If you’re talking about conspiracy theories, sooner or later you’re going to talk about extraterrestrial activity, be it ancient aliens, UFO sightings, abductions, or a combination of all three. Alien-based conspiracy theories are a dime a dozen, but one of them stands oversized grey head and shoulders above the rest, proving itself remarkably resilient even in the face of repeated debunkings: The crash at Roswell, New Mexico.

The Roswell UFO crash

Some time in June of 1947, something crashed to the earth on a ranch in the Roswell, New Mexico area. Something that, if you believe the conspiracy theorists, is, at the very least, a part of a UFO, if not a complete one, possibly including alien life forms, that may or may not have been experimented upon before or after their death. That’s a lot we just dropped on you, so let’s back up some. Here’s what we know.

On July 8, a press release was issued from the Roswell Army Air Field. This initial release acknowledged the crash and claimed that a “flying disc” had been recovered from it, and a subsequent statement from the Air Force claimed that the crash was simply a weather balloon that they had since recovered. They held a press conference, where they showed off wreckage from the crash that seemed to back up the weather balloon claim, and for a moment, it appeared that was that.

Here’s the sticky part though: The thing that crashed to the earth was not a weather balloon. This is not a conspiracy theory or a wild supposition, it’s a fact acknowledged by conspiracy theorists, skeptics and even the United States Air Force. The balloon that crashed to the earth in 1947 was actually part of Project Mogul, an initiative that involved using high-altitude balloons to keep tabs on the Soviet’s atomic bomb tests. But, seeing as the project was top secret at the time, the United Air Force kept the lid on the balloon’s true purpose, a fact that would later help to fuel the countless conspiracy theories around the crash.

Another piece of fuel for the Roswell conspiracy theory is the whole matter of “flying discs.” Prior to the discovery of the crash, civilians had reported sightings of flying discs in the area. Of course, while we can definitely understand how a balloon — especially at night — might resemble a flying disc, in hindsight, it was a poor choice of words for that initial press release, as “flying disc” is remarkably similar to a phrase most commonly associated with alien spacecraft: Flying saucers.

One of the most interesting things about the Roswell conspiracy theory is that it didn’t really pick up steam for more than 30 years. The Air Force’s weather balloon explanation — while not entirely truthful — was more or less accepted by pretty much everyone, until 1978.

That was the year that Stanton T. Friedman, a nuclear physicist and author, kickstarted the conspiracy theories with his research into the event, which prominently featured interviews with Jesse Marcel, who accompanied the crash wreckage from its recovery site to the press conference. Two years later, The Roswell Incident was published, a book that, claiming to have interviewed more than 90 witnesses, suggested that the crash was a UFO that contained alien organisms.

Books about the crash site continued to be published through the nineties, as more and more “witnesses” came out of the shadows, and conspiracy theorists combined their reports, secondhand accounts and a general disbelief in official government stories to build up a massive corpus of oftentimes spurious research. In fact, there are so many books and theories about Roswell that the conspiracy theorists can no longer even agree on simple questions such as how the UFO crashed or how many bodies were recovered from it.

The biggest problem with all of these theories — aside from the fact that they took a full three decades to come to light — is the quality of the witnesses. Though The Roswell Incident claims to have interviewed more than 90 of them, only 25 appear in the book, only seven saw the crash’s wreckage, and of those, only five actually touched it. Other books about the subject share this problem, one where they assign firsthand weight to accounts that are, at absolute best, secondhand — and even that’s being generous.

As a result of the steadily growing interest in the Roswell incident, in 1994, the Air Force came clean about what actually crashed in the desert. It was then that they acknowledged that the crash was actually part of Project Mogul. Three years later, the Air Force even addressed reports of alien bodies, by suggesting that the rumors and conspiracy theories are a result of civilian sightings of casualties from military accidents or even just test dummies. Of course, as one might expect, conspiracy theorists discounted these statements as simply another layer of the cover up.

Another one of the more fascinating aspects of the Roswell conspiracy theories is that they feature practically no hard evidence. While other conspiracy theories can point to photos, videos, eyewitness accounts and a slew of other sources to point out inconsistencies in the official stories they are meant to debunk, when it comes to the Roswell UFO incident, it’s the conspiracy theories themselves that are riddled with inconsistencies and claims that are, quite simply, without any real basis in reality. Even the heavily publicized 1995 alien autopsy video was later revealed to be nothing more than a reconstruction of events that were said to have occurred.

Of course, none of that has kept the true believers from continuing to point at Roswell as an example of both UFO activity as well as the government’s commitment to covering it up, leading to it becoming one of America’s most enduring conspiracy theories.

What do you think? Was the 1947 crash near Roswell simply a test balloon, as the Air Force claims, or even now, almost 70 years later, are they still hiding what really happened? Tell us below in the comments.

Aubrey Sitterson is the creator of SKALD, the ongoing sword & sorcery serial podcast, available on iTunes, Stitcher & Podomatic. Follow him on Twitter or visit his website for more information.