In the years immediately following the end of the Second World War, a spate of observations of mysterious airborne objects began to accumulate around the globe.


Similar Unidentified Flying Objects (UFOs) had been described by Allied pilots during the Second World War (the so-called ‘foo fighters’).

Alongside such aerial phenomena, the Nazi regime’s experimentation with rocket-propelled missiles (the V1 and V2 programmes), and its post-war appropriation by the Allies, launched a post-war revolution in weapons technology.

Amid rising Cold War tensions between the United States and the Soviet Union, anxiety over a missile gap soon led to an arms race, while wild rumours about the other’s technological innovation soon became rife.

But in 1947, these Earthly fears were eclipsed by a seemingly extraterrestrial ‘visitation’, which brought the city of Roswell, New Mexico, to the world’s attention.

The conspiracy theory: the US government covered up the crash of an alien spacecraft

In late June 1947, W W ‘Mac’ Brazel, a rancher living in New Mexico, discovered an unusual debris field on his land near Roswell.

Days later, he alerted the local authorities, who in turn notified Roswell Army Air Field (RAAF). Military personnel were dispatched to the location whereupon they supposedly recovered material from a damaged extraterrestrial spacecraft and even the bodies of its alien crew.

The base issued a statement confirming that a “flying disc” had been recovered in the vicinity and “inspected at the Roswell Army Air Field”. Yet the following day a correction was released that clarified the debris was in fact a downed weather balloon.

Decades later, in 1978, the so-called ‘Roswell incident’ returned to the spotlight. According to a whistle-blower who had been involved in the operation, the weather balloon story was a cover-up. Photographs of the balloon wreckage had been carefully staged, while the actual spacecraft was spirited away for investigation. At the same time, everyone connected to the incident was sworn to silence.

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Researchers tracked down several witnesses who corroborated that a crashed alien spaceship had indeed been salvaged and taken to the enigmatic Area 51 in Nevada where technicians had subsequently reverse-engineered it for the US military.

Not only that, but it was said that extraterrestrial beings had been retrieved from the crash site and had been subjected to autopsies.

What is the source of the theory?

To understand the origins of the Roswell incident, historian and broadcaster, David Clarke, believes it is necessary to begin two weeks earlier on 24 June 1947 and over 1,000 miles northwest.

“Kenneth Arnold, who was a private pilot, was out flying a small aircraft over the Cascade [Range] mountains in Washington state,” says Clarke, who was speaking on our Conspiracy podcast series. “As he was flying towards Mount Rainier, in the distance he saw what he described as a formation of ‘strange aircraft’. They were flying in echelon formation, the way that geese or ducks [do].”

Arnold reckoned that these strange vessels, which he later described as ‘batwing-shaped’, were travelling at supersonic speed. Incidentally, the sound barrier would not be broken until 14 October later that same year by US Air Force officer, Charles Yeager.

“He radioed Yakima airbase and when he landed … [it had been] transmitted all around the United States that this guy had seen some weird objects in the sky. He was surrounded by newspaper reporters,” says Clarke.

His description of the objects’ movement as being akin to a saucer skipping over a pond caught journalists’ imagination, who coined the term ‘flying saucer’.

“The story went viral to use a modern expression,” says Clarke.

“Within 48 hours of Kenneth Arnold reporting what he’d seen, flying saucers were on the newswires across the United States, across North America and Europe. And people started seeing and reporting saucer-shaped flying objects in the sky”.

It was during this craze that the RAAF dispatched Major Jesse Marcel and Captain Sheridan Cavitt to inspect the debris found near Roswell.

But whereas Cavitt maintained that the wreckage was ostensibly ‘normal’, Marcel convinced himself “that it was something very, very unusual and not something that was manufactured in the United States”, explains Clarke.

The reasons why the theory of the Roswell Incident took hold

The airbase’s correction, insisting that the discovery was in fact that of a weather balloon, negated the idea that something more peculiar had been found. That summer in New Mexico soon faded from popular memory – at least for the time being.

“I’ve got a huge collection of books on UFOs and flying saucers from the 1950s up to the present,” says Clarke, “the Roswell incident is not mentioned in any of those books and articles and magazines during the 1950s, during the 1960s”.

Decades later, after trust in the US government had been badly damaged in the wake of the JFK assassination and the unpopular Vietnam War, a more cynical audience was primed to reconsider the official narrative around the Roswell incident.

Clarke believes that this context is the reason why the 1980 book The Roswell Incident by Charles Berlitz and William Moore was so successful in introducing the idea of a government cover-up.

“They went and re-interviewed some of the people who were there at the time. Jesse Marcel, for instance – there’s no other way to describe him – he was a UFO believer. He bought into the idea that flying saucers were craft from outer space,” says Clarke.

According to conspiracists like Marcel, the cover-up even entailed intimidating would-be whistle-blowers with murder: “‘Bullets are cheap’ was the phrase that was used,” explains Clarke.

“There are people who worked in the morgue at Roswell [who] said that they remembered this truck turning up with armed guards and these small bodies of creatures being offloaded”.

