Prospero is a relatively small retrograde

Retrograde motion

Retrograde motion is motion in the direction opposite to the movement of something else, and is the contrary of direct or prograde motion. This motion can be the orbit of one body about another body or about some other point, or the rotation of a single body about its axis, or other phenomena such...

 irregular satellite

Irregular satellite

In astronomy, an irregular moon is a natural satellite following a distant, inclined, and often eccentric and retrograde orbit. They are believed to have been captured by their parent planet, unlike regular satellites, which form in situ....

 of Uranus

Uranus

Uranus is the seventh planet from the Sun. It has the third-largest planetary radius and fourth-largest planetary mass in the Solar System. It is named after the ancient Greek deity of the sky Uranus , the father of Cronus and grandfather of Zeus...

 discovered on 18 July 1999 by the astrophysicist Matthew Holman and his team, and given the provisional designation S/1999 U 3. Confirmed as Uranus XVIII it was named after the sorcerer Prospero

Prospero

Prospero is the protagonist in The Tempest, a play by William Shakespeare.- The Tempest :Prospero is the rightful Duke of Milan, who was put to sea on "a rotten carcass of a butt [boat]" to die by his usurping brother, Antonio, twelve years before the play begins. Prospero and Miranda survived,...

 in William Shakespeare

William Shakespeare

William Shakespeare was an English poet and playwright, widely regarded as the greatest writer in the English language and the world's pre-eminent dramatist. He is often called England's national poet and the "Bard of Avon"...

's play The Tempest.

The orbital parameters suggest that it may belong to the same dynamic cluster as Sycorax

Sycorax (moon)

Sycorax is the largest retrograde irregular satellite of Uranus. Sycorax was discovered on 6 September 1997 by Brett J. Gladman, Philip D. Nicholson, Joseph A. Burns, and John J...

 and Setebos

Setebos (moon)

Setebos is one of the outermost retrograde irregular satellites of Uranus. It was discovered on 18 July 1999 by John J. Kavelaars et al. and provisionally designated S/1999 U 1....

, suggesting common origin. However, this suggestion does not appear to be supported by the observed colours. The satellite appears neutral (grey) in visible light (colour indices

Color index

In astronomy, the color index is a simple numerical expression that determines the color of an object, which in the case of a star gives its temperature...

 B-V=0.80, R-V=0.39), similar to Setebos but different from Sycorax (which is light red).

External links

• Prospero Profile by NASA's Solar System Exploration
• David Jewitt pages
• Uranus' Known Satellites (by Scott S. Sheppard
  Scott S. Sheppard
  Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and...
  
  )
• MPC: Natural Satellites Ephemeris Service