seen a correspondingly wide variety of responses from mainstream critics or supporters

United States

  • Aerial Phenomena Research Organization (APRO) (1952-1988): Started and run by Jim and Coral Lorenzen; New Mexico based with many state branches; stressed scientific field investigations with a large staff of consulting Ph.D. scientists. history (http://mimufon.org/1970%20articles/Apro_History.htm)
  • National Investigations Committee On Aerial Phenomena (NICAP) (1956-1980): Washington D.C. based; largest and most politically influential of early UFO research organizations, with many scientists and high ranking military officers involved. Run by Donald Keyhoe for most of its duration, author of many best-selling UFO books. Research through 1963 summarized in The UFO Evidence, edited by Richard Hall; eventually absorbed by CUFOS (below). research archive (http://www.nicap.org)
  • Mutual UFO Network (MUFON) (1969- ): Started by Walt Andrus; Texas based, largest current U.S. UFO organization with branches in most states; stress field investigations and symposiums. home page (http://www.mufon.com)
  • Center for UFO Studies (CUFOS) (1973- ): Started by astronomer, Dr. J. Allen Hynek, consultant to Project Blue Book; Chicago based, small research organization stressing scientific analysis of UFO cases; currently run by Dr. Mark Rodeghier; contains much archival information, including old NICAP files. home page (http://www.cufos.org)
  • Fund for UFO Research (FUFOR) (1976- ): Small, Maryland based, scientifically oriented group with many Ph.D. scientists providing research grants for UFO research; does a lot of photoanalysis. home page (http://www.fufor.com)
  • National Institute of Discovery Science (NIDS) (1996- ): Small, private, controversial, somewhat clandestine Las Vegas based scientific research group with insider government scientists and military people, stressing UFO and paranormal research. home page (http://www.nidsci.org)

Political Action Groups

  • Citizens Against UFO Secrecy (CAUS) (~1978- ): Small, Arizona based research and judicially oriented organization filing many FOIA applications and lawsuits to declassify and release government UFO information. home page (http://www.caus.org/home.shtml)
  • Paradigm Research Group (PRG) & Extraterrestrial Phenomena Political Action Committee (X-PPAC) (1996- ): Small, Washington D.C. based group founded and headed by political activist/lobbyist Stephen Bassett, pushing for government UFO disclosure. home page (http://www.paradigmclock.com)
  • Center for the Study of Extraterrestrial Intelligence (CSETI) (1990- ): Maryland based, founded and run by the controversial Dr. Steven Greer. Education and lobbying group that runs the Disclosure Project, an effort to get government disclosure on UFOs and other topics, claiming to currently have over 400 government, military, and intelligence witnesses. home page (http://www.cseti.org)

Science and UFOs

Since the late 1940s, people throughout the world have become familiar with UFO reports. These reports have been attributed to a wide range of causes including planets, stars, meteors, cloud formations, ball lightning, deliberate hoaxes, experimental military aircraft, hallucinations, and extraterrestrial spacecraft. Despite the large number of reports and great public interest, the scientific community has shown little interest in UFOs. This may be due in part to the fact that there are no public or government funds to support UFO research. Scientists also assume that the 1969 Condon Report settled the issue, hence UFO data is no longer worth examining. It has also been contended that the CIA's 1953 Robertson Panel recommendations of official public ridicule through the mass media has made the subject scientifically and politically taboo. Each of these may have had some impact in dampening the interest of the scientific community in regards to UFO research.

Other reasons often cited for the disdain shown by many scientists for the subject are:

  • Arguments that aliens could not be here because of the distances and energies required for interstellar travel in a reasonable period of time, according to present-day understanding of physical law
  • Lack of indisputable physical evidence
  • The unreliability or scientific inadequacy of many reports
  • The many circumstances that can lead to misidentification of ordinary objects seen at a distance in the sky--a scientific skeptical approach can cast reasonable doubt on the "strangeness" of cases that appear at first glance to be very impressive.
  • The general sensationalization surrounding the subject, including the perception that many amateur researchers lack proper scientific training and instead have a "readiness to believe"

While many scientists would agree that the sighting of a genuine extraterrestrial craft is not an impossibility, some also argue that that the patterns of reported UFO behavior do not personally strike them as rational. E.g., why would sightings occur with great frequency for decades without any attempt by the alien intelligence to commmunicate its presence unambiguously? Or if an extraterrestrial civilization was engaged in mapping or otherwise investigating the earth, as some have hypothesized, why would it take so long, when present-day terrestrial technology, such as satellites, can do the job so quickly?

