Used to play with gravitational attraction simulations ages ago. One thing I noticed it was difficult to get a small object to collide with a bigger spherical one vertically and far more likely to hit at an angle far from 0. Has the math of this been worked out for asteroids entering the earth's atmosphere? Maybe the distribution of the angle of entry has a peak at 45 degrees or whatever? Maybe observation data shows where the peak is and the shape is not symmetrical ?