It was just a normal day's flying for Alex Dietrich – until it wasn't. Streaking through the sky over the tranquil expanse of the Pacific Ocean near San Diego, the US Navy lieutenant commander was taking her F/A-18F Super Hornet fighter jet on a training mission with a colleague in another plane. Then came a voice through the crackle of the radio.
It was an operations officer aboard the warship USS Princeton, asking them to investigate a suspicious object flitting around: on several occasions, it had been spotted 80,000ft (24.2km) high, before suddenly dropping close to the sea and apparently vanishing.
When the two jets arrived at its last known location, close to the ocean's surface, the water seemed almost to be boiling. Moments later Dietrich saw it: what seemed to be a whitish, oblong object around 40ft (12m) long, hovering just above the water – like a wingless capsule, which she described as resembling a Tic Tac. As they edged in closer, it was gone, accelerating off into the sky at what seemed an impossible speed, leaving a glassy expanse of regular sea behind.
This was the infamous "Tic Tac" incident of 2004, which later went viral when a video captured by advanced tracking equipment on one of the planes was leaked to the New York Times. In the footage, eventually confirmed to be authentic by the US Department of Defense, the object can be seen as an oblong shadow against a bright sky, before suddenly lurching off-camera to the left at uncanny speed.
It's just one of hundreds of peculiar incidents that have made it into the hands of serious officials in recent years. First there was the US government's 2021 assessment of UFOs – which have been rebranded, rather disappointingly, as the more sober-sounding "Unidentified Aerial Phenomena" (UAPs). Now Nasa is expected to release the results of its first-ever study into Unidentified Anomalous Phenomena – their own twist on the historically dubious designation – and the US Congress subcommittee on National Security, the Border and Foreign Affairs is holding a hearing on them.
Around 76 years into America's obsession with aliens – during which the nation has been gripped by reports of flying saucers, weird lights, and the mysteries of Area 51 – the scientific community is finally taking charge. But how do you sift the fancies of conspiracy theories from incidents worthy of investigation? What hallmarks separate a genuine anomaly from a curiously shaped cloud or Chinese balloon? And why are researchers finally paying attention?