Back in the 1980’s, a now-defunct magazine called Science Digest held a contest to name Planet X — the still-undiscovered world that astronomers believed might lie out beyond Pluto. One of the best ...

The International Astronomical Union (IAU) announced Tuesday that names voted on by the public had been accepted for Pluto's fourth and fifth moons. Kerberos and Styx, formerly known as P4 and P5, ...

The discovery of another moon around Pluto is exciting news for planetary science, but it's also likely causing some anxiety for the team in charge of New Horizons, a spacecraft set to be the first ...

Pluto may be small, but it has one of the most unusual moons in the solar system. Charon is so big compared to Pluto that the two worlds orbit each other like a pair. In this video, we explain why ...