UFO redirects here. For other uses, see UFO (disambiguation).

A UFO or Unidentified Flying Object is any object or optical phenomenon observed in the sky which cannot be identified, even after being thoroughly investigated by qualified people.

History

Reports of strange apparitions in the sky have been recorded throughout history, some which may have been comets, bright meteors, or atmospheric optical phenomena such as parhelia; others remain unexplained. The army of Alexander the Great in 329 BC saw "two silver shields" in the sky. In 1235 the army of Oritsume in Japan saw mysterious lights in the sky. On April 14 1561 the skies over Nuremberg were reportedly filled with a multitude of objects, including cylinders and spheres, seemingly engaged in an aerial battle. Previously treated as divine portents, angels, and other religious omens, such phenomena came to be regarded as a non-supernatural, suitable for scientific investigation, in the immediate aftermath of World War II, when the term "UFO" was coined.

There were several reports of unidentified aircraft in the Scandinavian nations in the 1930s. In both the European and Japanese aerial theatres during World War II, "Foo-fighters" (balls of light that followed aircraft) were reported by both Allied and Axis pilots. In 1946, there were numerous reports of unidentified aircraft in the Scandinavian nations, along with isolated reports from France and Portugal, broadly referred to as "Russian hail" because it was thought for a time that these mysterious objects were Russian tests of captured German V1 or V2 rockets. This was subsequently shown to not be the case, and the phenomenon remains unexplained to this day, although experts generally believe that a significant fraction of the reports were based on misperceptions of natural phenomena. Today, the "Russian Hail" is more generally referred to as "Ghost Rockets."

The post World War II phase in UFOs began with a by American businessman Kenneth Arnold on June 24 1947, near Mount Rainier, Washington. Arnold was helping to search for the wreckage of a downed U.S. Marine transport plane. He reported seeing nine brilliantly bright objects flying across the face of Rainier towards nearby Mount Adams at "an incredible speed", which he calculated at at least 1200 miles an hour by timing their travel between Rainier and Adams. His sighting subsequently received significant mainstream media and public attention. Arnold said that they "flew like a saucer would if you skipped it across the water" and described their shape as "flat like a pie pan" although the shapes varied from object to object, one being almost crescent-shaped. The term flying saucer itself is sometimes ascribed to a reporter, Bill Bequette who interviewed Arnold for the East Oregonian.

Arnold's sighting was followed in the next few weeks by several thousand other reported sightings, mostly from the U.S., but in other countries as well.

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" did not reflect the diversity of the sightings. Ruppelt suggested that "UFO" should be pronounced as a word — "you-foe". However it is generally pronounced by forming each letter: "U.F.O." His term was quickly adopted by the Air Force, who also briefly used "UFOB" circa 1954. Ruppelt recounted his experiences with Project Blue Book in his memoir, The Report on Unidentified Flying Objects (1956), also the first book to use the term.

Air Force Regulation 200-2, issued in 1954, defined an Unidentified Flying Object (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." The regulation also said UFOBs were to be investigated for national security reasons and to "determine technical aspects."

UFOs in popular culture

Beginning in the 1950s, UFO-related spiritual sects began to appear. The Aetherius Society is an early example; more recent ones include Raël and the Ashtar Command.

By the 1970s, popular sentiment had it that spacecraft, and that the aliens involved were benevolent, reinforced through movies such as Close Encounters of the Third Kind ,E.T., and Klaatu's song Calling Occupants (of Interplanetary Craft), later made popular by Karen Carpenter.

This sentiment gained a new twist during the 1980s, primarily in the USA, with the publication of books by Whitley Strieber (beginning with Communion) and Jacques Vallee (Passport to Magonia). Strieber, a horror writer, felt that aliens were harassing him and were responsible for "missing time" during which he was subjected to strange experiments by 'grey' aliens. This newer, darker model can be seen in the subsequent wave of "alien abduction" literature, and in the background mythos of TV's X-Files.

Another key development in 1970s UFO folklore came with the publication of Erich von Däniken's book Chariots of the Gods. The book argued that aliens have been visiting Earth for thousands of years, which explained UFO-like images from various archeological sources as well as unsolved mysteries. This "ancient astronauts" theory inspired numerous imitators, sequels, and fictional adaptations, including one book (Barry Downing's The Bible and Flying Saucers) which interprets miraculous aerial phenomena in the Bible as records of alien contact. Many of these theories posit that aliens have been guiding human evolution, an idea taken up earlier by the novel and film 2001: A Space Odyssey.

