[SunkenCiv]

"To Pluto And Far Beyond" By David H. Levy, Parade, January 15, 2006 -- We don't have a dictionary definition yet that includes all the contingencies. In the wake of the new discovery, however, the International Astronomical Union has set up a group to develop a workable definition of planet. For our part, in consultation with several experienced planetary astronomers, Parade offers this definition: A planet is a body large enough that, when it formed, it condensed under its own gravity to be shaped like a sphere. It orbits a star directly and is not a moon of another planet.

[supercat]

How does the mass of Pluto compare with the mass of the largest closer thing that isn't a planet, and how do their orbital radii compare?

I wonder if it would be meaningful to classify objects as planets based upon how strong their gravity field is at the object they're orbiting? I would think such a definition might be especially useful with extrasolar planets, given that AFAIK the only way we even discover their existence is by their gravitational influence on the stars they orbit.

Obviously Pluto is much further away than the asteroid belt, and this greater distance would make it hard to compete by that measure, but it would still come out well ahead of the objects that are even further out.

What do other people think of that idea for a metric?

[JerseyJohn61]

Regulairity is what most ASStronomers and people want.
Pluto has given that; as in predictability....JJ61