By the end of the 20th century, the Roswell incident had acquired an iconic status within the ufology community but also within popular culture generally. During the 1990s, the conspiracy was woven into the X-Files TV drama series and the blockbuster movie, Independence Day.

“That shows how much it’s become a part of the collective American imagination – almost to rival the JFK conspiracies,” says Clarke.

The evidence that debunks the Roswell Incident

The UFO ‘wreckage’ that Brazel came across on his ranch – and later confirmed by Cavitt – consisted of balsa wood, tinfoil, metal strips and other detritus.

As was officially established that summer, these materials, though certainly incongruous to the location in which they were found, were the remnants of a high-altitude balloon.

Clarke points out that “there was a cover-up in some respects, in that when they announced that this thing that had been found was just a weather balloon that wasn’t true because it wasn’t just a weather balloon, it was [part of] a top secret balloon experiment”.

In 1994, the US Congress launched an official investigation into the events of summer 1947. Its conclusions formed part of a two-volume report that revealed that a highly clandestine operation code-named ‘Mogul’ had been conducted at the time from Alamogordo Army Air Field, less than 150 miles west of Roswell.

“The US Navy and the CIA were launching enormous balloon trains from Alamogordo. Everyone will remember at the beginning of 2023, the Chinese spy balloon that was shot down by the US Air Force. A very similar thing was going on in 1947,” says Clarke, citing a recent incident that sparked speculation about alien aircraft visiting Earth.

With the Cold War just getting underway at the time, the US was keen to establish whether the Soviets were conducting nuclear tests.

“They were sending these enormous balloons up,” explains Clarke, “and they were riding the jet stream across the Atlantic, and they had a gondola underneath with cameras inside and a radiosonde where they could track the balloons”.

“One of these balloon trains in the logbook from Alamogordo was lost in the desert shortly before the debris [at Brazel’s ranch] was found,” says Clarke – though he stresses that a direct link between the two cannot be definitively made despite the circumstances.

A few years later, in 1997, the US Air Force published another report. One of its findings attributed the reports about humanoid ‘creatures’ turning up at facilities in and around Roswell to false memories.

According to Clarke, the report “tried to explain where some of the ideas about bodies being retrieved from the desert came from”.

As part of that later investigation, “it turned out that they were actually throwing dummies from aircraft over the desert”.

These tests were part of a secret programme to assess the effect on the human body if pilots ejected from aircraft and fell from high altitudes.

For Clarke, the Roswell incident also bears many of the age-old tropes about celestial visitors descending to Earth in a revelatory fashion.

“Effectively you could see the aliens in the flying saucer as being representative of gods or angels coming to give us their sacred knowledge. And they always crash in a remote area. They’re never crashing in Tunbridge Wells or anywhere like that. It’s always some remote area of desert”.

More than this, Clarke asserts that Roswell became an urban legend for the atomic age and that its DNA is typical of American folklore.

He cites the case of Aurora, Texas – where, in 1897, a UFO allegedly collided with a windmill. The locals “retrieved the body of this Martian pilot, buried it in the local cemetery, and they retrieved bits of metal from this airship that had hieroglyphics on it”.

Clarke says that this was in fact a hoax concocted to attract visitors to the small town after the railway had bypassed it, and he notes that the story is almost “a carbon copy of the Roswell incident”.

Perhaps the most expedient angle on Roswell is that the longevity of this conspiracy theory serves the US military’s interests and may even explain why some ex-military and ex-intelligence personnel have gone on record to suggest that extraterrestrials crashed there in 1947.

For example, ongoing rumours about Area 51 and the back-engineering of otherworldly technology makes for a formidable strategy.

“There’s no two ways about it that there’s some very good evidence that they just encourage that story because it’s a useful disinformation tool against an enemy … don’t mess with us because we’ve got alien technology,” says Clarke.

As conspiracy theories go, he believes that Roswell is among the more ‘harmless’ ones. “The idea that out there in the cold dead Universe there is someone who is interested in us, that we’re not alone, that they’re going to come and save us, that’s quite a comforting thought,” says Clarke, “and I think that out of all the conspiracy theories and myths, this is probably the most positive one of all”.

Earlier this year the US Government admitted that it has developed, tested and flown prototype aircraft some of which have been seen and reported as UFOs.

The Pentagon said “some of these systems had a ‘saucer’ or triangle-shaped appearance and were capable of hovering aloft”.

The US Department of Defence’s All Domain Anomaly Resolution Office (AARO), released the first volume of its historical investigation of UAP (unidentified anomalous phenomena) in February.


The report traces military technology linked to UFOs back to the end of the second world war and the famous Roswell incident of 1947. It says that all the evidence points to “misidentified authentic highly sensitive national security programs”.


Danny BirdStaff Writer, BBC History Magazine

Danny Bird is the Staff Writer at BBC History Magazine. Danny Bird is the Staff Writer at BBC History Magazine and previously held the same role on BBC History Revealed. He joined the brand in 2022. Fascinated with the past since childhood, Danny completed his History BA at the University of Sheffield, developing a special interest in the Spanish Civil War and the Paris Commune. He subsequently gained his History MA from University College London, studying at its School of Slavonic and East European Studies (SSEES)