Cressida (moon)

There is also an asteroid called 548 Kressida.
Cressida

Voyager 2 image of the Uranian moons Portia, Cressida, and Ophelia
Discovery
Discovered by Stephen P. Synnott / Voyager 2
Discovery date January 9, 1986
Orbital characteristics
Mean orbit radius
 61,766.730 ± 0.046 km[1]
Eccentricity 0.00036 ± 0.00011[1]
0.463569601 ± 0.000000013 d[1]
Inclination 0.006 ± 0.040° (to Uranus' equator)[1]
Satellite of Uranus
Physical characteristics
Dimensions 92 × 74 × 74 km[2]
Mean radius
 39.8 ± 2 km[2][3][4]
~20,000 km²[lower-alpha 1]
Volume ~260,000 km³[lower-alpha 1]
Mass ~3.4×1017 kg[lower-alpha 1]
Mean density
 ~1.3 g/cm³ (assumed)[3]
~0.013 m/s2[lower-alpha 1]
~0.034 km/s[lower-alpha 1]
synchronous[2]
zero[2]
Albedo
Temperature ~64 K[lower-alpha 1]

    Cressida (/ˈkrɛsɨdə/ KRES-i-də, Greek: Χρησίδα) 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.[6] 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.[7]

    Cressida belongs to the Portia Group of satellites, which includes Bianca, Desdemona, Juliet, Portia, Rosalind, Cupid, Belinda and Perdita.[5] These satellites have similar orbits and photometric properties.[5] Other than its orbit,[1] radius of 41 km[2] and geometric albedo of 0.08[5] virtually nothing is known about it.

    At the Voyager 2 images Cressida appears as an elongated object, the major axis pointing towards Uranus. The ratio of axes of the Cressida's prolate spheroid is 0.8 ± 0.3.[2] Its surface is grey in color.[2]

    Cressida may collide with Desdemona within the next 100 million years.[8]

    See also

    References

    Explanatory notes

    1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Calculated on the basis of other parameters.

    Citations

    1. ↑ 1.0 1.1 1.2 1.3 1.4 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.
    2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 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.
    3. ↑ 3.0 3.1 3.2 "Planetary Satellite Physical Parameters". JPL (Solar System Dynamics). 24 October 2008. Retrieved 12 December 2008.
    4. ↑ 4.0 4.1 Williams, Dr. David R. (23 November 2007). "Uranian Satellite Fact Sheet". NASA (National Space Science Data Center). Retrieved 12 December 2008.
    5. ↑ 5.0 5.1 5.2 5.3 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.
    6. ↑ Smith, B. A. (January 16, 1986). "Satellites of Uranus". IAU Circular 4164. Retrieved 29 October 2011.
    7. ↑ "Planet and Satellite Names and Discoverers". Gazetteer of Planetary Nomenclature. USGS Astrogeology. July 21, 2006. Retrieved 6 August 2006.
    8. ↑ 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