Moons of Saturn

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The planet Saturn has 53 named moons, and another nine which are still being studied.[1] Many of the moons are very small: 33 are less than 10 km (6 mi) in diameter and thirteen moons are less than 50 km (31 mi).[2] Many of the moons are named after Titans, Giants, or minor Greek or Roman gods. Some of Saturn's moons are very large; the moon Titan is bigger than the planet Mercury.

Confirmed moons[change | change source]

The Saturnian moons are listed here by orbital period (or semi-major axis), from shortest to longest. Moons massive enough for their surfaces to have collapsed into a spheroid are highlighted in bold, while the irregular moons are listed in red, orange and gray background.
Key

Major icy moons

Titan

Inuit group

Gallic group

Norse group
Order Label
[a]
Name Pronunciation Image Diameter (km)[b] Mass
(×1015 kg) [c]
Semi-major axis (km) [d] Orbital period (d)[d][e] Inclination [d][f] Eccentricity Position Discovery
year
Discoverer
1 S/2009 S/2009 S 1 PIA11665 moonlet in B Ring cropped.jpg ≈ 0.3 < 0.0001 ≈ 117000 ≈ 0.47 ≈ 0° ≈ 0 outer B Ring 2009 Cassini
(moonlets) A noisy image showing a few bright dots marked by circles 0.04 to 0.4 (Earhart) < 0.0001 ≈ 130000 ≈ 0.55 ≈ 0° ≈ 0 Three 1000 km bands within A Ring 2006 Cassini
2 XVIII Pan Pan /ˈpæn/ A bright fuzzy band (rings of Saturn) is running from the left to right. In the center a bright irregularity shaped body is superimposed on its upper edge. A narrow grayish band, which is a part of the main band, partially covers the body. 28.2±2.6
(34 × 31 × 20)
4.95±0.75 133584 +0.57505 0.001° 0.000035 in Encke Division 1990 M. Showalter
3 XXXV Daphnis Daphnis /ˈdæfnɪs/ Two bright bands run from the left to right. In the narrow gap between them (Keeler gap), which has wavy edges, a small oblong object can be seen. 7.6±1.6
(9 × 8 × 6)
0.084±0.012 136505 +0.59408 ≈ 0° ≈ 0 in Keeler Gap 2005 Cassini
4 XV Atlas Atlas /ˈætləs/ An irregularly shaped body is fully illuminated. The body, which looks like a cone viewed from the south pole, is elongated downward. 30.2±1.8
(41 × 35 × 19)
6.6±0.045 137670 +0.60169 0.003° 0.0012 outer A Ring shepherd 1980 Voyager 2
5 XVI Prometheus Prometheus /prˈmθiəs/ An irregularly shaped oblong body is fully illuminated. It is elongated in the direction from the right to left. Its surface is covered by craters. There is valley at the top. 86.2±5.4
(136 × 79 × 59)
159.5±1.5 139380 +0.61299 0.008° 0.0022 inner F Ring shepherd 1980 Voyager 2
6 XVII Pandora Pandora /pænˈdɔːrə/ An irregularly shaped body is half illuminated from the bottom. The terminator runs from the left to right. The surface is covered by numerous craters. 81.4±3.0
(104 × 81 × 64)
137.1±1.9 141720 +0.62850 0.050° 0.0042 outer F Ring Shepherd 1980 Voyager 2
7a XI Epimetheus Epimetheus /ɛpɪˈmθiəs/ A partially-illuminated irregular body, which has a shape remotely resembling a cube. The body's surface consists of ridges and valleys and is covered by craters. 116.2±3.6
(130 × 114 × 106)
526.6±0.6 151422 +0.69433 0.335° 0.0098 co-orbital with Janus 1977 J. Fountain, and S. Larson
7b X Janus Janus /ˈnəs/ An irregular body, whose outline looks like an approximate circle in this image. It is illuminated from the bottom-left. The terminator runs from the top-left to bottom-right. The surface is covered by craters. 179.0±2.8
