Extinction Event

I've already talked about the KT-Boundary event that destroyed the dinosaurs and about the possibility of an asteroid or comet colliding with Earth. What I want to discuss here is what are we going to do about a big rock from space hitting the Earth and destroying everything.

I've been watching the docudrama 'Salvation'. This made for TV series is a drama about a select group of people knowing that a giant asteroid is on a collision course for Earth in 186 days. The military knows about it, but it turns out that a MIT astrophysics student discovered it by himself. He, in turn, alerts a young Tycoon who just happens to be working on space launching technology, and the MIT student's professor just happens to be working on an EM drive engine. Throw in a good-looking female that works as a government secret agent and you have a goofy science fiction yarn. The idea has been used before many times, but not quite like this.

First of all, the military's plan to stop this asteroid, which is declared to be an extinction event maker, is to first try to gravity tractor the asteroid with a special unmanned spaceship. This, however, fails and the next step is to pull a Jupiter probe out of Jupiter's orbit just in time to smash into the asteroid and break it up. Unfortunately, this will still wipe out 1.5 billion people, mostly in China and Russia.

The tycoon's plan is to send a rocket with an EM drive to the asteroid to gravity tractor it just enough to miss Earth. However, he doesn't have the EM drive perfected and he needs several kilos of enriched uranium, which the female government agent gets for him using her secret clearance. Turns out, the uranium was not for the EM drive but for an arc to carry a select group of humans to another habitable planet. Even worse, secret project Atlas was the United States idea of using an asteroid to destroy Russia, an event that raises the tension between the United States and Russia.
First of all, it's unlikely that the U.S would be the only country that knew about an extinction-sized asteroid on a collision course for Earth. The other thing I found wrong with this plot is trying to break up a large asteroid with a space probe. I doubt that the flimsy nature of space probes (the weight is kept down to a minimum to avoid using too much fuel) would cause an asteroid, especially one containing iron, to break up enough to lessen the impact of the collision. The gravity traction idea would require lots of time, probably many months if not years to change the course of the asteroid.

I sensed that another plan was to create a space ark ship to save a select group of humans to colonize some other planet. That idea would work if they had a warp drive or could make hibernation safe. Sending them to Mars would be risky because there would have to be lots of supplies and equipment there to have any chance of survival.
So, what are the options for diverting a large asteroid from colliding with Earth? I define a large asteroid as being at least 5 kilometers in size. Keep in mind that these rocks could be moving as fast as 100 kilometers per second. Changing the course of something with that much momentum would not be easy. Blowing it up wouldn't help that much because the fragments would cause all sorts of serious damage when they plunged down through Earth's atmosphere.
One idea involves using a rocket engine on the asteroid to move it slightly. However, if the asteroid were spinning, this would not work. Even if it weren't spinning, trying to land on the asteroid is difficult because of its low gravity.
There are methods involving laser light, which would move the asteroid, but it would require powerful laser light to change its course in a short time frame.

Most of the methods I've discovered involve lots of time to achieve any effective course change. Personally, I'm not certain that there is a plan to divert a large asteroid from a collision with Earth. I hope NASA and ESA are working on this problem. If not we could end up like the dinosaurs.

Thanks for reading.