Saturn's natural satellites
Encyclopedia
The moons
of Saturn are numerous and diverse, ranging from tiny moonlet
s less than 1 kilometre across, to the enormous Titan
, which is larger than the planet Mercury
. Saturn
has 62 moons
with confirmed orbits, fifty-three of which have names, and only thirteen of which have diameters larger than 50 kilometres. Saturn has seven moons that are large enough to become spherical
, and dense ring
s with complex orbital motions of their own. Particularly notable among Saturn's moons are Titan, the second largest moon in the Solar System, with a nitrogen-rich Earth-like atmosphere and a landscape including hydrocarbon lakes
and dry river networks, and Enceladus
, which emits jets of gas and dust and may harbor liquid water under its south pole region.
Twenty-four of Saturn's moons are regular satellites; they have prograde orbits not greatly inclined
to Saturn's equatorial plane. They include the seven major satellites, four small moons which exist in a Trojan orbit with larger moons, two mutually co-orbital moon
s and two moons which act as shepherds of Saturn's F Ring. Two other known regular satellites orbit within gaps in Saturn's rings. The relatively large Hyperion
is locked in a resonance
with Titan. The remaining regular moons orbit near the outer edge of the A Ring, within G 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 thirty-eight, all small except one, are irregular satellites, whose orbits are much farther from Saturn, have high inclinations, and are mixed between prograde and retrograde
. These moons are probably captured minor planet
s, or debris from the breakup of such bodies after they were captured, creating collisional families
. The irregular satellites have been classified by their orbital characteristics into the Inuit
, Norse
, and Gallic
groups, and their names are chosen from the corresponding mythologies. The largest of the irregular moons is Phoebe
, the ninth moon of Saturn, discovered at the end of the 19th century.
The rings of Saturn are made up of objects ranging in size from microscopic to hundreds of meters, each of which is on its own orbit about the planet. Thus a precise number of Saturnian moons cannot be given, as there is no objective boundary between the countless small anonymous objects that form Saturn's ring system and the larger objects that have been named as moons. At least 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.
, eight moons of Saturn were discovered by direct observation using optical telescope
s. Saturn's largest moon, Titan
, was discovered in 1655 by Christiaan Huygens using a 57 millimetres (2.2 in) objective lens on a refracting telescope
of his own design. Tethys
, Dione
, Rhea
and Iapetus
(the "Sidera Lodoicea
") were discovered in 1671–1672 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-orbital
s 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
).
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, which arrived at Saturn in the summer of 2004, initially discovered three small inner moons including Methone
and Pallene
between Mimas and Enceladus as well as the second Lagrangian 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
, has been visually confirmed so far (in 2005). 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.
s which replaced photographic plates. For the entire 20th century, Phoebe stood alone among Saturn's known moons with its highly irregular orbit. Beginning in 2000, however, three dozen additional irregular moons have been 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 further nine irregular moons. In , Tarqeq
(S/2007 S 1) was announced. In May of the same year S/2007 S 2
and S/2007 S 3
were reported.
in 1847. He proposed to name them after mythological figures associated with the Roman god of agriculture and harvest, Saturn
(equated to the Greek Kronos). In particular, the then known seven satellites were named after Titans
and Titanesses—brothers and sisters of Saturn. In 1848 Lassell proposed that the eighth satellite of Saturn was named Hyperion after another Titan. 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) are named after Inuit
and Gallic
gods and after Norse
ice giants.
Some asteroid
s share the same names
as moons of Saturn: 55 Pandora
, 106 Dione
, 577 Rhea
, 1809 Prometheus
, 1810 Epimetheus
, and 4450 Pan
. In addition, two more asteroids previously shared the names of Saturnian moons until spelling differences were made permanent by the International Astronomical Union
(IAU): Calypso
and asteroid 53 Kalypso
; and Helene
and asteroid 101 Helena
.
The Saturnian moon system is very lopsided: one moon, Titan, comprises more than 96% of the mass in orbit around the planet. The six other oblate moons constitute roughly 4%, while the remaining 54 small moons, together with the rings, comprise only 0.04%.
