Stephano, a moon of Uranus
4,973,445 miles
20 miles
Stephano is one of Uranus’s outer irregular moons and follows a retrograde orbit, meaning it travels in the opposite direction to Uranus’s rotation. With an estimated diameter of just 32 kilometres (20 miles), it is a small, faint satellite that was only discovered relatively recently.
Stephano was first spotted in 1999 by a team of astronomers led by Brett J. Gladman, using images captured by the 8.2-metre Subaru Telescope at Mauna Kea Observatory, Hawaii. Its great distance from Uranus, combined with its tiny size, makes it one of the more difficult Uranian moons to observe.
Like other irregular moons, Stephano is thought to be a captured object, possibly originating from the Kuiper Belt or the outer Solar System before Uranus’s gravity trapped it. Its orbit is inclined and elongated, adding to the evidence of a capture origin rather than formation alongside the regular moons.
Stephano is named after the comical, drunken butler in William Shakespeare’s The Tempest. In the play, Stephano washes ashore after a shipwreck, carrying a bottle of wine. He encounters Caliban and, along with the jester Trinculo, conspires to overthrow Prospero and take control of the island. His plot ultimately fails, but he remains a memorable source of comic relief in the story.
The naming continues Uranus’s tradition of using characters from many of Shakespeare's plays for its moons, and especially The Tempest for its outer irregular satellites.
