UAP vs UFO: What’s the Difference

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UFO and UAP look the same. The difference: UAP covers underwater, transmedium, and aerial phenomena. Here’s why the government switched.

TL;DR
UFO stands for “Unidentified Flying Object.” UAP stands for “Unidentified Anomalous Phenomena.” They describe similar things, but UAP is now the official term used by the U.S. government, the military, NASA, and the FAA. The switch was deliberate: UFO carries decades of cultural baggage from flying saucer movies and conspiracy theories, while UAP allows officials to investigate these incidents as national security and aviation safety concerns without the stigma. As of March 2026, every branch of the U.S. government uses UAP in official documents.

What Does UFO Actually Mean?

The difference between UFO and UAP comes down to history, politics, and stigma. Captain Edward J. Ruppelt, the first director of Project Blue Book, coined the term “UFO” in 1952. He introduced it to replace “flying saucer” and bring a more professional tone to the Air Force’s investigation program. Before that, the most common term was “flying saucer,” which came from a misquoting of pilot Kenneth Arnold’s 1947 report. Arnold described objects that moved “like a saucer skipping across water.” Newspapers reported he saw “flying saucers,” and the name stuck.

The Air Force needed a more neutral term for official reports. The result was “Unidentified Flying Object.” It was deliberately clinical. The idea was to describe something without implying what it was. The term appeared in thousands of official reports between 1947 and 1969, most of them through Project Blue Book, the Air Force’s formal UFO investigation program.

But “UFO” did not stay clinical for long. By the 1960s, it had become inseparable from the idea of alien spacecraft. Movies, television shows, and tabloid newspapers all used “UFO” as shorthand for “alien visitation.” By the time the government shut down Project Blue Book in 1969, the term had accumulated so much cultural weight that using it in a serious government report invited ridicule.

This stigma became a real problem. Military pilots who observed unidentified objects were reluctant to file reports because the term “UFO” made them sound like they were claiming to have seen aliens. Intelligence analysts avoided the topic. Congressional staffers treated it as a career risk. The word itself became a barrier to investigation.

What Does UAP Actually Mean?

UAP stands for “Unidentified Anomalous Phenomena.” As of December 2022, that is the official definition used in U.S. law. But the term has gone through two definitions in a short time.

Original definition (2020-2022): “Unidentified Aerial Phenomena.” When the Pentagon created the Unidentified Aerial Phenomena Task Force (UAPTF) in August 2020, “aerial” was the operative word. The task force focused on objects observed in the air, primarily by military pilots.

Updated definition (2022-present): “Unidentified Anomalous Phenomena.” In December 2022, both the Pentagon and NASA expanded the definition. “Anomalous” replaced “aerial” to cover not just objects in the sky, but phenomena observed in water, in space, and phenomena that appear to transition between domains (called “transmedium” objects). The FY 2023 National Defense Authorization Act codified this expanded definition.

The key word is “anomalous.” It means something that does not fit expected patterns. It does not imply that the thing is alien, or advanced technology, or anything specific. It just means: this happened, we observed it, and we cannot currently explain it with existing data.

The Timeline: How the Government Switched from UFO to UAP

The switch did not happen overnight. It was a gradual process driven by specific events:

2017: The New York Times published a story about the Advanced Aerospace Threat Identification Program (AATIP), a previously secret Pentagon program that had investigated UAP since 2007. The story included declassified Navy pilot videos of unidentified objects. This was the first time “UAP” entered public consciousness as a serious government term.

2020: In April, the Pentagon officially released three widely circulated videos filmed by Navy pilots in 2004 and 2015, confirming they showed “unidentified aerial phenomena.” This was the first time the Pentagon publicly used UAP instead of UFO to describe Navy pilot observations. In August, the Pentagon established the Unidentified Aerial Phenomena Task Force (UAPTF), led by the Navy. Former Deputy Secretary of Defense David Norquist approved its creation on August 4, 2020. The UAPTF was the first official DOD entity to use “UAP” in its name.

December 2021: The FY 2022 National Defense Authorization Act was signed into law. Senator Kirsten Gillibrand’s amendment created new UAP reporting requirements and established the All-domain Anomaly Resolution Office (AARO). The law used “unidentified aerial phenomena” (not “UFO”) throughout its text. This was the moment UAP became a legal term.

December 2022: The Pentagon expanded the definition from “Unidentified Aerial Phenomena” to “Unidentified Anomalous Phenomena.” NASA followed the same month, updating its official definition to match the NDAA. The expansion acknowledged that these incidents were not limited to the sky.

January 2026: The FAA amended Order JO 7110.65 (“Air Traffic Control”), replacing the term “UFO” with “UAP” in paragraphs 1-2-6 (“Abbreviations”) and 9-8-1 (“General”). The update also established mandatory UAP reporting requirements for air traffic controllers. This was the last major holdout: the FAA was one of the last government agencies still using the old term in its operational procedures.

Why the Change Matters: More Than a Name

The switch from UFO to UAP is not just a rebranding exercise. It reflects three real shifts in how the government approaches the subject:

1. Reduced stigma. The term “UFO” made it almost impossible to discuss these incidents seriously in professional settings. A military pilot who reported a “UFO” was treated as either a crackpot or a security risk. “UAP” does not carry the same weight. It sounds bureaucratic, which is exactly the point.

