List of natural satellites
Uranus has 27 named moons, five of which are massive enough to have achieved hydrostatic equilibrium. There are another 13 inner moons that orbit within Uranus's ring system, and another nine outer irregular moons. Unlike most planetary moons, which are named from antiquity, all the moons of Uranus are named after characters from the works of Shakespeare and Alexander Pope's work "The Rape of the Lock".
Exploration of Uranus
"Voyager 2" made its closest approach to Uranus on January 24, 1986, coming within of the planet's cloud tops. This was the probe's first solo planetary flyby, since "Voyager 1" ended its tour of the outer planets at Saturn's moon Titan.
Uranus is the third-largest planet in the Solar System. It orbits the Sun at a distance of about and completes one orbit every 84 years. The length of a day on Uranus as measured by "Voyager 2" is 17 hours and 14 minutes. Uranus is distinguished by the fact that it is tipped on its side. Its unusual position is thought to be the result of a collision with a planet-sized body early in the Solar System's history. Given its odd orientation, with its polar regions exposed to sunlight or darkness for long periods and "Voyager 2" set to arrive around the time of Uranus's solstice, scientists were not sure what to expect at Uranus.