The moons of Saturn are numerous and diverse, ranging from tiny moonlets only tens of meters across to the enormous Titan, which is larger than the planet Mercury. There are 146 moons with confirmed orbits, the most of any planet in the solar system. This number does not include the many thousands of moonlets embedded within Saturn's dense rings, nor hundreds of possible kilometer-sized distant moons that have been observed on single occasions. Seven Saturnian moons are large enough to have collapsed into a relaxed, ellipsoidal shape, though only one or two of those, Titan and possibly Rhea, are currently in hydrostatic equilibrium. Three moons are particularly notable. Titan is the second-largest moon in the Solar System (after Jupiter's Ganymede), with a nitrogen-rich Earth-like atmosphere and a landscape featuring river networks and hydrocarbon lakes.[1] Enceladus emits jets of ice from its south-polar region and is covered in a deep layer of snow.[2] Iapetus has contrasting black and white hemispheres as well as an extensive ridge of equatorial mountains among the tallest in the solar system.
Of the known moons, 24 are regular satellites; they have prograde orbits not greatly inclined to Saturn's equatorial plane,[3] with the exception of Iapetus which has a prograde but highly inclined orbit,[4] [5] an unusual characteristic for a regular moon. They include the seven major satellites, four small moons that exist in a trojan orbit with larger moons, and five that act as shepherd moons, of which two are mutually co-orbital. Two tiny moons orbit inside of Saturn's B and G rings. The relatively large Hyperion is locked in an orbital resonance with Titan. The remaining regular moons orbit near the outer edges of the dense A Ring and the narrow F Ring, and between the major moons Mimas and Enceladus. The regular satellites are traditionally named after Titans and Titanesses or other figures associated with the mythological Saturn.
The remaining 122, with mean diameters ranging from, orbit much farther from Saturn. They are irregular satellites, having high orbital inclinations and eccentricities mixed between prograde and retrograde. These moons are probably captured minor planets, or fragments from the collisional breakup of such bodies after they were captured, creating collisional families. Saturn is expected to have around 150 irregular satellites larger than in diameter, plus many hundreds more that are even smaller. The irregular satellites are classified by their orbital characteristics into the prograde Inuit and Gallic groups and the large retrograde Norse group, and their names are chosen from the corresponding mythologies (with the Gallic group corresponding to Celtic mythology). The sole exception is Phoebe, the largest irregular Saturnian moon, discovered at the end of the 19th century; it is part of the Norse group but named for a Greek Titaness.
The rings of Saturn are made up of objects ranging in size from microscopic to moonlets hundreds of meters across, each in its own orbit around Saturn. Thus an absolute number of Saturnian moons cannot be given, because there is no consensus on a boundary between the countless small unnamed objects that form Saturn's ring system and the larger objects that have been named as moons. Over 150 moonlets embedded in the rings have been detected by the disturbance they create in the surrounding ring material, though this is thought to be only a small sample of the total population of such objects.
, there are 83 designated moons that are still unnamed; all but one (the designated B-ring moonlet S/2009 S 1) are irregular. (There are many other undesignated ring moonlets.) If named, most of the irregulars will receive names from Gallic, Norse and Inuit mythology based on the orbital group of which they are a member.[6]
Before the advent of telescopic photography, eight moons of Saturn were discovered by direct observation using optical telescopes. Saturn's largest moon, Titan, was discovered in 1655 by Christiaan Huygens using a 57mm objective lens on a refracting telescope of his own design. Tethys, Dione, Rhea and Iapetus (the "Sidera Lodoicea") were discovered between 1671 and 1684 by Giovanni Domenico Cassini. Mimas and Enceladus were discovered in 1789 by William Herschel. Hyperion was discovered in 1848 by W. C. Bond, G. P. Bond and William Lassell.
The use of long-exposure photographic plates made possible the discovery of additional moons. The first to be discovered in this manner, Phoebe, was found in 1899 by W. H. Pickering. In 1966 the tenth satellite of Saturn was discovered by Audouin Dollfus, when the rings were observed edge-on near an equinox. It was later named Janus. A few years later it was realized that all observations of 1966 could only be explained if another satellite had been present and that it had an orbit similar to that of Janus. This object is now known as Epimetheus, the eleventh moon of Saturn. It shares the same orbit with Janus—the only known example of co-orbitals in the Solar System. In 1980, three additional Saturnian moons were discovered from the ground and later confirmed by the Voyager probes. They are trojan moons of Dione (Helene) and Tethys (Telesto and Calypso).
The study of the outer planets has since been revolutionized by the use of uncrewed space probes. The arrival of the Voyager spacecraft at Saturn in 1980–1981 resulted in the discovery of three additional moons—Atlas, Prometheus and Pandora—bringing the total to 17. In addition, Epimetheus was confirmed as distinct from Janus. In 1990, Pan was discovered in archival Voyager images.
