Calypso (moon)

Infobox Planet
name = Calypso


bgcolour = #a0ffa0
discovery = yes
discoverer = Pascu, Seidelmann,
Baum and Currie
discovered = March 13, 1980
semimajor = 294,619 km
eccentricity = 0.000
period = 1.887802 d [ [http://exp.arc.nasa.gov/downloads/celestia/data/solarsys.ssc NASA Celestia] ]
inclination = 1.56° (to Saturn's equator)
satellite_of = Saturn
physical_characteristics = yes
dimensions = 30 × 23 × 14 km cite journal | author= Porco, C. C.; "et al."| title= "Physical Characteristics and Possible Accretionary Origins for Saturn's Small Satellites"| journal= Bulletin of the American Astronomical Society| year= 2006| volume= 37| pages= 768| url=http://www.lpi.usra.edu/meetings/lpsc2006/pdf/2289.pdf]
mean_radius = 10.7 ± 1.0 km
rotation = synchronous
axial_tilt = zero
albedo = 1.34 ± 0.10 (geometric)Verbiscer, A.; French, R.; Showalter, M.; and Helfenstein, P.; [http://www.sciencemag.org/cgi/content/abstract/315/5813/815 "Enceladus: Cosmic Graffiti Artist Caught in the Act"] , Science, Vol. 315, No. 5813 (February 9, 2007), p. 815 (supporting online material, table S1)]
adjectives = Calypsonian

Calypso (pronEng|kəˈlɪpsoʊ respell|kə|LIP|soh, or as in Greek "Καλυψώ)" is a moon of Saturn. It was discovered by Pascu, Seidelmann, Baum and Currie in 1980 from ground-based observations, and was provisionally designated nowrap|S/1980 S 25 [ [http://cfa-www.harvard.edu/iauc/03400/03496.html IAUC 3496: "Satellites of Saturn"] 1980 July 31 (discovery)] . Several other apparitions of it were recorded in the following months: nowrap|S/1980 S 29, nowrap|S/1980 S 30 [ [http://cfa-www.harvard.edu/iauc/03500/03549.html IAUC 3549: "Satellites of Saturn"] 1980 December 11] , nowrap|S/1980 S 32 [ [http://cfa-www.harvard.edu/iauc/03600/03605.html IAUC 3605: "Satellites of Saturn"] 1981 May 18] , and nowrap|S/1981 S 2 [ [http://cfa-www.harvard.edu/iauc/03500/03593.html IAUC 3593: "Satellites of Saturn"] 1981 April 16] .

In 1983 it was officially named after Calypso of Greek mythology [Transactions of the International Astronomical Union, Vol. XVIIIA, 1982 (confirms Janus, names Epimetheus, Telesto, Calypso) (mentioned in [http://cfa-www.harvard.edu/iauc/03800/03872.html IAUC 3872: "Satellites of Jupiter and Saturn"] , 1983 September 30)] . It is also designated as nowrap|Saturn XIV or Tethys C.

Calypso is co-orbital with the moon Tethys, and resides in Tethys' trailing Lagrangian point (L₅) 60 degrees behind Tethys. This relationship was first identified by Seidelmann "et al." in 1981.Seidelmann, P. K.; Harrington, R. S.; Pascu, D.; Baum, W. A.; Currie, D. G.; Westphal, J. A.; and Danielson, G. E.; [http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1981Icar...47..282S&db_key=AST&data_type=HTML&format=&high=45eb6e10af20904 "Saturn Satellite Observations and Orbits from the 1980 Ring Plane Crossing"] , Icarus, Vol. 47 (August 1981), pp. 282–287] The moon Telesto also resides in the other (leading) lagrangian point of Tethys, 60 degrees in the other direction from Tethys.

Like many other small Saturnian moons and small asteroids, Calypso is irregularly shaped, has overlapping large craters, and appears to also have loose surface material capable of smoothing the craters' appearance. Its surface is one of the most reflective (at visual wavelengths) in the solar system, with a visual geometric albedo of 1.34. This very high albedo is the result of the sandblasting of particles from Saturn's E-ring, a faint ring composed of small, water-ice particle generated by Enceladus' south polar geysers.

Not to be confused with asteroid 53 Kalypso.

References

External links

* [http://solarsystem.nasa.gov/planets/profile.cfm?Object=Sat_Calypso Calypso Profile] by [http://solarsystem.nasa.gov NASA's Solar System Exploration]
* [http://www.planetary.org/explore/topics/saturn/calypso.html The Planetary Society: Calypso]