The hydrostatic equilibrium definition was definitely better than the current definition and not because it included Pluto… so much for “sentimentalism”. It wasn’t hopelessly linked to our particular solar system for starters, and it recognized that whether or not something is a planet pretty much had to do with its own internal properties and not external factors like its local neighborhood being cleared of other bodies. Mercury’s orbit is pretty clear too, and Mercury isn’t the responsible party. But there’s no talk of changing the classification of that world.

If you were to isomorphically take the current definition and use it to describe flowers, a single rose in a vase would be a flower, but a rose in a bouquet would not. That’s not what I would call “rational”.

Sounds more like a group of people reacting irrationally to the idea that there might be hundreds of planets in our solar system, and trying to stop that from happening, as if that is somehow a bad thing. In other words, the new definition has more to do with *people* and less to do with *planets*. Forgive me if I remain unimpressed.

All the arguments I hear against strike me as quite silly.

“But it’s made of largely ice!” So what? We have planets made largely of GAS.

“But it’s in a cockeyed orbit!” So what? My car is still a car even if I park it in your swimming pool. The fact that it isn’t where you usually keep a car doesn’t make it not-a-car.

“But there will be hundreds of planets if Pluto is a planet!” So what? Please give me a break, that’s the silliest argument of all. We’re going to make the determination of the meaning of a scientific term based on our desire to have a short list of planets to memorize? Piffle. That’s sentimentalism my friend, longing for the good old days when the distant solar system was a dark an unknown place, and the list of known worlds was comfortingly short and easy to understand.

“But it’s so small!” It’s big enough to be round under its own gravity, and that, my friend, means it is in fact quite large indeed.

It may be among the smallest of planets, but we’re talking small on a *planetary* scale. Pluto’s about half the size of Mercury. A hike around its equator would be a journey of 4,400 miles. If you had the means to spend your entire life on Pluto it’s unlikely you would be able to visit all of its 10.3 million square miles of surface area.

Doesn’t anyone have a GOOD argument why Pluto, UB313, Ceres, and so forth shouldn’t be considered planets? I’m still waiting to hear one. Because as near as I can tell, Pluto is a *world* in ways that a chunk of rock like Gaspra, Ida, or Phobos and Deimos are not.