According to Quantum FFF Theory, comet nuclei are plasma producing new physics black holes with a Fermion repelling around the nucleus. (see Orientale basin). Blue colored ring around the red center, seems to represent the Fermion repelling zone around the central large cometary black hole with extra gravity ( red) .
Crashed comets even seem often to split before crashing into planets or moons leaving extra peculiar gravity patterns behind.
see:
Insights into giant impacts on moon, Earth and Mars
https://www.sciencedaily.com/releases/2016/10/161027141000.htm
