Uranus

What is Uranus?

Planets· Diameter 50,724 km. An ice giant rolling on its side — each pole gets 42 years of daylight, then 42 of night. Voyager 2 remains its only visitor (1986).

Where Uranus is in your sky right now: https://nowsky.org/solar/sky?sel=uranus — location and time set automatically, no login.

Orbit and size

Figures are representative approximations. Source: compiled from NASA and IAU public data.

Moons of Uranus

Frequently asked

How big is Uranus?

50,724 km.

How far is Uranus from Earth?

19.2 AU.

What are the main moons of Uranus?

Titania, Oberon, Miranda, Ariel, Umbriel.

Where is Uranus in the sky right now?

Open the sky view for your location and time and it shows the position in the sky right now.

How "George's Star" became Uranus

In 1781 Herschel named the new planet "Georgium Sidus", George's Star, after his patron George III. Outside Britain the name never took; the French called it "Herschel". Germany's Bode proposed following the mythological lineage — Saturn is Jupiter's father, so Saturn's father Uranus should come next — and that name was adopted by the British Nautical Almanac only in 1850, seventy years later.

Uranus is the only planet whose mythological name is Greek rather than Roman (the Roman form would be Caelus). It had been seen many times before its discovery: Flamsteed catalogued it in 1690 as the star 34 Tauri, and Le Monnier recorded it a dozen times between 1750 and 1769 without realising it was a planet. At magnitude 5.7 it sits at the naked-eye limit, visible under dark skies, but it moves too slowly to be taken for anything but a star.

The planet in depth

Uranus rolls around the Sun on its side — its axis tipped 98 degrees, almost certainly by a giant impact during formation. The poles therefore trade 42 years of daylight for 42 years of night: the strangest seasons in the solar system.

Found by Herschel in 1781, it was the first planet discovered by telescope; Voyager 2's 1986 flyby remains its only visit, which is why we know it so poorly. Recent JWST infrared images showing its rings crisp and bright have re-energized the case for a dedicated Uranus orbiter.

Methane absorbs red light, giving the teal hue. Check its rings and reclined axis in the orbit view.

Uranus's moons form a literary family, named from Shakespeare and Pope — Miranda, Titania, Oberon, Ariel. Miranda sports Verona Rupes, a 20-km cliff where the gravity is so weak a jumper would fall for over ten minutes. The Uranus orbiter proposed for the 2030s would give this family its first long, careful look.

Related

Figures are representative approximations. Simulated positions use J2000 mean elements.