Pluto

Pluto

Dwarf planet · 39.48 AU from the Sun

Pluto facts

Type
Dwarf planet
Distance from the Sun
39.48 AU (5.91 × 10⁹ km)
Orbital period (year)
248 Earth years
Diameter
2,377 km
Mass
1.3 × 10²² kg
Moons
5
Rotation period (day)
6.4 Earth days (retrograde)
Axial tilt
122.5°
Mean temperature
-229 °C
Discovered
1930, by Clyde Tombaugh

Orbit

Compressed scale; positions shown for 2026. Position is approximate.

About Pluto

Pluto is a dwarf planet in the Kuiper Belt beyond Neptune, and was counted as the ninth planet until 2006. Its eccentric, tilted orbit sometimes brings it closer to the Sun than Neptune. Its largest moon, Charon, is so big the two orbit a point between them.

Pluto: frequently asked questions

What is Pluto?
Pluto is a dwarf planet in our Solar System, orbiting the Sun at an average distance of 39.48 AU (5.91 × 10⁹ km). Pluto is a dwarf planet in the Kuiper Belt beyond Neptune, and was counted as the ninth planet until 2006.
How far is Pluto from the Sun?
Pluto orbits the Sun at an average distance of 39.48 AU, about 5.91 × 10⁹ km. One AU is the Earth-Sun distance, so Pluto is roughly 39.5 times Earth's distance from the Sun.
How long is a year on Pluto?
Pluto takes 248 Earth years to complete one orbit of the Sun, which is one Pluto year. By Kepler's third law, bodies farther from the Sun take longer to go around.
How many moons does Pluto have?
Pluto has 5 known moons.
How big is Pluto?
Pluto has a diameter of about 2,377 km and a mass of roughly 1.3 × 10²² kg.
Why is Pluto a dwarf planet and not a planet?
Pluto orbits the Sun and is round, but it has not cleared its orbital neighbourhood of other objects, the third rule the International Astronomical Union set in 2006. Bodies that meet the first two rules but not the third are called dwarf planets.

See Pluto in motion

Open the interactive Solar System orrery →

Data from NASA/JPL and NSSDCA. Source.