Proponents, however, note that there are counterarguments to all of these objections. Some of these are:

  • Many of the skeptical arguments rest on hidden assumptions about alien intentions and technology. Why would aliens necessarily make their presence unambiguously known? Why would alien interests necessarily be restricted to simple physical surveys? Why assume interstellar travel to be nearly impossible, basically an assumption that alien science and technology would not be that much more advanced than that of present-day humans?
  • Some arguments show a lack of knowledge of the available evidence. E.g., many sightings are not of distant "lights in the sky," which might easily be simple misidentifications, but are of structured objects at close range, often with associated physical effects and evidence (see below).
  • Why focus on only poor cases when there are also many high-quality, unexplainable ones, even when investigated by trained scientists, such as those involved with the Battelle Institute investigation for the U.S. Air Force in the 1950's or the 1960's Condon Commission?

The Condon Report's negative conclusions seem to have been particularly damaging to the likelihood of large numbers of scientists involving themselves seriously in the investigation of UFOs. However, the conclusions section of the report was written by Condon, who expressed public disdain for the subject long before the investigation was concluded. Subsequent reviews by the American Institute of Aeronautics and Astronautics, and more recently by a scientific panel organized by Dr. Peter Sturrock [3] (http://www.ufoevidence.org/documents/doc535.htm), have shown that the conclusions section was badly at variance with the report's actual contents, where about 30% of the cases examined could not be explained. When the report came out in late 1969, atmospheric physicist Dr. James E. McDonald wrote a paper called "Science in Default," criticizing the Condon Report for bad science and mainstream science as well for its failure to deal with the subject. [4] (http://www.cufon.org/cufon/mcdon2.htm) Nonetheless, other scientists have found the positive evidence presented by Sturrock and others in support of UFO reality to be unpersuasive.

Recently, hopes that this theme might be about to become respectable again were raised when a peer reviewed article on UFOs and SETI appeared in JBIS, the Journal of the British Interplanetary Society. A good introduction to this aspect of the subject is given by one of the authors, astronomer Bernard Haisch, in his website [5] (http://www.ufoskeptic.org), an introduction to the area for scientists, which has a link to the JBIS article.

Still, the general perception in the scientific community remains that, if UFO reports pose a scientific problem at all, it has more to do with psychology and the science of perception than with physical science. Indeed, most reports simply comprise narrative accounts of what someone saw or thought he saw in the sky. Sometimes the reports involve more than one witness, and sometimes an event is witnessed from two or more different locations. There have, however, also been mass sightings, sometimes involving hundreds or even thousands of witnesses.

Some feel that physical scientists cannot get involved in the UFO problem unless there is associated physical evidence. If there is no physical evidence, then it is contended there is no way that physical scientists can contribute to the resolution of this problem.

One objection to this argument is that even eyewitness accounts can be treated with scientific methods to obtain important information. E.g., witnesses to meteor fireballs can be interviewed to reconstruct trajectories, and this often leads to recovery of meteorite fragments. Accuracy and reliability of individual accounts is not essential if large numbers of sightings are analyzed, because statistical analysis can reveal important trends. One example of applying such techniques in researching UFO reports occurred during investigations of the mysterious Green Fireballs that suddenly appeared over sensitive military and research installations in New Mexico in the late 1940s. Hundreds of witnesses were interviewed to determine object characteristics and also to try to recover fragments through determination of trajectories.

A massive statistical analysis of UFO cases, called Project Blue Book Special Report No. 14, was commissioned by the USAF and carried out from 1952 to 1954 by the Battelle Memorial Institute (see United States government studies above). Statistician Dr. David Saunders, a member of the Condon Commission, recommended compiling a statistical data base of cases to determine trends, which eventually resulted in a catalog of over 10,000 cases compiled by Saunders and others. [6] (http://www.cufos.org/UFOCAT.html) Various other researchers have also compiled such databases, such as Dr. Jacques Vallee, [7] (http://ufoinfo.com/magonia/index.shtml) or Larry Hatch, who maintains a public database of thousands of cases with online statistical analyses. [8] (http://www.larryhatch.net)

It has also been argued by various people, such as physicist Dr. Michio Kaku, that the demand for hard physical evidence (the fabled "alien hubcap") is an unreasonably restrictive one. People like Kaku note that much of physical science consists of indirect physical evidence, such as spectrograms of stars to determine composition. Nobody, e.g., demands an actual piece of a neutron star for analysis.