(203 × 185 × 153)
1897.5±0.6 151472 +0.69466 0.165° 0.0068 co-orbital with Epimetheus 1966 A. Dollfus
9 LIII Aegaeon Aegaeon /ˈən/ Image of Aegaeon. ≈ 0.5 ≈ 0.0001 167500 +0.80812 0.001° 0.0002 G Ring moonlet 2008 Cassini
10 I MimasMimas /ˈmməs/ A spherical body is half illuminated from the left. The terminator runs from the top to bottom in the vicinity of the right limb. A large crater with a central peak sits on the terminator slightly to the right and above the center of the body. It makes the body look like the Death Star. There are numerous smaller craters. 396.4±0.8
(416 × 393 × 381)
37493±31 185404 +0.942422 1.566° 0.0202   1789 W. Herschel
11 XXXII Methone Methone /mɪˈθn/ From May 2012 flyby 3.2±1.2 ≈ 0.02 194440 +1.00957 0.007° 0.0001 Alkyonides 2004 Cassini
12 XLIX Anthe Anthe /ˈænθ/ Anthe N1832831075 1.jpg 1.8 ≈ 0.0015 197700 +1.05089 0.1° 0.0011 Alkyonides 2007 Cassini
13 XXXIII Pallene Pallene /pəˈln/ In the center is Pallene, a moon of Saturn 5.0±1.2
(6 × 6 × 4)
≈ 0.05 212280 +1.15375 0.181° 0.0040 Alkyonides 2004 Cassini
14 II EnceladusEnceladus /ɛnˈsɛlədəs/ A spherical body is half illuminated from the right. The terminator runs from the top to bottom in the vicinity of the left limb. In the center and at the top there are heavily cratered areas. 504.2±0.4
(513 × 503 × 497)
108022±101 237950 +1.370218 0.010° 0.0047 Generates the E ring 1789 W. Herschel
15 III TethysTethys /ˈtθɪs/ A spherical heavily cratered body is illuminated from the bottom. The terminator runs from the left to right in the vicinity of the top limb. There is a wide curved graben running from the center of the body to the bottom. It is Ithaca Chasma. 1062±1.2
(1077 × 1057 × 1053)
617449±132 294619 +1.887802 0.168° 0.0001   1684 G. Cassini
15a XIII Telesto Telesto /tɪˈlɛst/ Telesto cassini closeup.jpg 24.8±0.8
(33 × 24 × 20)
≈ 9.41 294619 +1.887802 1.158° 0.000 leading Tethys trojan 1980 B. Smith, H. Reitsema, S. Larson, and J. Fountain
15b XIV Calypso Calypso /kəˈlɪps/ An oblong reddish body is seen in this low resolution image. 21.4±1.4
(30 × 23 × 14)
≈ 6.3 294619 +1.887802 1.473° 0.000 trailing Tethys trojan 1980 D. Pascu, P. Seidelmann, W. Baum, and D. Currie
18 IV DioneDione /dˈn/ A spherical body is half illuminated from the right. The terminator is running from the top to bottom slightly to the left off the center. The central part of the body is smooth and has only a few craters. A heavily cratered terrain is near the right limb. A part of a large crater is intersected by the terminator in the lower-left corner. To the left of it there is a long crack running parallel to the terminator. 1122.8±0.8
(1128 × 1123 × 1119)
1095452±168 377396 +2.736915 0.002° 0.0022   1684 G. Cassini
18a XII Helene Helene /ˈhɛlɪn/ An irregularly shaped body illuminated from the left. Its surface is covered by numerous impact craters. 35.2±0.8
(43 × 38 × 26)
≈ 24.46 377396 +2.736915 0.212° 0.0022 leading Dione trojan 1980 P. Laques and J. Lecacheux
18b XXXIV Polydeuces Polydeuces /pɒliˈdjsz/ A small oblong body is barely resolved in this image. 2.6±0.8
(3 × 2 × 1)
≈ 0.03 377396 +2.736915 0.177° 0.0192 trailing Dione trojan 2004 Cassini
21 V RheaRhea /ˈrə/ A spherical body is almost fully illuminated. The terminator is running near the top edge. The surface is covered by numerous craters. Two partially overlapping large craters can be seen above the center. One that is younger is above and to the right from the older one. 1527.0±1.2