The Cassini mission,[7] which arrived at Saturn in July 2004, initially discovered three small inner moons: Methone and Pallene between Mimas and Enceladus, and the second trojan moon of Dione, Polydeuces. It also observed three suspected but unconfirmed moons in the F Ring. In Cassini scientists announced that the structure of Saturn's rings indicates the presence of several more moons orbiting within the rings, although only one, Daphnis, had been visually confirmed at the time. In 2007 Anthe was announced. In 2008 it was reported that Cassini observations of a depletion of energetic electrons in Saturn's magnetosphere near Rhea might be the signature of a tenuous ring system around Saturn's second largest moon. In, Aegaeon, a moonlet within the G Ring, was announced. In July of the same year, S/2009 S 1, the first moonlet within the B Ring, was observed. In April 2014, the possible beginning of a new moon, within the A Ring, was reported.[8] (related image)
Study of Saturn's moons has also been aided by advances in telescope instrumentation, primarily the introduction of digital charge-coupled devices which replaced photographic plates. For the 20th century, Phoebe stood alone among Saturn's known moons with its highly irregular orbit. Then in 2000, three dozen additional irregular moons were discovered using ground-based telescopes. A survey starting in late 2000 and conducted using three medium-size telescopes found thirteen new moons orbiting Saturn at a great distance, in eccentric orbits, which are highly inclined to both the equator of Saturn and the ecliptic. They are probably fragments of larger bodies captured by Saturn's gravitational pull. In 2005, astronomers using the Mauna Kea Observatory announced the discovery of twelve more small outer moons, in 2006, astronomers using the Subaru 8.2 m telescope reported the discovery of nine more irregular moons, in, Tarqeq (S/2007 S 1) was announced and in May of the same year S/2007 S 2 and S/2007 S 3 were reported. In 2019, twenty new irregular satellites of Saturn were reported, resulting in Saturn overtaking Jupiter as the planet with the most known moons for the first time since 2000.[9]
In 2019, researchers Edward Ashton, Brett Gladman, and Matthew Beaudoin conducted a survey of Saturn's Hill sphere using the 3.6-meter Canada–France–Hawaii Telescope and discovered about 80 new Saturnian irregular moons. Follow-up observations of these new moons took place over 2019–2021, eventually leading to S/2019 S 1 being announced in November 2021 and an additional 62 moons being announced from 3–16 May 2023. These discoveries brought Saturn's total number of confirmed moons up to 145, making it the first planet known to have over 100 moons.[10] [11] Yet another moon, S/2006 S 20, was announced on 23 May 2023, bringing Saturn's total count moons to 146. All of these new moons are small and faint, with diameters over and apparent magnitudes of 25–27. The researchers found that the Saturnian irregular moon population is more abundant at smaller sizes, suggesting that they are likely fragments from a collision that occurred a few hundred million years ago. The researchers extrapolated that the true population of Saturnian irregular moons larger than in diameter amounts to, which is approximately three times as many Jovian irregular moons down to the same size. If this size distribution applies to even smaller diameters, Saturn would therefore intrinsically have more irregular moons than Jupiter.
See main article: Naming of moons. The modern names for Saturnian moons were suggested by John Herschel in 1847. He proposed to name them after mythological figures associated with the Roman god of agriculture and harvest, Saturn (equated to the Greek Cronus). In particular, the then known seven satellites were named after Titans, Titanesses and Giants – brothers and sisters of Cronus. The idea was similar to Simon Marius' mythological naming scheme for the moons of Jupiter.[12]
As Saturn devoured his children, his family could not be assembled around him, so that the choice lay among his brothers and sister, the Titans and Titanesses. The name Iapetus seemed indicated by the obscurity and remoteness of the exterior satellite, Titan by the superior size of the Huyghenian, while the three female appellations [''Rhea'', ''Dione'', and ''Tethys''] class together the three intermediate Cassinian satellites. The minute interior ones seemed appropriately characterized by a return to male appellations [''Enceladus'' and ''Mimas''] chosen from a younger and inferior (though still superhuman) brood. [''Results of the Astronomical Observations made ... at the Cape of Good Hope'', p. 415]
In 1848, Lassell proposed that the eighth satellite of Saturn be named Hyperion after another Titan.[12] When in the 20th century the names of Titans were exhausted, the moons were named after different characters of the Greco-Roman mythology or giants from other mythologies. All the irregular moons (except Phoebe, discovered about a century before the others) are named after Inuit, and Gallic gods, and after Norse ice giants.
Some asteroids share the same names as moons of Saturn: 55 Pandora, 106 Dione, 577 Rhea, 1809 Prometheus, 1810 Epimetheus, and 4450 Pan. In addition, three more asteroids would share the names of Saturnian moons but for spelling differences made permanent by the International Astronomical Union (IAU): Calypso and asteroid 53 Kalypso; Helene and asteroid 101 Helena; and Gunnlod and asteroid 657 Gunlöd.
Saturn's satellite system is very lopsided: one moon, Titan, comprises more than 96% of the mass in orbit around the planet. The six other planemo (ellipsoidal) moons constitute roughly 4% of the mass, and the remaining small moons, together with the rings, comprise only 0.04%.
| Name | data-sort-type="number" | Diameter (km) | data-sort-type="number" | Mass (kg) | data-sort-type="number" | Orbital radius (km) | data-sort-type="number" | Orbital period (days) |
|---|---|---|---|---|---|---|---|---|
| Mimas | 396 (0.12 D☾) | data-sort-value=4.0E19 | 4×1019 (0.0005 M☾) | 185,539 (0.48 a☾) | 0.9 (0.03 T☾) | |||
| Enceladus | 504 (0.14 D☾) | data-sort-value=1.1E20 | 1.1×1020 (0.002 M☾) | 237,948 (0.62 a☾) | 1.4 (0.05 T☾) | |||
| Tethys | 1,062 (0.30 D☾) | data-sort-value=6.2E20 | 6.2×1020 (0.008 M☾) | 294,619 (0.77 a☾) | 1.9 (0.07 T☾) | |||
| Dione | 1,123 (0.32 D☾) | data-sort-value=1.1E21 | 1.1×1021 (0.015 M☾) | 377,396 (0.98 a☾) | 2.7 (0.10 T☾) | |||
| Rhea | 1,527 (0.44 D☾) | data-sort-value=2.3E21 | 2.3×1021 (0.03 M☾) | 527,108 (1.37 a☾) | 4.5 (0.20 T☾) | |||
| Titan | 5,149 (1.48 D☾) (0.75 D♂) | data-sort-value=1.35E23 | 1.35×1023 (1.80 M☾) (0.21 M♂) | 1,221,870 (3.18 a☾) | 16 (0.60 T☾) | |||
| Iapetus | 1,470 (0.42 D☾) | data-sort-value=1.8E21 | 1.8×1021 (0.025 M☾) | 3,560,820 (9.26 a☾) | 79 (2.90 T☾) |
Although the boundaries may be somewhat vague, Saturn's moons can be divided into ten groups according to their orbital characteristics. Many of them, such as Pan and Daphnis, orbit within Saturn's ring system and have orbital periods only slightly longer than the planet's rotation period. The innermost moons and most regular satellites all have mean orbital inclinations ranging from less than a degree to about 1.5 degrees (except Iapetus, which has an inclination of 7.57 degrees) and small orbital eccentricities. On the other hand, irregular satellites in the outermost regions of Saturn's moon system, in particular the Norse group, have orbital radii of millions of kilometers and orbital periods lasting several years. The moons of the Norse group also orbit in the opposite direction to Saturn's rotation.
