Besides clearing its neighborhood, what fundamental geometric requirement must a celestial body meet to qualify as a planet under the current IAU framework?

Answer

It must be large enough for its own gravity to pull it into a nearly round state (hydrostatic equilibrium).

The modern definition requires two main components: hydrostatic equilibrium (being round) and gravitational dominance (clearing the neighborhood).

Besides clearing its neighborhood, what fundamental geometric requirement must a celestial body meet to qualify as a planet under the current IAU framework?

#Videos

Clearing the neighbourhood - YouTube

DefinitionastronomyorbitplanetIAUclearing the neighborhood