As if the elves cared

Drow possibly, but elves?

Why not have the term Wanderer, out of defrence for what Planet meant in Greek. So up there we would have The Wanderers.

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More and more moons/satellites of Saturn are "discovered", smaller and smaller. About half the 61 (currently) catalogued moons are less than 10km across. The smallest of those, Anthe, is about 2km across.

Apparently some Cassini images of the A-ring show four individually distinguishable rocks, in the range 500m to 40m across, described as uncatalogued "moonlets". Some objects seen in images of the F-ring might be more, or maybe just clumps of particles. http://en.wikipedia.org/wiki/Moons_o...-Ring_moonlets

When does moon end and moonlet start? Can there be a natural boundary? Or should we set an arbitrary boundary, and if so at what size? 1km? 100km? Presumably there is a continuum all the way down to dust particles. Can "How many moons has Saturn?" ever be a question with a well-defined answer? Or indeed Jupiter, now we know it has rings? Or indeed anything, given that there are bound to be some dust particles in orbit?

Perhaps there should be a category of moons (natural satellites) that are massive enough to become round under their own gravity, similar to the Planet definition. Then maybe we could call them "Moons" and everything smaller "Moonlets" or "Dwarf Moons". Just an idea.

Anyway back to the original topic, is there any good reason why Charon cannot be considered a Dwarf Planet and if so, why is it not so defined? (And if it's not a dwarf planet, then what is it exactly?).

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The Sky is no longer the Limit

I swear this IAU definition just made it more confusing and didn't clarify anything at all...

Why would Pluto-Charon be defined as a double-planet in the first place? Why should the location of the barycentre of a system (whether it's inside or outside the larger planet) make any difference to whether the smaller body should be considered a moon or a twin planet?

I don't know why exactly, I'm sure you could argue against it, but as far as I'm aware the barycentre being outside the bigger body is usually taken to mean it is a double planet system. You can reject that definition if you want, but I think a lot of people find it makes sense.

So are you saying that a double planet system is just an impossible concept and we should just name the bigger body a planet and the smaller body a moon, even if they are very close is size? What would you suggest if we found two orbiting bodies that were exactly the same size? How then do you classify it other than a double or twin planet?

The possibility still exists that we could discover two dwarf planet-sized KBOs orbiting one another that are so similar in size and mass that we cannot distinguish which is bigger or smaller.

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The Sky is no longer the Limit

What if you had a weird situation where you had a large low density (icy?) body orbited by a small high density (mercury-like?) body, such that their barycentre was between the two bodies? Is that a "double planet" too? Or would it be a planet orbited by a massive moon?

One will always be more massive or larger. Labelling them a double planet (or not) is just adding another layer of arbitrariness to the already confused definitions. And it doesn't really signify anything useful.

Look at binary stars. They usually orbit barycentres, yet one star (the more massive one) is often referred to as the "primary star" and the other (the less massive one) is referred to as the "companion star". If the barycentre was within one of the stars, would we change the names that we refer to them by? I don't think we would - so why do it for planets? By analogy, the more massive body in a planetary system should be the "planet" and the less massive one should be the "satellite".

It's been mentioned that calling Pluto a dwarf planet gets confusing.
My answer to the problem, if we are going to continue to use the term "Dwarf Planet", would be to start over and rename Pluto.
First change the P in Pluto to a B
Now, instead of a cartoon named after a planet, you have a dwarf planet named after a cartoon.

With Pluto's name changed to Bluto, you simply change Charon's name to Popeye.
When people are confused by the change from being a planet to being Binary Dwarf Planets, you can simply say:
"They are what they are and that's all what they are"

My personal opinion is this:
If it's spherical and orbits the sun, it's a planet.
If it orbits a Planet, it's a moon.
If that definition isn't good enough for people, then I think the entire solar system needs an overhaul in they way it has been categorized.
If Pluto (aka Bluto) and Charon (aka Popeye) are separated out, then it's time we stopped pretending that terrestrial planets and gas giants are the same thing!
/steps down from soap box
Thank you

No, it isn't good enough for most people. I won't deal with its incompleteness and inconsistency as a definition, because I don't think you intended to present a complete and consistent definition.

But what is clear is that you are happy with rather more than 9 planets. I think that is probably an even more unpopular answer than 8.

Actually, I think that the inconsistencies should either be ignored or addressed but fully and completely.
Either make it simple, or make it complicated in a logical way and separate out All things that differ from each other IE: Gas Giants and Terrestrial Planets.

One way your going to end up with less "planets" then 8, but you'll have at least four different categories of "Planet", the other way you end up with more then 8 planets.
Either choice would be more acceptable then the current "Dwarf Planet" label IMHO.