During late July 2009, a moonlet, S/2009 S 1, was discovered in the B Ring, 480 km from the outer edge of the ring, by the shadow it cast. It is estimated to be 300 m in diameter. Unlike the A Ring moonlets (see below), it does not induce a 'propeller' feature, probably due to the density of the B Ring.
In 2006, four tiny moonlets were found in Cassini images of the A Ring. Before this discovery only two larger moons had been known within gaps in the A Ring: Pan and Daphnis. These are large enough to clear continuous gaps in the ring. In contrast, a moonlet is only massive enough to clear two small—about 10 km across—partial gaps in the immediate vicinity of the moonlet itself creating a structure shaped like an airplane propeller. The moonlets themselves are tiny, ranging from about 40 to 500 meters in diameter, and are too small to be seen directly.
In 2007, the discovery of 150 more moonlets revealed that they (with the exception of two that have been seen outside the Encke gap) are confined to three narrow bands in the A Ring between 126,750 and 132,000 km from Saturn's center. Each band is about a thousand kilometers wide, which is less than 1% the width of Saturn's rings. This region is relatively free from the disturbances caused by resonances with larger satellites, although other areas of the A Ring without disturbances are apparently free of moonlets. The moonlets were probably formed from the breakup of a larger satellite. It is estimated that the A Ring contains 7,000–8,000 propellers larger than 0.8 km in size and millions larger than 0.25 km. In April 2014, NASA scientists reported the possible consolidation of a new moon within the A Ring, implying that Saturn's present moons may have formed in a similar process in the past when Saturn's ring system was much more massive.[8]
Similar moonlets may reside in the F Ring. There, "jets" of material may be due to collisions, initiated by perturbations from the nearby small moon Prometheus, of these moonlets with the core of the F Ring. One of the largest F Ring moonlets may be the as-yet unconfirmed object S/2004 S 6. The F Ring also contains transient "fans" which are thought to result from even smaller moonlets, about 1 km in diameter, orbiting near the F Ring core.
One recently discovered moon, Aegaeon, resides within the bright arc of G Ring and is trapped in the 7:6 mean-motion resonance with Mimas. This means that it makes exactly seven revolutions around Saturn while Mimas makes exactly six. The moon is the largest among the population of bodies that are sources of dust in this ring.
Shepherd satellites are small 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 (Encke gap), Daphnis (Keeler gap), Prometheus (F Ring), Janus (A Ring), and Epimetheus (A Ring). These moons probably formed as a result of accretion of the friable ring material on preexisting denser cores. The cores with sizes from one-third to one-half the present-day moons may be themselves collisional shards formed when a parental satellite of the rings disintegrated.
Janus and Epimetheus are co-orbital moons. They are of similar size, with Janus being somewhat larger than Epimetheus. They have orbits with less than a 100-kilometer difference in semi-major axis, close enough that they would collide if they attempted to pass each other. Instead of colliding, their gravitational interaction causes them to swap orbits every four years.
Other inner moons that are neither ring shepherds nor ring moonlets include Atlas and Pandora.
The innermost large moons of Saturn orbit within its tenuous E Ring, along with three smaller moons of the Alkyonides group.
Three small moons orbit between Mimas and Enceladus: Methone, Anthe, and Pallene. Named after the Alkyonides of Greek mythology, they are some of the smallest moons in the Saturn system. Anthe and Methone have very faint ring arcs along their orbits, whereas Pallene has a faint complete ring. Of these three moons, only Methone has been photographed at close range, showing it to be egg-shaped with very few or no craters.[14]
Trojan moons are a unique feature only known from the Saturnian system. A trojan body orbits at either the leading L4 or trailing L5 Lagrange point of a much larger object, such as a large moon or planet. Tethys has two trojan moons, Telesto (leading) and Calypso (trailing), and Dione also has two, Helene (leading) and Polydeuces (trailing). Helene is by far the largest trojan moon, while Polydeuces is the smallest and has the most chaotic orbit. These moons are coated with dusty material that has smoothed out their surfaces.[15]
These moons all orbit beyond the E Ring. They are:
Irregular moons are small satellites with large-radii, inclined, and frequently retrograde orbits, believed to have been acquired by the parent planet through a capture process. They often occur as collisional families or groups. The precise size as well as albedo of the irregular moons are not known for sure because the moons are very small to be resolved by a telescope, although the latter is usually assumed to be quite low—around 6% (albedo of Phoebe) or less. The irregulars generally have featureless visible and near infrared spectra dominated by water absorption bands. They are neutral or moderately red in color—similar to C-type, P-type, or D-type asteroids, though they are much less red than Kuiper belt objects.
