Caliban is a moon of Uranus, part of the Solar System in the universe. Uranus is a planet associated with the Sun, our star, and this space encyclopedia describes the moon’s identity and place in its planetary system.

Caliban — A natural satellite of Uranus. Its physical properties and orbital motion are shown from the available catalogue and ephemeris data.

No object-specific chemical/elemental dataset has been verified and imported for this record. This does not mean none is publicly available. Appearance may be imagined; chemistry is not.

Discovery and designation
Caliban was discovered in 1997. JPL credits B.J. Gladman, P.D. Nicholson, J.A. Burns, J.J. Kavelaars. Its provisional designation is S/1997 U1. The name and discovery entry identify this particular satellite of Uranus; similarly named asteroids are separate objects.

Caliban was discovered on Sept. 6, 1997 at Palomar Observatory by B. Gladman, P. Nicholson, J. A. Burns, and J. Kavelaars. This group of astronomers also discovered another Uranian moon at the same time, which was named Sycorax after the mother of Caliban in William Shakespeare's play The Tempest.

Caliban orbits Uranus in the opposite direction from the regular moons and the rotation of the planet itself (called a retrograde orbit). Its orbit is also somewhat inclined and eccentric, and very far from the planet―more than 10 times farther than Oberon, the farthest regular moon. These characteristics suggest that Caliban was an independent body that was captured by Uranus' gravity. It is thought to be about 72 km in diameter, and to be the second largest irregular satellite of Uranus (about half the size of Sycorax). The size estimate is based on the brightness of the moon and an assumed albedo of 0.04, typical of captured asteroids in the outer solar system.

Originally called S/1997 U1, Caliban was named for a character in Shakespeare's play, "The Tempest." Caliban was forced into labor on an island owned by Prospero. He was human, but "not honour'd with a human shape," and is referred to as a mooncalf or freckled monster.