You are here

Pluto's Moons

As of summer 2012, astronomers had discovered five moons orbiting Pluto. The largest, Charon, discovered in 1978, is roughly half the diameter of Pluto itself. Of the other moons, two have been named by the International Astronomical Union — Nix and Hydra. The other two, discovered in 2011 and 2012, have received the provisional designations P4 and P5, pending approval of formal names. Nix, Hydra, P4, and P5 are all quite small, with none larger than about 100 miles (160 km) in diameter, with the smallest only about 10 percent of that size.


Pluto February 19, 2016

Featured Images

Building Worlds July 13, 2021

Enhanced-color image of Charon from New Horizons

Charonian Chapeau December 27, 2016

Global view of Charon, Pluto's largest moon

Red Roof Moon October 2, 2015

July 12 views of Charon and Pluto from New Horizons

Hours Away July 13, 2015

July 8 view of Charon, Pluto from New Horizons

Dynamic Duo July 10, 2015

Artist's concept of New Horizons passing by Pluto

First Encounter July 9, 2015

New Horizons view of Pluto and Charon, July 1, 2015

Best Shot July 7, 2015

Three dwarf planets shown to scale with Earth and Moon

Dwarf Planets January 5, 2015

Radio Programs

Getting Moons Many ways to acquire moons September 23, 2020

Land of Explorers A land fit for exploration April 29, 2020