See main article: Inuit group. The Inuit group includes twelve prograde outer moons that are similar enough in their distances from the planet (190–300 radii of Saturn), their orbital inclinations (45–50°) and their colors that they can be considered a group. The Inuit group is further split into three distinct subgroups at different semi-major axes, and are named after their respective largest members. Ordered by increasing semi-major axis, these subgroups are the Kiviuq group, the Paaliaq group, and the Siarnaq group. The Kiviuq group includes five members: Kiviuq, Ijiraq, S/2005 S 4, S/2019 S 1, and S/2020 S 1. The Siarnaq group includes six members: Siarnaq, Tarqeq, S/2004 S 31, S/2019 S 14, S/2020 S 3, and S/2020 S 5. In contrast to the Kiviuq and Siarnaq subgroups, the Paaliaq subgroup does not contain any other known members besides Paaliaq itself. Of the entire Inuit group, Siarnaq is the largest member with an estimated size of about 39 km.
See main article: Gallic group. The Gallic group includes seven prograde outer moons that are similar enough in their distance from the planet (200–300 radii of Saturn), their orbital inclination (35–40°) and their color that they can be considered a group. They are Albiorix, Bebhionn, Erriapus, Tarvos, Saturn LX, S/2007 S 8, and S/2020 S 4. The largest of these moons is Albiorix with an estimated diameter of about 29 km.
See main article: Norse group.
All 100 retrograde outer moons of Saturn are broadly classified into the Norse group. They are Aegir, Angrboda, Alvaldi, Beli, Bergelmir, Bestla, Eggther, Farbauti, Fenrir, Fornjot, Geirrod, Gerd, Greip, Gridr, Gunnlod, Hati, Hyrrokkin, Jarnsaxa, Kari, Loge, Mundilfari, Narvi, Phoebe, Skathi, Skoll, Skrymir, Surtur, Suttungr, Thiazzi, Thrymr, Ymir, and 69 unnamed satellites. After Phoebe, Ymir is the largest of the known retrograde irregular moons, with an estimated diameter of only 22 km.
Three prograde moons of Saturn do not definitively belong to either the Inuit or Gallic groups. S/2004 S 24 and S/2006 S 12 have similar orbital inclinations as the Gallic group, but have much more distant orbits with semi-major axes of ~400 Saturn radii and ~340 Saturn radii, respectively. Whether S/2019 S 6 is in the Gallic group or Inuit group is disputed.
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 and marked with a blue background, while the irregular moons are listed in red, orange, green, and gray background. The orbits and mean distances of the irregular moons are strongly variable over short timescales due to frequent planetary and solar perturbations, so the orbital elements of irregular moons listed here are averaged over a 5,000-year numerical integration by the Jet Propulsion Laboratory. These may sometimes strongly differ from the osculating orbital elements provided by other sources. Their orbital elements are all based on a reference epoch of 1 January 2000.[25]
| + Key | |||
| Small regular moons (17) | ♠ Major moons (7) | ♦ Inuit group (12) | |
| ♣ Gallic group (7) | ‡ Norse group (100) | § Outlier prograde irregular moons (3) |
| Label | Name | Pronunciation | Image | data-sort-type="number" | Abs. magn. | data-sort-type="number" | Diameter (km) | data-sort-type="number" | Mass (kg) | data-sort-type="number" | Semi-major axis (km) | data-sort-type="number" | Orbital period (d) | data-sort-type="number" | Inclination (°) | data-sort-type="number" | Eccentricity | Position | Discovery year[26] | Year announced | Discoverer |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| S/2009 S 1 | — | 0.3 | outer B Ring | 2009 | 2009 | Cassini | |||||||||||||||
| (moonlets) | — | Three 1,000 km bands within A Ring | 2006 | — | Cassini | ||||||||||||||||
| 9.2 | 0.0 | 0.000 | in Encke Division | 1990 | 1990 | Showalter | |||||||||||||||
| — | 0.0 | 0.000 | in Keeler Gap | 2005 | 2005 | Cassini | |||||||||||||||
| 8.5 | 0.0 | 0.001 | 1980 | 1980 | Voyager 1 | ||||||||||||||||
| 6.7 | 0.0 | 0.002 | F Ring shepherd | 1980 | 1980 | Voyager 1 | |||||||||||||||
