Why are impact craters symmetrical?

Regardless of the physical shape of an incoming meteor or the angle at which a meteorite hits the ground, the crater it makes will almost always be round. That’s because the energy of its impact is so great that the object explodes like a bomb when it hits. Since explosions are mostly symmetrical, the crater is usually circular because the resulting debris is thrown equally in every direction, regardless of the angle of impact. An extremely shallow impact can sometimes form an elliptical crater, but the phenomenon is rare.