Titania

What is Titania?

Moons· Diameter 1,578 km. The largest moon of Uranus, named for Shakespeare's fairy queen — an icy world cut by a 1,500-km canyon that may still hold a thin internal ocean. Watch the moons circle the tipped-over planet in the orbit view.

The orbit of Titania at this moment: https://nowsky.org/solar/orbit?fw=moon:uranus:titania&sp=0.01 — replayed live, no login.

Orbit and size

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

Parent planet and sibling moons

Frequently asked

How big is Titania?

1,578 km.

How far is Titania from Earth?

436,300 km.

What is notable about Titania?

1,500-km Messina Chasma.

Which planet does Titania orbit?

Uranus.

The carbon-dioxide frost on Titania

In 2001 ground-based infrared observations detected carbon-dioxide ice on Titania's surface — a first among the Uranian moons, shared with Ariel, and later confirmed on Umbriel and Oberon. The carbon dioxide is concentrated on the trailing hemisphere rather than the leading one, which is read as the product of particles carried by Uranus's magnetic field striking the surface ice.

With surface gravity 3.7 percent of Earth's, the carbon dioxide sublimates by day and resettles on the night side or in the cold of the poles. Because Uranus's seasons last 42 years, this frost is calculated to migrate between hemispheres over decades. In 2023 the Webb telescope re-observed the surfaces of four Uranian moons, and on Titania and Oberon traces of carbon monoxide were reported alongside the carbon dioxide.

The moon in depth

Titania was discovered by William Herschel in 1787, together with Oberon. At 1,578 km across it is the largest moon of Uranus and the eighth-largest in the solar system, orbiting 436,300 km from the planet every 8.71 days. Uniquely, the Uranian moons are named not from mythology but from Shakespeare and Pope; Titania is the fairy queen of A Midsummer Night's Dream.

Voyager 2's 1986 flyby, the only close look so far, revealed craters alongside enormous fault canyons. The longest, Messina Chasma, runs 1,500 km and spans 50 km in width — scars from water freezing and expanding inside, splitting the crust. Ground-based spectra in 2001 detected carbon dioxide frost, and recent models suggest a thin ocean may still survive beneath the ice.

Follow Uranus in the orbit view and you will see its moons circling in a plane tilted nearly upright, following the planet's 98-degree axial tilt. Titania sits outside Miranda, Ariel and Umbriel and inside Oberon. NASA's proposed Uranus orbiter, a top priority for the 2030s, would deliver the first new images in four decades.

Related

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