Modeling a Death Star For Asteroids

If an asteroid was heading toward Earth, what would we do to stop it? We will investigate how much energy and how big of a superweapon like the DEATH STAR would need to be/have in order to destroy an asteroid depending on the size, speed, composition, and the distance of the asteroid to Earth. The question matters because if a real giant asteroid in the far future was heading to Earth, the damage would be immense and many people would likely die. We will produce a value of how much energy the Death Star would need and how big it would need to be to produce that kind of energy depending on the speed, size, distance, velocity, and composition of an asteroid.