Unidentified flying object (commonly abbreviated as UFO or
U.F.O.) is the popular term for any apparent aerial
phenomenon whose cause cannot be easily or immediately identified by the
observer. The United States
Air Force, which coined the term in 1952, initially defined UFOs as those
objects that remain unidentified after scrutiny by expert investigators, though today the
term UFO is colloquially used to refer to any unidentifiable sighting regardless
of whether it has been investigated. UFO reports increased precipitously after
the first widely publicized U.S. sighting, reported by private pilot Kenneth Arnold in June 24
1947, that gave rise to the popular terms "flying saucer" and "flying disc." The term
UFO is popularly taken as a synonym for alien spacecraft and generally most
discussions of UFOs revolve around this presumption. UFO enthusiasts and devotees have created organizations, religious cults have adopted extraterrestrial themes,
and in general the UFO concept has evolved into a prominent mythos in modern
investigators now prefer to use the broader term unidentified aerial
phenomenon (or UAP), to avoid the confusion and speculative
associations that have become attached to UFO.
Unexplained aerial observations have been reported throughout history. Some were
undoubtedly astronomical in nature: comets, bright meteors, one or more of the five planets that can be
seen with the naked eye, planetary conjunctions, or atmospheric optical phenomena
such as parhelia
- On January 25, 1878, The Denison Daily News wrote that local farmer
John Martin had reported seeing a large, dark, circular flying object resembling
a balloon flying "at wonderful speed." Martin also said it appeared to be about
the size of a saucer, the first known use of the word "saucer" in association
with a UFO.
- On February 28, 1904, there was a sighting by three crew members on the
Supply 300 miles west of San Francisco, reported by Lt. Frank
Schofield, later to become Commander-in-Chief of the Pacific Battle Fleet. Schofield wrote
of three bright red egg-shaped and circular objects flying in echelon formation
that approached beneath the cloud layer, then changed course and "soared" above
the clouds, departing directly away from the earth after two to three minutes.
The largest had an apparent size of about six suns.
- 1916 and 1926: The three oldest known pilot UFO sightings, of 1305 cataloged
by NARCAP. On January 31, 1916, a UK pilot near Rochford reported a row of lights, like lighted
windows on a railway carriage, that rose and disappeared. In January 1926, a
pilot reported six "flying manhole covers" between Wichita, Kansas and Colorado Springs, Colorado. In late
September 1926, an airmail pilot over Nevada was forced to land by a huge, wingless
- On August 5, 1926, while traveling in the Humboldt Mountains of Tibet's Kokonor
Roerich reported that members of his expedition saw "something big and shiny
reflecting the sun, like a huge oval moving at great speed. Crossing our camp
the thing changed in its direction from south to southwest. And we saw how it
disappeared in the intense blue sky. We even had time to take our field glasses
and saw quite distinctly an oval form with shiny surface, one side of which was
brilliant from the sun.” Another
description by Roerich was, "...A shiny body flying from north to south. Field
glasses are at hand. It is a huge body. One side glows in the sun. It is oval in
shape. Then it somehow turns in another direction and disappears in the
- In the Pacific and European theatres during World War II, "Foo-fighters" (metallic spheres, balls of light and
other shapes that followed aircraft) were reported and on occasion photographed
by Allied and Axis pilots. Some proposed Allied explanations at the time
included St. Elmo's Fire, the planet Venus,
hallucinations from oxygen deprivation, or German secret weapon.
- On February 25, 1942, U.S. Army observers reported unidentified aircraft
both visually and on radar over the Los
Angeles, California region.
Antiaircraft artillery was fired at what was presumed to be Japanese planes. No
readily apparent explanation was offered, though some officials dismissed the
reports of aircraft as being triggered by anxieties over expected Japanese air
attacks on California. However, Army Chief of Staff Gen. George C.
Marshall and Secretary of War Henry Stimson insisted real aircraft were
involved. The incident later became known as the Battle of Los
Angeles, or the West coast air raid.
- In 1946, there were over 2000 reports, collected primarily by the Swedish
military, of unidentified aerial objects in the Scandinavian nations, along with
isolated reports from France, Portugal, Italy and Greece, then referred to as
"Russian hail", and later as "ghost rockets", because it was thought that these
mysterious objects were possibly Russian tests of captured German V1 or
V2 rockets. Although most were thought to be
natural phenomena like meteors, over 200 were tracked on radar and deemed to be
"real physical objects" by the Swedish military. In a 1948 top secret document, the Swedish
military told the USAF Europe in 1948 that some of their investigators believed
them to be extraterrestrial in origin.
The post World War II UFO phase in the United States began with a famous
sighting by American businessman Kenneth Arnold on June 24, 1947 while flying his
private plane near Mount
Rainier, Washington. He reported seeing nine
brilliantly bright objects flying across the face of Rainier.
