Pluto was more like: 1. We know 9 planets in the Sol solar system 2. Oh shit, there are way more of those small ones, where do we draw the line? Is there a th

Pluto was more like: 1. We know 9 planets in the Sol solar system 2. Oh shit, there are way more of those small ones, where do we draw the line? Is there a thing differenciating a big asteroid from a planet? 3. Let's go with (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighborhood around its orbit. 4. Pluto doesn't satisfy (c) 5. People get angry without proposing their own criteria