What is a UAP? What the acronym means, why they're different from UFOs, and what a Congressional hearing revealed

• Recent testimonies before Congress and meetings with NASA have renewed interest in UAPs and UFOs.
• There are differences between UAPs and UFOs, especially related to potential proof of alien life.

On Wednesday, a former intelligence officer testified in front of Congress that the US government has evidence of alien life.

While ex-Air Force officer David Grusch's comments were shocking — but in line with his previous wild claims that the Vatican was part of a massive UFO cover-up — they did renew public interest in UAPs and UFOs.

There are differences between a UAP and a UFO. Here's what the two terms mean, and how seriously should we take the testimony that the US military is keeping the existence of aliens a secret.

What does UAP mean?

UAP stands for "unidentified anomalous phenomena."

It was previously an acronym for "unidentified aerial phenomena," but the Pentagon, NASA, and other organizations tweaked it in December 2022 in order to represent "submerged and trans-medium objects," a defense official said at the time.

The term describes documented events or objects in the sky that cannot be explained naturally. These could be instances not entirely understood on a scientific level, or instances where an aerial object does something in the sky that can't be explained under normal circumstances.

Hundreds of military commercial pilots have reported UAP encounters, often citing video footage, photographs, or sensor readings that supposedly show inexplicable objects.

While some turn out to be weather balloons or drones, others aren't immediately identifiable.

UAP vs. UFO

UFO — which stands for "unidentified flying object" — was coined by the Air Force in 1952.

Before that, interest in UFOs really took off in 1947 when pilot Kenneth Arnold claimed to having seen a flying disc while on a flight. Shortly after, conspiracy theories spread that an alien flying saucer crashed in Roswell, New Mexico. Military officials insisted it was part of a weather balloon.

Both of these events cemented UFOs in the public consciousness, creating a cultural phenomenon that would persist for decades.

Portrayals of UFOs haven't changed much from those initial events. In popular culture, UFOs are typically represented as flying saucers, while extraterrestrial beings are typically portrayed as two-legged, almost humanoid grey or green creatures.

"Unidentified aerial phenomena" became a more common phrase in recent decades, and in 2020, the Pentagon established a Navy-led UAP Task Force to spearhead investigations into reports and rumored sightings.

Do UFOs exist?

Grusch, an ex-intelligence officer and now whistleblower, told lawmakers on Wednesday that he knew of "a multi-decade UAP crash retrieval and reverse-engineering program" by the government, and had knowledge of crashed aircraft that contained non-human biologics.

Two other witnesses, Navy pilots David Fravor and Ryan Graves, also told Congress about their experiences with flying objects.

"The American people deserve to know what is happening in our skies," Graves said.

Fravor had previously told The New York Times about a 2004 encouter with a whitlish, oval-shaped aircraft that "accelerated like nothing I've ever seen."

"I have no idea what I saw," Fravor told a pilot at the time. "It had no plumes, wings or rotors and outran our F-18s." But, he added, "I want to fly one."

Despite their testimony under oath, the witnesses didn't provide evidence supporting their claims.

While it's unclear what exactly UAPs are or whether or not they definitely exist, the government is still taking investigations into reports of UAPs seriously.

In June 2022, NASA announced a study team focusing on available UAP data. The group, along with the All-doman Anomaly Resolution Office — a portion of the US Office of the Secretary of Defense — said in May 2023 that they needed better data to identify UAPs.

They proposed a method using "unclassified crowd-sourced data" from the general public to collect information on potential sightings to figure out what the anomalies are.