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
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 related to 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.
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 of the recently discovered moons, 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.
. 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), Atlas
(A Ring), Prometheus
(F Ring) and Pandora
(F Ring). These moons together with co-orbitals (see below) 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.
and Epimetheus
are called co-orbital moons. They are of roughly equal size, with Janus being slightly larger than Epimetheus. Janus and Epimetheus have orbits with only a few kilometers difference in semi-major axis, 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.
, Anthe
, and Pallene
. Named after the Alkyonides
of Greek mythology, they are some of the smallest moons in the Saturn system. All Alkyonides possess very faint ring arcs along their orbits.
(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.
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 asteroid
s, though they are much less red than Kuiper Belt objects.
, Kiviuq
, Paaliaq
, Siarnaq
, and Tarqeq
. The largest among them is Siarnaq with an estimated size of about 40 km.
, Bebhionn, Erriapus, and Tarvos
. Tarvos, as of 2009, is the most distant of Saturn's moons with a prograde orbit. The largest among these moons is Albiorix with an estimated size of about 32 km.
outer moons. They are Aegir, Bergelmir, Bestla, Farbauti, Fenrir, Fornjot, Greip, Hati, Hyrrokkin, Jarnsaxa, Kari, Loge, Mundilfari
, Narvi
, Phoebe
, Skathi
, Skoll, Surtur, Suttungr
, Thrymr, Ymir
, S/2004 S 7
, S/2004 S 12
, S/2004 S 13
, S/2004 S 17
, S/2006 S 1
, S/2006 S 3
, S/2007 S 2
, and S/2007 S 3
. After Phoebe, Ymir is the largest of the known retrograde irregular moons, with an estimated diameter of only 18 km. The Norse group may itself consist of several smaller subgroups.
and Hyperion
.
Natural satellite
A natural satellite or moon is a celestial body that orbits a planet or smaller body, which is called its primary. The two terms are used synonymously for non-artificial satellites of planets, of dwarf planets, and of minor planets....
of Saturn are numerous and diverse, ranging from tiny moonlet
Moonlet
Moonlet is an informal term for a particularly small natural satellite. In astronomical literature, it has been used in at least two situations:...
s less than 1 kilometre across, to the enormous Titan
Titan (moon)
Titan , or Saturn VI, is the largest moon of Saturn, the only natural satellite known to have a dense atmosphere, and the only object other than Earth for which clear evidence of stable bodies of surface liquid has been found....
, which is larger than the planet Mercury
Mercury (planet)
Mercury is the innermost and smallest planet in the Solar System, orbiting the Sun once every 87.969 Earth days. The orbit of Mercury has the highest eccentricity of all the Solar System planets, and it has the smallest axial tilt. It completes three rotations about its axis for every two orbits...
. Saturn
Saturn
Saturn is the sixth planet from the Sun and the second largest planet in the Solar System, after Jupiter. Saturn is named after the Roman god Saturn, equated to the Greek Cronus , the Babylonian Ninurta and the Hindu Shani. Saturn's astronomical symbol represents the Roman god's sickle.Saturn,...
has 62 moons
Natural satellite
A natural satellite or moon is a celestial body that orbits a planet or smaller body, which is called its primary. The two terms are used synonymously for non-artificial satellites of planets, of dwarf planets, and of minor planets....
with confirmed orbits, fifty-three of which have names, and only thirteen of which have diameters larger than 50 kilometres. Saturn has seven moons that are large enough to become spherical
Hydrostatic equilibrium
Hydrostatic equilibrium or hydrostatic balance is the condition in fluid mechanics where a volume of a fluid is at rest or at constant velocity. This occurs when compression due to gravity is balanced by a pressure gradient force...
