H. Armstrong Roberts/ClassicStock/Archive Photos/Getty ImagesThe marketing for Disclosure Day has been unusually cagey, and if you haven’t had the chance to catch Steven Spielberg’s new alien movie yet, we won’t spoil it here. As the name implies, though, Spielberg’s latest sci-fi involves American officials keeping secrets about extraterrestrial life, and those secrets date back to the 1947 Roswell incident.Roswell wasn’t modern America’s first UFO claim, but it’s the one now woven into the country’s mythos. We could spend all day simply listing the pop culture it’s influenced: The X-Files, Independence Day, The Day the Earth Stood Still, Perfect Dark, Deus Ex, XCOM, a TV movie called Roswell that’s unrelated to the book and TV series called Roswell… you get the idea. Disclosure Day is the latest in a decadeslong display of pop culture dominance that owes its existence to a series of bizarre coincidences.Spielberg’s latest aliens have a lineage as long as their fingers. | Universal PicturesThe Summer of UFO LoveOn June 24, 1947, amateur pilot Kenneth Arnold claimed he saw nine shiny objects zoom around Mount Rainer at unheard-of speeds. Arnold, who initially assumed he’d witnessed a military test project, said “They flew like a saucer if you skip it across the water.” Based on what may have been a misunderstanding of Arnold’s description, journalists coined the term “flying saucer.”Considered a credible witness, the businessman and his sighting kicked off a media frenzy as a curious reporter’s brief Associated Press dispatch grew into a national phenomenon. Post-WWII America was primed for stories of high-tech threats and miracles, and hundreds of copycat sightings across the country followed.Many witnesses were unreliable, or the victims of pranks or hoaxes, but other sightings had no obvious explanation aside from the fact that everyone was suddenly talking about UFOs, making every glint in the sky a matter of national interest. It struck some contemporary observers as mass hysteria, but to future folklorists, the summer of 1947 represented the birth of a modern mythology.Kenneth Arnold (middle) with two other pilots. | Bettmann/Bettmann/Getty ImagesWhile aliens were floated as an explanation, more credible theorists speculated that these sightings were cutting-edge American or Soviet aircraft. The relationship between the erstwhile allies was collapsing into long conflict, and the Soviet Union was beginning to develop bombers capable of reaching North America. Others suggested a link between the sightings and a yet-to-be understood byproduct of America’s growing number of atomic sites. As fears of a horrifying nuclear destruction became mainstream, all things atomic drew suspicion.That summer, New Mexico rancher Mac Brazel found tinfoil, rubber, tape, and other detritus on his property. Not one to keep up with the reports, Brazel initially thought nothing of it. But when a trip to town taught him about the UFO craze, he informed the sheriff of nearby Roswell, who told the local air base. The Army recovered more debris from Brazel’s property and issued a fateful press release stating that a flying disc had been found.A UFO-mad media jumped on the story, although a day later, an army press conference identified the debris as part of a crashed weather balloon. Naturally, the press and public… bought this explanation and immediately moved on to Twin Falls, Idaho, which had been an epicenter of disc sightings. That drama culminated in the discovery of a flying disc on a woman’s lawn, which FBI and military agents soon determined was a set of trussed radio tubes planted by four teenagers. While not the decade’s last UFO claim (or hoax), the whole affair was so silly that press coverage of UFOs slowly faded. In 1967, a fresh hoax briefly gripped Britain. | Mirrorpix/Mirrorpix/Getty ImagesAliens & WatergateFringe books published throughout the 1950s alleged that some saucer incidents had been genuine alien encounters, and that the United States was hiding the proof. One, by huckster Gray Barker, alleged that mysterious “men in black” were involved in the conspiracy, birthing another persistent trope. The writings of aviator Donald Keyhoe were particularly influential, although his anodyne view of the state — he didn’t blame it for trying to avoid a public panic — is unrecognizable among conspiracy theorists today.But the Roswell incident was almost forgotten until 1978, when the scholars at the National Enquirer dredged up the story for content. Jesse Marcel, an officer who’d helped recover the Roswell debris, had since told a ufologist that he believed it wasn’t a weather balloon they’d found, but pieces of an alien spacecraft. Marcel later shared this belief in an interview with the Enquirer, the era’s equivalent of taking your story to Alex Jones.In 1980, Marcel appeared on an episode of In Search Of, a series hosted by Leonard Nimoy that “explored” historical mysteries ranging from the identity of Jack the Ripper and the location of Jimmy Hoffa to the supposed truth behind Bigfoot and the Loch Ness Monster. That series was a follow-up to a trio of mid-’70s specials Rod Serling hosted about the pseudohistoric claim that ancient aliens were responsible for shaping the ancient world, which in turn had been inspired by a popular book and film, Chariots of the Gods; Roswell is pop culture all the way down.Jesse Marcel stars in the most famous photo of the Roswell debris. | Universal History Archive/Universal Images Group/Getty ImagesDecades after Keyhoe and Barker, the mass media