10 Ridiculous Movie Premises Everybody Fell For
4. A Nuclear Bomb Can Save Earth From A Giant Asteroid - Armageddon (1998)
No, a collision with a comet couldn't change the path of an asteroid that massive. No, the asteroid wouldn't go unnoticed until 18 days before it hit Earth: it'd be visible to the naked eye long before that. Yes, it would be much quicker, easier and cheaper to train astronauts to drill holes in the asteroid than to train drillers to be astronauts (why they didn't just make the whole lot of them astronauts in the first place is beyond me). But these are just details.
No, the film's resolution requires you to believe that a nuclear weapon, buried about 250 metres into the surface of the asteroid along a natural fissure, will blow the fissure wide open, splitting the giant rock in two, and causing the two halves to take radically different courses, each missing the Earth.
Firstly, the asteroid is 1000 kilometres across: the bomb is only being buried about 0.025% of the way in. It might as well be on the surface. Secondly, it's been calculated how much energy would be needed for a nuke to split an asteroid that size, moving that fast, so that the two halves sheared to either side of our planet: roughly 800 trillion terajoules. The most powerful nuclear weapon ever detonated was the USSRs 50 megaton Big Ivan, which cleared around 418,000 terajoules. That means Armageddon's nuclear solution would need to be around 2 billion times more powerful than the most powerful nuke ever detonated.
Bruce Willis and company were wasting their time. It's the equivalent of trying to split an apple in half by taking a very, very, very shallow bite out of it. Their maths was obviously way, way off but then that was obvious from the beginning of the film. The rich, strong tones of Charlton Heston inform us that the rock that killed the dinosaurs hit the earth with the force of ten thousand nuclear weapons. Where did Moses get that figure? Out of his rear end, apparently: a conservative estimate says that the impact of that asteroid is likely to have released 80 million megatons of energy, or around 1.6 million Big Ivans, not ten thousand.
Clearly the nine writers who worked on the script were trying for an impressive-sounding number but didn't know what on Earth they were talking about.