, and dense ring
Rings of Saturn
The rings of Saturn are the most extensive planetary ring system of any planet in the Solar System. They consist of countless small particles, ranging in size from micrometres to metres, that form clumps that in turn orbit about Saturn...
s with complex orbital motions of their own. Particularly notable among Saturn's moons are Titan, the second largest moon in the Solar System, with a nitrogen-rich Earth-like atmosphere and a landscape including hydrocarbon lakes
Lakes of Titan
The Lakes of Titan, a moon of Saturn, are bodies of liquid ethane and methane that have been detected by the Cassini–Huygens space probe, and had been suspected long before. The large ones are known as maria and the small ones as lacūs .-History:The possibility that there were hydrocarbon seas on...
and dry river networks, and Enceladus
Enceladus (moon)
Enceladus is the sixth-largest of the moons of Saturn. It was discovered in 1789 by William Herschel. Until the two Voyager spacecraft passed near it in the early 1980s very little was known about this small moon besides the identification of water ice on its surface...
, which emits jets of gas and dust and may harbor liquid water under its south pole region.
Twenty-four of Saturn's moons are regular satellites; they have prograde orbits not greatly inclined
Inclination
Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...
to Saturn's equatorial plane. They include the seven major satellites, four small moons which exist in a Trojan orbit with larger moons, two mutually co-orbital moon
Co-orbital moon
In astronomy, a co-orbital configuration refers to two or more celestial objects that orbit at the same, or very similar, distance from their parent object as each other, i.e. they are in a 1:1 mean motion resonance....
s and two moons which act as shepherds of Saturn's F Ring. Two other known regular satellites orbit within gaps in Saturn's rings. The relatively large Hyperion
Hyperion (moon)
Hyperion , also known as Saturn VII, is a moon of Saturn discovered by William Cranch Bond, George Phillips Bond and William Lassell in 1848. It is distinguished by its irregular shape, its chaotic rotation, and its unexplained sponge-like appearance...
is locked in a resonance
Orbital resonance
In celestial mechanics, an orbital resonance occurs when two orbiting bodies exert a regular, periodic gravitational influence on each other, usually due to their orbital periods being related by a ratio of two small integers. Orbital resonances greatly enhance the mutual gravitational influence of...
with Titan. The remaining regular moons orbit near the outer edge of the A Ring, within G Ring and between the major moons Mimas
Mimas (moon)
Mimas is a moon of Saturn which was discovered in 1789 by William Herschel. It is named after Mimas, a son of Gaia in Greek mythology, and is also designated Saturn I....
and Enceladus. The regular satellites are traditionally named after Titans
Titan (mythology)
In Greek mythology, the Titans were a race of powerful deities, descendants of Gaia and Uranus, that ruled during the legendary Golden Age....
and Titanesses or other figures associated with the mythological Saturn
Saturn (mythology)
In ancient Roman religion and myth, Saturn was a major god presiding over agriculture and the harvest time. His reign was depicted as a Golden Age of abundance and peace by many Roman authors. In medieval times he was known as the Roman god of agriculture, justice and strength. He held a sickle in...
.
The remaining thirty-eight, all small except one, are irregular satellites, whose orbits are much farther from Saturn, have high inclinations, and are mixed between prograde and retrograde
Retrograde motion
Retrograde motion is motion in the direction opposite to the movement of something else, and is the contrary of direct or prograde motion. This motion can be the orbit of one body about another body or about some other point, or the rotation of a single body about its axis, or other phenomena such...
. These moons are probably captured minor planet
Minor planet
An asteroid group or minor-planet group is a population of minor planets that have a share broadly similar orbits. Members are generally unrelated to each other, unlike in an asteroid family, which often results from the break-up of a single asteroid...
s, or debris from the breakup of such bodies after they were captured, creating collisional families
Collisional family
In astronomy, a collisional family is a group of objects that are thought to have a common origin in an impact . They have similar compositions, and most share similar orbital elements....
. The irregular satellites have been classified by their orbital characteristics into the Inuit
Saturn's Inuit group of satellites
The Inuit group is a dynamical grouping of the prograde irregular satellites Saturn which follow similar orbits. Their semi-major axes range between 11 and 18 Gm, their inclinations between 40° and 50°, and their eccentricities between 0.15 and 0.48....
