EDITORIAL GUIDE
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What Is a UAP? — The Government's Official Definition
UAP stands for Unidentified Aerial Phenomena — the term the U.S. government officially uses in place of UFO. This guide explains the official definition, why the terminology changed, what distinguishes a UAP from a UFO in a legal and archival context, and what the U.S. government's records actually document when they use the term.
UAP vs UFO — Why the Terminology Changed
The shift from 'UFO' (Unidentified Flying Object) to 'UAP' (Unidentified Aerial Phenomena) is not merely a rebranding exercise. The change reflects a substantive expansion of scope and a deliberate effort to remove the cultural stigma that had accumulated around the UFO label. In government usage, 'UAP' is the term adopted by AARO, the 2024 NDAA, NARA Record Group 615, and all post-2020 official documentation.
The key reason for the terminology change: 'object' implies a physical, structured craft — but many reported anomalies have no confirmed material form. 'Phenomena' is deliberately broader and covers a wider range of possible explanations, including plasma phenomena, exotic propulsion signatures, or genuinely novel technology. The move from 'flying' to 'aerial' (and in practice, 'domain' in AARO's 'all-domain anomaly' formulation) also acknowledges that many UAP reports involve transitions between air, water, and near-space environments — capabilities the word 'flying' does not encompass.
The Official Government Definition of UAP
The official U.S. government definition of a UAP, as used by AARO and codified in the 2024 NDAA, describes UAP as 'airborne objects or other phenomena that are unidentified and authorized U.S. Government personnel have been unable to identify' through standard analysis. This definition deliberately encompasses both objects — things with physical form and radar cross-section — and phenomena, which may not behave like conventional material objects.
AAROE's working definition adds a critical qualifier: a UAP is not simply an unidentified flying object in the colloquial sense. It is specifically a case where standard identification tools — visual identification, radar analysis, FLIR thermal imaging, electronic spectrum analysis, and database comparison against known military and civilian aircraft — have all failed to produce an explanation. A commercial aircraft whose transponder has failed is not a UAP; it is an unidentified aircraft with a presumed prosaic explanation. A UAP is a case where the prosaic explanation has been exhausted.
What the Archive Documents When It Uses the Term UAP
When NARA Record Group 615, AARO, and the DoD PURSUE program describe an incident as involving a UAP, they mean it in this precise technical sense: an event where government sensors and analysis processes could not identify the object or phenomenon using any available reference framework. The 35+ incidents indexed in the Now Declassified archive all meet this threshold — each traces to official source documents where the reporting agency designated the case as unresolved or unidentified after standard analysis.
This is why the indexing standard for this archive requires a primary source link. An incident described as a UAP in a media article does not meet the threshold; an incident described as unresolved in an official AARO case-resolution entry, a NARA-archived radar log, or a declassified DIA assessment does. The UAP label in government records is a technical finding, not a statement about the nature of the object.
How UAP Relates to the AARO Reporting Framework
AARO's 'all-domain anomaly' formulation extends the UAP concept beyond aerial phenomena. The full AARO mandate covers 'airborne objects, submerged objects, transmedium objects or devices, and anomalies in space' — reflecting that documented UAP behavior frequently involves transitions between environments (air-to-water transmedium travel is documented in the archive) and occasional tracking by space-based sensors.
For researchers, this means the formal UAP definition is now formally domain-agnostic. A phenomenon reported by submarine sonar in the same location as an aerial sighting can be part of the same AARO case record. The transmedium cases in the archive — including the Pacific Naval Zone transmedium incident and the Shag Harbour 1967 case — represent exactly this expanded understanding. When you see 'UAP' in a government document, the scope of what that term covers is now formally much wider than the UFO concept it replaced.