What is a planet?

( Some background history. )

Just what is a planet? There is some disagreement about Pluto. Does it qualify as a planet, or is it too small, its orbit too eccentric, or have some other disqualification? There is no set answer as what a planet is has never been formally defined.

I don't have an answer, but I do have a preference for one proposal. Someone suggested that a planet has sufficient mass that its gravity forms it into a nearly spherical shape, but isn't as massive as a star. I like this as it depends on the body itself, and not some arbitrary view of things from Earth.

It would change things. Pluto would be a planet, but so would some of the other objects in the outer solar system. And perhaps some of the larger asteroids would qualify as planets rather than "minor planets." There would be more than just the traditional planets - and what those are has changed over time anyway, so I don't see it as a big deal. Perhaps the degree of sphericity will be arbitrary. How close to a sphere is close enough? What about things not quite there, but not too oblong? Would these be the new minor planets, and the truly oblong things be asteroids?

Silly Question Time...

So.. what's a Klondike bar ever done for you?