Remember the '90s? Snap bracelets? 'N Sync? Friends? Accusing the Navy of taking down a U.S. passenger plane with a missile? That's right—our favorite '90s conspiracy theory is back, thanks to a new documentary purporting to show "new evidence" that TWA Flight 800 crashed because it was hit by a missile. Here's everything you need to know.

What was TWA Flight 800?

TWA Flight 800, a Boeing 747 that crashed into the Atlantic in July 1996, around 10 miles off the southern coast of Long Island, is one of the deadliest aviation crashes in U.S. history: All 230 people on board were killed in the accident, which came 12 minutes after takeoff.

What happened?

According to the NTSB, which conducted an investigation and review that took four years—the longest in U.S. history—the most likely cause was a fuel tank explosion caused by a spark from a short circuit. A concurrent investigation by the FBI closed after 16 months, concluding that no evidence existed connecting terrorism or criminal activity to the accident.

Officially.

...and unofficially?

A missile! A bomb! A meteorite! Electromagnetic interference! The Navy! Osama! Aliens!

Wait, really?

Yeah. For a bunch of weird reasons, TWA 800 has been the focus of a dozen rumors, alternative explanations, and conspiracy theories. Some are elegantly articulated and detailed forensic examinations of the possibility that electromagnetic interference caused a fatal spark in one of the plane's gas tanks. But most of them focus on the idea that the U.S. Navy shot down the plane with a missile and the government is covering it up.

Why would they believe that?

Pretty quickly after the plane went down, eyewitnesses reported seeing a "streak of light" moving upwards in the vicinity of the plane. (This was later established to probably have been the plane itself.) Fears that terrorism was involved led the FBI to launch its own investigation—one that, unlike the NTSB's, assumed criminality.

The scattered debris made it hard to move the NTSB's investigation along as quickly as people would have liked, and the FBI's aggressive prosecution of the missile theory in its inquiry fueled speculation among conspiracy nuts, especially on message boards on the newly popular internet.

Eventually, Pierre Salinger, JFK's former press secretary, announced that he had evidence of a government plot. As it turns out, he just had an email from a crank ex-pilot that had already been floating around on the internet for a few weeks, but the theory had gained a slightly-more-legitimate veneer.

Obviously, both federal bodies eventually concluded that there was no missile. But thanks to that particular '90s flavor of anti-Clinton conspiracy theorizing, and the sudden ability of cranks to encourage each other on message boards, the theory persisted for years.

But why am I hearing about it now, again, all of a sudden?

A new documentary called Flight 800 is going to be shown on "Epix," which I suppose I am willing to believe is a real cable channel. It purports to show "new evidence" that the official explanation for the accident is inadequate, and brings together six former NTSB investigators who believe that there was a missile.

"New evidence"?

The new evidence is an analysis of radar that producers claim shows "that the explosion that caused the crash did not result from a low-velocity fuel-air explosion as the NTSB has determined" but was rather cause "by a detonation or high-velocity explosion." (Those quotes are from a petition filed with the NTSB by the film's producers on Wednesday.)

The rest of the stuff in the film is, as Alex Seitz-Wald points out in Salon, is at least a decade old—the product of longtime TWA "truthers" since before that was even a word we used to describe conspiracy theorists. Key NTSB "whistleblower" Hank Hughes, for example, appears in the film claiming that FBI agents were entering the hangar where the wreckage was kept "in the wee hours of the morning... for purposes unknown"—the same claims he testified to in a Senate hearing convened by Chuck Grassley (at which he also accused the FBI of tampering with evidence and using psychics, among other things).

Much of the rest of the evidence is claims from former NTSB investigators that the FBI improperly handled eyewitness interviews, or that the NTSB was warned off or pushed away from investigating closely. The producer of the film has been parading these same accusations around for years as founder of the "Flight 800 Independent Researchers Organization." (Rule of thumb: Do not trust an organization that feels the need to assert its "independent" bona fides in its name.)

So why are news organizations like ABC and CBS giving it any kind of credibility?

Well, obviously, '90s nostalgia is big right now. But mostly because of the internet. Like most conspiracy theories, TWA 800 is search-engine optimization gold, but more than that it's one of the web's first widespread Truther movements, as observed by the Times in 1996:

On the World Wide Web, some of the various discussion groups on the crash have detailed a possibility in which a Navy Aegis guided missile cruiser known to be operating south of the jet's flight path on the night of the crash let loose a practice shot that went awry. The Pentagon has insisted that no missiles were fired from that ship or any other in the area that night. [...]

On the Web, [the meteorite] theory is also the subject of a spirited discussion. Circulating recently among astronomy buffs was a list of recent meteorite strikes on man-made objects: ''12-06-89 Opotiki, New Zealand: Building hit. 15-08-89 Sixiangkou, China: Building hit. 02-07-90 Masvingo, Zimbabwe: Person missed by 5 meters. 31-08-91 Noblesville, Ind.: Meteorite fall missed two boys by 3.5 meters. 09-10-92 Peekskill, N.Y.: Car trunk, floor pierced by meteorite.''

And people still talk about this?

Oh, you bet. A quick visit to Godlike Productions, the web's pre-eminent site for "UFOs/Conspiracy Theorists/[and the] Lunatic Fringe," turns up some wonderful stuff: