The reason for the descent of the fourth floor is right, because everything wants to be kept in the most stable state.

But not all celestial bodies are like this.

The conclusion of the third layer is correct, but it doesn't seem to explain why. I want to add something here.

There are two reasons. First, why comets are not round, because their gravity does not pay attention to overcoming their own rigidity, so it is very strange.

The other also said that its own activities and other physical influences led to its deformation. For example, the O (Omicron) star in the constellation Cetacea is influenced by its companion star, resulting in an obvious belt made of matter between the two stars, or some celestial bodies rotate at high speed, resulting in centrifugal force near the equatorial plane, so it is flat. Or a nova explosion (not a supernova) will also be a temporary deformation of the surface every day.