Momentum doesn't really work this way. The only things that change the difficulty of deflecting something are it's mass, and the remaining time to impact. Hav

Momentum doesn't really work this way. The only things that change the difficulty of deflecting something are it's mass, and the remaining time to impact. Having a lot of momentum doesn't change how much force is required to give something a given acceleration until relativistic effects start to matter. (I guess distance also makes it harder, because you need to travel further to start deflection, but that's not really a momentum thing)