Another 1970s-era development was the association of UFOs with supernatural subjects such as occultism, cryptozoology, and parapsychology. Many participants in the New Age movement came to believe in alien contact, perhaps through channeling. A prominent spokesperson for this trend was Shirley MacLaine, especially in her book and miniseries, Out On a Limb.

Noting the variance of the above theories with Christian tradition, a number of conservative Protestant writers (e.g., Hal Lindsey) have suggested that UFOs and their occupants are demonic in origin, intent on seducing humanity into accepting non-Christian doctrines such as evolution. This is echoed in the character of the parson Nathaniel in Jeff Wayne's Musical Version of The War of the Worlds.

UFOs constitute a widespread international cultural phenomenon of the last half-century. Folklorist Dr. Thomas E. Bullard writes, "UFOs have invaded modern consciousness in overwhelming force, and endless streams books, magazine articles, tabloid covers, movies, TV shows, cartoons, advertisements, greeting cards, toys, T-shirts, even alien-head salt and pepper shakers, attest to the popularity of this phenomenon, its ability to

In his classic study psychologist Martin Kottmeyer argues that many elements of UFO stories contain the same bad science and irrationality as low-budget science fiction movies.

UFOs have played a role in tourism, such as in Roswell, New Mexico. According to a popular myth, in 1947 a UFO crashed in a desolate area about 75 miles from Roswell (see Roswell UFO incident).

A 1996 Gallup poll reported that 71% of the United States' population believed that the government was covering up information regarding UFOs. A 2002 Roper poll for the Sci Fi channel found similar results, but with more people believing UFOs were extraterrestrial craft. Again about 70% felt the government was not sharing everything it knew about UFOs or extraterrestrial life. But 56% thought UFOs were real craft and 48% that UFOs had visited the Earth. The younger the person was, the more likely the person were to hold such beliefs.

Research

Ufology is the study of UFO reports and associated evidence. While most academics prefer to ignore the subject, UFOs have been subject to various investigations over the years, varying widely in scope and scientific rigor. Governments or independent academics in the United States, Canada, the United Kingdom, France, Belgium, Sweden, Brazil, Mexico, Spain, and the Soviet Union are known to have investigated 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. Perhaps the best known study was Project Blue Book, previously Project Sign, conducted by the United States Air Force from 1952 until 1969. Other notable investigations include the Robertson Panel, the Brookings Report, and the Condon Committee.

UFO categorization

Some researchers recommend that observations be classified according to the features of the phenomenon or object that are reported or recorded. Typical categories include:

• 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." Disc-shaped craft are sometimes reported to move in an irregular or "wobbly" manner at low speeds.
• Large triangular "craft" or triangular light pattern
• Cigar-shaped "craft" with lighted windows (Meteor fireballs are sometimes reported this way).
• Other: chevrons, equilateral triangles, spheres, domes, diamonds, shapeless black masses, eggs, and cylinders.

Evidence

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.

A small fraction of these cases have been shown to be deliberate hoaxes. A larger 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).
• Images recorded by SOHO and other Sun watching probes. A has been compiled complete with links to the official government versions of the images.
• Recorded visual spectrograms (extremely rare) — (see Spectrometer)
• Recorded gravimetric and magnetic disturbances (extremely rare)
• Landing physical trace evidence, including ground impressions, burned and/or desiccated soil, burned and broken foliage, magnetic anomalies, increased radiation levels, and metallic traces. See, e.g. Height 611 UFO Incident or the 1964 Lonnie Zamora's Socorro, New Mexico encounter, considered one of the most inexplicable of the USAF Project Blue Book cases). A well-known example from December 1980 was the USAF Rendlesham Forest Incident in England. Another less than 2 weeks later, in January 1981, occurred in Trans-en-Provence and was investigated by GEPAN, then France's official government UFO-investigation agency. Catalogs of several thousand such cases have been compiled, particularly by researcher Ted Phillips.
• 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.
• So-called Animal/Cattle Mutilation cases, that some feel are also part of the UFO phenomenon. Such cases can and have been analyzed using forensic science techniques.
• 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.
• 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.
• Actual hard physical evidence cases, such as 1957, Ubatuba, Brazil, magnesium fragments analyzed in the Condon Report and by others. The 1964 Socorro incident also left metal traces, analyzed by NASA.
• 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; 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.

Despite the low opinion of the subject matter possibly held by many 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.