| 6.5 | 0.0 | 0.004 | 1980 | 1980 | Voyager 1 | ||||||||||||||||
| 5.5 | 0.3 | 0.020 | co-orbital with Janus | 1966 | 1967 | Fountain & Larson | |||||||||||||||
| 4.5 | 0.2 | 0.007 | co-orbital with Epimetheus | 1966 | 1967 | Dollfus | |||||||||||||||
| — | 0.0 | 0.000 | G Ring moonlet | 2008 | 2009 | Cassini | |||||||||||||||
| ♠Mimas | 3.2 | 1.6 | 0.020 | 1789 | 1789 | Herschel | |||||||||||||||
| — | 0.0 | 0.002 | Alkyonides | 2004 | 2004 | Cassini | |||||||||||||||
| — | 1.8 | 0.0 | 0.002 | Alkyonides | 2007 | 2007 | Cassini | ||||||||||||||
| — | 0.2 | 0.004 | Alkyonides | 2004 | 2004 | Cassini | |||||||||||||||
| ♠Enceladus | 2.1 | 0.0 | 0.005 | Generates the E ring | 1789 | 1789 | Herschel | ||||||||||||||
| ♠Tethys | 0.7 | 1.1 | 0.001 | 1684 | 1684 | Cassini | |||||||||||||||
| 8.7 | 1.2 | 0.001 | leading Tethys trojan | 1980 | 1980 | Smith et al. | |||||||||||||||
| 9.2 | 1.5 | 0.001 | trailing Tethys trojan | 1980 | 1980 | Pascu et al. | |||||||||||||||
| 8.2 | 0.2 | 0.007 | leading Dione trojan | 1980 | 1980 | Laques & Lecacheux | |||||||||||||||
| — | 0.2 | 0.019 | trailing Dione trojan | 2004 | 2004 | Cassini | |||||||||||||||
| ♠Dione | 0.8 | 0.0 | 0.002 | 1684 | 1684 | Cassini | |||||||||||||||
| ♠Rhea | 0.1 | 0.3 | 0.001 | 1672 | 1673 | Cassini | |||||||||||||||
| ♠Titan | –1.3 | 0.3 | 0.029 | 1655 | 1656 | Huygens | |||||||||||||||
| 4.8 | 0.6 | 0.105 | in 4:3 resonance with Titan | 1848 | 1848 | Bond & Lassell | |||||||||||||||
| ♠Iapetus | 1.2 | 7.6 | 0.028 | 1671 | 1673 | Cassini | |||||||||||||||
| ♦S/2019 S 1 | — | 15.3 | 49.5 | 0.384 | Inuit group (Kiviuq) | 2019 | 2021 | Ashton et al. | |||||||||||||
| 12.7 | 48.9 | 0.182 | Inuit group (Kiviuq) | 2000 | 2000 | Gladman et al. | |||||||||||||||
| ♦S/2005 S 4 | — | 15.7 | 48.0 | 0.315 | Inuit group (Kiviuq) | 2005 | 2023 | Sheppard et al. | |||||||||||||
| ♦S/2020 S 1 | — | 15.9 | 48.2 | 0.337 | Inuit group (Kiviuq) | 2020 | 2023 | Ashton et al. | |||||||||||||
| 13.3 | 49.2 | 0.353 | Inuit group (Kiviuq) | 2000 | 2000 | Gladman et al. | |||||||||||||||
| 6.7 | 175.2 | 0.164 | Norse group (Phoebe) | 1898 | 1899 | Pickering | |||||||||||||||
| ‡S/2006 S 20 | — | 15.7 | 173.1 | 0.206 | Norse group (Phoebe) | 2006 | 2023 | Sheppard et al. | |||||||||||||
| ‡S/2006 S 9 | — | 16.5 | 173.0 | 0.248 | Norse group (Phoebe) | 2006 | 2023 | Sheppard et al. | |||||||||||||
| 11.7 | 47.1 | 0.384 | Inuit group (Paaliaq) | 2000 | 2000 | Gladman et al. | |||||||||||||||
| 14.4 | 149.7 | 0.265 | Norse group | 2000 | 2000 | Gladman et al. | |||||||||||||||
| ‡S/2007 S 5 | — | 16.2 | 158.4 | 0.104 | Norse group | 2007 | 2023 | Sheppard et al. | |||||||||||||
| ‡S/2007 S 7 | — | 16.2 | 169.2 | 0.217 | Norse group | 2007 | 2023 | Sheppard et al. | |||||||||||||
| ‡S/2007 S 2 | — | 15.6 | 174.1 | 0.232 | Norse group | 2007 | 2007 | Sheppard et al. | |||||||||||||
| ‡S/2004 S 37 | — | 15.9 | 158.2 | 0.447 | Norse group | 2004 | 2019 | Sheppard et al. | |||||||||||||
| ‡S/2004 S 47 | — | 16.3 | 160.9 | 0.291 | Norse group | 2004 | 2023 | Sheppard et al. | |||||||||||||
| ‡S/2004 S 40 | — | 16.3 | 169.2 | 0.297 | Norse group | 2004 | 2023 | Sheppard et al. | |||||||||||||
| 11.2 | 28.6 | 38.9 | 0.470 | 2000 | 2000 | Holman | |||||||||||||||
| ‡S/2019 S 2 | — | 16.5 | 173.3 | 0.279 | Norse group | 2019 | 2023 | Ashton et al. | |||||||||||||
| 15.0 | 37.4 | 0.482 | Gallic group | 2004 | 2005 | Sheppard et al. | |||||||||||||||
| ♣S/2007 S 8 | — | 16.0 | 36.2 | 0.490 | Gallic group | 2007 | 2023 | Sheppard et al. | |||||||||||||
| ♣S/2004 S 29 | — | 15.8 | 38.6 | 0.485 | Gallic group | 2004 | 2019 | Sheppard et al. | |||||||||||||
| ‡S/2019 S 3 | — | 16.2 | 166.9 | 0.249 | Norse group | 2019 | 2023 | Ashton et al. | |||||||||||||
| ‡S/2020 S 7 | — | 16.8 | 161.5 | 0.500 | Norse group | 2020 | 2023 | Ashton et al. | |||||||||||||
| ♦S/2004 S 31 | — | 15.6 | 48.1 | 0.159 | Inuit group (Siarnaq) | 2004 | 2019 | Sheppard et al. | |||||||||||||
| 13.7 | 38.7 | 0.462 | Gallic group | 2000 | 2000 | Gladman et al. | |||||||||||||||
