Uranus

Uranus spins on its side — its poles face the Sun! It is an ice giant about 4 Earths wide.

What it is

Ice giant tipped completely on its side, pale blue-green from methane.

Planet: Round, orbits a star, and has swept its orbit clear. Every kind of thing there is →

How to find Uranus

What you will really see

Worth knowing about Uranus

Uranus is 4 Earths could line up across it. In weight, about 14.5 Earths' worth. 20 times Earth's distance from the Sun. Sunlight takes 2.7 hours to reach Uranus — on average, because that distance changes as it goes round. Its year: longer than most people's whole lifetime. Its day: ~17.2 hours, retrograde.

What it is made of

Ice giant: water, ammonia, and methane ices around a rocky core.

Its weather

Methane gives it a pale blue-green color; it's tipped completely on its side, so it rolls around the Sun like a ball.

Its rings

Uranus has narrow dark rings -- and they were found without anyone seeing them, when the planet passed in front of a star and the star blinked before it arrived and again after it left.

The machines we sent

Voyager 2 flew by in 1986 -- still the only visit ever.

The numbers

Across	50 724 km
Distance from the Sun, on average	19 AU ~2.9 billion km · sunlight takes 2.7 hours
Once round its orbit	84.0 Earth years
One day there	-17.2 hours
Temperature	-195 °C (from -224 to -153)
Made of, among other things	methane, water, ammonia

How anyone knows this

Nobody flew a tape measure out there. Every number on this page was worked out from the ground:

• What shape is the solar system?
• How far away is the Sun?

What it belongs to

Then go outside

Clear tonight? The Planetarium will show you what is worth a look. Then just go out.