Some scientists and engineers have attempted to reverse 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 and NACA/NASA engineer Paul R. 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

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 reverse engineering efforts. In late 1998, 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. A microwave crowd control nonlethal weapon causing heating and intense pain was announced in 2001. Other microwave weapons have been proposed that would cause loss of bodily functions. (See also wonder weapons)

Notable UFO-related sightings and events

• List of major UFO sightings

Theories

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.

Nevertheless, many cases remained unexplained. An Air Force study by Battelle Memorial Institute scientists in 1954 of 3200 USAF cases found 22% were unknowns, and with the best cases, 35% remained unsolved. Similarly about one third of the UFO cases studied by the 1969 USAF Condon Committee were listed as unsolved. The official French government UFO scientific study (GEPAN/SEPRA) from 1979 to 2004 listed about one quarter of all cases as unknowns.

Despite many unexplained cases, perhaps the general opinion of the mainstream scientific community is 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 dreaming/sleep paralysis (often given as an explanation for purported alien abductions).

Such opinions among scientists are certainly not universal. For example, polls of scientific colleagues by astrophysicist Peter Sturrock found strong interest in investigating the subject. Further, antagonism to studying UFOs correlated directly with ignorance about the subject matter. Sturrock also assembled his own scientific panel in 1998 for an independent review of the evidence. The panel concluded the physical evidence linked to some sightings deserved additional scientific study.

Popular ideas for explaining UFOs

To account for hardcore unsolved cases, a number of theories have been proposed by both proponents and skeptics. Among proponents, some of the more common explanations for UFOs are:

• The Extraterrestrial Visitation Hypothesis (ETH) (most popular)
• The Interdimensional Hypothesis
• The Paranormal/Occult Hypothesis
• A possibility they are time machines or vehicles built in a future time.

Similarly, skeptics usually propose the following theories:

• The Psychological-Social Hypothesis
• The man-made craft hypothesis (see Military flying saucers)
• The unknown natural phenomena hypothesis, e.g. ball lightning, sprites
• The earthlights/tectonic stress hypothesis

Usually a combination of theories is cited to explain all cases, and even proponents will sometimes invoke skeptical explanations, such as man-made craft, to possibly account for some unsolved cases.

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.

However, the actual percentages of IFOs vs. UFOs depends on who is doing the study and can vary widely depending on criteria. For example, scientists for the Battelle Memorial Institute, who did a study for the USAF of 3201 UFO cases in the 1950s, ended up with 22% being unidentified, using the stringent criteria that all four analysts had to agree that the case had no prosaic explanation, whereas agreement of only two analysts was needed to list the case as explained.

In contrast, much more conservative numbers for the percentage of UFOs were arrived at individually by Allen Hendry, who was the chief investigator for the Center for UFO Studies . 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 prosaic 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 (60 m to 200 km). 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 (and particularly satellite flares, which can be surprisingly bright)
• 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). Venus is so bright at times that people commonly mistake it for a disk in the sky. Venus accounts for the majority of UFO reports (Plait 2002:205).
• 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).

Hoaxes

Among the many people who have reported UFO sightings, some have been exposed as hoaxers. Many have held to their stories in spite of persuasive evidence of a hoax, and the determination of specific cases as hoaxes has been contentious. Some are widely suspected of hoaxing, though some still have defenders among their supporters:

• Contactees such as George Adamski, who claimed he went on flights in UFOs and Billy Meier, a busy photographer whose work has largely been discredited.
• Ed Walters of the Gulf Breeze, Florida UFO reports.
• Majestic 12, purportedly a secret, high-level United States UFO study group.
• The Maury Island Incident
• Bob Lazar who claimed to have examined UFOs at Area 51
• The Ummo affair, a series of detailed letters and documents allegedly from extraterrestrials.
• An online list of
• There are many USA and Russians astronauts that have also declared their sightings, example: L. Gordon Cooper, Col. USAF, (ret) Astronaut in letter to the UN in November 9, 1978.

Psychology

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 UFOs a part of their core beliefs. See Paranormal and Occult Hypotheses About UFOs.

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

Conspiracy theories

UFOs are sometimes an element of various elaborate UFO conspiracy theories 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.

Probably most Ufologists believe the basic premise that various world governments are covering up UFO information. In the U.S., opinion polls again indicate that a strong majority of people believe the U.S. government is witholding such information. Various notables have also expressed such views. Some examples are astronauts Gordon Cooper and Edgar Mitchell, Senator Barry Goldwater, Admiral Lord Hill-Norton, former British Chief of Defense Staff and NATO head, and the 1999 high-level French COMETA report by various French generals and aerospace experts.

