Pluto Is Beautiful, Complex and Thoroughly Puzzling for Scientists

The first-ever flyby of Pluto may have raised more questions than it answered. NASA's New Horizons spacecraft discovered a staggering diversity of terrain during its close approach on July 14, from towering water-ice mountains to a vast, crater-free plain largely divided into mysterious "cells" dozens of kilometers wide. New Horizons' observations also revealed that Charon, the dwarf planet's largest moon, sports a canyon system at least 650 miles (1,050 km) long and a dark polar cap that resear