Uranus
Ice giant · The tilted ice giant · William Herschel, 1781 — the first planet found with a telescope
An icy world of water, methane and ammonia, Uranus is tipped almost completely on its side, so it appears to roll along its orbit.
Key facts
Time & motion
Mass & physical characteristics
Atmosphere & magnetosphere
Atmosphere
About 83% hydrogen, 15% helium and 2% methane. Methane absorbs red light, giving Uranus its pale cyan colour.
Magnetic field
A lopsided field, tilted 59° from the axis and offset from the planet's centre.
Moons & rings
Rings
Thirteen narrow, dark rings of rocky and icy debris — faint and hard to see.
Make-up
Composition
Water, methane and ammonia ices over a small rocky core; methane tints it blue-green.
Notable features
- Miranda — a moon of chasms and cliffs more than 10 km high.
Fun facts
- Uranus's extreme tilt gives each pole roughly 42 years of continuous sunlight, then 42 of darkness.
- It rotates almost on its side, as if rolling along its orbit.
- Uranus was the first planet discovered with a telescope, by William Herschel in 1781.
- Methane in its air absorbs red light, giving the planet its cyan colour.
- Its magnetic field is tilted 59° from its axis and offset from the planet's centre.
Exploration
Voyager 2
1986
The only spacecraft to visit — found 10 new moons.
James Webb Telescope
2023–
Imaged its rings and auroras from afar.