When is a moon a moon

[dragon]

In this case the moons of Pluto.

By definition a moon is.

A natural satellite revolving around a planet.

link

And since Pluto is no longer a planet but has 4 orbiting bodies are they still moons?

[Terralthra]

It's a dwarf planet. Still works for me.

[Eternal_Freedom]

It's a dwarf planet. Still works for me.

Very much this. Pluto is one of the Plutons/Plutoids, a class of dwarf planets. Consequently, Nix and Hydra are still moons but Charon moves up in the cosmos and is now Pluto's companion dwarf planet.

[Terralthra]

Ceres is also now a dwarf planet, interestingly enough.

[Eternal_Freedom]

Ceres is also now a dwarf planet, interestingly enough.

Yeah, but Vesta and Pallas aren't. I think the definition is over 1,000 km in diamter or something.

[Grandmaster Jogurt]

The requirement is that it be massive enough that gravity dominates over chemical and mechanical bonds. Vesta and Pallas are more lumpy potato than sphere and so they don't fit.

[Eternal_Freedom]

The requirement is that it be massive enough that gravity dominates over chemical and mechanical bonds. Vesta and Pallas are more lumpy potato than sphere and so they don't fit.

Ah yes. I remember the conditions for "planet" being something like 1. Orbits the Sun 2. Is massive enough to pull itself into a sphere 3. has cleared it's own orbital path of major debris, with dwarf planets not meeting number 3. Of course, planetary geology was two and a half years ago so I may be off.

[Terralthra]

Nope, you're quite correct. 2 Pallas and 4 Vesta are not quite spherical, though 4 Vesta is fairly close.