Science

to wipe out 7/8ths of us in a day. Big 'ol piece of nickle and iron going into the ocean at 50 or 60k mph would be preferred. Super virus would leave it way to stinky. Nuclear war would be similar to the big metal ball but the radiation, nah don't want that hanging around making 3 headed skunks and radioactive brussel sprouts for 10k years. I've always liked the big metal ball idea. Plus, the planets plenty used to it. Kind of like a dog shaking itchy things off its back.