, Norse
Saturn's Norse group of satellites
The Norse group is a large group of retrograde irregular satellites of Saturn. Their semi-major axes range between 12 and 24 Gm, their inclinations between 136° and 175° and their eccentricities between 0.13 and 0.77....
, and Gallic
Saturn's Gallic group of satellites
The Gallic group is a dynamical grouping of the prograde irregular satellites of Saturn following similar orbits. Their semi-major axes range between 16 and 19 Gm, their inclinations between 35° and 40°, and their eccentricities around 0.53....
groups, and their names are chosen from the corresponding mythologies. The largest of the irregular moons is Phoebe
Phoebe (moon)
Phoebe is an irregular satellite of Saturn. It was discovered by William Henry Pickering on 17 March 1899 from photographic plates that had been taken starting on 16 August 1898 at the Boyden Observatory near Arequipa, Peru, by DeLisle Stewart...
, the ninth moon of Saturn, discovered at the end of the 19th century.
The rings of Saturn are made up of objects ranging in size from microscopic to hundreds of meters, each of which is on its own orbit about the planet. Thus a precise number of Saturnian moons cannot be given, as there is no objective boundary between the countless small anonymous objects that form Saturn's ring system and the larger objects that have been named as moons. At least 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.
Discovery and naming
Early observations
Before the advent of telescopic photographyAstrophotography
Astrophotography is a specialized type of photography that entails recording images of astronomical objects and large areas of the night sky. The first photographs of an astronomical object were taken in the 1840s, but it was not until the late 19th century that advances in technology allowed for...
, eight moons of Saturn were discovered by direct observation using optical telescope
Optical telescope
An optical telescope is a telescope which is used to gather and focus light mainly from the visible part of the electromagnetic spectrum for directly viewing a magnified image for making a photograph, or collecting data through electronic image sensors....
s. Saturn's largest moon, Titan
Titan (moon)
Titan , or Saturn VI, is the largest moon of Saturn, the only natural satellite known to have a dense atmosphere, and the only object other than Earth for which clear evidence of stable bodies of surface liquid has been found....
, was discovered in 1655 by Christiaan Huygens using a 57 millimetres (2.2 in) objective lens on a refracting telescope
Refracting telescope
A refracting or refractor telescope is a type of optical telescope that uses a lens as its objective to form an image . The refracting telescope design was originally used in spy glasses and astronomical telescopes but is also used for long focus camera lenses...
of his own design. Tethys
Tethys (moon)
Tethys or Saturn III is a mid-sized moon of Saturn about across. It was discovered by G. D. Cassini in 1684 and is named after titan Tethys of Greek mythology. Tethys is pronounced |Odysseus]] is about 400 km in diameter, while the largest graben—Ithaca Chasma is about 100 km wide and...
, Dione
Dione (moon)
Dione is a moon of Saturn discovered by Cassini in 1684. It is named after the titan Dione of Greek mythology. It is also designated Saturn IV.- Name :...
, Rhea
Rhea (moon)
Rhea is the second-largest moon of Saturn and the ninth largest moon in the Solar System. It was discovered in 1672 by Giovanni Domenico Cassini.-Name:Rhea is named after the Titan Rhea of Greek mythology, "mother of the gods"...
and Iapetus
Iapetus (moon)
Iapetus ), occasionally Japetus , is the third-largest moon of Saturn, and eleventh in the Solar System. It was discovered by Giovanni Domenico Cassini in 1671...
(the "Sidera Lodoicea
Sidera Lodoicea
Sidera Lodoicea is the name given by the astronomer Giovanni Domenico Cassini to the four moons of Saturn discovered by him in the years 1671, 1672, and 1684 and published in his Découverte de deux nouvelles planètes autour de Saturne in 1673 and in the Journal des sçavans in 1686...
