Oh Crap, an Asteroid is Coming Our Way! But Wait....

We've had our share of discussions regarding an asteroid impact on Earth. I have one more tidbit to add to the pile, that I don't think I've seen. So I'm prompting a discussion on this idea, and asking if it has been brought up anywhere before, that you can remember? I know it didn't really come up in the movie Armageddon.

If an 10 km diameter asteroid coming to earth, moving at 25,000 kilometers per hour will cause the end of life on earth, and the ratio of earth size to asteroid size is 4000:1, then I think the least we can do is shoot a 10+ meter dia solid steel bullet at it, and target for a side impact.

Even to get an object to leave earth, it has to be moving at 40233.6+ kilometers per hour.. (25,000 mph).. so for round numbers, lets say 50,000 km/h.. slingshot round the moon (and/or mars) for steering and boooom!!! way out there the two meet, at a combined velocity of say 75,000 km/h, or greater. if the angle from the moon slingshot was enough to deflect it.. great.. if not, we might have to deflect also around mars and and hit it more sideways. (bullet shooting bullet, I know, but I believe we have already done a version of this) Even a head on collision would help, as it would impact earth with less energy. A side impact with 1/2 or 1/3 of the the energy of a head on impact may be enough to deflect?

the basic idea is to use the massive velocity differential to create a deflecting impulse. I imagine steering can be accomplished with a laser guidance system, which will allow corrections to be made in time, in the 'zone' so to speak. small corrections early on will conserve fuel.

If a SaturnV can go to the moon and back, then perhaps if we boosted a SaturnV with SRB's, it would have enough fuel usable in space to reach some very high velocity differentials.

So this system would be able to impact an asteroid for less than the cost of a moon mission, because there doesn't have to be any allowance for astronauts or science projects, or lunar landing... just fuel, engine, guidance, and payload. I'm sure that steering by the moon and mars are not necessary to achieve the velocities, but they are very helpful in the steering to a side impact.

I'm not a mathematician... Is there a way to rough out the mass/inertia/velocity-of-bullet calculations to make a different on mass X sized asteroids? maybe it should be DU instead of steel? Maybe it could have a nuke to add to the boom, if necessary, although that puts the cost up, and may not produce more than the amount of energy an equal amount of fuel might produce in added velocity.

Here is an image that shows most asteroids being outside the orbit of Mars. Detection is everything as has been said many time.. Perhaps if we had a better plan for defense, we might obtain more money for detection?

I appreciate your thoughts, calculations, criticisms and humour.

Chris