The Committee to Nuke Elysium

One of the latest ideas put forward is that perhaps the collision that likely formed Pluto and Charon heated the interior of Pluto enough to give it an internal liquid water ocean, which also gave the small world a short-lived plate tectonics system, like that of Earth.

“We predict that when New Horizons gets there it will see evidence of ancient tectonism,” said Brown University’s Amy Barr, coauthor of a new paper with Geoffrey Collins in the latest issue of the journal Icarus. By “ancient,” Barr means sometime way back during the first billion years of the solar system’s history.

Barr and Collins modeled the Pluto-Charon system based on the idea that the initial collision of the two bodies would have generated enough heat to melt the interior of Pluto creating ocean that would have survived for quite a while under an icy crust.

“Once you create an ocean on an icy body, it’s hard to get rid of it,” said Barr. That’s because as the ocean freezes, the remaining liquid portion gets enriched with salts and ammonia – which serve as antifreeze.