Five years ago today, our New Horizons mission reached Pluto. The spacecraft revealed that what we once knew only as a tiny dot is a complex and beautiful world: solarsystem.nasa.gov/pluto | NASA Solar System Exploration

Pluto has a thin atmosphere with a blue tint. Find out what else makes the "King of the Kuiper Belt" interesting. Stream "The Planets: Ice Worlds" online or on the @PBS app now: https://to.pbs.org/2YztewN | NOVA l PBS