Cressida (moon)
| File:Cressida 01-24-1986 V2.png Cressida imaged by Voyager 2 on January 24, 1986 at a resolution of 10 km/pixel | |
| Discovery | |
|---|---|
| Discovered by | Stephen P. Synnott with Voyager 2 |
| Discovery date | January 9, 1986 |
| Designations | |
Designation | Uranus IX |
| Pronunciation | /ˈkrɛsɪdə/[1] |
Named after | Χρησίδα |
| Adjectives | Cressidian /krɛˈsɪdiən/[2] |
| Orbital characteristics[3] | |
| 61 766.730 ± 0.046 km | |
| Eccentricity | 0.00036 ± 0.00011 |
| 0.463569601 ± 0.000000013 d | |
| Inclination | 0.006 ± 0.040° (to Uranus' equator) |
| Satellite of | Uranus |
| Physical characteristics | |
| Dimensions | 92 × 74 km[4][note 1] |
| Volume | 263800 km3 ± 38.0%[5][lower-alpha 1] |
| Mass | |
Mean density |
|
| synchronous[4] | |
| zero[4] | |
| Albedo | |
| Temperature | ~65 K[lower-alpha 3] |
| 21.58 (at opposition) | |
| |
Cressida /ˈkrɛsɪdə/ 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.[9] It was named after Cressida, the Trojan daughter of Calchas, a tragic heroine who appears in William Shakespeare's play Troilus and Cressida (as well as in tales by Geoffrey Chaucer and others). It is also designated Uranus IX.[10]
Cressida belongs to the Portia group of satellites, which includes Bianca, Desdemona, Juliet, Portia, Rosalind, Cupid, Belinda, and Perdita.[7] These satellites have similar orbits and photometric properties.[7] Other than its orbit,[3] size of Template:Cvt,[4] and geometric albedo of 0.08,[7] little is known about it.
In Voyager 2 imagery Cressida appears as an elongated object, with its major axis pointing towards Uranus. The ratio of axes of Cressida's prolate spheroid is 0.8 ± 0.3.[4] Its surface is grey in color.[4]
Cressida orbits close to a 3:2 resonance with the η ring, one of the rings of Uranus. Perturbations of the ring's shape provide a way to measure the mass of Cressida, which in 2024 was found to be (1.839±0.212)×1017 kg.[5] Cressida is one of the few small satellites of Uranus for which the mass has been directly measured.[5][6]
Cressida may collide with Desdemona within the next 100 million years.[11]
See also
[edit | edit source]Notes
[edit | edit source]References
[edit | edit source]- ↑ "Collins English Dictionary".
- ↑ Kellog (1995). Boccaccio's and Chaucer's Cressida.
- ↑ 3.0 3.1 Jacobson, R. A. (1998). "The Orbits of the Inner Uranian Satellites From Hubble Space Telescope and Voyager 2 Observations". The Astronomical Journal. 115 (3): 1195–1199. Bibcode:1998AJ....115.1195J. doi:10.1086/300263. S2CID 118616209.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 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.
- ↑ 5.0 5.1 5.2 5.3 5.4 Lua error in package.lua at line 80: module 'Module:Citation/CS1/Suggestions' not found.
- ↑ 6.0 6.1 6.2 Chancia, Robert. A.; Hedman, Matthew M.; French, Richard G. (28 August 2017). "Weighing Uranus' moon Cressida with the η ring". The Astronomical Journal. 154 (4): 153. arXiv:1708.07566. Bibcode:2017AJ....154..153C. doi:10.3847/1538-3881/aa880e. S2CID 54827255.
- ↑ 7.0 7.1 7.2 7.3 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.
- ↑ Williams, Dr. David R. (23 November 2007). "Uranian Satellite Fact Sheet". NASA (National Space Science Data Center). Retrieved 12 December 2008.
- ↑ Smith, B. A. (January 16, 1986). "Satellites of Uranus". IAU Circular. 4164. Retrieved 29 October 2011.
- ↑ "Planet and Satellite Names and Discoverers". Gazetteer of Planetary Nomenclature. USGS Astrogeology. July 21, 2006. Retrieved 6 August 2006.
- ↑ Duncan, Martin J.; Lissauer, Jack J. (1997). "Orbital Stability of the Uranian Satellite System". Icarus. 125 (1): 1–12. Bibcode:1997Icar..125....1D. doi:10.1006/icar.1996.5568.
External links
[edit | edit source]Template:Moons of Uranus Template:Uranus Template:Solar System moons (compact)