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Saturn the sixth planet in our solar system has 56 confirmed moons in orbit around it.


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Saturn moons number 56 confirmed, and 3 additional un-confirmed, hypothetical moons. However, a precise number of Saturn's moons can never be given, as there is no objective dividing line between the anonymous orbiting fragments that form Saturn's ring system and the larger objects that have already been named as moons.

Saturn's moons.
Saturn's rings cut across an eerie scene that is ruled by Titan's luminous crescent and globe-encircling haze, broken by the small moon Enceladus, whose icy jets are dimly visible at its south pole. North is up.

Before the advent of telescopic photography, eight moons of Saturn were discovered by direct observation using an optical telescope:

  • Titan, discovered in 1655 by Christiaan Huygens;.
  • Tethys, Dione, Rhea and Iapetus (the "Sidera Lodoicea") discovered 1671-1684 by Giovanni Domenico Cassini;.
  • Mimas and Enceladus, discovered 1789 by William Herschel;.
  • Hyperion, discovered 1848 by W.C. Bond, G.P. Bond and Lassell.

The use of long-exposure photographic plates made it possible to discover additional moons:

  • Phoebe was the first satellite discovered by telescopic photograph in 1899 by W.H. Pickering.
  • In 1966, the satellites Janus and Epimetheus were observed, but not confirmed, and it was not realized that there were two distinct moons sharing an orbit.

The study of the outer planets has since been revolutionized, first by the use of unmanned space probes, and then by advances in telescopy:

  • From 1980, when the first of the the Voyager space probes arrived at Saturn, to 1990, analysis of Voyager images revealed 8 more moons in the inner Saturnian system. The last discovered was Pan.
  • A survey starting in late 2000 found 13 new moons orbiting Saturn at a great distance in orbits that suggest they are fragments of larger bodies captured by Saturn's gravitational pull (Nature vol. 412, pp. 163-166).
  • The Cassini mission, which arrived at Saturn in the summer of 2004, discovered three small moons in the inner Saturnian system as well as three suspected but unconfirmed moons in the F Ring. This increased the total to 37 moons, confirmed and unconfirmed.
  • On November 16, 2004, Cassini scientists announced that the structure of Saturn's rings indicates the presence of several more moons orbiting within the rings, but only one, Daphnis, has been visually confirmed so far (its confirmation was announced on May 6, 2005)..
  • On May 3, 2005, astronomers using the Mauna Kea Observatory announced the discovery of 12 more small outer moons.
  • On June 30, 2006, astronomers using the Subaru 8.2 m telescope announced the discovery of 9 more small outer moons.

The spurious satellite Chiron, "discovered" in 1861, is now known not to exist. Themis, "discovered" in 1905, also was later proven not to exist.

Table of known moons

The Saturnian moons are listed here by orbital period, from shortest to longest. Moons massive enough for their surfaces to have collapsed into a spheroid are highlighted in light purple. Titan, which is planetary in size, has darker highlighting. The irregular (captured) moons are indicated in grey: light grey for prograde satellites, darker grey for retrograde satellites.

OrderName (spheroidal moons in bold)

(Pronunciation key)