(1530 × 1526 × 1525)
2306518±353 527108 +4.518212 0.327° 0.001258   1672 G. Cassini
22 VI TitanTitan /ˈttən/ An orange spherical body is half illuminated from the right. The terminator is running from the top to bottom slightly to the left off the center. Both limb and terminator are fuzzy due to light scattering in the atmosphere. 5149.46±0.18
(5149 × 5149 × 5150)
134520000±20000 1221930 +15.94542 0.3485° 0.0288   1655 C. Huygens
23 VII HyperionHyperion /hˈpɪəriən/ An irregularly shaped oblong body is illuminated from the left. The terminator is near the right limb. The body is elongated in the top-bottom direction. The surface is punctured by numerous impact craters, which make it look like a sponge or cheese. 270±8
(360 × 266 × 205)
5620±50 1481010 +21.27661 0.568° 0.123006 in 4:3 resonance with Titan 1848 W. Bond
G. Bond
W. Lassell
24 VIII IapetusIapetus /ˈæpɪtəs/ A walnut shaped body illuminated from the bottom-left. The terminator runs from the top to right along the top-right limb. An equatorial ridge runs from the left to right and is convex in the direction of the bottom-left. Above and below it there are dark areas. Above the upper dark area and below the lower one there are bright poles. There numerous craters. Three among them are very large: one sits on the limb at the right another is in the center above the ridge. The third is below the ridge near the left limb. 1468.6±5.6
(1491 × 1491 × 1424)
1805635±375 3560820 +79.3215 15.47° 0.028613   1671 G. Cassini
25 XXIV KiviuqKiviuq /ˈkɪviək/ ≈ 16 ≈ 2.79 11294800 +448.16 49.087° 0.3288 Inuit group 2000 B. Gladman, J. Kavelaars, et al.
26 XXII IjiraqIjiraq /ˈɪrɒk/ Ijiraq discovery.gif ≈ 12 ≈ 1.18 11355316 +451.77 50.212° 0.3161 Inuit group 2000 B. Gladman, J. Kavelaars, et al.
27 IX Phoebe ♣†Phoebe /ˈfb/ An approximately spherical heavily cratered body is illuminated from the bottom-right. The terminator runs near the left and top limbs. There is huge crater at the top, which affects the shape, and another slightly smaller at the bottom. 213.0±1.4
(219 × 217 × 204)
8292±10 12869700 −545.09 173.047° 0.156242 Norse group 1899 W. Pickering
28 XX PaaliaqPaaliaq /ˈpɑːliɒk/ Paaliaq.jpg ≈ 22 ≈ 7.25 15103400 +692.98 46.151° 0.3631 Inuit group 2000 B. Gladman, J. Kavelaars, et al.
29 XXVII SkathiSkathi /ˈskɒði/ ≈ 8 ≈ 0.35 15672500 −732.52 149.084° 0.246 Norse (Skathi) Group 2000 B. Gladman, J. Kavelaars, et al.
30 XXVI AlbiorixAlbiorix /ˌælbiˈɒrɪks/ ≈ 32 ≈ 22.3 16266700 +774.58 38.042° 0.477 Gallic group 2000 M. Holman
31   S/2007AS/2007 S 2 ≈ 6 ≈ 0.15 16560000 −792.96 176.68° 0.2418 Norse group 2007 S. Sheppard, D. Jewitt, J. Kleyna, B. Marsden
32 XXXVII BebhionnBebhionn /bɛˈvn/ ≈ 6 ≈ 0.15 17153520 +838.77 40.484° 0.333 Gallic group 2004 S. Sheppard, D. Jewitt, J. Kleyna
33 XXVIII ErriapusErriapus /ɛriˈæpəs/ ≈ 10 ≈ 0.68 17236900 +844.89 38.109° 0.4724 Gallic group 2000 B. Gladman, J. Kavelaars, et al.
34 XLVII SkollSkoll /ˈskɒl/ ≈ 6 ≈ 0.15 17473800 −862.37 155.624° 0.418 Norse (Skathi) group 2006 S. Sheppard, D. Jewitt, J. Kleyna
35 XXIX SiarnaqSiarnaq /ˈsɑːrnək/ ≈ 40 ≈ 43.5 17776600 +884.88 45.798° 0.24961 Inuit group 2000 B. Gladman, J. Kavelaars, et al.
36 LII TarqeqTarqeq /ˈtɑːrkk/ ≈ 7 ≈ 0.23 17910600 +894.86 49.904° 0.1081 Inuit group 2007 S. Sheppard, D. Jewitt, J. Kleyna
