Perdita (moon)
Encyclopedia : P : PE : PER : Perdita (moon)
| Discovery | |||||||
|---|---|---|---|---|---|---|---|
| Discovered by | Erich Karkoschka | ||||||
| Discovered in | May 18, 1999 (in images dating back to January 18, 1986) | ||||||
| Orbital characteristics | |||||||
| Semi-major axis | 76,416 km | ||||||
| Eccentricity | 0.003 | ||||||
| Orbital period | 0.638 d | ||||||
| Inclination | 0.07° (to Uranus' equator) | ||||||
| Is a satellite of | Uranus | ||||||
| Physical characteristics | |||||||
| Mean diameter | ~27 km (estimate) | ||||||
| Surface area | ~2,200 km2 (estimate) | ||||||
| Volume | ~98,000 km3 (estimate) | ||||||
| Mass | kg (estimate) | ||||||
| Mean density | ~1.3 g/cm3 (estimate) | ||||||
| Surface gravity | ~0.0047 m/s2 (estimate) | ||||||
| Escape velocity | ~0.011 km/s (estimate) | ||||||
| Rotation period | synchronous (assumed) | ||||||
| Axial tilt | zero (assumed) | ||||||
| Albedo | 0.07 (assumed) | ||||||
| Surface temp. |
| ||||||
| Atmospheric pressure | 0 kPa | ||||||
Perdita (pər'-di-tə, IPA [ˈpərdɪtə]) is a moon of Uranus. It is about 20 km in diameter. Its orbit lies between those of Belinda and Puck. It was named after the daughter of Leontes and Hermione in William Shakespeare's play The Winter's Tale.
The first photographs of Perdita were taken by the Voyager 2 spacecraft in 1986, but it was not recognized that there was a moon in those 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.
In 2003, pictures taken by the Hubble Space Telescope managed to pick up an object where Perdita was supposed to be, confirming its existence.
Following its discovery in 1999, Perdita was given the temporary designation of S/1986 U 10. In addition to Perdita, this moon is also designated Uranus XXV.
References
Uranus (satellites) [http://encycl.opentopia.com/ edit]
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