Bestla (moon)


Bestla imaged by the Cassini spacecraft in September 2015
Discovered byScott S. Sheppard
David C. Jewitt
Jan T. Kleyna
Brian G. Marsden
Discovery date2004
Saturn XXXIX
S/2004 S 18
Orbital characteristics[1]
20129000 km
−1083.6 days
Satellite ofSaturn
GroupNorse group
Physical characteristics
Mean diameter
14.6238±0.0001 h[2]

Bestla /ˈbɛstlə/ or Saturn XXXIX is a retrograde irregular moon of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on 4 May 2005, from observations taken between 13 December 2004 and 5 March 2005.


Bestla is about 7 kilometres in diameter, and orbits Saturn at an average distance of 20,192,000 km in 1088 days, at an inclination of 147° to the ecliptic (151° to Saturn's equator), in a retrograde direction and with an eccentricity of 0.5145.[3] Early observations from 2005 suggested that Bestla had a very high eccentricity of 0.77.[4] Like many of the outer irregular moons of the giant planets, Bestla's eccentricity may vary as a result of the Kozai mechanism. Besta's rotation period is 14.6238±0.0001 hours.[2]


This moon was named in April 2007 after Bestla, a frost giantess from Norse mythology, who is a mother of Odin.


  1. ^ S.S. Sheppard (2019), Moons of Saturn, Carnegie Science, on line
  2. ^ a b c Denk, T.; Mottola, S. (2019). Cassini Observations of Saturn's Irregular Moons (PDF). 50th Lunar and Planetary Science Conference. Lunar and Planetary Institute.
  3. ^ Jacobson, R.A. (2007-06-28). "Planetary Satellite Mean Orbital Parameters". JPL/NASA. Retrieved 2008-01-19.
  4. ^ Brian G. Marsden (2005-05-03). "MPEC 2005-J13 : Twelve New Satellites of Saturn". Minor Planet Center. Retrieved 2008-01-19.

External links

  • Saturn's Known Satellites (by Scott S. Sheppard)
  • Jewitt's New Satellites of Saturn page
  • IAUC 8523: New Satellites of Saturn[permanent dead link] May 4, 2005 (discovery)
  • IAUC 8826: Satellites of Jupiter and Saturn[permanent dead link] April 5, 2007 (naming the moon)
  • raw Images