Titania
Titania ("ti TAY nee uh") is the fourteenth and largest of Uranus's known satellites:
orbit: 436,270 km from Uranus
diameter: 1578 km
mass: 3.49e21 kg
Titania is the Queen of the Fairies and wife of Oberon in Shakespeare's Midsummer-Night's Dream.
Discovered by Herschel in 1787.
Titania and Ariel appear quite similar though Ariel is 25% smaller. All of Uranus' large moons are a mixture of about 40-50% water ice with the rest rock, a somewhat larger fraction of rock than Saturn's large moons such as Rhea.
Titania's surface is a mixture of cratered terrain and systems of
interconnected
valleys hundreds of kilometers long. Some of the craters appear to
be half-submerged.
Titania's surface is clearly relatively young
(though older
than some such as Enceladus); obviously some sort
of resurfacing processes have been at work.
One theory of Titania's history is that it was once hot enough to be liquid. The surface probably cooled first; when the interior froze it expanded forcing the surface to crack and resulting in the valleys that we see today.