The U.S. Navy has confirmed that three F-18 gun-camera videos first released by The New York Times and a UFO research organization show “unidentified aerial phenomena,” or UAPs—a more formal term for UFOs that doesn’t have all the little-green-men baggage.

The Times originally released two of the videos in a December 2017 article revealing that the Pentagon had operated a secret UFO investigatory project, called the Advanced Aerospace Threat Identification Program (AATIP). All three videos were published on the website of To the Stars Academy of Arts and Sciences, a UFO research organization founded by former Blink-182 singer and guitarist Tom DeLonge.

The news that the Navy considers the three videos—unofficially known as “FLIR1,” “Gimbal” and “GoFast”—as examples of UAPs first appeared on The Black Vault, a web site that specializes in declassified government documents. “FLIR1” is from November 14, 2004, and “Gimbal” and “GoFast” are from January 21, 2015. Joseph Gradisher, official spokesperson for the deputy chief of naval operations for information warfare, emphasized to HISTORY that these videos represent only some of the UAP sightings the Navy is investigating.

“Those three videos are just part of a larger effort by the U.S. Navy to try and investigate a series of incursions into our training ranges by phenomena that we’re calling unidentified aerial phenomena,” says Gradisher, who declined to say how many sightings there have been. “Our aviators train as they fight. So when they’re out there training, if there’s an incursion by any kind of aerial vehicle phenomena, whatever, it puts the safety of our aviators at risk as well as the security of our training operations.”

To be clear, the Navy is not saying that these videos show evidence of alien life. Rather, the Navy is saying it can’t identify the phenomena in the videos. The Navy considers UAPs like these a national security and safety problem because they are not authorized to be in U.S. airspace. After a series of classified briefings featuring Navy pilots and lawmakers this summer, the Navy announced it had formalized its process for pilots and other personnel to report UAPs so that records of these sightings are more consistent, and therefore easier to investigate.

Gradisher told HISTORY the Navy is trying to reduce the stigma of reporting UAPs, which in the past pilots may have been disparaged—or ignored—for reporting. “We want to get beyond that stigma, and encourage our aviators to report anything that they’re seeing out there.”

It was during the production of HISTORY’s series “Unidentified: Inside America's UFO Investigation,” the first season of which explored UAP phenomena in military contexts, that the active-duty Navy pilots who encountered the crafts captured in the three videos initially came forward to share their stories. The series, in partnership with To the Stars Academy, helped spark a dialogue that resulted in official acknowledgment of these crafts.

Nick Pope, who worked for the U.K. Ministry of Defense’s UFO program from 1991 to 1994, has previously speculated that there are four possible explanations for the more recent UAPs identified by the U.S. Navy: errors in pilot or computer perception, a secret U.S. project being blind tested without the Navy’s knowledge, a foreign government’s aircraft or something completely unknown.

“What I think the Navy’s recent statement does, is it probably takes off the table the first of those explanations,” he says. “I think the clear perception is the Navy thinks we’re dealing with something real and tangible here. So not misidentifications, misperceptions, glitches or such.”

The U.S. military has actually been interested in UFOs for a long time, going back to 1948 with the U.S. Air Force’s Project Sign. The year before, a businessman named Kenneth Arnold had claimed that, while flying a plane near Mount Rainier in Washington state, he’d spied nine crescent-shaped objects speeding along “like saucers skipping on water.” Newspaper accounts that mixed up his words helped popularize the term “flying saucer.” Reports of this sighting led more people to claim they’d seen UFOs, and the Air Force decided to study these claims. In the Cold War context, the military was eager to know whether the growing numbers of reports about supposed “flying saucers” might actually be some kind of advanced Soviet spy crafts.

Project Sign was succeeded by another Air Force program called Project Grudge, which started and ended in 1949. The people who worked on Project Grudge concluded that UFO sightings were the result of hysteria, hoaxes, mental illness or the misidentification of known objects. Even so, in 1952 the Air Force established another program called Project Blue Book, the longest-running official government inquiry into UFOs. By the time Project Blue Book ended in 1969, the Air Force had investigated more than 12,000 UFO sightings, 701 of which remained unexplained.

Unlike the Navy’s current system for its pilots and personnel to report UAP sightings, Project Blue Book documented and investigated accounts from anyone, military or civilian. At one point, it even had a questionnaire that allowed people to document their UFO sighting. “Draw a picture that will show the shape of the object or objects,” instructed one part of the questionnaire. “Label and include in your sketch any details of the object that you saw such as wings, protrusions, etc., and especially exhaust trails or vapor trails. Place an arrow beside the drawing to show the direction the object was moving.”

For now, the Navy isn’t releasing many details on the UAPs it’s investigating, including speculation on who might be behind them.

“We’re not going to characterize what any potential sources might be,” Gradisher says. “But as I’ve stated, there are two aspects of concern: the safety of our aviators, and the security of our operation. We don’t want people to see how we’re training, because we train as we fight.”