An unidentified flying object (UFO), or unidentified anomalous phenomenon (UAP), is any perceived airborne, submerged or transmedium phenomenon that cannot be immediately identified or explained. Upon investigation, most UAPs are identified as known objects or atmospheric phenomena, while a small number remain unexplained.
UFO conspiracy theories are a subset of conspiracy theories which argue that various governments and politicians globally, in particular the United States government, are suppressing evidence that unidentified flying objects are controlled by a non-human intelligence or built using alien technology. Such conspiracy theories usually argue that Earth governments are in communication or cooperation with extraterrestrial visitors despite public disclaimers, and further that some of these theories claim that the governments are explicitly allowing alien abduction.
Kenneth Albert Arnold was an American aviator, businessman, and politician.
On January 7, 1948, 25-year-old Captain Thomas F. Mantell, a Kentucky Air National Guard pilot, died when he crashed his P-51 Mustang fighter plane near Franklin, Kentucky, United States, after being sent in pursuit of an unidentified flying object (UFO). Mantell pursued the object in a steep climb and disregarded suggestions to level his altitude. At high altitude, he blacked out from a lack of oxygen; his plane went into a downward spiral and crashed. The incident was among the most publicized of early UFO reports. Later investigation by the United States Air Force's Project Blue Book indicated that Mantell died chasing a Skyhook balloon, which, in 1948, was a top-secret project that he would not have known about.
The extraterrestrial hypothesis (ETH) proposes that some unidentified flying objects (UFOs) are best explained as being physical spacecraft occupied by extraterrestrial intelligence or non-human aliens, or non-occupied alien probes from other planets visiting Earth.
The "Maury Island incident" refers to claims made by Fred Crisman and Harold Dahl of falling debris and threats by men in black following sightings of unidentified flying objects in the sky over Maury Island in Puget Sound. The pair would later claim the events had occurred on June 21, 1947.
The Robertson Panel was a scientific committee which met in January 1953 headed by Howard P. Robertson. The Panel arose from a recommendation to the Intelligence Advisory Committee (IAC) in December 1952 from a Central Intelligence Agency (CIA) review of the U.S. Air Force investigation into unidentified flying objects, Project Blue Book. The CIA review itself was in response to widespread reports of unidentified flying objects, especially in the Washington, D.C. area during the summer of 1952.
Project Sign or Project Saucer was an official U.S. government study of unidentified flying objects (UFOs) undertaken by the United States Air Force (USAF) and active for most of 1948. It was the precursor to Project Grudge.
The Mariana UFO incident occurred in August 1950 in Great Falls, Montana. The film footage of the sighting is believed to be among the first ever taken of what came to be called an unidentified flying object. The footage was investigated by the U.S. Air Force, and initially found to be reflections from two F-94 jet fighters, which was later retracted.
The Levelland UFO case occurred on November 2–3, 1957, on the highways around the small town of Levelland, Texas. Levelland, which in 1957 had a population of about 10,000, is located west of Lubbock on the flat prairie of the Texas South Plains. The case is considered by ufologists to be one of the most impressive in UFO history, mainly because of the large number of witnesses involved over a relatively short period of time. However, both the US Air Force and UFO sceptics have described the incident as being caused by either ball lightning or a severe electrical storm.
From July 12 to 29, 1952, a series of unidentified flying object (UFO) sightings were reported in Washington, D.C., and later became known as the Washington flap, the Washington National Airport Sightings, or the Invasion of Washington. The most publicized sightings took place on consecutive weekends, July 19–20 and July 26–27. UFO historian Curtis Peebles called the incident "the climax of the 1952 (UFO) flap" - "Never before or after did Project Blue Book and the Air Force undergo such a tidal wave of (UFO) reports."
A flying saucer is a descriptive term for a type of flying craft having a disc or saucer-shaped body, commonly used generically to refer to an anomalous flying object. The term was coined in 1947 but has generally been supplanted since 1952 by the United States Air Force term unidentified flying objects. Early reported sightings of unknown "flying saucers" usually described them as silver or metallic, sometimes reported as covered with navigation lights or surrounded with a glowing light, hovering or moving rapidly, either alone or in tight formations with other similar craft, and exhibiting high maneuverability.
The Gorman dogfight was a widely publicized UFO incident which took place on October 1, 1948, in the skies over Fargo, North Dakota, United States. United States Air Force (USAF) Captain Edward J. Ruppelt wrote in his bestselling and influential The Report on Unidentified Flying Objects that the "dogfight" was one of three "classic" UFO incidents in 1948 that "proved to [Air Force] intelligence specialists that UFOs were real," along with the Chiles-Whitted UFO encounter and the Mantell UFO incident. However, in 1949 the USAF concluded that the Gorman dogfight had been caused by a lighted weather balloon.
The Sperry UFO case was a sighting of an Unidentified Flying Object by the captain, Willis Sperry, and other crew of an American Airlines DC-6 airborne near Mount Vernon, Maryland on 29 May 1950.
The Kenneth Arnold UFO sighting occurred on June 24, 1947, when private pilot Kenneth Arnold claimed that he saw a string of nine, shiny unidentified flying objects flying past Mount Rainier at speeds that Arnold estimated at a minimum of 1,200 miles an hour (1,932 km/h). This was the first post-World War II sighting in the United States that garnered nationwide news coverage and is credited with being the first of the modern era of UFO sightings, including numerous reported sightings over the next two to three weeks. Arnold's description of the objects also led to the press quickly coining the terms flying saucer and flying disc as popular descriptive terms for UFOs.
UFOs: Past, Present, and Future is a 1974 documentary film that examines several prominent UFO sightings from the post-war to contemporary era. It was re-released in 1976 and 1979 under the title UFOs: It Has Begun to coincide with renewed interest in the subject due to the release of Steven Spielberg's Close Encounters of the Third Kind. It is based on the book UFOs: Past, Present, and Future by Robert Emenegger.
The Coming of the Saucers is a 1952 book by original 'flying saucer' witness Kenneth Arnold and pulp magazine publisher Raymond Palmer. The book reprints and expands early articles the two had published in Palmer's Fate magazine. The work blends first-person accounts attributed to Arnold with third-person summations of UFO reports.
The Rhodes UFO photos, sometimes called the shoe-heel UFO photos, are two photos that were reportedly taken on July 7, 1947 by amateur astronomer and inventor William Albert Rhodes. The photographs purport to show a disc-like object flying above Phoenix, Arizona. Rhodes's account and photographs were published by the Arizona Republic on July 9.
The Report on Unidentified Flying Objects is a 1956 book by then-retired Air Force UFO investigator Edward J. Ruppelt, detailing his experience running Project Bluebook. The book was noted for its suggestion that a few UFO sightings might be linked to spikes of atomic radiation. Contemporary media summarized four topics discussed in the book:
On the night of January 29, 1952, amid the Korean War, four American military personnel aboard two different B-29 bombers reported seeing an orange globe-shaped light over two different cities in northern Korea: Wonsan and Sunchon. Air Force UFO experts argue that widespread reporting of the incident contributed to the 1952 UFO flap that culminated in sightings over the nation's capital.
