Moons of Saturn

The planet Saturn has 146 named moons, and another 29 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

Confirmed moons

The moons of Saturn 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

Very recently, there have been 20 new discoveries of moons on Saturn that have not yet been named.

Order	Label ^[a]	Name	Pronunciation	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	baaniroop	S/2009 S 1	—	≈ 0.3	< 0.0001	≈ 117000	≈ 0.47	≈ 0°	≈ 0	outer B Ring	2009	Cassini
		(moonlets)	—	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	/ˈpæn/	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	/ˈdæfnɪs/	7.6±1.6 (9 × 8 × 6)	0.084±0.012	136505	+0.59408	≈ 0°	≈ 0	in Keeler Gap	2005	Cassini
4	XV	Atlas	/ˈætləs/	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	/proʊˈmiːθiəs/	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	/pænˈdɔːrə/	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	/ɛpɪˈmiːθiəs/	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	/ˈdʒeɪnəs/	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	/iːˈdʒiːən/	≈ 0.5	≈ 0.0001	167500	+0.80812	0.001°	0.0002	G Ring moonlet	2008	Cassini
10	I	†Mimas	/ˈmaɪməs/	396.4±0.8 (416 × 393 × 381)	37493±31	185404	+0.942422	1.566°	0.0202		1789	W. Herschel
11	XXXII	Methone	/mɪˈθoʊniː/	3.2±1.2	≈ 0.02	194440	+1.00957	0.007°	0.0001	Alkyonides	2004	Cassini
12	XLIX	Anthe	/ˈænθiː/	1.8	≈ 0.0015	197700	+1.05089	0.1°	0.0011	Alkyonides	2007	Cassini
13	XXXIII	Pallene	/pəˈliːniː/	5.0±1.2 (6 × 6 × 4)	≈ 0.05	212280	+1.15375	0.181°	0.0040	Alkyonides	2004	Cassini
14	II	†Enceladus	/ɛnˈsɛlədəs/	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	†Tethys	/ˈtiːθɪs/	1062±1.2 (1077 × 1057 × 1053)	617449±132	294619	+1.887802	0.168°	0.0001		1684	G. Cassini
15a	XIII	Telesto	/tɪˈlɛstoʊ/	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	/kəˈlɪpsoʊ/	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	†Dione	/daɪˈoʊniː/	1122.8±0.8 (1128 × 1123 × 1119)	1095452±168	377396	+2.736915	0.002°	0.0022		1684	G. Cassini
18a	XII	Helene	/ˈhɛlɪniː/	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	/pɒliˈdjuːsiːz/	2.6±0.8 (3 × 2 × 1)	≈ 0.03	377396	+2.736915	0.177°	0.0192	trailing Dione trojan	2004	Cassini
21	V	†Rhea	/ˈriːə/	1527.0±1.2 (1530 × 1526 × 1525)	2306518±353	527108	+4.518212	0.327°	0.001258		1672	G. Cassini
22	VI	♠Titan	/ˈtaɪtən/	5149.46±0.18 (5149 × 5149 × 5150)	134520000±20000	1221930	+15.94542	0.3485°	0.0288		1655	C. Huygens
23	VII	†Hyperion	/haɪˈpɪəriən/	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	†Iapetus	/aɪˈæpɪtəs/	1468.6±5.6 (1491 × 1491 × 1424)	1805635±375	3560820	+79.3215	15.47°	0.028613		1671	G. Cassini
25	XXIV	‡Kiviuq	/ˈkɪviək/	≈ 16	≈ 2.79	11294800	+448.16	49.087°	0.3288	Inuit group	2000	B. Gladman, J. Kavelaars, et al.
26	XXII	‡Ijiraq	/ˈiːɪrɒk/	≈ 12	≈ 1.18	11355316	+451.77	50.212°	0.3161	Inuit group	2000	B. Gladman, J. Kavelaars, et al.
27	IX	♣†Phoebe	/ˈfiːbiː/	213.0±1.4 (219 × 217 × 204)	8292±10	12869700	−545.09	173.047°	0.156242	Norse group	1899	W. Pickering
28	XX	‡Paaliaq	/ˈpɑːliɒk/	≈ 22	≈ 7.25	15103400	+692.98	46.151°	0.3631	Inuit group	2000	B. Gladman, J. Kavelaars, et al.
29	XXVII	♣Skathi	/ˈskɒði/	≈ 8	≈ 0.35	15672500	−732.52	149.084°	0.246	Norse (Skathi) Group	2000	B. Gladman, J. Kavelaars, et al.
30	XXVI	♦Albiorix	/ˌælbiˈɒrɪks/	≈ 32	≈ 22.3	16266700	+774.58	38.042°	0.477	Gallic group	2000	M. Holman
31		♣S/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	♦Bebhionn	/bɛˈviːn/	≈ 6	≈ 0.15	17153520	+838.77	40.484°	0.333	Gallic group	2004	S. Sheppard, D. Jewitt, J. Kleyna
