Planets, Dwarf planets, plutons, and apathy

The international astronomical union is going to vote on a new system for classifying heavenly bodies as planets [LINK]. Essentially the new rule is if a thing orbits a star, but is not a star or a moon, and it has enough mass to make it round, then yes, it is a planet. Well done, boys. Here's a potential new schematic of the solar system (LATimes):

People always have to make up labels and categories, despite the fact that nature certainly has shades of grey. We deal with it in clouds classification schemes all the time... cumulus, altocumulus, altostratus, cirrostratus, stratocumulus, and it goes on ad nauseam. Some things are categorized easily. Mammals are different from birds, and both are different from reptiles. Animals are different from plants. Galaxies are different from stars, and both are different from rocks (planet or not). Water clouds are different from dust clouds. Lakes are different from oceans. You get my point. Yet, at some level, the system starts to break down. Is Pluto a planet? Is Ceres? Does it matter what we call them at all? Is this the right way to spend our time? Instead of arguing over whether to have an official definition for planet or dwarf planet or "pluton," why don't we get back to work and figure out some meaningful scientific questions. As for elementary school science books, well, if you grew up in public schools like I did, you know it doesn't matter what the new books say, because the students won't see them until they are obsolete too.

1 comment:

.brian said...


Pluto is now officially a "dwarf planet" according to the International Astronomical Union, as are Ceres and UB313. There are 8 planets in the solar system. Here's how the LA Times condensed the definition of planet: "a celestial body that is in orbit around the sun, has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a ... nearly round shape, and has cleared the neighborhood around its orbit." [LINK]