Imagine the moon quakes when one of those big hits came.
Think I read here that the Copernicus? hit was actually seen on earth.
From my fallible memory -
An armature astronomer was photographing the moon through a home/backyard size telescope, and when his picture was processed, there was a small but distinct flash in the lower part of it, on the moons surface.
He sent the picture to NASA(?) and they looked more closely at that spot on the Moon with a larger telescope, and found what looked like a new crater. A comparison of older pictures of the site showed no crater there. I think he got naming rights, (fallible memory, again!)
Any large enough impact can be seen. IF you are looking . . .