Abstract: NASA’s New Horizons spacecraft has revealed the complex geology of Pluto and Charon. Pluto shows ongoing surface geological activity centered on a vast basin containing a thick layer of volatile ices that is involved in convection and advection, with a crater retention age no greater than 10 Ma. Surrounding terrains show active glacial flow, apparent transport and rotation of large buoyant water-ice crustal blocks, and pitting by sublimation erosion and/or collapse. More enigmatic features in…