There have, in fact been many UFO reports accompanied by physical evidence of various kinds, both direct and indirect. Hynek's close encounter scale would define indirect physical evidence as data obtained from "close encounters of the first kind," i.e. data obtained from afar, such as radar contacts or photographs. More direct physical evidence comes from "close encounters of the second kind," interactions occurring at close range, which include so-called "landing traces," and physiological effects.

Some fraction of these cases have been shown to be deliberate hoaxes. However, another fraction, including those researched by governmental and military authorities, have been labeled unidentified or unexplainable. Analyses of most cases have results that are ambiguous or inconclusive. However, even the ambiguous physical cases should be amenable to statistical analysis to reveal possible underlying trends across cases.

A list of various physical evidence cases includes:

  • Radar contact and tracking, sometimes from multiple sites. These are often considered among the best cases since they usually involve trained military personnel, simultaneous visual sightings, and aircraft intercepts. One such recent example were the mass sightings of large, silent, low-flying black triangles in 1989 and 1990 over Belgium.
  • Photograpic evidence, including still photos, movie film, and video, including some in infrared spectrum (rare).
  • Recorded visual spectrograms (extremely rare)--(see Spectrometer)
  • Recorded gravimetric and magnetic disturbances (extremely rare)
  • Landing physical trace evidence, including ground impressions, burned and/or dessicated soil, burned and broken foliage, metallic and other traces (see e.g. Height 611 UFO Incident), magnetic anomalies, and increased radiation levels. A well-known example from 1980 was the USAF Rendlesham Incident in England. Another from 1964 occurred at Socorro, N.M. and was considered one of the most inexplicable of the USAF Project Blue Book cases. Catalogs of several thousand such cases have been compiled, particularly by researcher Ted Phillips.[9] (http://www.ufoevidence.org/topics/physicaltracecases.htm)[10] (http://www.ufoevidence.org/documents/doc201.htm)
  • Physiological effects on people and animals including temporary paralysis, skin burns and rashes, corneal burns, and symptoms resembling radiation poisoning, such as the Cash-Landrum incident in 1980. One such case dates back to 1886, a Venezuelan incident reported in Scientific American magazine. [11] (http://www.nuforc.org/GNSciAm.html)
  • Biological effects on plants such as increased or decreased growth, germination effects on seeds, and blown-out stem nodes (usually associated with physical trace cases or crop circles)
  • Electromagnetic interference effects, including stalled cars, power black-outs, radio/TV interference, magnetic compass deflections, and aircraft navigation, communication, and engine disruption.[12] (http://www.ufoevidence.org/topics/emeffects.htm)
  • Remote radiation detection, some noted in FBI and CIA documents occurring over government nuclear installations at Los Alamos National Laboratory and Oak Ridge National Laboratory in 1950, also reported by Project Blue Book director Ed Ruppelt in his book. [13] (http://ufologie.net/books/ruppeltbook15.htm)
  • Actual hard physical evidence, such as the 1957 Ubatuba, Brazil, magnesium fragments analyzed in the Condon Report and by others. The 1964 Socorro incident also left metal traces, analyzed by NASA.
  • Evidence associated with alleged alien abduction cases, such as unexplained scars or "scoop marks" and "alien implants" recovered by surgery.
  • Misc: Recorded electromagnetic emissions, such as microwaves detected in the well-known 1957 RB-47 surveillance aircraft case, which was also a visual and radar case; [14] (http://ufologie.net/htm/rb47.htm) polarization rings observed around a UFO by a scientist, theorized by Dr. James Harder as intense magnetic fields from the UFO causing the Faraday effect. [15] (http://ncas.sawco.com/ufosymposium/harder.html)

Despite the low opinion of the subject matter probably held by most scientists, many reported physical effects would seem to be ripe for scientific analysis. A comprehensive scientific review of physical evidence cases was carried out by the 1997 Sturrock UFO panel.[16] (http://www.scientificexploration.org/jse/articles/ufo_reports/sturrock/toc.html) Dr. Jacques Vallee claims many scientists are interested in investigating UFOs but prefer to work quietly in the background because of the attached "ridicule factor." Vallee refers to these scientists as the "invisible college."