| 15.4 | 158.4 | 0.470 | Norse group | 2006 | 2006 | Sheppard et al. | |||||||||||||||
| 14.8 | 49.7 | 0.119 | Inuit group (Siarnaq) | 2007 | 2007 | Sheppard et al. | |||||||||||||||
| ♦S/2019 S 14 | — | 16.3 | 46.2 | 0.172 | Inuit group (Siarnaq) | 2019 | 2023 | Ashton et al. | |||||||||||||
| ‡S/2020 S 2 | — | 16.9 | 170.7 | 0.152 | Norse group | 2020 | 2023 | Ashton et al. | |||||||||||||
| 10.6 | 39.3 | 48.2 | 0.311 | Inuit group (Siarnaq) | 2000 | 2000 | Gladman et al. | ||||||||||||||
| ‡S/2019 S 4 | — | 16.5 | 170.1 | 0.409 | Norse group | 2019 | 2023 | Ashton et al. | |||||||||||||
| ♦S/2020 S 3 | — | 16.4 | 46.1 | 0.144 | Inuit group (Siarnaq) | 2020 | 2023 | Ashton et al. | |||||||||||||
| ‡S/2004 S 41 | — | 16.3 | 165.7 | 0.300 | Norse group | 2004 | 2023 | Sheppard et al. | |||||||||||||
| 13.1 | 38.6 | 0.528 | Gallic group | 2000 | 2000 | Gladman et al. | |||||||||||||||
| ♣S/2020 S 4 | — | 17.0 | 40.1 | 0.495 | Gallic group | 2020 | 2023 | Ashton et al. | |||||||||||||
| ‡S/2004 S 42 | — | 16.1 | 165.7 | 0.158 | Norse group | 2004 | 2023 | Sheppard et al. | |||||||||||||
| 14.3 | 150.3 | 0.331 | Norse group | 2004 | 2005 | Sheppard et al. | |||||||||||||||
| 15.3 | 173.4 | 0.317 | Norse group | 2006 | 2006 | Sheppard et al. | |||||||||||||||
| ♦S/2020 S 5 | — | 16.6 | 48.2 | 0.220 | Inuit group (Siarnaq) | 2020 | 2023 | Ashton et al. | |||||||||||||
| ‡S/2004 S 13 | — | 16.3 | 169.0 | 0.265 | Norse group | 2004 | 2005 | Sheppard et al. | |||||||||||||
| ‡S/2007 S 6 | — | 16.4 | 166.5 | 0.169 | Norse group | 2007 | 2023 | Sheppard et al. | |||||||||||||
| 14.6 | 168.4 | 0.210 | Norse group | 2000 | 2000 | Gladman et al. | |||||||||||||||
| ‡S/2006 S 1 | — | 15.6 | 156.0 | 0.105 | Norse group | 2006 | 2006 | Sheppard et al. | |||||||||||||
| ‡S/2004 S 43 | — | 16.3 | 171.1 | 0.432 | Norse group | 2004 | 2023 | Sheppard et al. | |||||||||||||
| ‡S/2006 S 10 | — | 16.4 | 161.6 | 0.151 | Norse group | 2006 | 2023 | Sheppard et al. | |||||||||||||
| ‡S/2019 S 5 | — | 16.6 | 158.8 | 0.215 | Norse group | 2019 | 2023 | Ashton et al. | |||||||||||||
| 15.8 | 163.9 | 0.187 | Norse group | 2004 | 2019 | Sheppard et al. | |||||||||||||||
| 15.2 | 158.7 | 0.144 | Norse group | 2004 | 2005 | Sheppard et al. | |||||||||||||||
| 15.6 | 163.0 | 0.219 | Norse group | 2006 | 2006 | Sheppard et al. | |||||||||||||||
| 14.5 | 143.7 | 0.449 | Norse group | 2003 | 2003 | Sheppard et al. | |||||||||||||||
| 14.6 | 175.0 | 0.116 | Norse group | 2000 | 2000 | Gladman et al. | |||||||||||||||
| ‡S/2007 S 3 | — | 15.7 | 175.6 | 0.162 | Norse group | 2007 | 2007 | Sheppard et al. | |||||||||||||
| ‡S/2004 S 44 | — | 15.8 | 167.7 | 0.129 | Norse group | 2004 | 2023 | Sheppard et al. | |||||||||||||
| §S/2006 S 12 | — | 16.2 | 38.6 | 0.542 | Gallic group? | 2006 | 2023 | Sheppard et al. | |||||||||||||
| ‡S/2004 S 45 | — | 16.0 | 154.0 | 0.551 | Norse group | 2004 | 2023 | Sheppard et al. | |||||||||||||
| 15.4 | 164.1 | 0.375 | Norse group | 2004 | 2005 | Sheppard et al. | |||||||||||||||
| ‡S/2004 S 17 | — | 16.0 | 167.9 | 0.162 | Norse group | 2004 | 2005 | Sheppard et al. | |||||||||||||
| ‡S/2006 S 11 | — | 16.5 | 174.1 | 0.144 | Norse group | 2004 | 2023 | Sheppard et al. | |||||||||||||
| ‡S/2004 S 12 | — | 15.9 | 164.7 | 0.337 | Norse group | 2004 | 2005 | Sheppard et al. | |||||||||||||
| 15.4 | 165.0 | 0.157 | Norse group | 2004 | 2019 | Sheppard et al. | |||||||||||||||
| ‡S/2006 S 13 | — | 16.1 | 162.0 | 0.313 | Norse group | 2006 | 2023 | Sheppard et al. | |||||||||||||
| §S/2019 S 6 | — | 16.1 | 41.3 | 0.259 | Inuit/Gallic group | 2019 | 2023 | Ashton et al. | |||||||||||||
| ‡S/2007 S 9 | — | 16.1 | 159.3 | 0.360 | Norse group | 2007 | 2023 | Sheppard et al. | |||||||||||||
| ‡S/2019 S 7 | — | 16.3 | 174.2 | 0.232 | Norse group | 2019 | 2023 | Ashton et al. | |||||||||||||
| ‡S/2019 S 8 | — | 16.3 | 172.8 | 0.311 | Norse group | 2019 | 2023 | Ashton et al. | |||||||||||||
| 15.8 | 157.7 | 0.248 | Norse group | 2004 | 2005 | Sheppard et al. | |||||||||||||||
