Jupiter is Massive because it formed just past the condensation point of ice. At 5 AU this represents a small portion of the solar system. Should we say Jupiter isn't really a gas giant simply because if it formed closer in it wouldn't have retained all that hydrogen? Should we say Titan doesn't really have a significant atmosphere because it couldn't have retained it at a mere half its distance from the sun (versus the 10% for Pluto to have a problem)? This is nonsensical. "Planet" should have a simple relatively rigorous definition that is not extremely sensitive to location. The original proposal was such, although the inclusion of Charon was a tweak that was probably fatal. The proposal passed was a horrible nonrigorous piece of crap designed specifically and arbitrarily to exclude Pluto. Worse yet it could exclude classical planets depending how you apply the poorly defined "local area" clause specifically added to axe pluto. That was a stupid emotional response. "Hey we had problems with Pluto and you want us to take Charon too?". What you or any astronomers have emotional problems with should be irrelevant in determining a rigorous definition.

History should not matter, emotions should not matter. Being rigorous should. It's supposed to be a hard science not sociology. It is completely arbitrary to say Pluto is too small to be planet when the size ratio between Earth and Jupiter is less than pluto to Earth. "Size" is an arbitrary line drawn in the sand. The basis of defining a planet as anything that is massive enough to cause collapse into a round object is one of the few nonarbitrary standards for a planet. No comets are round. Only one asteroid is for sure. There are millions of solid irregular objects in the solar system big enough to cause wide spread disaster if striking the Earth wich are insignicant compared to Pluto or even Ceres. These are not inconsequential bodies in terms of resources or danger yet they are clearly vastly inferior to Pluto, Charon, and Ceres unlike the relative size difference between those and Earth. What exactly would constitute a double planet by the way if being half as big doesn't qualify based on the relatively simple and staightforward barycenter rule?

If there are hundreds of "planets" so what. Definitions should not be made based on how many objects will fit the class but rather on a common set of characteristics. Can you name one rigorous scientific definition based on such? Anyone concerned with over burdening school children can just teach the terrestrial planets (which should include Ceres), the gas giants and the largest ice dwarfs of which Pluto will probably remain one.

Regards,
Mark