...because, yes, we're all Pluto obsessed this week. It's going to take months to even transmit all of the data New Horizons got in a brief flyby.
Pluto has mountains. Not little mountains, either. Mountains that, according to scientist John Spencer, "Would stand up respectably against the Rocky Mountains."
And those mountains are mostly made up out of, uh, good old fashioned H2O. Water ice. It's the only thing that could exist on Pluto that could give topography like that.
On top of that? Pluto has no impact craters. None.
What does that mean? It means that Pluto's surface is being constantly renewed. We don't know what by, but this actually means that Pluto is more of a living, active world than Mars is. It means some form of tectonic activity is happening. On Pluto.
Probably involving water.