| 14.3 | 174.8 | 0.467 | Norse group | 2000 | 2000 | Gladman et al. | |||||||||||||||
| 14.6 | 136.3 | 0.461 | Norse group | 2004 | 2005 | Sheppard et al. | |||||||||||||||
| ‡S/2019 S 9 | — | 16.3 | 159.5 | 0.433 | Norse group | 2019 | 2023 | Ashton et al. | |||||||||||||
| ‡S/2004 S 46 | — | 16.4 | 177.2 | 0.249 | Norse group | 2004 | 2023 | Sheppard et al. | |||||||||||||
| 16.2 | 177.4 | 0.216 | Norse group | 2004 | 2019 | Sheppard et al. | |||||||||||||||
| ‡S/2019 S 11 | — | 16.2 | 144.6 | 0.513 | Norse group | 2019 | 2023 | Ashton et al. | |||||||||||||
| 15.5 | 166.9 | 0.255 | Norse group | 2004 | 2005 | Sheppard et al. | |||||||||||||||
| 16.1 | 158.9 | 0.087 | Norse group | 2004 | 2019 | Sheppard et al. | |||||||||||||||
| ‡S/2019 S 10 | — | 16.7 | 163.9 | 0.249 | Norse group | 2019 | 2023 | Ashton et al. | |||||||||||||
| ‡S/2019 S 12 | — | 16.3 | 167.1 | 0.476 | Norse group | 2019 | 2023 | Ashton et al. | |||||||||||||
| 15.9 | 174.4 | 0.517 | Norse group | 2004 | 2019 | Sheppard et al. | |||||||||||||||
| ‡S/2019 S 13 | — | 16.7 | 177.3 | 0.318 | Norse group | 2019 | 2023 | Ashton et al. | |||||||||||||
| ‡S/2006 S 14 | — | 16.5 | 166.7 | 0.060 | Norse group | 2006 | 2023 | Sheppard et al. | |||||||||||||
| 15.6 | 160.4 | 0.251 | Norse group | 2004 | 2019 | Sheppard et al. | |||||||||||||||
| ‡S/2019 S 15 | — | 16.6 | 157.7 | 0.257 | Norse group | 2019 | 2023 | Ashton et al. | |||||||||||||
| ‡S/2020 S 6 | — | 16.6 | 166.9 | 0.481 | Norse group | 2020 | 2023 | Ashton et al. | |||||||||||||
| ‡S/2004 S 7 | — | 15.6 | 164.9 | 0.511 | Norse group | 2004 | 2005 | Sheppard et al. | |||||||||||||
| ‡S/2006 S 3 | — | 15.6 | 156.1 | 0.432 | Norse group | 2006 | 2006 | Sheppard et al. | |||||||||||||
| ‡S/2005 S 5 | — | 16.4 | 169.5 | 0.588 | Norse group | 2005 | 2023 | Sheppard et al. | |||||||||||||
| 15.6 | 175.6 | 0.437 | Norse group | 2004 | 2019 | Sheppard et al. | |||||||||||||||
| ‡S/2006 S 16 | — | 16.5 | 164.1 | 0.204 | Norse group | 2006 | 2023 | Sheppard et al. | |||||||||||||
| ‡S/2006 S 15 | — | 16.2 | 161.1 | 0.117 | Norse group | 2006 | 2023 | Sheppard et al. | |||||||||||||
| ‡S/2004 S 28 | — | 15.8 | 167.9 | 0.159 | Norse group | 2004 | 2019 | Sheppard et al. | |||||||||||||
| ‡S/2020 S 8 | — | 16.4 | 161.8 | 0.252 | Norse group | 2020 | 2023 | Ashton et al. | |||||||||||||
| 15.6 | 177.4 | 0.238 | Norse group | 2004 | 2019 | Sheppard et al. | |||||||||||||||
| 14.5 | 153.0 | 0.482 | Norse group | 2006 | 2006 | Sheppard et al. | |||||||||||||||
| ‡S/2004 S 48 | — | 16.0 | 161.9 | 0.374 | Norse group | 2004 | 2023 | Sheppard et al. | |||||||||||||
| 15.9 | 154.4 | 0.539 | Norse group | 2004 | 2019 | Sheppard et al. | |||||||||||||||
| 15.9 | 164.3 | 0.136 | Norse group | 2004 | 2005 | Sheppard et al. | |||||||||||||||
| ‡S/2004 S 50 | — | 16.4 | 164.0 | 0.450 | Norse group | 2004 | 2023 | Sheppard et al. | |||||||||||||
| ‡S/2006 S 17 | — | 16.0 | 168.7 | 0.425 | Norse group | 2006 | 2023 | Sheppard et al. | |||||||||||||
| ‡S/2004 S 49 | — | 16.0 | 159.7 | 0.453 | Norse group | 2004 | 2023 | Sheppard et al. | |||||||||||||
| ‡S/2019 S 17 | — | 15.9 | 155.5 | 0.546 | Norse group | 2019 | 2023 | Ashton et al. | |||||||||||||
| 15.8 | 168.3 | 0.449 | Norse group | 2006 | 2006 | Sheppard et al. | |||||||||||||||
| ‡S/2006 S 18 | — | 16.1 | 169.5 | 0.131 | Norse group | 2006 | 2023 | Sheppard et al. | |||||||||||||
| 15.4 | 166.9 | 0.192 | Norse group | 2006 | 2006 | Sheppard et al. | |||||||||||||||
| 12.4 | 173.1 | 0.337 | Norse group | 2000 | 2000 | Gladman et al. | |||||||||||||||
| ‡S/2019 S 19 | — | 16.5 | 151.8 | 0.458 | Norse group | 2019 | 2023 | Ashton et al. | |||||||||||||
| ‡S/2004 S 21 | — | 16.2 | 153.2 | 0.394 | Norse group | 2004 | 2019 | Sheppard et al. | |||||||||||||
| ‡S/2019 S 18 | — | 16.6 | 154.6 | 0.509 | Norse group | 2019 | 2023 | Ashton et al. | |||||||||||||
| ‡S/2004 S 39 | — | 16.1 | 165.9 | 0.101 | Norse group | 2004 | 2019 | Sheppard et al. | |||||||||||||
| ‡S/2019 S 16 | — | 16.7 | 162.0 | 0.250 | Norse group | 2019 | 2023 | Ashton et al. | |||||||||||||