There is also 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 has also been suggested by a few fringe authors that all or most human technology and culture is based on extraterrestrial contact. See also ancient astronauts.

Evidence and suppression

Some also contend regarding physical evidence that it exists abundantly but is swiftly and sometimes clumsily suppressed by governments, aiming to insulate a population they regard as unprepared for the social, theological, and security implications of such evidence. See the Brookings Report.

There have been scattered reports of suppression of UFO related evidence for many decades: In 1950, Nicholas Mariana filmed some unusal aerial objects and eventually turned the film over to the U.S. Air Force, but insisted that the clearest shots of the objects had been removed from the film when it was returned to him; Jacques Vallee reported that in 1961 he witnessed the destruction of the tracking tapes of unknown objects orbiting the earth; Edward J. Ruppelt reported that, in 1952, a U.S. Air Force pilot fired his jet's machine guns at a UFO, and that the official report which should have been sent to Blue Book was quashed.

Ufology - people and organizations

See also List of UFO researchers.

Organizations

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

• Aerial Phenomena Research Organization (APRO) (1952-1988)
• National Investigations Committee On Aerial Phenomena (NICAP) (1956-1980)
• Mutual UFO Network (MUFON) (1969-present)
• Center for UFO Studies (CUFOS) (1973-present)
• Fund for UFO Research (FUFOR) (1976-present)
• National Institute of Discovery Science (NIDS) (1996-present)
• Citizens Against UFO Secrecy (CAUS) (~1978- ): Small, Arizona based research and FOIA interest group.
• Paradigm Research Group (PRG) & Extraterrestrial Phenomena Political Action Committee (X-PPAC) (1996- ): Small, Washington D.C. group pushing for government UFO disclosure.
• Center for the Study of Extraterrestrial Intelligence (CSETI) (1990- ): Maryland group that runs The Disclosure Project, an effort to get government disclosure on UFOs.
• UFO Casebook
• Malevolent Alien Abduction Research

Film and television

• Close Encounters Of The Third Kind
• Communion
• Dark Skies
• Earth vs the Flying Saucers
• E.T. the Extra-Terrestrial
• Fire in the Sky
• Flight of the Navigator
• Hangar 18
• Independence Day
• Mars Attacks!
• Night Skies
• Project UFO
• Psi-Factor
• Roswell (TV series)
• Sci-Fi Channel's Alien Siege
• Signs
• Sphere
• Taken
• The Day the Earth Stood Still
• The Invaders (1970s TV series)
• The Thing from Another World
• UFO (TV series)
• U.F.O. (1993 movie)
• V (TV series)
• War of the Worlds
• X-Files
• Alien
• Predator
• Bhavathra

See also

• AUFORN Australian Disclosure Project
• Australian Ufology
• Alien abduction
• Ancient astronauts
• Anomalous phenomenon
• Black triangles
• Condon Committee
• Conspiracy theory
• Contactees
• UFO Phil
• Crop circle
• Extraterrestrial life
• Extraterrestrial hypothesis
• Forteana
• Green Fireballs
• Hollow earth
• Kecksburg UFO incident
• Kenneth Arnold
• List of magazines of anomalous phenomena
• Lonnie Zamora
• Military flying saucers
• Prophet Yahweh
• Project Blue Book
• Project Grudge
• Project Sign
• Scientific skepticism
• UFO conspiracy theory
• Ufology
• Ummo
• Rendlesham UFO incident
• Roswell UFO incident
• Shag Harbor
• The X-Files
• UFO Casebook
• Valentich Disappearance
• Robertson Panel

Sources

• Dr. Thomas E. Bullard, "UFOs: Lost in the Myths", pages 141-191 in "UFOs, the Military, and the Early Cold War Era", pages 82-121 in "UFOs and Abductions: Challenging the Borders of Knowledge" David M. Jacobs, editor; 2000, University Press of Kansas, ISBN 0700610324

• Philip Plait (2002). Bad Astronomy: Misconceptions and Misuses Revealed, from Astrology to the Moon Landing "Hoax". John Wiley & Sons, ISBN 0-471-40976-6. (Chapter 20: Misidentified Flying Objects: UFOs and Illusions of the Mind and Eye.)

• Sturrock, Peter A. (1999). The UFO Enigma: A New Review of the Physical Evidence. New York: Warner Books. ISBN 0446525650

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