Perdita (moon)

Perdita Template:IPAc-en is an inner satellite of Uranus. Perdita's discovery was very complicated, as the first photographs of Perdita were taken by the Voyager 2 spacecraft in 1986, but it was not recognized from the photographs for more than a decade. In 1999, the moon was noticed by Erich Karkoschka and reported.Template:SfnTemplate:Sfn But because no further pictures could be taken to confirm its existence, it was officially demoted in 2001.Template:Sfn However, in 2003, pictures taken by the Hubble Space Telescope managed to pick up an object where Perdita was supposed to be, finally confirming its existence.Template:SfnTemplate:Sfn

Following its discovery in 1999, it was given the temporary designation of S/1986 U 10.Template:Sfn It was named Perdita (Latin for 'lost') after the daughter of Leontes and Hermione in William Shakespeare's play The Winter's Tale. The moon is also designated Uranus XXV.Template:Sfn

File:Uranus' Satellite 1986 U10 Discovery Image.jpg

Discovery image of Perdita taken by Voyager 2 on 23 January 1986. The location of the moon is indicated by the arrow on the upper right.

The moon orbits between Belinda and Puck. The above-mentioned Hubble measurements prove that Perdita does not follow a direct Keplerian motion around Uranus. Instead, it is clearly caught in a 43:44 orbital resonance with the nearby moon Belinda, and from this resonance it has been determined that Belinda's mass is 26 or 27Template:Sfn times that of Perdita. It is also close to an 8:7 resonance with Rosalind.Template:SfnTemplate:Sfn

Perdita belongs to the Portia group of satellites, which also includes Bianca, Cressida, Desdemona, Portia, Juliet, Cupid, Rosalind, and Belinda.Template:Sfn These satellites have similar orbits and photometric properties.Template:Sfn Little is known about Perdita apart from its orbit,Template:SfnTemplate:Sfn radius of 13.3 km,Template:Refn and geometric albedo of 0.08.Template:SfnTemplate:Sfn

See also

• Moons of Uranus

External links

• Uranus 'Loses' a Moon: The 'New' Official Moon Count of the Solar System (Archived), Melanie Melton, The Planetary Society, 20 December 2001