ImageDiameter (km)Semi-major
axis (km)
Orbital
period (d)
Inclination (º)
(to Saturn's
equator)
PositionDiscovered
1 XVIII Pan
Saturn moon Pan.
30 (35 35 23) 133,584 +0.57505 0.000º in Encke Division 1990
2 XXXV Daphnis
Saturn moon Daphnis.
6 - 8 136,505 +0.59408 0.000º in Keeler Gap 2005
3 XV Atlas
Saturn moon Atlas.
31 (46 38 19) 137,670 +0.60169 outer A Ring shepherd 1980
4 XVI Prometheus
Saturn moon Prometheus.
86 (119 87 61) 139,380 +0.61299 0.000º inner F Ring shepherd 1980
*   S/2004 S 6  
Saturn moon S/2004 s 6.
~3-5 140,130 +0.61801 *Uncertain objects
around the F-ring
2004
*   S/2004 S 4   ~3-5 ~140,100 +0.619 2004
*   S/2004 S 3  
Saturn moon.
~3-5 ~140,300 ~ +0.62 2004
5 XVII Pandora
Saturn moon Pandora.
81 (103 80 64) 141,720 +0.62850 outer F Ring Shepherd 1980
6 XI Epimetheus Saturn moon Epimetheus. 113 (135 108 105) 151,422 +0.69433 0.335º co-orbitals 1980
7 X Janus
Saturn moon Janus.
179 (193 173 137) 151,472 +0.69466 0.165º 1966
8 I Mimas
Saturn moon Mimas.
397 (415 394 381) 185,404 +0.942422 1.566º   1789
9 XXXII Methone
Saturn moon Methone.
3 194,440 +1.00957   2004
10 XXXIII Pallene
Saturn moon Pallene.
4 212,280 +1.15375   2004
11 II Enceladus
Saturn moon Enceladus.
504 (513 503 497) 237,950 +1.370218 0.010º In the thick of E ring 1789
12 III Tethys
Saturn moon Tethys.
1066 (1081 1062 1055) 294,619 +1.887802 0.168º   1684
12a XIII Telesto
Saturn moon Telesto.
24 (29 22 20) 1.158º leading Tethys trojan 1980
12b XIV Calypso
Saturn moon Calypso.
21 (30 23 14) 1.473º trailing Tethys trojan 1980
15 IV Dione
Saturn moon Dione.
1123 (1128 1122 1121) 377,396 +2.736915 0.002º   1684
15a XII Helene
Saturn moon Helene.
33 (36 32 30) 0.212º leading Dione trojan 1980
15b XXXIV Polydeuces
Saturn moon Polydeuces.
3.5 trailing Dione trojan 2004
18 V Rhea
Saturn moon Rhea.
1529 (1535 1525 1526) 527,108 +4.518212 0.327º   1672
19 VI Titan
Saturn moon Titan.
5151 1,221,930 +15.94542 1.634º   1655
20 VII Hyperion
Saturn moon Hyperion.
292 (360 280 225) 1,481,010 +21.27661 0.568º   1848
21 VIII Iapetus
Saturn moon Iapetus.
1472 (1494 1498 1425) 3,560,820 +79.3215 7.570º   1671
22 XXIV Kiviuq ~16 11 294 800 +448.16 49.087º Inuit group 2000
23 XXII Ijiraq ~12 11 355 316 +451.77 50.212º 2000
24 IX Phoebe
Saturn moon Phoebe.
220 (230 220 210) 12 869 700 -545.09 173.047º Norse group 1899
25 XX Paaliaq ~22 15 103 400 +692.98 46.151º Inuit group 2000
26 XXVII Skathi ~8 15 672 500 -732.52 149.084º Norse (Skathi) Group 2000
27 XXVI Albiorix ~32 16 266 700 +774.58 38.042º Gallic group 2000
28 XXXVII S/2004 S 11 - ~6 17 153 520 +838.77 40.484º Inuit group 2004
29 XXVIII Erriapo ~10 17 236 900 +844.89 38.109º Gallic group 2000
30 XLVII S/2006 S 8 - ~6 17 473 800 -862.37 155.624º Norse group 2006
31 XXIX Siarnaq ~40 17 776 600 +884.88 45.798º Inuit group 2000
32   S/2004 S 13 - ~6 18 056 300 -905.85 167.379º Norse group 2004
33   S/2006 S 4 - ~6 18 065 700 -906.56 172.666º 2006
34 XLIV S/2004 S 19 - ~8 18 168 300 -914.29 153.272º 2006
35   S/2006 S 6 - ~6 18 556 900 -943.78 162.861º 2006
36 XXI Tarvos ~15 18 562 800 +944.23 34.679º Gallic group 2000
37 XXV Mundilfari ~7 18 725 800 -956.70 169.378º Norse group 2000
38   S/2006 S 1 - ~6 18 930 200 -972.41 154.232º 2006
39   S/2004 S 17 - ~4 19 099 200 -985.45 166.881º 2004
40 XXXVIII S/2004 S 15 - ~6 19 104 000 -985.83 157.384º Norse (Skathi) group 2004
41 XXXI Narvi ~7 19 395 200 -1008.45 137.292º Norse group 2003
42 XXIII Suttungr ~7 19 579 000 -1022.82 174.321º 2000
43 XLIII S/2004 S 14 - ~6 19 709 300 -1033.05 163.131º 2004
44   S/2004 S 12 - ~5 19 905 900 -1048.54 164.042º 2004
45 XL S/2004 S 9 - ~5 19 984 800 -1054.78 158.361º Norse (Skathi) group 2004
46 XXX Thrymr ~7 20 278 100 -1078.09 174.524º Norse group 2000
47 XXXVI S/2004 S 10 - ~6 20 482 900 -1094.46 167.425º 2004
48 XXXIX S/2004 S 18 - ~7 20 570 000 -1101.45 147.395º Norse (Skathi) group 2004
49   S/2004 S 7 - ~6 20 576 700 -1101.99 165.596º Norse group 2004
50   S/2006 S 3 - ~6 21 076 300 -1142.37 150.817º 2006
51 XLI S/2004 S 16 - ~4 21 930 644 -1212.53 162.832º 2004
52 XLVIII S/2006 S 7 - ~6 22 288 916 -1242.36 166.918º 2006
53 XLV S/2006 S 2 - ~7 22 321 200 -1245.06 148.384º 2006
54 XIX Ymir ~18 22 429 673 -1254.15 172.143º 2000
55 XLVI S/2006 S 5 - ~6 22 984 322 -1300.95 166.539º 2006
56 XLII S/2004 S 8 - ~6 24 504 879 -1432.16 167.886º 2004

