Proposal: Uranus et. al. should no longer be called "plane-ettes".

[halfeye]

Ice is a solid (okay, fine, most of the time), so if Pluto is mostly ice, then Pluto is mostly solid. Furthermore, any planet will become a liquid if you move it sufficiently close enough to its respective sun.

Yes, but the hot molten rock Jupiter mass things out there are not part of what I'm suggesting naming.

The Kuiper belt objects seem to be snow rather than ice, I don't know what happens with hydrogen snow but water snow is mostly much less dense than ice.

And now the core does matter, but only for Earth?

I'm talking about most of the Earth, all the hot high pressure rock between the crust and the core, which seems to be in a fluid-solid hybrid sort of state.

There's another issue that if we stop calling Jupiter, Saturn, Uranus, and Neptune planets (or plane-ettes, or wandering stars, or rudisplorks), we have another question to ask ourselves, "What are they?" I have lots of ideas, but I think the only category that is board appropriate is to call them Space Balls.

I find gas-giant-planet and rock-ball-planet to be overly long and cumbersome. "Planet" for the rock-balls and something else (hpefully equally concise) for the gas-giants would be an improvement in my view. I do hate it when people steal words which have a meaning already (like "colour" and "charm" in nuclear physics), so hopefully not one of those.