The unidentified flying object resembled a Tic Tac. That's how Navy pilot Chad Underwood described the thing he saw hurtling through the sky on November 10, 2004. Underwood recorded the object using an infrared camera after his commanding officer, David Fravor, spotted the unusual shape during a flight-training exercise. His video represents one of three known instances in which Navy pilots caught an unknown aerial object (the Navy prefers that term over UFO) on camera. The other two instances were on January 21, 2015. The videos were leaked to the public in 2007 and 2017. On Monday, the Pentagon officially released them "in order to clear up any misconceptions by the public on whether or not the footage that has been circulating was real." The objects in the videos remain "unidentified," the agency said. In a December interview with New York magazine, Underwood revealed what it was like to capture the video, after staying mostly silent about the encounter for 15 years. "At no point did I want to speculate as to what I thought this thing was — or be associated with, you know, 'alien beings' and 'alien aircraft' and all that stuff," Underwood told the magazine. "It is just what we call a UFO. I couldn't identify it. It was flying. And it was an object. It's as simple as that." Before Underwood spotted the flying object, he said, he received a tip from his commanding officer that there might be something strange in the sky. A few days earlier, a guided-missile cruiser called the USS Princeton had been tracking about eight to 10 mysterious flying objects near the Catalina and San Clemente islands in California. "Dave Fravor was like, 'Hey, dude. BOLO.' Like, be on the lookout for just something weird," Underwood told New York magazine. The two men were working on combat exercises on the Navy's Super Hornet fighter jets. The day Underwood recorded the UFO, weather reports indicate there was a clear blue sky — but all of a sudden, he spotted what he called "a blip on his radar." An unclassified report from the Department of Defense described the object as "solid white" and "smooth," with a shape resembling "an elongated egg." Underwood was the one who coined the nickname "Tic Tac." "The thing that stood out to me the most was how erratic it was behaving," he told New York magazine. "Its changes in altitude, air speed, and aspect were just unlike things that I've ever encountered before flying against other air targets." At one point, the object appeared to dart from a high altitude of about 60,000 feet to a low altitude of 50 feet "within seconds," according to the DOD report. At another point, it veered violently to the left. Underwood said the object definitely wasn't a bird or a weather balloon, and since it was moving at a speed of about 138 mph, it was presumably too slow to be an aircraft. It also had no wings or heat, which ruled out the possibility of a cruise missile. The DOD report said the object "possibly demonstrated the ability to 'cloak' or become invisible to the human eye" and might be able to "operate undersea completely undetectable by our most advanced sensors." Though UFOs are associated with aliens in popular culture, unidentified objects don't necessarily come from space — the term just applies to anything unknown. Seth Shostak, a senior astronomer at the Search for Extraterrestrial Intelligence Institute, previously told Business Insider that about 10% of UFO sightings didn't have explanations. Alien civilizations, he said, would know about our existence only if they were within about 35 light-years of Earth. "If they're more than 35 light-years away, there hasn't been enough time for our signals to get to them, and for them to decide, 'Well this is worth the money to go down there and fly around,'" he said. "The really good evidence that we're being visited still has failed to surface." Aliens aside, experts have offered other, far more plausible, explanations for Underwood's UFO sighting. Former members of the military have suggested that glitches in the infrared camera in Underwood's plane may have been playing tricks on the pilot's eye. Retired Air Force Maj. James McGaha also proposed that the object might have appeared to veer dramatically because of the way Underwood was maneuvering his aircraft. Underwood told New York magazine that he wasn't able to see the object when it veered to the left but believed it moved on its own. "That part kind of sucks, because I can't confirm that the object aggressively accelerated that way," he said. "But I have my feelings, based off of my experience with my equipment — and also just logic, when it comes to, you know, physics." He also dismissed the possibility that the UFO was part of covert tests done by NASA or the military. He told New York magazine that he was never instructed to keep silent about what he saw. "I've got top-secret clearance with a ton of special-project clearances," he said. "So, it's not like I wasn't cleared to know. Clearly, whatever it was, if it was a government project, I did not need to know." You can read the full New York magazine interview here.