Prospero, a moon of Uranus
10,100,991 miles
31 miles
Prospero is one of Uranus’s outer irregular moons and follows a retrograde orbit, travelling in the opposite direction to the planet’s rotation. With an estimated diameter of around 50 kilometres (31 miles), Prospero is relatively small and faint.
The moon was discovered in 1999 by Matthew J. Holman, John J. Kavelaars, Dan Milisavljevic, and Brett J. Gladman using the Canada-France-Hawaii Telescope at Mauna Kea Observatory, Hawaii. Its large, tilted, and elongated orbit is typical of irregular moons that are thought to have been captured rather than formed alongside their parent planet.
Prospero’s capture origin story suggests it may be related to other distant retrograde moons of Uranus, possibly fragments from a larger object that broke apart after being captured by the planet’s gravity.
Prospero is named after the central character in William Shakespeare’s The Tempest. Once the Duke of Milan, Prospero was betrayed by his brother and cast adrift with his daughter, Miranda. They landed on an isolated island, where Prospero became a powerful sorcerer. Using his magic, and the help of the spirit Ariel, Prospero conjures the storm that begins the play, setting in motion the events that lead to reconciliation and his eventual return to Milan.
The naming of Prospero continues Uranus’s tradition of choosing characters from Shakespeare and Alexander Pope. In this case, Prospero joins Miranda, Ariel, Caliban, Setebos, Sycorax, Stephano, and Trinculo as part of The Tempest's celestial cast.
