Yet even as the Navy indicates it’s willing to discuss the taboo topic, it’s also shying away from three notorious little letters. UFO carries an airport’s worth of baggage, bursting with urban legends, government secrecy, and over-the-top Hollywood movies. The statements and quotes that the Navy provided to news outlets are devoid of any reference to UFOs. Instead, they’re called “unexplained aerial phenomena,” “unidentified aircraft,” “unauthorized aircraft,” and, perhaps most intriguing, “suspected incursions.”

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The message is, if you see something, say something, but for God’s sake, lower your voice. Don’t call it a UFO. Which is funny, since the military came up with the name in the first place.

The earliest government programs dedicated to investigating UFO sightings in the late 1940s treated the claims, unsurprisingly, as a big joke. As a rule, officials dismissed and debunked any reports as hoaxes and hallucinations, according to UFOs and Government: A Historical Inquiry, a textbook-style deep dive published in 2012. This apparently didn’t sit well with some of the higher-ups.

In some ways, the Navy’s modern-day attempt to take seriously reports of UFO sightings is a rerun of what happened next. “I want an open mind,” Major General Charles Cabell, then the head of Air Force intelligence at the Pentagon, reportedly demanded at a meeting with subordinates in 1951. “Anyone who doesn’t keep an open mind can get out now.”

A new, secretive program, dubbed Project Blue Book, was quickly organized to investigate claims of strange visions in the sky without ridiculing them. Its director, Edward Ruppelt, introduced the term unidentified flying object sometime around 1953. The definition carried no hint of extraterrestrial life; in a national-security official’s scariest daydreams, the objects were probably Russian spycraft. For the military, a UFO was simply “any airborne object which by performance, aerodynamic characteristics, or unusual features, does not conform to any presently known aircraft or missile type, or which cannot be positively identified as a familiar object.”

By then, there had already been several high-profile reports of objects flying through or falling from the sky. For the public, these sightings didn’t just seem unfamiliar—they seemed not of this world. A civilian pilot had seen nine somethings flying in formation near Mount Rainier in Washington State. A rancher found mysterious wreckage on his property outside Roswell, New Mexico. Multiple people spotted a series of lights hovering over Washington, D.C., and moving toward the White House. The military even mobilized jets to intercept them, but found nothing.

In the meantime, UFOs further infiltrated the public consciousness. They sailed into Hollywood, which to this day remains obsessed with stories about aliens, from friendly creatures to nightmarish monsters. The fourth Men in Black movie is coming out this summer, and it’s probably not the last.