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Unpopular opinion: the IAU has no official authority to define the term "planet". The rest of us have no obligation to use their definitions. I think a planet is a place made round by its gravity, but not massive enough to be a star. Is Pluto a planet? Yes, and so is our Moon.

Planets orbit stars, moons orbit planets. Jupiter is a planet. Pluto is a planet. Mars is a planet. But Luna is our one precious moon that is a vital part of the way life on this planet exists, she drives the tides. She is part of earth, she came from Terra, they are each other 🥹🫶🏼

I don’t like “plants orbit stars” though. If Earth were flung out of the solar system, would it stop being a planet? What would it become? Or is every grain of dust orbiting the Sun a planet? Planets are big round places that aren’t stars. Earth’s moon is one.

We describe everything in space according to it's motion. What is the difference between an asteroid, meteor and comet? MOTION. If earth were "flung out of the solar system", it would rapidly shed pretty much everything and maybe become an asteroid, but realistically nothing would make it out.

I can respect that, but I still don't think it's a good idea. We hardly ever define things by their motion in any other field except this one. We don't define atoms or goats or rocks by how they move, but by what they are. Even stars aren't defined by their motion, but by their nature.

We do have words that define a thing by its motion, like wind or waves, but those are motions of objects, like air or a guitar string, that themselves are not defined by motion. Only for objects moving around our solar system do we have no words for the object itself distinct from its motion.