http://www.newsweek.com/pluto-crater-supervolcano-cryovolcano-discovery-1837367

A huge, bizarre crater on the surface of our cosmic neighbor Pluto may actually be an icy supervolcano lying dormant.

The Kiladze Crater, a 27-mile wide structure situated in Sputnik Planitia, a heart-shaped region on Pluto's surface, is thought to be a powerful cryovolcano, according to a new research paper on the pre-print server arXiv.