Perdita (moon)

Perdita

Discovery
Discovered by	Erich Karkoschka / Voyager 2
Discovery date	May 18, 1999 (in images dating back to January 18, 1986)
Designations
Designation	Uranus XXV
Pronunciation	/ˈpɜːrdətə/[1]
Adjectives	Perditean /pɜːrdəˈtiːən/[2]
Orbital characteristics
Mean orbit radius	76,417 ± 1 km[3]
Eccentricity	0.0012 ± 0.0005[3]
Orbital period (sidereal)	0.638021 ± 0.000013 d[3]
Inclination	0.0 ± 0.3° (to Uranus' equator)[3]
Satellite of	Uranus
Physical characteristics
Mean radius	13.3±0.7 km[4]
Surface area	~2220 km2[a]
Volume	~9850 km3[a]
Mass	~(4.93–8.87)×1015 kg[a]
Mean density	0.5–0.9 g/cm3[5][6]
Surface gravity	~0.002–0.003 m/s2[a]
Escape velocity	~0.007–0.009 km/s[a]
Synodic rotation period	synchronous[3]
Axial tilt	zero[3]
Albedo	0.08 ± 0.01 (assumed)[7]
Temperature	~64 K[a]

Perdita /ˈpɜːrdətə/ 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.^[3][8] But because no further pictures could be taken to confirm its existence, it was officially demoted in 2001.^[9] 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.^[7][10]

Following its discovery in 1999, it was given the temporary designation of S/1986 U 10.^[8] 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.^[11]

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 times that of Perdita.^[12] It is also close to an 8:7 resonance with Rosalind.^[3][7]

Perdita belongs to the Portia group of satellites, which also includes Bianca, Cressida, Desdemona, Portia, Juliet, Cupid, Rosalind and Belinda.^[13] These satellites have similar orbits and photometric properties.^[13] Little is known about Perdita apart from its orbit,^[3][7] radius of 13.3 km^[4] and geometric albedo of 0.08.^[13][7]

See also

• Moons of Uranus

Notes

References

Citations

Sources

• Karkoschka, Erich (2001). "Voyager's Eleventh Discovery of a Satellite of Uranus and Photometry and the First Size Measurements of Nine Satellites". Icarus. 151 (1): 69–77. Bibcode:2001Icar..151...69K. doi:10.1006/icar.2001.6597.
• Karkoschka, Erich (2001). "Comprehensive Photometry of the Rings and 16 Satellites of Uranus with the Hubble Space Telescope". Icarus. 151 (1): 51–68. Bibcode:2001Icar..151...51K. doi:10.1006/icar.2001.6596.
• Green, Daniel W. E. (May 18, 1999). "S/1986 U 10". IAU Circular. 7171: 1. Bibcode:1999IAUC.7171....1K. ISSN 0081-0304. Retrieved 2012-01-26.
• Foust, Jeff (December 31, 2001). "Moon of Uranus is demoted". Spaceflight Now. Retrieved 2012-01-26.
• Showalter, Mark R.; Lissauer, Jack J. (2006-02-17). "The Second Ring-Moon System of Uranus: Discovery and Dynamics". Science. 311 (5763): 973–977. Bibcode:2006Sci...311..973S. doi:10.1126/science.1122882. PMID 16373533. S2CID 13240973.
• Green, Daniel W. E. (September 3, 2003). "Satellites of Uranus". IAU Circular. 8194. ISSN 0081-0304. Retrieved 2012-01-26.
• USGS/IAU (July 21, 2006). "Planet and Satellite Names and Discoverers". Gazetteer of Planetary Nomenclature. USGS Astrogeology. Retrieved 2012-01-26.
• Ćuk, Matija; French, Robert S.; Showalter, Mark R.; Tiscareno, Matthew S.; Moutamid, Maryame El (2022-07-16). "Cupid is not Doomed Yet: On the Stability of the Inner Moons of Uranus". The Astronomical Journal. 164 (2): 38. arXiv:2205.14272. doi:10.3847/1538-3881/ac745d. ISSN 1538-3881.
• French, Robert S.; Showalter, Mark R. (August 2012). "Cupid is Doomed: An Analysis of the Stability of the Inner Uranian Satellites". Icarus. 220 (2): 911–921. arXiv:1408.2543. doi:10.1016/j.icarus.2012.06.031.

External links

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

This page was last edited on 16 March 2024, at 23:59