Depth 10 · Ice giant

Uranus

Uranus is the seventh planet from the Sun, an ice giant whose interior is mostly a hot, dense fluid of water, methane and ammonia. It spins tipped almost completely on its side, which gives it the most extreme seasons of any planet.

Fact sheet

Type

Ice giant planet

Distance

About 2.9 billion km (1.8 billion miles), or about 19 AU, from the Sun on average

Size

Equatorial diameter about 51,118 km (31,763 miles), about four times as wide as Earth

Discovered

Discovered 13 March 1781 by William Herschel

On the voyage

Depth 10, in the Outer Sol section of the route, between Titan and Neptune

Things to know

• Uranus's axis is tilted about 97.8 degrees, so it rolls around the Sun on its side and each pole spends about 21 years in darkness during its winter. NASA
• A year on Uranus lasts about 84 Earth years, while one rotation takes about 17 hours, and it spins in the opposite direction to most planets. NASA
• Parts of its atmosphere drop to about 49 K (-224°C), making them colder than Neptune even though Neptune is farther from the Sun. NASA
• William Herschel spotted Uranus on 13 March 1781; he first took it for a comet or a star. NASA
• During its 1986 flyby, Voyager 2 found 10 new moons and two new rings, and passed about 81,500 km (50,640 miles) from the planet. NASA

Missions

Voyager 2 is the only spacecraft to have visited Uranus, flying past on 24 January 1986.

Sources

• NASA – Uranus Facts
• NSSDC – Uranus Fact Sheet
• NASA – Voyager 2