Sycorax, a moon of Uranus
7,567,665 miles
93 miles
Sycorax is the largest of Uranus’s irregular moons and follows a retrograde orbit, travelling opposite to the planet’s spin. With an estimated diameter of around 150 kilometres (93 miles), it is much larger than most of Uranus’s other distant satellites.
Sycorax was discovered in September 1997 by Brett J. Gladman, Philip D. Nicholson, Joseph A. Burns, and John J. Kavelaars using the 200-inch Hale Telescope at Palomar Observatory, California. Its size and brightness make it the most prominent of Uranus’s irregular moons, though it is still extremely faint compared to the planet’s larger regular satellites.
Its retrograde, elongated orbit suggests that Sycorax did not form in place around Uranus but was captured, likely from the Kuiper Belt or as an icy body wandering in the outer Solar System. Some astronomers believe it may be related in origin to other distant moons of Uranus such as Caliban and Stephano, possibly captured during the same event.
Sycorax is named after a character in Shakespeare’s The Tempest. In the play, she is the unseen but influential mother of Caliban and the original ruler of the island where the story takes place. Banished from her homeland while pregnant, she arrived on the island and used her magical powers to enslave spirits, including Ariel. She died before the events of the play, but her legacy shapes much of the story’s background.
The naming continues Uranus’s tradition of drawing from the works of William Shakespeare for many of its moons, and in particular The Tempest for lots of its most distant moons. Sycorax joins her “son” Caliban and her former captive Ariel in orbit around the planet.
