We know very little about Pluto.
Mostly because it's very small (about a third of the Moon) and because its unusual orbit confines it to the outskirts of our solar system.
It's actually so small and far away that even the best picture we have from the mighty Hubble telescope is just a reddish blur.
So scientists demoted Pluto to "dwarf planet" and dubbed it part of the Kuiper Belt, a band of rocky and icy debris orbiting at the edge of our solar system since its birth. But we're about to learn...