37   S/2004BS/2004 S 13 ≈ 6 ≈ 0.15 18056300 −905.85 167.379° 0.261 Norse group 2004 S. Sheppard, D. Jewitt, J. Kleyna
38 LI GreipGreip /ˈɡrp/ ≈ 6 ≈ 0.15 18065700 −906.56 172.666° 0.3735 Norse group 2006 S. Sheppard, D. Jewitt, J. Kleyna
39 XLIV HyrrokkinHyrrokkin /hɪˈrɒkɪn/ ≈ 8 ≈ 0.35 18168300 −914.29 153.272° 0.3604 Norse (Skathi) group 2006 S. Sheppard, D. Jewitt, J. Kleyna
40 L JarnsaxaJarnsaxa /jɑːrnˈsæksə/ ≈ 6 ≈ 0.15 18556900 −943.78 162.861° 0.1918 Norse group 2006 S. Sheppard, D. Jewitt, J. Kleyna
41 XXI TarvosTarvos /ˈtɑːrvəs/ ≈ 15 ≈ 2.3 18562800 +944.23 34.679° 0.5305 Gallic group 2000 B. Gladman, J. Kavelaars, et al.
42 XXV MundilfariMundilfari /mʊndəlˈværi/ ≈ 7 ≈ 0.23 18725800 −956.70 169.378° 0.198 Norse group 2000 B. Gladman, J. Kavelaars, et al.
43   S/2006S/2006 S 1 ≈ 6 ≈ 0.15 18930200 −972.41 154.232° 0.1303 Norse (Skathi) group 2006 S. Sheppard, D.C. Jewitt, J. Kleyna
44   S/2004CS/2004 S 17 ≈ 4 ≈ 0.05 19099200 −985.45 166.881° 0.226 Norse group 2004 S. Sheppard, D. Jewitt, J. Kleyna
45 XXXVIII BergelmirBergelmir /bɛərˈjɛlmɪər/ ≈ 6 ≈ 0.15 19104000 −985.83 157.384° 0.152 Norse (Skathi) group 2004 S. Sheppard, D. Jewitt, J. Kleyna
46 XXXI NarviNarvi /ˈnɑːrvi/ Narvi.jpg ≈ 7 ≈ 0.23 19395200 −1008.45 137.292° 0.320 Norse (Narvi) group 2003 S. Sheppard, D. Jewitt, J. Kleyna
47 XXIII SuttungrSuttungr /ˈsʊtʊŋɡər/ ≈ 7 ≈ 0.23 19579000 −1022.82 174.321° 0.131 Norse group 2000 B. Gladman, J. Kavelaars, et al.
48 XLIII HatiHati /ˈhɑːti/ ≈ 6 ≈ 0.15 19709300 −1033.05 163.131° 0.291 Norse group 2004 S. Sheppard, D. Jewitt, J. Kleyna
49   S/2004AS/2004 S 12 ≈ 5 ≈ 0.09 19905900 −1048.54 164.042° 0.396 Norse group 2004 S. Sheppard, D. Jewitt, J. Kleyna
50 XL FarbautiFarbauti /fɑːrˈbti/ ≈ 5 ≈ 0.09 19984800 −1054.78 158.361° 0.209 Norse (Skathi) group 2004 S. Sheppard, D. Jewitt, J. Kleyna
51 XXX ThrymrThrymr /ˈθrɪmər/ ≈ 7 ≈ 0.23 20278100 −1078.09 174.524° 0.453 Norse group 2000 B. Gladman, J. Kavelaars, et al.
52 XXXVI AegirAegir /ˈ.ɪər/ ≈ 6 ≈ 0.15 20482900 −1094.46 167.425° 0.237 Norse group 2004 S. Sheppard, D. Jewitt, J. Kleyna
53   S/2007BS/2007 S 3 ≈ 5 ≈ 0.09 20518500 ≈ −1100 177.22° 0.130 Norse group 2007 S. Sheppard, D. Jewitt, J. Kleyna
54 XXXIX BestlaBestla /ˈbɛstlə/ ≈ 7 ≈ 0.23 20570000 −1101.45 147.395° 0.5145 Norse (Narvi) group 2004 S. Sheppard, D. Jewitt, J. Kleyna
55   S/2007CS/2004 S 7 ≈ 6 ≈ 0.15 20576700 −1101.99 165.596° 0.5299 Norse group 2004 S. Sheppard, D. Jewitt, J. Kleyna
56   S/2006S/2006 S 3 ≈ 6 ≈ 0.15 21076300 −1142.37 150.817° 0.4710 Norse (Skathi) group 2006 S. Sheppard, D. Jewitt, J. Kleyna
57 XLI FenrirFenrir /ˈfɛnrɪər/ ≈ 4 ≈ 0.05 21930644 −1212.53 162.832° 0.131 Norse group 2004 S. Sheppard, D. Jewitt, J. Kleyna
58 XLVIII SurturSurtur /ˈsɜːrtər/ ≈ 6 ≈ 0.15 22288916 −1242.36 166.918° 0.3680 Norse group 2006 S. Sheppard, D. Jewitt, J. Kleyna
59 XLV KariKari /ˈkɑːri/ ≈ 7 ≈ 0.23 22321200 −1245.06 148.384° 0.3405 Norse (Skathi) group 2006 S. Sheppard, D. Jewitt, J. Kleyna
60 XIX YmirYmir /ˈɪmɪər/ ≈ 18 ≈ 3.97 22429673 −1254.15 172.143° 0.3349 Norse group 2000 B. Gladman, J. Kavelaars, et al.
61 XLVI LogeLoge /ˈlɔɪ./ ≈ 6 ≈ 0.15 22984322 −1300.95 166.539° 0.1390 Norse group 2006 S. Sheppard, D. Jewitt, J. Kleyna
62 XLII FornjotFornjot /ˈfɔːrnjɒt/ ≈ 6 ≈ 0.15 24504879 −1432.16 167.886° 0.186 Norse group 2004 S. Sheppard, D. Jewitt, J. Kleyna

