Calypso (moon)

Calypso is a moon of Saturn. It was discovered in 1980, from ground-based observations, by Dan Pascu, P. Kenneth Seidelmann, William A. Baum, and Douglas G. Currie, and was provisionally designated S/1980 S 25 (the 25th satellite of Saturn discovered in 1980).Template:Sfn Several other apparitions of it were recorded in the following months: S/1980 S 29, S/1980 S 30,Template:Sfn S/1980 S 32,Template:Sfn and S/1981 S 2.Template:Sfn In 1983 it was officially named after Calypso of Greek mythology.Template:Efn It is also designated Saturn XIV or Tethys C.

Calypso is co-orbital with the moon Tethys, and resides in Tethys's trailing Lagrangian point (Template:L5), 60 degrees behind Tethys. This relationship was first identified by [[#Template:SfnRef|Seidelmann et al.]] in 1981.Template:Sfn The moon Telesto resides in the other (leading) Lagrangian point of Tethys, 60 degrees in the other direction from Tethys. Calypso and Telesto have been termed "Tethys trojans", by analogy to the trojan asteroids, and are half of the four presently known trojan moons.

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.Template:Sfn 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 particles generated by Enceladus's south polar geysers.Template:Sfn

Gallery

• Another February 13, 2010 image showing flow-like albedo features
  Another February 13, 2010 image showing flow-like albedo features
• Cassini image from September 23, 2005
  Cassini image from September 23, 2005
• Calypso as seen by Voyager 2 (August 1981)
  Calypso as seen by Voyager 2 (August 1981)

See also

• List of natural satellites

References

Sources

• (supporting online material, table S1)

External links

• Calypso Profile by NASA's Solar System Exploration
• The Planetary Society: Calypso
• Animation of photos from Cassini 2010-02-13 flyby on YouTube
• Raw images