environment was far more receptive to outlandish conspiracy theories. Not only did 98 percent of American households now own televisions, but those televisions had been broadcasting unsettling images. The John F. Kennedy assassination had unleashed a wave of conspiracy theories (including those that allege the CIA shot Kennedy before he could reveal the truth about aliens), while Watergate shattered any lingering illusions of the state always having one’s best interests at heart. Meanwhile, the booming New Age movement had made the embrace of strange ideas far more acceptable, and it also didn’t hurt that, in 1977, Spielberg released Close Encounters of the Third Kind.Spielberg’s earlier UFO movie starts with the discovery of ships that had been lost in the mysterious Bermuda Triangle; the idea that the region could make planes vanish, in another high-profile example of the growing symbiosis between pop culture and conspiracy, had been popularized in part by Keyhoe. Flying saucers had been a pulp fiction staple for decades, but Close Encounters was a big-budget example of a dying approach where officials were proactive rather than full of spooks keeping old secrets fit for, well, a disclosure day.With Roswell back in the press, Marcel contributed to a 1980 book called The Roswell Incident that outlined the basics of the conspiracy everyone now knows. According to the book’s many dubious sources, an alien spaceship crashed in 1947, and officials recovered the vessel and bodies. The Roswell story only spiraled from there, compounded and confused by competing theories, a growing number of myths and legends, and America’s ever-growing ability to produce and consume outlandish beliefs. Roswell became like those who said they saw Johnny Rotten and Sid Vicious play their first show — thousands of people claimed to be one of the handful actually present.Kyle MacLachlan played Marcel in a 1994 TV movie that took the cover-up story for granted. | Viacom PicturesThe Roswell AutopsyIn 1995, Jonathan Frakes hosted Alien Autopsy: Fact or Fiction, which purported to be an autopsy conducted shortly after the Roswell crash. Millions watched the hoax on TV, and it later became a VHS hit. The tacky culmination of conspiracies merging with entertainment, Fox even wrapped X-Files episodes around the airing, further cementing the link between conspiracy and fanciful fiction. But while Mulder and Scully were unraveling a Roswell-heavy plot, Deep Space Nine turned Roswell into a farce, showing how the story had become ingrained to the point of cliche.But Roswell still had its believers, and once ufologists could start to gather and theorize online, aliens became a permanent fixture of America’s vast conspiracy landscape. Today, administrations seem to dump a batch of old UFO files online whenever they need a respite from other headlines. That’s a tactic acknowledgment of a statistical reality: One-third of Americans believe it’s “plausible” aliens were involved in the Roswell incident, and whatever UFO sightings really are, 84 percent think those in power know more about them than has been revealed. Roswell remains fiercely debated online today.Alien Autopsy’s infamy made it the basis of a 2006 comedy and a 2026 documentary. | Kiviat/Green ProductionsOfficially, Kenneth Arnold’s sighting was ruled a mirage, while other skeptics have floated ideas ranging from meteors to pelicans. There was, in fact, a cover-up at Roswell; what Brazel had really found was almost certainly pieces of a balloon built for Project Mogul, which mounted sensitive microphones on balloons capable of holding altitude and listening for sound waves from Soviet atom-bomb tests. Soon superseded by superior seismic monitors, Mogul’s legacy is still with us and in theaters today. But this didn’t emerge until a 1994 Congressional inquiry, allowing generations of outlandish conspiracies to flourish.If aliens are out there, their continued silence has allowed us to impart our own beliefs and biases onto them. While many American believers see a shadowy conspiracy, others take a different view. The Argentine Trotskyist J. Posadas claimed that UFOs were proof of communism’s inherent superiority because, in a rather tautological argument, only a communist society would be able to build interstellar spacecraft. To Posadists, the aliens are here to help the revolution, while other long-standing UFO religions have built complicated philosophies around pet causes like nuclear disarmament.Today, UFOs have become Roswell’s stock-in-trade. | PATRICK T. FALLON/AFP/Getty ImagesCompared with such grand ambitions, the photos of the Roswell debris are almost laughingly mundane: Marcel and other bemused soldiers pose with damaged sheets of tinfoil, unaware they’d one day become figures in a national drama. That some old scraps are still helping Hollywood rake in hundreds of millions of dollars feels like it should be the subject of a movie in its own right, although conspiracy theorists would presumably accuse it of being a cover story.In 1947, Sen. Glen H. Taylor said that he almost hoped the UFO craze was proof of alien life, because that “could end our petty arguments on Earth.” If UFOs were only “a psychological phenomenon,” Taylor claimed, “it is a sign of what the world is coming to. If we don’t ease the tensions, the whole world will be full of psychological cases and eventually turn into a global nuthouse.” Neither outcome has happened yet, but thanks to a rogue balloon, both scenarios now routinely play out onscreen.Disclosure Day is playing in theaters.