Some scientists and engineers have attempted to "back-engineer" the possible physics behind UFOs through analysis of both eyewitness reports and the physical evidence. Examples are former NASA engineer James McCampbell in his book Ufology online (http://www.nicap.dabsol.co.uk/ufology.htm) and NACA/NASA engineer Paul Hill in his book Unconventional Flying Objects. Among subjects tackled by both McCampbell and Hill was the question of how UFOs can fly at supersonic speeds without creating a sonic boom. McCampbell's solution of a microwave plasma parting the air in front of the craft is currently being researched by Dr. Leik Myrabo, Professor of Engineering Physics at the Rensselaer Polytechnic Institute as a possible advance in hypersonic flight.[17] (http://www.rpi.edu/dept/mane/deptweb/faculty/member/myrabo.html)

Some recently reported developments in electronic warfare mimic electromagnetic interference and physiologic effects described in UFO cases dating back to the 1940s and 1950s, and may conceivably be examples of military back-engineering efforts. In 1997, the U.S. Air Force Scientific Advisory Board issued a report on 21st Century Air Force weaponry, in which they described microwave directed energy weapons that could be used to stall vehicles, making them easy targets for bombing. The same weapon is also reported capable of disrupting aircraft navigation and communication systems, as well as ground electronics and power grids. [18] (http://www.memagazine.org/backissues/nov03/features/airpow/airpow.html) A microwave crowd control weapon causing heating and intense pain was announced in 2001. [19] (http://www.newscientist.com/article.ns?id=dn1470) Other microwave weapons have been proposed that would cause loss of bodily functions. [20] (http://www.sciam.com/article.cfm?articleID=000CBC91-B6FD-1E51-A98A809EC5880105) (See also wonder weapons)

Identified Flying Objects (IFOs)

It has been estimated that up to 90% of all reported UFO sightings are eventually identified. While a small percentage of UFO reports are deliberate hoaxes, most are misidentifications of natural and man-made phenomena.

Allen Hendry was the chief investigator for the Center for UFO Studies (CUFOS) (http://www.cufos.org/). CUFOS was founded by Dr. Allen Hynek (who had been a consultant for the Air Force’s Project Blue Book) to provide a serious scientific investigation into UFOs. Hendry spent 15 months personally investigating 1,307 UFO reports. In 1979, Hendry published his conclusions in The UFO Handbook: A Guide to Investigating, Evaluating, and Reporting UFO Sightings. Hendry admitted that he would like to find evidence for extraterrestrials but noted that the vast majority of cases had prosiac explanations. Hendry’s conclusions were:

  • "Out of 1,307 cases: 1,194 (91.4%) had clear prosaic (non-extraterrestrial) explanations; 93 (7.1%) had possible prosaic explanations; and 20 (1.5%) were unexplained.
  • Statistics: 28% of the UFO reports were bright stars or planets; 1.7% were the tip of the crescent moon; 18% were advertising plane banners (usually seen edge-on rather than the face-on); and 9% were fireballs and reentering space debris.
  • Distortions in the atmosphere can cause celestial bodies to appear to “dart up and down,” “execute loops and figure eights,” “meander in a square pattern,” or even “zigzag.” This helps explain why celestial bodies can so easily fool observers.
  • In 49 of the UFO reports caused by celestial bodies, the witness’ estimated distance to the UFO ranged from 200 feet to 125 miles! Similarly, some witnesses believed that the UFO was “following them” even though the celestial body was actually stationary. Even police and other reliable witnesses can easily be fooled by sightings of stars and planets.
  • Reentering space debris or meteors may appear as a string of lights, which can be misinterpreted as lights coming from windows of a spacecraft. The human brain then creates the illusion of a spacecraft based on this misinterpretation, which then fools the observer."