") were discovered in 1671–1672 by Giovanni Domenico Cassini
Giovanni Domenico Cassini
This article is about the Italian-born astronomer. For his French-born great-grandson, see Jean-Dominique Cassini.Giovanni Domenico Cassini was an Italian/French mathematician, astronomer, engineer, and astrologer...
. Mimas
Mimas (moon)
Mimas is a moon of Saturn which was discovered in 1789 by William Herschel. It is named after Mimas, a son of Gaia in Greek mythology, and is also designated Saturn I....
and Enceladus
Enceladus (moon)
Enceladus is the sixth-largest of the moons of Saturn. It was discovered in 1789 by William Herschel. Until the two Voyager spacecraft passed near it in the early 1980s very little was known about this small moon besides the identification of water ice on its surface...
were discovered in 1789 by William Herschel
William Herschel
Sir Frederick William Herschel, KH, FRS, German: Friedrich Wilhelm Herschel was a German-born British astronomer, technical expert, and composer. Born in Hanover, Wilhelm first followed his father into the Military Band of Hanover, but emigrated to Britain at age 19...
. Hyperion
Hyperion (moon)
Hyperion , also known as Saturn VII, is a moon of Saturn discovered by William Cranch Bond, George Phillips Bond and William Lassell in 1848. It is distinguished by its irregular shape, its chaotic rotation, and its unexplained sponge-like appearance...
was discovered in 1848 by W.C. Bond
William Cranch Bond
William Cranch Bond was an American astronomer, and the first director of Harvard College Observatory.- Upbringing :William Cranch Bond was born in Falmouth, Maine on September 9, 1789...
, G.P. Bond
George Phillips Bond
George Phillips Bond was an American astronomer. He was the son of William Cranch Bond. Some sources give his year of birth as 1826....
and William Lassell
William Lassell
William Lassell FRS was an English merchant and astronomer.Born in Bolton and educated in Rochdale after the death of his father, he was apprenticed from 1814 to 1821 to a merchant in Liverpool. He then made his fortune as a beer brewer, which enabled him to indulge his interest in astronomy...
.
The use of long-exposure
Long exposure photography
Long-exposure photography or time-exposure photography involves using a long-duration shutter speed to sharply capture the stationary elements of images while blurring, smearing, or obscuring the moving elements.-Technique:...
photographic plates made possible the discovery of additional moons. The first to be discovered in this manner, Phoebe
Phoebe (moon)
Phoebe is an irregular satellite of Saturn. It was discovered by William Henry Pickering on 17 March 1899 from photographic plates that had been taken starting on 16 August 1898 at the Boyden Observatory near Arequipa, Peru, by DeLisle Stewart...
, was found in 1899 by W.H. Pickering
William Henry Pickering
William Henry Pickering was an American astronomer, brother of Edward Charles Pickering. He was elected a Fellow of the American Academy of Arts and Sciences in 1883.-Work:...
. In 1966 the tenth satellite of Saturn was discovered by Audouin Dollfus
Audouin Dollfus
Audouin Charles Dollfus was a French astronomer and aeronaut, specialist in studies of the solar system and discoverer of Janus, a moon of Saturn.-Astronomical Career and Research:...
, when the rings were observed edge-on near an equinox
Equinox
An equinox occurs twice a year, when the tilt of the Earth's axis is inclined neither away from nor towards the Sun, the center of the Sun being in the same plane as the Earth's equator...
. It was later named Janus
Janus (moon)
Janus is an inner satellite of Saturn. It is also known as Saturn X . It is named after the mythological Janus.-Discovery and orbit:Janus occupies practically the same orbit as the moon Epimetheus...
. 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
Epimetheus (moon)
Epimetheus is an inner satellite of Saturn. It is also known as Saturn XI. It is named after the mythological Epimetheus, brother of Prometheus.-Discovery:Epimetheus occupies essentially the same orbit as the moon Janus...
