We are Not Alone

An unidentified flying object, often abbreviated UFO or U.F.O., is an unusual apparent anomaly in the sky that is not readily identifiable to the observer as any known object, often associated with extraterrestrial life.

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, thus ending official Air Force UFO investigations. However, a 1969 USAF document, known as the Bolender memo, along with later government documents, revealed that non-public 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 already were handled outside 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 a chapter on UFOs in the Space Sciences course at the U.S. Air Force Academy gave serious consideration to possible extraterrestrial origins. When word of the curriculum became public, the Air Force in 1970 issued a statement to the effect that the book was outdated and that cadets instead were being informed of the Condon report's negative conclusion.

Thousands of documents released under FOIA also indicate that many U.S. intelligence agencies collected and still collect, information on UFOs. These agencies include the Defense Intelligence Agency (DIA), FBI, CIA, National Security Agency (NSA), as well as military intelligence agencies of the Army and Navy, in addition to the Air Force.

The investigation of UFOs has also attracted many civilians, who in the U.S formed research groups such as National Investigations Committee On Aerial Phenomena (NICAP, active 1956–1980), Aerial Phenomena Research Organization (APRO, 1952–1988), Mutual UFO Network (MUFON, 1969), and Center for UFO Studies (CUFOS, 1973).

In November 2011, the White House released an official response to two petitions asking the U.S. government to acknowledge formally that aliens have visited this planet and to disclose any intentional withholding of government interactions with extraterrestrial beings. According to the response, "The U.S. government has no evidence that any life exists outside our planet, or that an extraterrestrial presence has contacted or engaged any member of the human race."Also, according to the response, there is "no credible information to suggest that any evidence is being hidden from the public's eye." The response further noted that efforts, like SET, the Kepler space telescope and the NASA Mars rover, continue looking for signs of life. The response noted "odds are pretty high" that there may be life on other planets but "the odds of us making contact with any of them especially any intelligent ones are extremely small, given the distances involved

The UK's Flying Saucer Working Party published its final report in 1951, which remained secret for over 50 years. The Working Party concluded that all UFO sightings could be explained as misidentifications of ordinary objects or phenomena, optical illusions, psychological misperceptions/aberrations, or hoaxes. The report stated: "We accordingly recommend very strongly that no further investigation of reported mysterious aerial phenomena be undertaken, unless and until some material evidence becomes available."

Eight file collections on UFO sightings, dating from 1978 to 1987, were first released on May 14, 2008, to the UK National Archives by the Ministry of Defence. Although kept secret from the public for many years, most of the files have low levels of classification and none are classified Top Secret. 200 files are set to be made public by 2012. The files are correspondence from the public sent to government officials, such as the MoD and Margaret Thatcher. The MoD released the files under the Freedom of Information Act due to requests from researchers.These files include, but are not limited to, UFOs over Liverpool and the Waterloo Bridge in London.

On October 20, 2008 more UFO files were released. One case released detailed that in 1991 an Alitalia passenger aircraft was approaching Heathrow Airport when the pilots saw what they described as a "cruise missile" fly extremely close to the cockpit. The pilots believed that a collision was imminent. UFO expert David Clarke says that this is one of the most convincing cases for a UFO he has come across.

A secret study of UFOs was undertaken for the UK’s Ministry of Defence (MoD) between 1996 and 2000 and was code-named Project Condign. The resulting report, titled "Unidentified Aerial Phenomena in the UK Defence Region", was publicly released in 2006, but the identity and credentials of whomever constituted Project Condign remains classified. The report confirmed earlier findings that the main causes of UFO sightings are misidentification of man-made and natural objects.

The report noted: "No artefacts of unknown or unexplained origin have been reported or handed to the UK authorities, despite thousands of UAP reports. There are no SIGINT, ELINT or radiation measurements and little useful video or still IMINT." It concluded: "There is no evidence that any UAP, seen in the UKADR [UK Air Defence Region], are incursions by air-objects of any intelligent (extraterrestrial or foreign) origin, or that they represent any hostile intent." A little-discussed conclusion of the report was that novel meteorological plasma phenomenon akin to Ball Lightning are responsible for "the majority, if not all" of otherwise inexplicable sightings, especially reports of Black Triangle UFOs