Common misidentifications of man-made phenomena include:

  • Balloons (meteorological or passenger).
  • Military aircraft.
  • Flashing landing lights of conventional aircraft.
  • Unconventional aircraft or advanced technology (i.e., the SR-71 Blackbird or the B-2 Stealth bomber).
  • Advertising planes.
  • Artificial earth satellites.
  • Hovering aircraft (such as helicopters).
  • Blimps.
  • Rockets and rocket launches.
  • Kites.
  • Model aircraft.
  • Hang-gliders.
  • Fireworks.
  • Lasers aimed at the clouds.
  • Searchlights.
  • Deliberate hoaxes.
  • Jiffy Fire Starters.

Common misidentifications of natural objects include:

  • The moon, stars, and planets (for example, the cusps of the rising crescent moon in the tropics, and Venus at maximum brightness)
  • Unusual weather conditions (such as lenticular cloud formations, noctilucent clouds, rainbow effects, and high-altitude ice crystals).
  • Comets.
  • Meteor Swarms.
  • Near or large meteors.
  • Flocks of birds.
  • Swarms of flying insects.
  • Reflections from atmospheric inversion layers.
  • Hot ionized gas (natural or man-made).
  • Earth lights (luminous electrical events from low-level earthquakes and tectonic-geological phenomena.)
  • Ball lightning.
  • Atmospheric inversion layers.
  • Reflected light (especially through broken clouds).
  • Aurora borealis (northern lights).

Popular hypotheses for explaining UFOs

Depending on who is doing the evaluation, between about 3% and 30% of all cases remain unexplained. The remaining residue of unexplained UFO sightings constitute a debate on their ultimate origin. Some of the more popular hypotheses for explaining UFOs are:

Evidence and explanations

Some feel that UFO study is still a worthwhile topic because of open questions, especially due to occasional reports of UFOs from professional or military astronomers or pilots - individuals whose careers, and often their very lives, rely on their ability to recognize and assess aircraft, weather conditions, distances, and other factors vital to flight. Some Ufologists argue such cases are more difficult to dismiss as misidentification of mundane objects. Gordon Cooper and Edgar Mitchell are two NASA astronauts who have expressed an interest in UFOs, and both have decried what they consider the biased attitudes of some professionals; Cooper claims to have seen UFOs in the early 1950s.

It is also noted that UFO evidence goes beyond just eyewitness accounts. There is sometimes corroborating evidence such as simultaneous radar contact, photographs/movies/video, or physical interactions with the environment, e.g., electromagnetic interference, physiological effects, or "landing traces." (see Science and UFOs section)

Skeptics and ufologists both agree that the vast majority of cases can be explained as natural phenomena, usually misidentification of objects that viewers are either unfamiliar with or see in unusual conditions. These turn out to be honest mistakes. Only a few percent of sightings have have been actual hoaxes.

After investigation, most UFOs actually become IFOs -- Identified Flying Objects. However, a small residual, from 3% to 30% depending on who is doing the counting, remain unexplained. The 1950s Battelle Memorial Institute statistical study, commissioned by Project Blue Book, found that it was actually the better cases with the better witnesses and evidence that tended to defy explanation. Their percentage of unexplained cases out of 3200 studied was 22%, which went up to 35% for the best cases.

However, even if the overwhelming majority of all UFOs become IFOs, one well documented case such as the Chile 1997 radar/visual case confirmed by the government in Santiago [21] (http://ufologie.net/htm/offichili.htm) is sufficient to negate the 'null hypothesis'. Similarly, Physicist Michio Kaku states that although "perhaps 99% of all sightings of UFO's can be dismissed as being caused by familiar phenomena" that "What is disturbing, to a physicist however, is the remaining 1% of these sightings, which are multiple sightings made by multiple methods of observations. Some of the most intriguing sightings have been made by seasoned pilots and passengers aboard air line flights which have also been tracked by radar and have been videotaped. Sightings like this are harder to dismiss."[22] (http://www.mkaku.org/articles/physics_of_space_travel.shtml)

On the other hand, many still inexplicable cases are either ignored by the media or, if a purported skeptic offers an explanation that fails to fit the facts (e.g., Zig-zagging formation of lights and confirmed by radar are blamed on misinterpreting 'Jupiter'), it is often taken up by the press and the case is closed, as far as the media is concerned.