, the eleventh moon of Saturn. It shares the same orbit with Janus—the only known example of co-orbital
Co-orbital moon
In astronomy, a co-orbital configuration refers to two or more celestial objects that orbit at the same, or very similar, distance from their parent object as each other, i.e. they are in a 1:1 mean motion resonance....
s in the Solar System. In 1980 three additional Saturnian moons were discovered from the ground and later confirmed by the Voyager
Voyager program
The Voyager program is a U.S program that launched two unmanned space missions, scientific probes Voyager 1 and Voyager 2. They were launched in 1977 to take advantage of a favorable planetary alignment of the late 1970s...
probes. They are trojan moons of Dione (Helene
Helene (moon)
Helene is a moon of Saturn. It was discovered by Pierre Laques and Jean Lecacheux in 1980 from ground-based observations at Pic du Midi Observatory, and was designated . In 1988 it was officially named after Helen of Troy, who was the granddaughter of Cronus in Greek mythology...
) and Tethys (Telesto
Telesto (moon)
Telesto is a moon of Saturn. It was discovered by Smith, Reitsema, Larson and Fountain in 1980 from ground-based observations, and was provisionally designated '. In the following months, several other apparitions were observed: , , and ....
and Calypso
Calypso (moon)
Calypso is a moon of Saturn. It was discovered in 1980, from ground-based observations, by Dan Pascu, P. Kenneth Seidelmann, William A. Baum, and Douglas G. Currie, and was provisionally designated ' . Several other apparitions of it were recorded in the following months: , , , and...
).
Observations by spacecraft
The study of the outer planets has since been revolutionized by the use of unmanned space probes. The arrival of the VoyagerVoyager program
The Voyager program is a U.S program that launched two unmanned space missions, scientific probes Voyager 1 and Voyager 2. They were launched in 1977 to take advantage of a favorable planetary alignment of the late 1970s...
spacecraft at Saturn in 1980–1981 resulted in the discovery of three additional moons—Atlas
Atlas (moon)
Atlas is an inner satellite of Saturn.Atlas was discovered by Richard Terrile in 1980 from Voyager photos and was designated '. In 1983 it was officially named after Atlas of Greek mythology, because it "holds the rings on its shoulders" like the Titan Atlas held the sky up above the Earth...
, Prometheus
Prometheus (moon)
-Animations:-External links:* at ** anaglyph view of Prometheus...
and Pandora
Pandora (moon)
Pandora is an inner satellite of Saturn. It was discovered in 1980 from photos taken by the Voyager 1 probe, and was provisionally designated '. In late 1985 it was officially named after Pandora from Greek mythology. It is also designated as '.Pandora is the outer shepherd satellite of the F Ring...
, bringing the total to 17. In addition, Epimetheus was confirmed as distinct from Janus. In 1990, Pan
Pan (moon)
Pan is the innermost moon of Saturn. It is a walnut-shaped small moon about 35 kilometres across and 23 km high that orbits within the Encke Gap in Saturn's A Ring. Pan acts as a ring shepherd and is responsible for keeping the Encke Gap free of ring particles.It was discovered by Mark R...
was discovered in archival Voyager images.
The Cassini mission, which arrived at Saturn in the summer of 2004, initially discovered three small inner moons including Methone
Methone (moon)
Methone is a very small natural satellite of Saturn lying between the orbits of Mimas and Enceladus.It was first seen by the Cassini Imaging Team and given the temporary designation '. Methone is also named '....
and Pallene
Pallene (moon)
Pallene is a very small natural satellite of Saturn. It is one of three small moons known as the Alkyonides that lie between the orbits of the larger Mimas and Enceladus. It is also designated as '.-Discovery:...
between Mimas and Enceladus as well as the second Lagrangian moon of Dione—Polydeuces
Polydeuces (moon)
Polydeuces is a very small natural satellite of Saturn that is co-orbital with Dione and librates around the trailing Lagrangian point . Its diameter is estimated to be about 3.5 km....
