Many asteroids are round. The list of planets, under your definition, would be so large it isn’t useful anymore. Even when Ceres, Pluto, and Eris were called planets the list was getting too long, and there are several larger than Ceres. Including every nominally round object would be insane.
Comment on Sad Ganymede noises
mech@feddit.org 4 months agoPlanets are round objects orbiting a star.
Cethin@lemmy.zip 4 months ago
yetAnotherUser@discuss.tchncs.de 4 months ago
I propose a better definition:
Planets are very large objects orbitting a star that dwarf everything nearby
I’m pretty sure this is the intent of the IAU’s definition. It’s just more specific.
Cethin@lemmy.zip 4 months ago
Ah, yes. “very large”, “dwarf everything”, and “nearby” are very specific terms…
yetAnotherUser@discuss.tchncs.de 4 months ago
Yes, that is why I mentioned the IAU’s definition was more specific.
Very large? Enough mass to have a round shape.
Dwarf everything nearby? Clear out its orbit by colliding with/capturing/ejecting shit.