2. Broader scope. “Flying object” implies something in the air. “Anomalous phenomena” covers anything that defies explanation, regardless of domain. The FY 2023 NDAA explicitly defines UAP to include objects observed in the air, in water, in space, and objects that move between domains. Many credible UAP reports involve objects that enter or exit water at high speed, which the old term could not describe.

3. Scientific legitimacy. In January 2025, a paper titled “The New Science of Unidentified Aerospace-Undersea Phenomena (UAP)” was published on arXiv, synthesizing decades of government studies. The paper was authored by researchers from multiple institutions and laid out research questions and methodologies for systematic study. The use of “UAP” in an academic context, rather than “UFO,” signaled that the subject was moving from speculation into mainstream research discourse.

As the Aerospace America year-in-review noted in January 2026, the shift has been driven by safety concerns. The Pentagon’s AARO now treats UAP reports as a “safety-of-flight concern rather than curiosities.” That framing (safety, not speculation) would have been impossible under the old terminology.

Do They Mean the Same Thing?

Technically, yes. In practice, not quite.

When someone says “UFO,” they usually mean one of two things: (1) an unidentified object observed in the sky, or (2) an alien spacecraft. The second meaning is the one that created the stigma problem.

When someone says “UAP,” they mean: an unexplained observation that has been or could be formally reported through official channels. The term does not imply alien origin, advanced technology, or anything extraordinary. It just means: something happened and we do not yet have a complete explanation.

The terms overlap. Most things that would be called a “UFO” would also qualify as a “UAP.” But “UAP” is broader. It includes underwater observations, transmedium objects, and sensor anomalies that do not involve anything “flying.” And “UFO” is narrower but more culturally loaded. It immediately brings to mind flying saucers and alien visitation.

In casual conversation, most people still say “UFO.” In government documents, scientific papers, and official reports, “UAP” is now the only term used. The public has not fully caught up with the institutional switch, which is why you will see both terms used interchangeably in news coverage. If you want to match what the government uses, say UAP. If you are talking to friends, either works.

The Opposing Perspectives

Some researchers argue the terminology change is cosmetic. They point out that renaming the phenomenon does not change what it is. If the government was not taking UFOs seriously before, calling them UAPs will not automatically fix the underlying institutional reluctance. The stigma, they argue, comes from the subject itself, not the name.

Others argue that UAP is too vague. The term covers everything from radar glitches to pilot observations to satellite anomalies. By making the definition so broad, critics say, the government has made it harder to focus on the most compelling cases. A “UAP” could be anything from a weather balloon to something genuinely unexplained.

Some in the UFO research community feel excluded. Decades of civilian research used the term “UFO.” Organizations like MUFON (Mutual UFO Network) still use “UFO” in their name. The switch to UAP, driven by government agencies, feels like an institutional takeover of a subject that civilian researchers have been studying since the 1940s.

The government’s position is clear. “UAP” is the term. It is in the law. It is in FAA procedures. It is in every Pentagon and intelligence community report. Whether the public adopts it fully is a separate question, but the institutional switch is complete.

FAQ

Is UAP just a fancy word for UFO?

In common usage, mostly yes. But UAP is broader. It covers underwater observations, transmedium objects, and space-based anomalies that “UFO” does not technically describe. The bigger difference is institutional: UAP is the official government term, while UFO is the popular culture term.

When did the government stop using the term UFO?

There was no single moment. The Pentagon started using UAP in 2020 with the creation of the UAPTF and the release of three Navy pilot videos. Congress codified it in law in December 2021 with the FY 2022 NDAA. The FAA completed the switch in January 2026 by amending Order JO 7110.65. Each agency moved at its own pace.

Does using UAP mean the government thinks these are alien?

No. The term is deliberately neutral. “Anomalous” means unexplained, not extraterrestrial. The government’s official position, as stated repeatedly by AARO and the ODNI, is that most UAP have conventional explanations. A small percentage remain unexplained due to insufficient data, not because they are confirmed alien technology.

Should I use UAP or UFO when talking about sightings?

Either works in casual conversation. If you want to match official terminology, use UAP. If you are filing a report with NUFORC or MUFON, both organizations still use “UFO” in their forms. If you are writing for a government or academic audience, UAP is the expected term.

Do other countries use UAP too?

Yes, increasingly. Canada’s Sky Canada Project (released December 2025) uses UAP throughout. The UK Ministry of Defence has used UAP in recent reports. France’s GEIPAN (the official French UAP investigation body) has used a French equivalent for decades. The term is becoming a global standard in official contexts.

Are there any government agencies that still use UFO?

As of March 2026, no major U.S. government agency uses “UFO” in official documents or procedures. The FAA completed the switch in January 2026. The Air Force, Navy, and intelligence community all use UAP. However, older documents and historical references still use UFO, and the term will likely remain in common public usage for years.

Additional Videos

2023 Congressional UAP Hearing: Full Session

Navy Pilots Recall Unsettling 2004 UAP Sighting: 60 Minutes

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