The Kuiper Belt, the vast asteroid belt of ice and rock that lies beyond Neptune, is home to three objects big enough to be considered dwarf planets: Haumea, Makemake, and our old friend Pluto. And now, we might have found three more.
Last week saw Neptune Day, the first anniversary - in Neptune years - of the planet's discovery on September 23, 1846. That got us thinking: what are the "birthdays" for all the other planets? Here's a handy, mildly insane guide.