Kuiper belt dwarf planet
Pluto
The best-known dwarf planet, a world of nitrogen glaciers, water-ice mountains and blue haze revealed by New Horizons in 2015.
- Distance from Earth today
- 5.35 billion km35.73 AU · light: 4 h 57 min
- Distance from the Sun today
- 5.33 billion km35.64 AU
- As of
- 2 November 2026Live distance and chart →
Where it is today
Top view of the plane of Earth’s orbit, compressed distance scale. Open on the big map with the time slider →
Facts
- Diameter
- 2,376 km
- Mass
- 0.0130 × 10²⁴ kg
- Density
- 1,850 kg/m³
- Surface gravity
- 0.7 m/s²
- Escape velocity
- 1.3 km/s
- Rotation period
- 6.4 days (retrograde)
- Length of day
- 6.4 days
- Mean distance from the Sun
- 5.91 billion km (39.48 AU)
- Perihelion
- 4.44 billion km
- Aphelion
- 7.38 billion km
- Orbital period
- 247.9 years
- Mean orbital velocity
- 4.7 km/s
- Orbital eccentricity
- 0.249
- Orbital inclination
- 17.4°
- Axial tilt
- 119.5°
- Mean temperature
- -225 °C
- Surface pressure
- 0.000010 bar
- Known moons
- 5
- Rings
- no
- Global magnetic field
- unknown
Source of the figures: NASA Planetary Fact Sheet, JPL Small-Body Database (public domain).
Discovery: 1930 – Clyde Tombaugh
Description
Pluto was discovered by Clyde Tombaugh at Lowell Observatory in 1930 and was considered the ninth planet until 2006, when it was reclassified as a dwarf planet. It is one of the largest bodies of the Kuiper belt and shares a mutual dance with its big moon Charon. When New Horizons flew past in July 2015, it found a surprisingly active world: the heart-shaped Tombaugh Regio, whose western half is a vast plain of slowly churning nitrogen ice called Sputnik Planitia, mountains of water ice, and a thin atmosphere layered with bluish haze. Pluto has five known moons.
Moons
We describe 3 of the 5 known moons (count from the NASA Planetary Fact Sheet) – the largest and most interesting.