It happened before, it will happen again, its just a question of when. Here is a collection of 5 famous meteorite craters on earth, reminding that the Earth was not always a peaceful place, and that there will always be a bullet in space for us.
Barringer, Arizona, US
Some 50 thousand years ago, a 46 meters meteorite hit Earth with a velovity of 65.000 kmph. The huge crater is he best evidence we have of such collisions.
Gosses Bluff, Australia
About 142 million years ago, a huge asteroid or comet with a diameter of 22 kilometers hit Earth. The collision released energy which equals to 22.000 megatons of TNT!
Deep Bay, Canada
This crater was created some 100 milion years ago, and has a diameter of 12.9 kilometers.
This corroded crater was created before 200 to 300 million years ago in the territory of Sahara.
This crater was made some 1.3 million years ago, and has a diameter of 9.6 kilometers