Like a cosmic lava lamp, a large section of Pluto's icy surface is being constantly renewed by a process called convection that replaces older surface ices with fresher material.
Scientists from NASA's New Horizons mission used state-of-the-art computer simulations to show that the surface of Pluto's informally named Sputnik Planum is covered with churning ice "cells" that are geologically young and turning over due to a process called convection. The scene above, which is about 250 miles (400 kilometers) across, uses data from the New Horizons Ralph/Multispectral Visible Imaging Camera (MVIC), gathered July 14, 2015. Their findings are published in the June 2, 2016, issue of the journal Nature.
http://photojournal.jpl.nasa.gov/catalog/PIA20726