A long time ago, I wrote a script about the Earth being on a collision course with a very large asteroid. In the first draft of the script, civilization broke down because the certainty of the collision was known far in advance of the projected impact. That makes for a boring movie, or for a movie that won’t get made. So I changed the composition of the asteroid and gave it very little reflectivity. In my script, society still breaks down, but there is a military coup and the President is put on trial for treason. I wrote that in 1996.
One of the problems I thought about is what do you do with a very large piece of rock that is heading toward Earth? I rejected nuking it because nuking it would just break it up into smaller pieces and make them harder to target. Meteor Crator, in Arizona, was formed by a meteorite that was only 50 meters across but travelling at a speed of around 20 km/sec (45,000 mph). That crater is 1200 meters in diameter and about 170 meters deep.
If an asteroid about 1000 meters in diameter was struck by nukes, it would vaporize some of it, but the rest would be broken into pieces about this size or smaller. The asteroid has a volume equal to around 8000 meteorites of the size that hit Arizona. Some of them would be vaporized. How many would still strike the Earth?
Well, there are people who have been thinking about this and they think that nuke are not the way to go. The official government position is that nukes are still the way to go, but we’ll see.
Nuclear weapons could be used to stop earth-bound asteroids, but in most instances, they are not the best option, said Apollo astronaut Rusty Schweickart during a public lecture this Wednesday in San Francisco.
The venerable scientist explained that all but the largest heavenly bodies can be redirected by rear-ending or towing them with an unmanned spacecraft. But last year, NASA issued a report stating that using nukes is the best strategy to prevent a catastrophic collision with earth.
Although Schweickart has a great deal of faith in the agency, enough to risk his life piloting their lunar lander, he feels that they issued the misleading statement — under immense political pressure. It was a nefarious excuse to put nuclear weapons in space.
His own organization, the B612 Foundation, intends to use gentler tactics to alter the course of an asteroid by 2015.
My solution to the problem was to use nukes in a sequence to cause a wave effect that would deflect the pieces of the asteroid after the military took a shot with straight on nukes and failed. I don’t know if that would work, but what the heck, it was just a movie.