Although there were other 1947 U.S. sightings of similar objects that
preceded this, it was Arnold's sighting that first received significant media
attention and captured the public's imagination. Arnold described what he saw as
being "flat like a pie pan", "shaped like saucers and were so thin I could
barely see them… ", "half-moon shaped, oval in front and convex in the rear. …
they looked like a big flat disk" (see Arnold's drawing at right), and flew
"like a saucer would if you skipped it across the water". (One of the objects,
however, he would describe later as crescent-shaped, as shown in illustration at
left.) Arnold’s descriptions were widely reported and within a few days gave
rise to the terms flying saucer and flying disk. Arnold’s sighting
was followed in the next few weeks by hundreds of other reported sightings,
mostly in the U.S., but in other countries as well. After reports of the Arnold
sighting hit the media, other cases began to be reported in increasing numbers.
In one instance a United
Airlines crew sighting of nine more disc-like objects over Idaho on the evening of July 4. At the time, this
sighting was even more widely reported than Arnold’s and lent considerable
credence to Arnold’s report.
American UFO researcher Ted Bloecher, in his comprehensive review of
newspaper reports (including cases that preceded Arnold's), found a sudden surge
upwards in sightings on July 4, peaking on July 6–8. Bloecher noted that for the
next few days most American newspapers were filled with front-page stories of
the new "flying saucers" or "flying discs". Reports began to rapidly tail off
after July 8, when officials
began issuing press statements on the Roswell UFO
incident, in which they explained debris found on the ground by a rancher as
being that of a weather balloon.
Over several years in the 1960s, Bloecher (aided by physicist James E. McDonald)
discovered 853 flying disc sightings that year from 140 newspapers from Canada,
Washington D.C, and every U.S. state except Montana
UFOs have been subject to investigations over the years that vary widely in
scope and scientific rigor. Governments or independent academics in the United
States, Canada, the United Kingdom, Japan, Peru, France, Belgium, Sweden,
Brazil, Chile, Uruguay, Mexico, Spain, and the Soviet Union are known to have
investigated UFO reports at various times.
Following the large U.S. surge in sightings in June and early July 1947, on
July 9, 1947, Army Air Force (AAF)
intelligence, in cooperation with the FBI, began a formal investigation into selected best
sightings with characteristics that could not be immediately rationalized, which
Arnold’s and that of the United Airlines crew. The AAF used "all of its top
scientists" to determine whether or not "such a phenomenon could, in fact,
occur". The research was "being conducted with the thought that the flying
objects might be a celestial phenomenon," or that "they might be a foreign body
mechanically devised and controlled." Three weeks later
in a preliminary defense estimate, the air force investigation decided that,
"This ‘flying saucer’ situation is not all imaginary or seeing too much in some
natural phenomenon. Something is really flying around."
A further review by the intelligence and technical divisions of the Air Materiel Command at Wright Field reached the same conclusion,
that "the phenomenon is something real and not visionary or fictitious," that
there were objects in the shape of a disc, metallic in appearance, and as big as
man-made aircraft. They were characterized by "extreme rates of climb [and]
maneuverability," general lack of noise, absence of trail, occasional formation
flying, and "evasive" behavior "when sighted or contacted by friendly aircraft
and radar," suggesting a controlled craft. It was thus recommended in late
September 1947 that an official Air Force investigation be set up to investigate
the phenomenon. It was also recommended that other government agencies should
assist in the investigation.
This led to the creation of the Air Force’s Project Sign at the end of 1947, one of the
earliest government studies to come to a secret extraterrestrial conclusion. In
August 1948, Sign investigators wrote a top-secret intelligence estimate to
that effect. The Air Force Chief of Staff Hoyt Vandenberg ordered
it destroyed. The existence of this suppressed report was revealed by several
insiders who had read it, such as astronomer and USAF consultant J. Allen Hynek and Capt.
Ruppelt, the first head of the USAF's Project Blue Book.
Project Sign was dismantled and became Project Grudge at the end of 1948. Angered by
the low quality of investigations by Grudge, the Air Force Director of
Intelligence reorganized it as Project Blue Book in late 1951, placing
Ruppelt in charge. Blue Book closed down in 1970, using the Condon Commission's
negative conclusion as a rationale, ending the official Air Force UFO
investigations. However, a 1969 USAF document, known as the Bolender memo, plus
later government documents revealed that nonpublic U.S. government UFO
investigations continued after 1970. The Bollender memo first stated that
"reports of unidentified flying objects that could affect national security… are
not part of the Blue Book system," indicating that more serious UFO incidents
were already handled outside of the public Blue Book investigation. The memo
then added, "reports of UFOs which could affect national security would continue
to be handled through the standard Air Force procedures designed for this
purpose." In addition, in
the late 1960s, there was a chapter on UFOs at the U.S. Air Force Academy in
their Space Sciences course, giving serious consideration to possible
extraterrestrial origins. When word of the curriculum became public, the Air
Force in 1970 put out a statement the book was outdated and that cadets were now
being informed of Condon's negative conclusion instead.
