The upper stage of the rocket hit near the Einstein Crater on the western side of the moon, which is difficult to see from Earth’s surface. If you had been watching, it was more likely that you would have seen the giant plume of moon dust after the fact than the actual impact.

The best way to see it is nice and easy: just head somewhere with a clear view of the sky and as little light pollution as possible. Look toward the moon as the eclipse gets underway, and you'll see Earth's shadow gradually cover part of its surface.