. It also observed three suspected but unconfirmed moons in the F Ring. In Cassini scientists announced that the structure of Saturn's rings
Rings of Saturn
The rings of Saturn are the most extensive planetary ring system of any planet in the Solar System. They consist of countless small particles, ranging in size from micrometres to metres, that form clumps that in turn orbit about Saturn...
indicates the presence of several more moons orbiting within the rings, although only one, Daphnis
Daphnis (moon)
Daphnis is an inner satellite of Saturn. It is also known as '; its provisional designation was '. Daphnis is about 8 kilometres in diameter, and orbits the planet in the Keeler Gap within the A ring.- Naming :...
, has been visually confirmed so far (in 2005). In 2007 Anthe
Anthe (moon)
Anthe is a very small natural satellite of Saturn lying between the orbits of Mimas and Enceladus. It is also known as Saturn XLIX; its provisional designation was S/2007 S 4. It is named after one of the Alkyonides; the name means flowery. It is the sixtieth confirmed moon of Saturn.It was...
was announced. In 2008 it was reported that Cassini observations of a depletion of energetic electrons in Saturn's magnetosphere
Magnetosphere
A magnetosphere is formed when a stream of charged particles, such as the solar wind, interacts with and is deflected by the intrinsic magnetic field of a planet or similar body. Earth is surrounded by a magnetosphere, as are the other planets with intrinsic magnetic fields: Mercury, Jupiter,...
near Rhea
Rhea (moon)
Rhea is the second-largest moon of Saturn and the ninth largest moon in the Solar System. It was discovered in 1672 by Giovanni Domenico Cassini.-Name:Rhea is named after the Titan Rhea of Greek mythology, "mother of the gods"...
might be the signature of a tenuous ring system
Rings of Rhea
The Saturnian moon Rhea may have a tenuous ring system consisting of three narrow, relatively dense bands within a particulate disk. This would be the first discovery of rings around a moon...
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
S/2009 S 1
S/2009 S 1 is a 'propeller moonlet' of Saturn orbiting at a distance of about , in the outer part of Saturn's B Ring, and with an approximate diameter of . It was discovered by the Cassini Imaging Team on July 26, 2009. The moon was noticed during the 2009 equinox event by an approximately long...
, the first moonlet within the B Ring, was observed.
Outer moons
Study of Saturn's moons has also been aided by advances in telescope instrumentation, primarily the introduction of digital charge-coupled deviceCharge-coupled device
A charge-coupled device is a device for the movement of electrical charge, usually from within the device to an area where the charge can be manipulated, for example conversion into a digital value. This is achieved by "shifting" the signals between stages within the device one at a time...
s which replaced photographic plates. For the entire 20th century, Phoebe stood alone among Saturn's known moons with its highly irregular orbit. Beginning in 2000, however, three dozen additional irregular moons have been 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
Ecliptic
The ecliptic is the plane of the earth's orbit around the sun. In more accurate terms, it is the intersection of the celestial sphere with the ecliptic plane, which is the geometric plane containing the mean orbit of the Earth around the Sun...
. They are probably fragments of larger bodies captured by Saturn's gravitational pull. In 2005, astronomers using the Mauna Kea Observatory
Mauna Kea Observatory
The Observatories at Mauna Kea, , are an independent collection of astronomical research facilities located on the summit of Mauna Kea on the Big Island of Hawai'i, USA. The facilities are located in a special land use zone known as the "Astronomy Precinct," which is located in the Mauna Kea...
announced the discovery of twelve more small outer moons. In 2006, astronomers using the Subaru 8.2 m telescope
Subaru (telescope)
Subaru Telescope is the 8.2 metre flagship telescope of the National Astronomical Observatory of Japan, located at the Mauna Kea Observatory on Hawaii. It is named after the open star cluster known in English as the Pleiades...
reported the discovery of further nine irregular moons. In , Tarqeq
Tarqeq (moon)
Tarqeq , also known as Saturn LII is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on April 13, 2007, from observations taken between January 5, 2006, and March 22, 2007...
