S/2004 S 24


S/2004 S 24
Discovery [1]
Discovered byScott S. Sheppard
David C. Jewitt
Jan T. Kleyna
Discovery date2019
Orbital characteristics[3][1]
Epoch 27 April 2019 (JD 2458600.5)
Observation arc2.27 yr (830 d)
Earliest precovery date12 December 2004
0.1530807 AU (22.90055 Gm)
3.545 yr (1,293.85 d)
0° 16m 41.665s / day
Inclination35.53797° (to the ecliptic)
Satellite ofSaturn
GroupGallic group?
Physical characteristics
Mean diameter
Albedo0.04 (assumed)[2]

S/2004 S 24 is a natural satellite of Saturn, and the outermost known prograde satellite. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, and Jan Kleyna on October 7, 2019 from observations taken between December 12, 2004 and March 22, 2007.[1]

S/2004 S 24 is about 3 kilometres in diameter, and orbits Saturn at an average distance of 22.901 Gm in 1294.25 days, at an inclination of 35.5° to the ecliptic, in a prograde direction and with an eccentricity of 0.085.[1] Due to its inclination being similar to the four known members of the Gallic group, S/2004 S 24 could belong to the Gallic group.[4] However, its orbit is much more distant, which puts this classification into question. It could very well be in a group of its own.

The exact formation mechanism of S/2004 S 24 is unknown, and due to its low eccentricity (0.085) a captured orbit is unlikely. Nonetheless, S/2004 S 24 orbits in the opposite direction of all other moons in its orbital region, making it unlikely to have survived in this orbit over the entire history of the Solar System.


  1. ^ a b c d e f "MPEC 2019-T131 : S/2004 S 24". Minor Planet Electronic Circular. Minor Planet Center. Retrieved 7 October 2019.
  2. ^ a b c d e Sheppard, Scott. "Scott S. Sheppard - Saturn Moons". Department of Terrestrial Magnetism. Carnegie Institution for Science. Retrieved 7 October 2019.
  3. ^ a b "M.P.C. 117075" (PDF). Minor Planet Circular. Minor Planet Center. 10 October 2019.
  4. ^ "Discovery of 20 new moons gives Saturn a solar system record". National Geographic. Oct 7, 2019. Retrieved Oct 8, 2019.