Pluto
Data as of July 2026
2,377 kmacross: smaller than the Moon
Pluto is 2,377 km across, smaller than Earth’s Moon, and orbits the Sun at an average of 39.48 AU (about 5,906,123,908 km), swinging between 29.7 and 49.3 AU on a stretched, tilted orbit. Sunlight takes about 5.5 hours to reach it. Discovered in 1930, it was the ninth planet until it was reclassified as a dwarf planet in 2006.
▶ Visit Pluto in 3D
What kind of world is it?
Pluto is the best known of the dwarf planets: a small, cold world of rock and ice out in the Kuiper Belt, the ring of frozen bodies beyond Neptune. For a long time it was just a faint dot, but in 14 July 2015 NASA’s New Horizons spacecraft flew past and revealed a startlingly complex place: nitrogen-ice glaciers, mountains of frozen water, a thin haze-layered atmosphere, and a vast pale plain shaped like a heart. Its largest moon, Charon, is over half Pluto’s size, so the two orbit a point in the empty space between them, more a double world than a planet and its moon.
undefined
Pluto by the numbers
Diameter
2,377 km
Average distance from Sun
39.48 AU
Closest / farthest
29.7 – 49.3 AU
Sunlight travel time
≈ 5.5 hours
Mass vs Earth
about 0.2%
Surface gravity
0.62 m/s²
Temperature
−229 °C
A day lasts
6.4 Earth days
A year lasts
248 Earth years
Known moons
5 (Charon is the largest)
Pluto is so small that seven moons in the solar system are bigger than it: Ganymede, Titan, Callisto, Io, our own Moon, Europa and Neptune’s Triton. By width, Earth is about 5.4× larger.
See it for yourself: in the interactive view Pluto sits far beyond Neptune on its tilted, stretched orbit. Switch to 1:1 scale and it becomes an all-but-invisible speck, 5.5 light-hours from the Sun.
Keep going
✓ Facts verified July 2026
Every figure on this page is a real, rounded value checked against primary sources. Found something out of date? See how we keep it accurate.