Perdita (moon)
Encyclopedia
Perdita is an inner satellite
of Uranus
. Perdita's discovery was complicated. 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. But because no further pictures could be taken to confirm its existence, it was officially demoted in 2001. 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.
Following its discovery in 1999, it was given the temporary designation of S/1986 U 10. 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.
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
. It is also close to an 8:7 resonance with Rosalind
.
Perdita belongs to Portia Group of satellites, which also includes Bianca
, Cressida
, Desdemona
, Portia
, Juliet
, Cupid
, Rosalind
and Belinda
. These satellites have similar orbits and photometric properties. Little is known about Perdita apart from its orbit, radius of 15 km and geometric albedo of 0.08.
Inner satellite
In astronomy, an inner moon is a natural satellite following a prograde, low inclination orbit inwards of the large satellites of the parent planet. They are generally thought to have been formed in situ at the same time as the coalescence of the original planet...
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...
. Perdita's discovery was complicated. The first photographs of Perdita were taken by the Voyager 2
Voyager 2
The Voyager 2 spacecraft is a 722-kilogram space probe launched by NASA on August 20, 1977 to study the outer Solar System and eventually interstellar space...
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
Erich Karkoschka
Erich Karkoschka is a planetary researcher at the Lunar and Planetary Lab of the University of Arizona. He discovered a satellite of Uranus, S/1986 U 10 on photographs taken by the Voyager 2 spacecraft...
and reported. But because no further pictures could be taken to confirm its existence, it was officially demoted in 2001. However, in 2003, pictures taken by the Hubble Space Telescope
Hubble Space Telescope
The Hubble Space Telescope is a space telescope that was carried into orbit by a Space Shuttle in 1990 and remains in operation. A 2.4 meter aperture telescope in low Earth orbit, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared...
managed to pick up an object where Perdita was supposed to be, finally confirming its existence.
Following its discovery in 1999, it was given the temporary designation of S/1986 U 10. It was named Perdita (Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
for 'lost') after the daughter
Perdita (The Winter's Tale)
Perdita is one of the heroines of William Shakespeare's play, The Winter's Tale. She is the daughter of Leontes, King of Sicilia, and his wife Hermione....
of Leontes
Leontes
King Leontes is the father of Perdita and husband to Queen Hermione in Shakespeare's play The Winter's Tale. He becomes obsessed with the belief that his wife has been having an affair with Polixenes, his childhood friend and King of Bohemia. Because of this, he tries to have his friend poisoned,...
and Hermione 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 Winter's Tale
The Winter's Tale
The Winter's Tale is a play by William Shakespeare, originally published in the First Folio of 1623. Although it was grouped among the comedies, some modern editors have relabelled the play as one of Shakespeare's late romances. Some critics, among them W. W...
. The moon is also designated Uranus XXV.
The moon orbits between Belinda
Belinda (moon)
- External links :* by *...
and Puck
Puck (moon)
Puck is an inner moon of Uranus. It was discovered in December 1985 by the Voyager 2 spacecraft. The name Puck comes from Celtic mythology and English folklore. The orbit of Puck lies between the rings of Uranus and the first of Uranus' large moons, Miranda. Puck is approximately spherical in...
. The above-mentioned Hubble measurements prove that Perdita does not follow a direct Keplerian
Kepler's laws of planetary motion
In astronomy, Kepler's laws give a description of the motion of planets around the Sun.Kepler's laws are:#The orbit of every planet is an ellipse with the Sun at one of the two foci....
motion around Uranus. Instead, it is clearly caught in a 43:44 orbital resonance
Orbital resonance
In celestial mechanics, an orbital resonance occurs when two orbiting bodies exert a regular, periodic gravitational influence on each other, usually due to their orbital periods being related by a ratio of two small integers. Orbital resonances greatly enhance the mutual gravitational influence of...
with the nearby moon Belinda
Belinda (moon)
- External links :* by *...
. It is also close to an 8:7 resonance with Rosalind
Rosalind (moon)
Rosalind is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on 13 January 1986, and was given the temporary designation S/1986 U 4. It was named after the daughter of the banished Duke in William Shakespeare's play As You Like It...
.
Perdita belongs to Portia Group of satellites, which also includes Bianca
Bianca (moon)
Bianca is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on January 23, 1986, and was given the temporary designation S/1986 U 9. It was named after the sister of Katherine in Shakespeare's play The Taming of the Shrew...
, Cressida
Cressida (moon)
Cressida is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on 9 January 1986, and was given the temporary designation S/1986 U 3. It was named after the Trojan daughter of Calchas, a tragic heroine who appears in William Shakespeare's play Troilus and...
, Desdemona
Desdemona (moon)
Desdemona is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on 13 January 1986, and was given the temporary designation S/1986 U 6. Desdemona is named after the wife of Othello in William Shakespeare's play Othello...
, Portia
Portia (moon)
Portia is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on 3 January 1986, and was given the temporary designation S/1986 U 1. The moon is named after Portia, the heroine of William Shakespeare's play The Merchant of Venice...
, Juliet
Juliet (moon)
Juliet is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on 3 January 1986, and was given the temporary designation S/1986 U 2. It is named after the heroine of William Shakespeare's play Romeo and Juliet...
, Cupid
Cupid (moon)
Cupid is an inner satellite of Uranus. It was discovered by Mark Showalter and Jack J. Lissauer in 2003 using the Hubble Space Telescope. It was named after a character in William Shakespeare's play Timon of Athens....
, Rosalind
Rosalind (moon)
Rosalind is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on 13 January 1986, and was given the temporary designation S/1986 U 4. It was named after the daughter of the banished Duke in William Shakespeare's play As You Like It...
and Belinda
Belinda (moon)
- External links :* by *...
. These satellites have similar orbits and photometric properties. Little is known about Perdita apart from its orbit, radius of 15 km and geometric albedo of 0.08.