It is sometimes said that "extraordinary claims require extraordinary evidence", but many pro-research groups only claim that the topic deserves further investigation, not that UFOs are necessarily alien craft. The threshold of evidence for further investigation is lower than that for a conclusion about the nature of UFOs.

Skeptics say there are indeed genuine sightings of strange flying objects, which are usually logically explained, that no physical evidence of an alien spacecraft has ever been produced, and that many claims have been proven as fraudulent. They also note that the burden of proof lies with whomever makes a claim. On the other hand, however, Marcello Truzzi, (sociology professor at Eastern Michigan University) contends that some self-described skeptics are misusing the term (or even misrepresenting their opinions): "Since 'skepticism' properly refers to doubt rather than denial - non-belief rather than belief - critics who take the negative rather than an agnostic position but still call themselves 'skeptics' are actually pseudo-skeptics and have, I believed, gained a false advantage by usurping that label."[23] (http://www.anomalist.com/commentaries/pseudo.html)

Supporters also often argue that the subject is prejudiced by ridicule and stigma, (Kaku agrees with this; in the article cited above he writes that "There is no funding for anyone seriously looking at unidentified objects in space, and one's reputation may suffer if one pursues an interest in these unorthodox matters"), and that an extremely large body of compelling evidence not as yet disproved or effectively countered also exists, including photography, motion video, and multiple independently corroborated sworn affidavits.

Evidence and suppression

Some also contend regarding physical evidence that it exists abundantly but is swiftly and sometimes clumsily suppressed by governmental entities, not always uniform, with a strong agenda to insulate a population they regard as psychologically not yet prepared for the social, theological, and security implications of such a reality. See the Brookings Report.


Among the many witnesses who report UFO sightings, a small percentage (only 2-3% according to U.S. Air Force statistics) have been exposed as hoaxers. Some have held to their stories in spite of persuasive evidence of a hoax, and the determination of specific cases as hoaxes has been contentious. The cases listed below--if lacking conclusive evidence--are at least widely suspected of hoaxing, though some still have defenders among prominent researchers:


The study of UFO claims over the years has led to valuable discoveries about atmospheric phenomena and psychology. In psychology, the study of UFO sightings has revealed information on misinterpretation, perceptual illusions, hallucination and fantasy-prone personality, which may explain why some people are willing to believe hoaxers such as George Adamski. Many have questioned the reliability of hypnosis in UFO abduction cases.

Paranormal, Mystical and Occult crossover

The field of UFOs does not always necessarily overlap the paranormal, although in practice it often does. Some researchers - such as John Keel and Jacques Vallee - argue that there is a direct relationship between UFOs and paranormal phenomena.

Also, some religious sects have made UFO's a part of their core beliefs. See Paranormal and Occult Hypotheses About UFOs.

Many ancient religious paintings contain images that have been interpreted as UFO's and alien beings. Some also believe that over long periods of history, nonhuman intelligences have influenced certain religions and customs.


UFOs are sometimes claimed to be part of an elaborate UFO conspiracy theory in which the government is said to be intentionally covering up the existence of aliens, or sometimes collaborating with them. There are many versions of this story; some are exclusive, while others overlap with various other conspiracy theories.

There is also the speculation that UFO phenomena are tests of experimental aircraft or advanced weapons. In this case UFOs are viewed as failures to retain secrecy, or deliberate attempts at disinformation: to deride the phenomenon so that it can be pursued unhindered. This theory may or may not feed back into the previous one, where current advanced military technology is considered to be adapted alien technology. (See also: skunk works and Area 51)

It's also been suggested that all or most human technology and culture is based on extraterrestrial contact. See also ancient astronauts

Notable UFO-related sightings and events

List of major UFO sightings

In December 1980, a UFO sighting known as the Rendlesham Incident near Ipswich, UK helped to increase the level of interest as a signed letter from the USAF (known as the Halt Memo) confirmed that something had been seen.

Prominent UFO Researchers


Movies and TV

See also

External links

ca:OVNI da:Ufo (objekt) de:UFO eo:Nifo es:OVNI fr:Objet volant non identifi it:UFO ja:UFO nl:UFO no:UFO pl:UFO pt:OVNI ru:НЛО fi:UFO sv:UFO zh:不明飛行物


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