Well, today is a huge day for astronomy. It may very well render all the astronomy books currently being ordered by schools and college students around the world as obsolete, even before they’re used. For those not caught in the whole debate, a final proposal has been submitted for vote this afternoon:
A planet is a celestial body that (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 neighbourhood around its orbit.
A dwarf planet is a celestial body that (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, (c) has not cleared the neighbourhood around its orbit, and (d) is not a satellite.
All other objects orbiting the Sun shall be referred to collectively as “Small Solar System Bodies”.
A separate resolution will be voted on to decide whether Pluto should be included as a “dwarf planet.” Now, while this doesn’t tail exactly with my suggestions from a few days ago, I consider it compatible enough to work. It effectively (if voted in this way) stops Pluto and those others from being one of the big, major planets. Although I don’t know what “clearing the neighborhood” means, it seems likely that it will be explained in the coming days, if this resolution passes.
I don’t have much more to say about it at the moment. Later today, I’ll have my analysis of what the decision means for society and the future if the resolution passes. If not, I’ll have to see what I’ll write about once I know more information.