Cosmic Scale
Uranus
Ice giant · 2.9 billion km from the Sun
How big is Uranus?
Uranus is about 50,720 km across.
See Uranus in 3D, at true scale
Uranus was the first planet discovered with a telescope, and it is tipped over: its axis lies almost in the plane of its orbit, so it rolls around the Sun on its side. Each pole gets 42 years of sunlight followed by 42 years of darkness.
At a glance
| Diameter | 50,720 km |
|---|---|
| Mass | 8.68 × 10²⁵ kg |
| Diameter compared with Earth | 3.98 × Earth |
| Year | 84 years |
| Day | 17 hours, backwards |
| Axis tilt | 98 degrees |
| Moons | 28 known |
Good to know
- Its atmosphere is the coldest in the Solar System, reaching −224 °C.
- Its moons are named after characters from Shakespeare and Alexander Pope, not mythology.
- The tilt was probably caused by one or more giant impacts early in its life.