Use of UFO instead of the popular flying saucer was first suggested in 1952 by
Ruppelt, 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, which also briefly
used "UFOB" circa 1954, for Unidentified Flying Object. 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.
Regulation 200-2, issued in 1953 and
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 as a "possible threat to the security of the United States"
and "to determine technical aspects involved." As to what the public was to be
told, "it is permissible to inform news media representatives on UFOB's when the
object is positively identified as a familiar object," but "For those objects
which are not explainable, only the fact that ATIC [Air Technical Intelligence
Center] will analyze the data is worthy of release, due to many unknowns
Well known American investigations include:
The Battle of Los Angeles in 1942, where an
unidentified flying object sequently was thought to be part of a Japanese airstrike.
Incident involved New Mexico residents, local law enforcement officers, and
the US military, the latter of whom allegedly collected physical evidence from
the UFO crash site.
In the Kecksburg Incident, Pennsylvania
residents reported seeing a bell shaped object crash in the area. Police
officers, and possibly military personnel, were sent to investigate.
The Betty and Barney Hill abduction
was the first reported abduction incident.
1975 Travis Walton
abduction case: The movie Fire in the Sky was based on this event, but
embellished greatly the original account.
Lights" March 13, 1997
Both US and British military personnel allegedly witnessed UFOs in the
forests near Rendlesham Rendlesham Forest incident and
Bentwaters. This case was reported in December 1980 and took place over several
nights at both the US and RAF military bases.
The Uruguayan Air Force has had an ongoing UFO investigations since 1989 and
analyzed 2100 cases, of which they consider only 40 (about 2%) definitely
lacking any conventional explanation. All files have recently been declassified.
The unexplained cases include military jet interceptions, abductions, cattle
mutilations, and physical landing trace evidence. Colonel Ariel Sanchez, who
currently heads the investigation, summarized their findings as follows: "The
commission managed to determine modifications to the chemical composition of the
soil where landings are reported. The phenomenon exists. It could be a
phenomenon that occurs in the lower sectors of the atmosphere, the landing of
aircraft from a foreign air force, up to the extraterrestrial hypothesis. It
could be a monitoring probe from outer space, much in the same way that we send
probes to explore distant worlds. The UFO phenomenon exists in the country. I
must stress that the Air Force does not dismiss an extraterrestrial hypothesis
based on our scientific analysis."
The Air Force's Project Blue Book files indicate that
approximately 1 % of all unknown
reports came from amateur and professional astronomers or other users of
telescopes (such as missile trackers or surveyors). In 1952, astronomer J. Allen Hynek, then a
consultant to Blue Book, conducted a small survey of 45 fellow professional
astronomers. Five reported UFO sightings (about 11%). In the 1970s,
A. Sturrock conducted two large surveys of the American
Institute of Aeronautics and Astronautics and American Astronomical Society.
About 5 % of the members polled indicated that they had had UFO sightings.
Tombaugh, who admitted to six UFO sightings, including three green fireballs,
supported the Extraterrestrial hypothesis (ETH) for UFOs and stated he thought
scientists who dismissed it without study were being "unscientific." Another
astronomer was Lincoln
LaPaz, who had headed the Air Force's investigation into the green fireballs
and other UFO phenomena in New Mexico. LaPaz reported two personal sightings,
one of a green fireball, the other of an anomalous disc-like object. (Both
Tombaugh and LaPaz were part of Hynek's 1952 survey.) Hynek himself took two
photos through the window of a commercial airliner of a disc-like object that
seemed to pace his aircraft. Even later UFO
debunker Donald Menzel filed a
UFO report in 1949.
In 1980, a survey of 1800 members of various amateur astronomer associations
by Gert Helb and Hynek for the Center for UFO Studies (CUFOS) found
that 24 % responded "yes" to the question "Have you ever observed an object
which resisted your most exhaustive efforts at identification?"
In August 2009 The
Black Vault internet archive announced the release by the British government
of more than 4,000 pages of declassified records. The records include information on the Rendlesham Forest incident, crop
circles, a UFO attack on a cemetery and even reports of alien abduction claims
On 1 December 2009, the British Ministry of
Defense (MoD) quietly closed down its UFO investigations unit. The unit's
hotline and email address were suspended by the Ministry of Defense on that
date. The MoD said there was no value in continuing to receive and investigate
sightings in a release, stating
- "... in over fifty years, no UFO report has revealed any evidence of a
potential threat to the United Kingdom. The MoD has no specific capability for
identifying the nature of such sightings. There is no Defence benefit in such
investigation and it would be an inappropriate use of defence resources.
Furthermore, responding to reported UFO sightings diverts MoD resources from
tasks that are relevant to Defence."
The Guardian reported
that the MoD claimed the closure would save the Ministry around £50,000 a year.
The MoD said that it would continue to release UFO files to the public through
the National Archives