33	XXVIII	♦Erriapus	/ɛriˈæpəs/	≈ 10	≈ 0.68	17236900	+844.89	38.109°	0.4724	Gallic group	2000	B. Gladman, J. Kavelaars, et al.
34	XLVII	♣Skoll	/ˈskɒl/	≈ 6	≈ 0.15	17473800	−862.37	155.624°	0.418	Norse (Skathi) group	2006	S. Sheppard, D. Jewitt, J. Kleyna
35	XXIX	‡Siarnaq	/ˈsiːɑːrnək/	≈ 40	≈ 43.5	17776600	+884.88	45.798°	0.24961	Inuit group	2000	B. Gladman, J. Kavelaars, et al.
36	LII	‡Tarqeq	/ˈtɑːrkeɪk/	≈ 7	≈ 0.23	17910600	+894.86	49.904°	0.1081	Inuit group	2007	S. Sheppard, D. Jewitt, J. Kleyna
37		♣S/2004 S 13	—	≈ 6	≈ 0.15	18056300	−905.85	167.379°	0.261	Norse group	2004	S. Sheppard, D. Jewitt, J. Kleyna
38	LI	♣Greip	/ˈɡreɪp/	≈ 6	≈ 0.15	18065700	−906.56	172.666°	0.3735	Norse group	2006	S. Sheppard, D. Jewitt, J. Kleyna
39	XLIV	♣Hyrrokkin	/hɪˈrɒkɪn/	≈ 8	≈ 0.35	18168300	−914.29	153.272°	0.3604	Norse (Skathi) group	2006	S. Sheppard, D. Jewitt, J. Kleyna
40	L	♣Jarnsaxa	/jɑːrnˈsæksə/	≈ 6	≈ 0.15	18556900	−943.78	162.861°	0.1918	Norse group	2006	S. Sheppard, D. Jewitt, J. Kleyna
41	XXI	♦Tarvos	/ˈtɑːrvəs/	≈ 15	≈ 2.3	18562800	+944.23	34.679°	0.5305	Gallic group	2000	B. Gladman, J. Kavelaars, et al.
42	XXV	♣Mundilfari	/mʊndəlˈværi/	≈ 7	≈ 0.23	18725800	−956.70	169.378°	0.198	Norse group	2000	B. Gladman, J. Kavelaars, et al.
43		♣S/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/2004 S 17	—	≈ 4	≈ 0.05	19099200	−985.45	166.881°	0.226	Norse group	2004	S. Sheppard, D. Jewitt, J. Kleyna
45	XXXVIII	♣Bergelmir	/bɛərˈjɛlmɪər/	≈ 6	≈ 0.15	19104000	−985.83	157.384°	0.152	Norse (Skathi) group	2004	S. Sheppard, D. Jewitt, J. Kleyna
46	XXXI	♣Narvi	/ˈnɑːrvi/	≈ 7	≈ 0.23	19395200	−1008.45	137.292°	0.320	Norse (Narvi) group	2003	S. Sheppard, D. Jewitt, J. Kleyna
47	XXIII	♣Suttungr	/ˈsʊtʊŋɡər/	≈ 7	≈ 0.23	19579000	−1022.82	174.321°	0.131	Norse group	2000	B. Gladman, J. Kavelaars, et al.
48	XLIII	♣Hati	/ˈhɑːti/	≈ 6	≈ 0.15	19709300	−1033.05	163.131°	0.291	Norse group	2004	S. Sheppard, D. Jewitt, J. Kleyna
49		♣S/2004 S 12	—	≈ 5	≈ 0.09	19905900	−1048.54	164.042°	0.396	Norse group	2004	S. Sheppard, D. Jewitt, J. Kleyna
50	XL	♣Farbauti	/fɑːrˈbaʊti/	≈ 5	≈ 0.09	19984800	−1054.78	158.361°	0.209	Norse (Skathi) group	2004	S. Sheppard, D. Jewitt, J. Kleyna
51	XXX	♣Thrymr	/ˈθrɪmər/	≈ 7	≈ 0.23	20278100	−1078.09	174.524°	0.453	Norse group	2000	B. Gladman, J. Kavelaars, et al.
52	XXXVI	♣Aegir	/ˈaɪ.ɪər/	≈ 6	≈ 0.15	20482900	−1094.46	167.425°	0.237	Norse group	2004	S. Sheppard, D. Jewitt, J. Kleyna
53		♣S/2007 S 3	—	≈ 5	≈ 0.09	20518500	≈ −1100	177.22°	0.130	Norse group	2007	S. Sheppard, D. Jewitt, J. Kleyna
54	XXXIX	♣Bestla	/ˈbɛstlə/	≈ 7	≈ 0.23	20570000	−1101.45	147.395°	0.5145	Norse (Narvi) group	2004	S. Sheppard, D. Jewitt, J. Kleyna
55		♣S/2004 S 7	—	≈ 6	≈ 0.15	20576700	−1101.99	165.596°	0.5299	Norse group	2004	S. Sheppard, D. Jewitt, J. Kleyna
56		♣S/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	♣Fenrir	/ˈfɛnrɪər/	≈ 4	≈ 0.05	21930644	−1212.53	162.832°	0.131	Norse group	2004	S. Sheppard, D. Jewitt, J. Kleyna
58	XLVIII	♣Surtur	/ˈsɜːrtər/	≈ 6	≈ 0.15	22288916	−1242.36	166.918°	0.3680	Norse group	2006	S. Sheppard, D. Jewitt, J. Kleyna
59	XLV	♣Kari	/ˈkɑːri/	≈ 7	≈ 0.23	22321200	−1245.06	148.384°	0.3405	Norse (Skathi) group	2006	S. Sheppard, D. Jewitt, J. Kleyna
60	XIX	♣Ymir	/ˈɪmɪər/	≈ 18	≈ 3.97	22429673	−1254.15	172.143°	0.3349	Norse group	2000	B. Gladman, J. Kavelaars, et al.
61	XLVI	♣Loge	/ˈlɔɪ.eɪ/	≈ 6	≈ 0.15	22984322	−1300.95	166.539°	0.1390	Norse group	2006	S. Sheppard, D. Jewitt, J. Kleyna
62	XLII	♣Fornjot	/ˈfɔːrnjɒt/	≈ 6	≈ 0.15	24504879	−1432.16	167.886°	0.186	Norse group	2004	S. Sheppard, D. Jewitt, J. Kleyna