| ‡S/2004 S 53 | — | 16.2 | 162.6 | 0.240 | Norse group | 2004 | 2023 | Sheppard et al. | |||||||||||||
| §S/2004 S 24 | — | 16.0 | 37.4 | 0.071 | Gallic group? | 2004 | 2019 | Sheppard et al. | |||||||||||||
| ‡S/2004 S 36 | — | 16.1 | 153.3 | 0.625 | Norse group | 2004 | 2019 | Sheppard et al. | |||||||||||||
| 15.9 | 158.8 | 0.511 | Norse group | 2004 | 2019 | Sheppard et al. | |||||||||||||||
| ‡S/2019 S 20 | — | 16.7 | 156.1 | 0.354 | Norse group | 2019 | 2023 | Ashton et al. | |||||||||||||
| ‡S/2006 S 19 | — | 16.1 | 175.5 | 0.467 | Norse group | 2006 | 2023 | Sheppard et al. | |||||||||||||
| ‡S/2004 S 34 | — | 16.2 | 168.3 | 0.279 | Norse group | 2004 | 2019 | Sheppard et al. | |||||||||||||
| 15.1 | 169.5 | 0.214 | Norse group | 2004 | 2005 | Sheppard et al. | |||||||||||||||
| ‡S/2004 S 51 | — | 16.1 | 171.2 | 0.201 | Norse group | 2004 | 2023 | Sheppard et al. | |||||||||||||
| ‡S/2020 S 10 | — | 16.9 | 165.6 | 0.295 | Norse group | 2020 | 2023 | Ashton et al. | |||||||||||||
| ‡S/2020 S 9 | — | 16.0 | 161.4 | 0.531 | Norse group | 2020 | 2023 | Ashton et al. | |||||||||||||
| ‡S/2004 S 26 | — | 15.7 | 172.9 | 0.148 | Norse group | 2004 | 2019 | Sheppard et al. | |||||||||||||
| ‡S/2019 S 21 | — | 16.2 | 171.9 | 0.155 | Norse group | 2019 | 2023 | Ashton et al. | |||||||||||||
| ‡S/2004 S 52 | — | 16.5 | 165.3 | 0.292 | Norse group | 2004 | 2023 | Sheppard et al. |
These F Ring moonlets listed in the following table (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 | Status |
|---|---|---|---|---|---|---|---|
| S/2004 S 3 and S 4 | ≈ 3–5 | ≈  | ≈ + | uncertain objects around the F Ring | 2004 | Were undetected in thorough imaging of the region in November 2004, making their existence improbable | |
| S/2004 S 6 | ≈ 3–5 | ≈  | + | 2004 | Consistently detected into 2005, may be surrounded by fine dust and have a very small physical core |
Two moons were claimed to be discovered by different astronomers but never seen again. Both moons were said to orbit between Titan and Hyperion.
In 2022, scientists of the Massachusetts Institute of Technology proposed the hypothetical former moon Chrysalis, using data from the Cassini–Huygens mission. Chrysalis would have orbited between Titan and Iapetus, but its orbit would have gradually become more eccentric until it was torn apart by Saturn. 99% of its mass would have been absorbed by Saturn, while the remaining 1% would have formed Saturn's rings.[27] [28]
Much like Jupiter, asteroids and comets will infrequently make close approaches to Saturn, even more infrequently becoming captured into orbit of the planet. The comet P/2020 F1 (Leonard) is calculated to have made a close approach of km (mi) to Saturn on 8 May 1936, closer than the orbit of Titan to the planet, with an orbital eccentricity of only . The comet may have been orbiting Saturn prior to this as a temporary satellite, but difficulty modelling the non-gravitational forces makes whether or not it was indeed a temporary satellite uncertain.[29]
Other comets and asteroids may have temporarily orbited Saturn at some point, but none are presently known to have.
It is thought that the Saturnian system of Titan, mid-sized moons, and rings developed from a set-up closer to the Galilean moons of Jupiter, though the details are unclear. It has been proposed either that a second Titan-sized moon broke up, producing the rings and inner mid-sized moons,[30] or that two large moons fused to form Titan, with the collision scattering icy debris that formed the mid-sized moons. On 23 June 2014, NASA claimed to have strong evidence that nitrogen in the atmosphere of Titan came from materials in the Oort cloud, associated with comets, and not from the materials that formed Saturn in earlier times. Studies based on Enceladus's tidal-based geologic activity and the lack of evidence of extensive past resonances in Tethys, Dione, and Rhea's orbits suggest that the moons up to and including Rhea may be only 100 million years old.[31]