The Report on the Historical Record of U.S. Government Involvement with Unidentified Anomalous Phenomena (UAP), Volume I is a historical review by the All-domain Anomaly Resolution Office (AARO) of United States Government activity concerning Unidentified Aerial Phenomena (UAP) since 1945.1 The Department of Defense (DoD) provided the report in response to a reporting requirement established by the United States Congress.2
Scope and method
According to the report, its evidential base included records of the Intelligence Community (IC) and DoD, oral-history interviews, open-source analysis, interviews with current and former government officials, and classified and unclassified archives.3 AARO conducted approximately 30 interviews during the research.4
AARO organised the work into six complementary lines of effort, conducted in parallel so that findings in one area could generate further research in another.5 These efforts included open-source historical research, classified-programme research, historical interviews, work with the United States National Archives, engagement with commercial entities, and research with the archives of intelligence and national-security organisations.
The report distinguishes between the initial identification of an observation and claims about its origin. It describes UAP as a category containing objects and events that are initially unidentified, rather than as a category with a common origin, purpose or threat. The report states that categories such as drones, balloons, aircraft, rockets, satellites, sensor artefacts, birds, planets and optical effects may all enter this category before being identified.
Principal findings
The report states that AARO found no evidence that a United States Government investigation, academic-sponsored study or official review panel had confirmed any UAP sighting as extraterrestrial technology.6 It further states that investigative efforts at all classification levels concluded that most sightings involved ordinary objects or phenomena and misidentification.7
According to the report, AARO found no empirical evidence that the United States Government or private companies had reverse-engineered extraterrestrial technology.8 The report also describes claims that authentic classified programmes were mistakenly associated with alien or extraterrestrial activity.
AARO’s review of these claims included the proposed KONA BLUE programme. The report characterises KONA BLUE as a UAP-related prospective special access programme proposed to the Department of Homeland Security (DHS), but states that it was never approved and that its supporters supplied no empirical evidence for their claims.9
The report also discusses an Intelligence Community Controlled Access Program whose scope was expanded in 2021 to include UAP reverse-engineering. It states that the programme recovered or reverse-engineered no UAP or extraterrestrial spacecraft, and that it was subsequently disestablished.10
Historical investigations
The report places particular emphasis on the sequence of post-war United States investigations. Project BLUE BOOK recorded 12,618 UFO sightings between 1947 and 1969, with 701 categorised as unidentified and never solved.11 Its conclusions, as presented in the report, were that no evaluated sighting indicated a threat to national security or technology beyond the scientific knowledge of the period.12
The earlier Project SIGN evaluated 243 reported sightings and concluded in February 1949 that there was no definite and conclusive evidence proving or disproving the existence of aircraft of unknown and unconventional configuration. It determined that nearly all cases resulted from misinterpretation, hysteria, hallucination or hoax. The report also discusses the alleged The Estimate of the Situation, describing it as an unsubstantiated account that claimed some UFOs were interplanetary in origin and stating that it was rejected for lack of proof.
The report describes two organisations known as Project GRUDGE and Project GRUDGE (Reestablishment). The first was terminated in 1949, while the later organisation was established in 1951 under Edward J. Ruppelt. The re-established organisation reviewed earlier cases and, according to the report, found no evidence of extraterrestrial origin.
The report also covers the The Robertson Panel, which reviewed United States Air Force data and concluded that most UFO reports had ordinary explanations. It found no evidence of a direct national-security threat or extraterrestrial origin, while recommending public-information measures intended to reduce what it regarded as the risk of mass hysteria and possible exploitation by the Soviet Union.
Modern programmes and organisational changes
The report identifies 2009 as the beginning of a modern period because of the establishment of the Advanced Aerospace Weapons System Application Program (AAWSAP), also known as the Advanced Aerospace Threat Identification Program (AATIP).13 It states that AAWSAP was intended to examine next-generation aerospace technologies in 12 areas. Although UFO investigation was not specifically set out in the contract’s statement of work, the contracted private organisation conducted UFO research with the support of a Defense Intelligence Agency (DIA) programme manager.
According to the report, AARO found no substantive AAWSAP/AATIP casework beyond reviews of Project BLUE BOOK and private cases, interviews with observers, and unrelated research into alleged paranormal activity at a property in Utah.14 The report states that AAWSAP/AATIP was terminated in 2012.
In August 2020, the Unidentified Aerial Phenomena Task Force (UAPTF) was approved to improve understanding of UAP and to detect, analyse and catalogue objects that might pose a threat to United States national security. According to the report, the UAPTF also helped standardise reporting and improve sensor calibration.
The UAPTF was followed by the Airborne Object Identification and Management Synchronization Group (AOIMSG). The report states that AOIMSG had not reached initial operating capability when legislation led to its renaming as AARO and expanded its mission.15 AARO subsequently organised its work around analysis, operations, science and technology, and strategic communications.
Assessment of UAP evidence
The report states that none of the UAP reports investigated and analysed by AARO represented extraterrestrial or off-world technology.16 It nevertheless records that a small percentage of cases had potentially anomalous or concerning characteristics. It attributes difficulties in resolving cases to limited or poor-quality data, including the frequent absence of reliable information about an object’s speed, altitude and size.
The report presents misidentification as a recurring feature of the historical record. Earlier cases were sometimes associated with balloons, aircraft, rockets, satellites, atmospheric phenomena, optical effects or experimental and operational systems that were not publicly known at the time. It also states that some reporting increases coincided with the observation of new technologies and testing.
In relation to alleged physical evidence, the report describes analyses of material said to have come from an off-world spacecraft. AARO concluded that the sample was a terrestrial metallic alloy, and that it did not possess exceptional qualities. The report states that another piece of alleged spacecraft material was likewise ordinary and terrestrial.
Status of the report
Volume I contains AARO’s findings from 1945 to 2023-10-31. The report states that some allegations remained under evaluation and that the results of unresolved allegations would be addressed in Volume II. AARO remains open to additional verifiable information that could alter the conclusions presented in Volume I.17