Aegir (moon)


Discovered byS. Sheppard, D. Jewitt, J. Kleyna, and B. Marsden
Discovery dateMay 4, 2005
Saturn XXXVI
Pronunciation/ˈjɪər, ˈæɡɪər/ etc.
Named after
S/2004 S 10
Adjectives[citation needed]
Orbital characteristics
20,735,000 km[1]
1,025.908 d
Satellite ofSaturn
GroupNorse group
Physical characteristics
Mean diameter

Aegir, also Saturn XXXVI (provisional designation S/2004 S 10), is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on May 4, 2005, from observations taken between December 12, 2004, and March 11, 2005.

Aegir is about 6 kilometres in diameter, and orbits Saturn at an average distance of 19,618 Mm in 1025.908 days, at an inclination of 167° to the ecliptic (140° to Saturn's equator), in a retrograde direction and with an eccentricity of 0.237.


The moon was named in April 2007 after Ægir, a giant from Norse mythology, the personification of tranquil seas, the one who soothes storms away. He is a son of Fornjót, and brother of Logi (fire, flame) and Kári (wind).

The name may be pronounced various ways. /ˈjɪər/ (with the 'g' pronounced as a y-sound) approximates modern Norwegian and Icelandic. /ˈæɡɪər/ (with a hard 'g') approximates what the Old Norse may have sounded like, while the Latinized/spelling pronunciations /ˈɪər/, /ˈɛɪər/ and /ˈɪər/ are also found.[2][3][4]


  1. ^ a b c d Ma, Yuehua; et al. (2010), "On the Origin of Retrograde Orbit Satellites around Saturn and Jupiter", Icy Bodies of the Solar System, Proceedings of the International Astronomical Union, IAU Symposium, 263, pp. 157–160, Bibcode:2010IAUS..263..157M, doi:10.1017/S1743921310001687.
  2. ^ Merriam-Webster's Encyclopedia of Literature (1995)
  3. ^ "Aegir". Unabridged. Random House.
  4. ^ Harold Stanford (1922) The Standard Reference Work: For the Home, School and Library

External links

  • T. Denk's Aegir website
  • Institute for Astronomy Saturn Satellite Data
  • D. Jewitt's New Satellites of Saturn page
  • IAUC 8523: New Satellites of Saturn[permanent dead link] May 4, 2005 (discovery)
  • MPEC 2005-J13: Twelve New Satellites of Saturn May 3, 2005 (discovery and ephemeris)
  • IAUC 8826: Satellites of Jupiter and Saturn[permanent dead link] April 5, 2007 (naming the moon)