Unconfirmed moons[change | change source]

The following objects (observed by Cassini) have not been confirmed as solid bodies. It is not yet clear if these are real satellites or merely persistent clumps within the F Ring.

Name Image Diameter (km) Semi-major
axis (km)
Orbital
period (d)
Position Discovery year
S/2004 S 6 A bright narrow band runs from the top to bottom. To the right of it in the diffuse halo the is a bright small object. ≈ 3–5 ≈ 140130 +0.61801 uncertain objects around the F Ring 2004
S/2004 S 3/S 4[g] S2004 S 3 - PIA06115.png ≈ 3–5 ≈ 140300 ≈ +0.619 2004

Hypothetical moons[change | change source]

Two moons were claimed to be discovered by different astronomers but never seen again. Both moons were said to orbit between Titan and Hyperion.

  • Chiron which was supposedly sighted by Hermann Goldschmidt in 1861, but never observed by anyone else.
  • Themis was allegedly discovered in 1905 by astronomer William Pickering, but never seen again. Nevertheless, it was included in numerous almanacs and astronomy books until the 1960s.

References[change | change source]

  1. "Saturn: Moons". Solar System Exploration: Planets. National Aeronautics and Space Administration. 2011. Retrieved 2011-04-21.
  2. "About Saturn & Its Moons". Cassini Solstice Mission. National Aeronautics and Space Administration. 2011. Retrieved 2011-06-25.

Notes

  1. A confirmed moon is given a permanent designation by the IAU consisting of a name and a Roman numeral. The nine moons that were known before 1900 (of which Phoebe is the only irregular) are numbered in order of their distance from Saturn; the rest are numbered in the order by which they received their permanent designations. Nine small moons of the Norse group and S/2009 S 1 have not yet received a permanent designation.
  2. The diameters and dimensions of the inner moons from Pan through Janus, Methone, Pallene, Telepso, Calypso, Helene, Hyperion and Phoebe were taken from Thomas 2010, Table 3. Diameters and dimensions of Mimas, Enceladus, Tethys, Dione, Rhea and Iapetus are from Thomas 2010, Table 1. The approximate sizes of other satellites are from the website of Scott Sheppard.
  3. Masses of the large moons were taken from Jacobson, 2006. Masses of Pan, Daphnis, Atlas, Prometheus, Pandora, Epimetheus, Janus, Hyperion and Phoebe were taken from Thomas, 2010, Table 3. Masses of other small moons were calculated assuming a density of 1.3 g/cm3.
  4. 4.0 4.1 4.2 The orbital parameters were taken from Spitale, et al. 2006, IAU-MPC Natural Satellites Ephemeris Service, and NASA/NSSDC.
  5. Negative orbital periods indicate a retrograde orbit around Saturn (opposite to the planet's rotation).
  6. To Saturn's equator for the regular satellites, and to the ecliptic for the irregular satellites
  7. S/2004 S 4 was most likely a transient clump—it has not been recovered since the first sighting.