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Uranus' Moons
Overview Uranus has 27 known moons. Titania, the largest, is about half the size of our own moon. The moons are all made of ice and rock. Most of the moons, including Titania, Oberon, and Umbriel, seem to be "normal" moons without anything interesting; however, Miranda and Ariel seem to have had violent pasts (see below). Most of the moons appear to be captured asteroids due to their size and orbits. Descriptions The two innermost moons of Uranus, Cordelia and Ophelia, act as shepherd moons. They have orbits on either side of the last ring, Epsilon, which keeps it narrow. Scientists believe that each of the other rings have shepherds, too, but they must have been too small for the Voyager 2's cameras to detect or for Earth-bound detection. The next eight moons are Bianca, Cressida, Desdemona, Juliet, Portia, Rosalind, Belinda, and Puck, all named for Shakespearian characters. Inside of Belinda's orbit is a moon designated as S/1986 U10. It has not been named because there is controversy over whether or not it really exists; the International Astronomical Union (IAU), the only official naming body, has yet to designate it as a real moon. Next out is Miranda. It is the smallest of Uranus' moons
that is visible from the Earth. It has some
of the most interesting surface features in the solar system: First,
it has a cliff that is about 19 km (12 miles) high. If this were scaled
to be on Earth, it would reach into the orbit of spacecraft. It also
has three long, rectangular shapes, called "coronae." Scientists
think that at one time the pull of the other moons warmed the interior
and caused the ice in Miranda to start to rise. The coronae mark where
it froze before coming to the surface. Ariel (right), next, is covered with complex fractures and grooves. Probably they are the result of ice seeping to the surface, then freezing and expanding. Ariel also has lava-filled valleys. The lava is made of a mixture of water and liquid ammonia Next comes Umbriel, equal in size to Ariel, but with a bland, nondescript surface.
The next moons, Caliban, Stephano, Sycorax, Prospero, and Setebos were discovered in just the past few years by re-examining Voyager 2 images. Very little is known about them, except that they all have retrograde - they orbit in the opposite direction of the planet's spin - orbits, leading to the conclusion that they are captured asteroids rather than native to the Uranian system. Inside of Sycorax's orbit is a moon designated as Trinculo, which also has retrograde motion. Data for Uranus' Moons
*This indicates that the moon orbits in a retrograde - the opposite direction to the planet's spin - motion. 
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out is Titania (left) and Oberon (right). Titania is the biggest moon
of Uranus. It looks like a larger version of Ariel. Oberon is only a
little smaller than Titania. Oberon has a crater-peppered surface of
little interest. However, it does posses a mountain that is twice the
height of Mt. Everest.