Dwarf planet
Pluto
A tilted dwarf planet dancing in a 3:2 rhythm with Neptune.
Pluto follows a tilted, oval orbit that takes 248 years and sometimes brings it closer to the Sun than Neptune. A 3:2 resonance (two Pluto orbits for every three of Neptune) keeps the two from ever colliding. Pluto spins backward on a steeply tilted axis, and it and Charon are locked face to face.
How it moves
- Pluto orbits the Sun every 90,560 days (about 248 years).
- Its orbit is both eccentric (0.2444) and inclined 17.16 degrees, ranging from about 30 to 49.3 AU from the Sun.
- From 1979 to 1999 Pluto was closer to the Sun than Neptune.
- Pluto makes two orbits for every three of Neptune, so the two never come close.
- It rotates retrograde once every 153.3 hours, matching Charon's orbit, so Pluto and Charon always show each other the same face.
Facts
- Mean radius
- 1,188 km
- Mass
- 1.303e+22 kg
- Surface gravity
- 0.62 m/s²
- Rotation period
- 153.2928 hours
- Orbital period
- 90,560 days
- Average distance from the Sun
- 39.48168677 AU
- Eccentricity
- 0.2444
- Axial tilt
- 119.51°
- Mean orbital speed
- 4.64 km/s
- Known moons
- 5
- Discovered
- 1930, by Clyde W. Tombaugh at Lowell Observatory
From 1979 to 1999, Pluto was closer to the Sun than Neptune was.
Sources: nssdc.gsfc.nasa.gov, science.nasa.gov, science.nasa.gov