Image via WikipediaFour years ago today, the International Astronomical Union voted to revise the current IAU definition of a planet -- adopting the one that didn't include Pluto. This, of course, led to some blowback in the astronomy community (and the sci-fi/internet community, too). Team Pluto, however, didn't have much in the way of empirical evidence to back the position Pluto deserved to stay -- especially since it wasn't even the largest member of the newly minted dwarf planet group to which it now belongs.How many dwarf planets are bigger than Pluto?
