From the Museum Of Hoaxes page on the ‘documentary’:

On June 20, 1977, Anglia TV in England broadcast a documentary titled Alternative 3. The show, presented as part of a regular series called ‘Science Report’, began with the announcer explaining that they had originally intended to broadcast a far different show, but something had gone wrong. They had intended to air a show about the British ‘brain-drain’, about how British scientists were leaving the country to find higher-paying jobs abroad, but in the course of their investigation they discovered that many of the scientists they sought to interview weren’t just leaving the country. They appeared to be mysteriously disappearing from the face of the Earth itself.

The disappearance of these scientists prompted the news team to investigate further, and what they ultimately uncovered was a vast, global conspiracy reaching to the very highest levels of the American and Soviet governments. Apparently back in the 1950s researchers had learned that the Earth, on account of man’s actions, was facing an unstoppable environmental catastrophe which would result in the almost certain extinction of humanity itself.

Through interviews with supposed astronauts and scientists, the documentary pieced together evidence that supposedly revealed that the Soviets and Americans, working together, had reached Mars as early as 1961, that the Apollo Space Program had been nothing but a publicity decoy to conceal the true purpose behind NASA’s numerous rocket launches, and that scientists were now being abducted to work on Mars.

A few were so convinced by the show that they refused to believe it wasn’t real, even after its producers announced that the entire thing had been a joke. These faithful few continue to insist that Alternative 3 is real, and that the show was part of the world government’s vast and sinister disinformation scheme. They argue that by making Alternative 3 appear to be a fanciful hoax, the world government has insured that no one will suspect that it is, in fact, the frightening truth.

(Via Gpod.)