Pluto Explored! NASA's Epic Voyage to the Edge of the Solar System
We have reached Pluto, the last of the classical planets, and the most remote world yet explored by humankind. Far from being dark, cold, and dead, Pluto and its family of moons are bright and variegated, if not gloriously, geologically alive. From giant floating mountains of water ice, to mysterious cryovolcanoes and convecting ice sheets, to valleys carved by now vanished glaciers of solid nitrogen, to towering blades of sun-burnt solid methane, Pluto has expanded the very meaning of geology, and the definition of planethood. And though modest in stature, Pluto has played a key role in revolutionizing our understanding of the early history of the Solar System.
Technical Talk: Geology Never Sleeps: Lessons from New Horizon's Exploration of the Pluto System
Pluto and its system of 5 moons are thought to have been born in a "giant impact" similar to that which created Earth's Moon. New Horizons data corroborates this view, and provides further insights into the planetary accretion process. Neither Pluto nor its big moon Charon betray evidence of their post-formation orbital tidal evolution, but the position of Pluto's major impact basin, Sputnik, near the tidal axis is circumstantial evidence for true polar wander. Sputnik and the vast sheet of convecting nitrogen ice it contains is the central engine of Pluto's geological and climatological activity, and the history of geological activity seen on Pluto and Charon bode well for continued exploration of the Kuiper belt.