Unconfirmed moons

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		≈ 3–5	≈ 140130	+0.61801	uncertain objects around the F Ring	2004
S/2004 S 3/S 4^[g]		≈ 3–5	≈ 140300	≈ +0.619	uncertain objects around the F Ring	2004

Hypothetical moons

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

↑ "Saturn: Moons". Solar System Exploration: Planets. National Aeronautics and Space Administration. 2011. Archived from the original on 2011-03-16. Retrieved 2011-04-21.
↑ "About Saturn & Its Moons". Cassini Solstice Mission. National Aeronautics and Space Administration. 2011. Retrieved 2011-06-25.

Notes

↑ 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.
↑ 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.
↑ 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.
↑ ^4.0 ^4.1 ^4.2 The orbital parameters were taken from Spitale, et al. 2006, IAU-MPC Natural Satellites Ephemeris Service, and NASA/NSSDC.
↑ Negative orbital periods indicate a retrograde orbit around Saturn (opposite to the planet's rotation).
↑ To Saturn's equator for the regular satellites, and to the ecliptic for the irregular satellites
↑ S/2004 S 4 was most likely a transient clump—it has not been recovered since the first sighting.

[1] "Saturn: Moons". Solar System Exploration: Planets. National Aeronautics and Space Administration. 2011. Archived from the original on 2011-03-16. Retrieved 2011-04-21.

[2] "About Saturn & Its Moons". Cassini Solstice Mission. National Aeronautics and Space Administration. 2011. Retrieved 2011-06-25.

[3] 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.

[diameter-4] 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.

[5] 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.

[orbital-6] 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.

[7] Negative orbital periods indicate a retrograde orbit around Saturn (opposite to the planet's rotation).

[8] To Saturn's equator for the regular satellites, and to the ecliptic for the irregular satellites

[note_2a-9] S/2004 S 4 was most likely a transient clump—it has not been recovered since the first sighting.

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