Planetary science used to be so simple. Our solar system had 9 planets, and a bunch of little leftover scraps called asteroids and comets. But over the last few decades, improvements in observing technology have helped astronomers to discover hundreds of new objects -- and they don't all fit the old, tidy categories (many of them don't even fit well into new categories). Since we now know of a dizzying variety of objects both in our solar system and elsewhere, astronomers have been caught up in "nomenclature wars" over how to describe and categorize things.

Listen in this week to find out how this whole mess got started, and how astronomers may (or may not) tidy things up.