Grouping the moons of Saturn.

Saturn System.
The Saturn System (photographic montage).

Although the borders may be somewhat nebulous, Saturn's moons can be divided into eight groups.

The Saturn ring shepherds.

shepherd satellites are moons that orbit within, or just beyond, a planet's ring system. They have the effect of sculpting the rings: giving them sharp edges, and creating gaps between them. Saturn's shepherd moons are Pan, Daphnis, Atlas, Prometheus, Pandora, S/2004 S 3, in addition to the unconfirmed moons S/2004 S 4 and S/2004 S 6.

The co-orbitals of Saturn.

Janus and Epimetheus are co-orbital moons. These two moons are of roughly equal size and have orbits with only a few kilometers difference in diameter, close enough that they would collide if they attempted to pass each other. Instead of colliding, however, their gravitational interaction causes them to swap orbits every four years. See Epimetheus' article for a more detailed explanation of this arrangement.

The inner large moons of Saturn.

The innermost large moons of Saturn orbit within its tenuous E Ring. They are Mimas, Enceladus, Tethys and Dione.

Two recently discovered tiny moons also orbit within this group: Methone and Pallene. So too do the co-orbital moons that form a group of their own (see below).

The Trojan moons of Saturn.

Trojan moons are another kind of co-orbitals. Like other co-orbitals, they are a feature unique to the Saturnian system. They are moons that orbit at exactly the same distance from Saturn as another moon, but at such a distance from the other moon that they never collide. Tethys has two tiny co-orbitals Telesto and Calypso, and Dione has also two, Helene and Polydeuces. All four of these moons orbit in the larger moons' Lagrangian points, one in each point.

The outer large moons

Saturn's largest moons all orbit beyond its E Ring and can thus be considered a distinct group. They are Rhea, Hyperion (which is relatively small and very irregular), Titan and Iapetus.

Irregular satellites of Saturn.

Irregular satellites of Saturn.
Irregular satellites of Saturn.

The Inuit group of Saturn's moons.

The Inuit group are five prograde outer moons that are similar enough in their distances from Saturn and their orbital inclinations that they can be considered a group. They are Kiviuq, Ijiraq, Paaliaq, Siarnaq, and S/2004 S 11.

The Norse group of Saturn's moons.

The Norse group are 18 retrograde outer moons that are similar enough in their distance from Saturn to be considered a group. They are Phoebe, Skathi, Narvi, Mundilfari, Suttungr, Thrymr, Ymir, S/2004 S 7 through S/2004 S 10, S/2004 S 12 through S/2004 S 19, and S/2006 S 1 through S/2006 S 8. All of these moons orbit Saturn in a retrograde direction.

The Gallic group of Saturn's moons.

The Gallic group are three prograde outer moons that are similar enough in their distance from Saturn and their orbital inclination that they can be considered a group. They are Albiorix, Erriapo and Tarvos.

The diagram illustrates the orbits of the irregular satellites of Saturn discovered so far1. The eccentricity of the orbits is represented by the segments (extending from the pericentre to the apocentre) with the inclination represented on Y axis. The satellites above the axis are prograde, the satellites beneath are retrograde. The X axis is labelled in Gm (milion km) and the fraction of the Hill sphere's (gravitational influence) radius (~65 Gm for Saturn). Prograde groups: Inuit and Gallic and the retrograde Norse group are clearly identifiable (from top to bottom).

1Named satellites are plotted in yellow; the unnamed satellites S/2004 Sxx (announced in 2005 and 2006) are plotted in white and S/2006 Sxx in grey.

Naming notes of Saturn's moons.

Some asteroids share the same names as moons of Saturn: 55 Pandora, 106 Dione, 577 Rhea, 1809 Prometheus, 1810 Epimetheus, 4450 Pan. See also Name conflicts of solar system bodies.




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