Titania (moon)

A round spherical body is almost fully illuminated. The surface has a mottled appearance with bright patches among relatively dark terrain. The terminator is located near the right edge. A large crater can be seen at the terminator in the upper half of the image. Another bright crater can be seen at the bottom. A large canyon runs from the darkness at the lower-right side to visible center of the body.
Voyager 2 image of Titania's southern hemisphere[caption 1]
Discovered byWilliam Herschel
Discovery dateJanuary 11, 1787[1]
Uranus III
Orbital characteristics
435910 km[3]
8.706234 d[3]
3.64 km/s[b]
Inclination0.340° (to Uranus's equator)[3]
Satellite ofUranus
Physical characteristics
Mean radius
788.4±0.6 km (0.1235 Earths)[4]
7820000 km2[c]
Volume2065000000 km3[d]
Mass(3.527±0.09)×1021 kg (5.908×10−4 Earths)[5]
Mean density
1.711±0.005 g/cm³[4]
0.379 m/s²[e]
0.773 km/s[f]
presumed synchronous[6]
  • 0.35 (geometrical)
  • 0.17 (Bond)[7]
Surface temp.minmeanmax
solstice[4]60 K70 ± 7 K89 K
Surface pressure
<1–2 mPa (10–20 nbar)
Composition by volume

Titania is the largest of the moons of Uranus and the eighth largest moon in the Solar System at a diameter of 1,578 kilometres (981 mi). Discovered by William Herschel in 1787, Titania is named after the queen of the fairies in Shakespeare's A Midsummer Night's Dream. Its orbit lies inside Uranus's magnetosphere.

Titania consists of approximately equal amounts of ice and rock, and is probably differentiated into a rocky core and an icy mantle. A layer of liquid water may be present at the core–mantle boundary. The surface of Titania, which is relatively dark and slightly red in color, appears to have been shaped by both impacts and endogenic processes. It is covered with numerous impact craters reaching up to 326 kilometres (203 mi) in diameter, but is less heavily cratered than Oberon, outermost of the five large moons of Uranus. Titania probably underwent an early endogenic resurfacing event which obliterated its older, heavily cratered surface. Titania's surface is cut by a system of enormous canyons and scarps, the result of the expansion of its interior during the later stages of its evolution. Like all major moons of Uranus, Titania probably formed from an accretion disk which surrounded the planet just after its formation.

Infrared spectroscopy conducted from 2001 to 2005 revealed the presence of water ice as well as frozen carbon dioxide on the surface of Titania, which in turn suggested that the moon may have a tenuous carbon dioxide atmosphere with a surface pressure of about 10 nanopascals (10−13 bar). Measurements during Titania's occultation of a star put an upper limit on the surface pressure of any possible atmosphere at 1–2 mPa (10–20 nbar).

The Uranian system has been studied up close only once, by the spacecraft Voyager 2 in January 1986. It took several images of Titania, which allowed mapping of about 40% of its surface.


Titania was discovered by William Herschel on January 11, 1787, the same day he discovered Uranus's second largest moon, Oberon.[1][9] He later reported the discoveries of four more satellites,[10] although they were subsequently revealed as spurious.[11] For nearly fifty years following their discovery, Titania and Oberon would not be observed by any instrument other than William Herschel's,[12] although the moon can be seen from Earth with a present-day high-end amateur telescope.[8]

Size comparison of Earth, the Moon, and Titania.

All of Uranus's moons are named after characters created by William Shakespeare or Alexander Pope. The name Titania was taken from the Queen of the Fairies in A Midsummer Night's Dream.[13] The names of all four satellites of Uranus then known were suggested by Herschel's son John in 1852, at the request of William Lassell,[14] who had discovered the other two moons, Ariel and Umbriel, the year before.[15]

Titania was initially referred to as "the first satellite of Uranus", and in 1848 was given the designation Uranus I by William Lassell,[16] although he sometimes used William Herschel's numbering (where Titania and Oberon are II and IV).[17] In 1851 Lassell eventually numbered all four known satellites in order of their distance from the planet by Roman numerals, and since then Titania has been designated Uranus III.[18]

Shakespeare's character's name is pronounced ə/, but the moon is often pronounced ə/, by analogy with the familiar chemical element titanium.[2] The adjectival form, Titanian, is homonymous with that of Saturn's moon Titan. The name Titania is ancient Greek in origin, meaning "Daughter of the Titans".

Other Languages
Afrikaans: Titania (maan)
Alemannisch: Titania (Mond)
العربية: تيتانيا (قمر)
Bân-lâm-gú: Titania (oē-chheⁿ)
беларуская (тарашкевіца)‎: Тытанія (спадарожнік Урана)
corsu: Titania
eesti: Titania
Esperanto: Titanjo (luno)
euskara: Titania
français: Titania (lune)
Bahasa Indonesia: Titania (satelit)
interlingua: Titania (luna)
коми: Титания
Kreyòl ayisyen: Titanya
latviešu: Titānija
മലയാളം: ടൈറ്റാനിയ
Bahasa Melayu: Titania (bulan)
Mìng-dĕ̤ng-ngṳ̄: Titania (ôi-sĭng)
Nederlands: Titania (maan)
norsk: Titania
norsk nynorsk: Uranusmånen Titania
occitan: Titània
Plattdüütsch: Titania (Maand)
sicilianu: Titania
Simple English: Titania (moon)
slovenčina: Titánia (mesiac)
slovenščina: Titanija (luna)
српски / srpski: Титанија (сателит)
suomi: Titania
svenska: Titania
Türkçe: Titania (uydu)
українська: Титанія (супутник)
اردو: ٹیٹانیہ
Tiếng Việt: Titania (vệ tinh)
文言: 天衛三
粵語: 天衛三
中文: 天卫三