(S/2007 S 1) was announced. In May of the same year S/2007 S 2
S/2007 S 2
S/2007 S 2 is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on May 1, 2007, from observations taken between January 18 and April 19, 2007....
and S/2007 S 3
S/2007 S 3
S/2007 S 3 is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on May 1, 2007 from observations taken between January 18 and April 19, 2007....
were reported.
Naming
The modern names for Saturnian moons were suggested by John HerschelJohn Herschel
Sir John Frederick William Herschel, 1st Baronet KH, FRS ,was an English mathematician, astronomer, chemist, and experimental photographer/inventor, who in some years also did valuable botanical work...
in 1847. He proposed to name them after mythological figures associated with the Roman god of agriculture and harvest, Saturn
Saturn (mythology)
In ancient Roman religion and myth, Saturn was a major god presiding over agriculture and the harvest time. His reign was depicted as a Golden Age of abundance and peace by many Roman authors. In medieval times he was known as the Roman god of agriculture, justice and strength. He held a sickle in...
(equated to the Greek Kronos). In particular, the then known seven satellites were named after Titans
Titan (mythology)
In Greek mythology, the Titans were a race of powerful deities, descendants of Gaia and Uranus, that ruled during the legendary Golden Age....
and Titanesses—brothers and sisters of Saturn. In 1848 Lassell proposed that the eighth satellite of Saturn was named Hyperion after another Titan. 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) are named after Inuit
Inuit mythology
Inuit mythology has many similarities to the religions of other polar regions. Inuit traditional religious practices could be very briefly summarised as a form of shamanism based on animist principles....
and Gallic
Celtic mythology
Celtic mythology is the mythology of Celtic polytheism, apparently the religion of the Iron Age Celts. Like other Iron Age Europeans, the early Celts maintained a polytheistic mythology and religious structure...
gods and after Norse
Norse mythology
Norse mythology, a subset of Germanic mythology, is the overall term for the myths, legends and beliefs about supernatural beings of Norse pagans. It flourished prior to the Christianization of Scandinavia, during the Early Middle Ages, and passed into Nordic folklore, with some aspects surviving...
ice giants.
Some asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
s share the same names
Name conflicts of Solar System objects
Although in principle every named body in the Solar System ought to have a distinct name, due to a variety of circumstances, there are several real or apparent name conflicts between different Solar System bodies. Most of these conflicts are between asteroids and natural satellites of planets,...
as moons of Saturn: 55 Pandora
55 Pandora
55 Pandora is a fairly large and very bright main belt asteroid. Pandora was discovered by George Mary Searle on September 10, 1858 from the Dudley Observatory near Albany, NY. It was his first and only asteroid discovery....
, 106 Dione
106 Dione
106 Dione is a large main-belt asteroid. It probably has a composition similar to 1 Ceres. It was discovered by J. C. Watson on October 10, 1868, and named after Dione, a Titaness in Greek mythology who was sometimes said to have been the mother of Aphrodite, the Greek goddess of love and beauty....
, 577 Rhea
577 Rhea
577 Rhea is a minor planet orbiting the sun. It is named after Rhea, one of the Titans in Greek mythology.It should not be confused with Saturn's moon Rhea.-External links:*...
, 1809 Prometheus
1809 Prometheus
1809 Prometheus is an asteroid that shares the name of one of the lesser-known Saturnian moons, Prometheus....
, 1810 Epimetheus
1810 Epimetheus
1810 Epimetheus is an asteroid that was discovered on September 24, 1960 by Cornelis Johannes Van Houten, Ingrid Van Houten-Groeneveld, and Tom Gehrels at Palomar Observatory near Pauma Valley, California....
, and 4450 Pan
4450 Pan
4450 Pan is an asteroid that was discovered on September 25, 1987 by Eugene and Carolyn Shoemaker. It is a Venus, Mars, and Earth crosser. Pan approaches nearer than 10 Gm to those three planets, and within 20 Gm of Mercury.-External links:...
. In addition, two more asteroids previously shared the names of Saturnian moons until spelling differences were made permanent by the International Astronomical Union
International Astronomical Union
The International Astronomical Union IAU is a collection of professional astronomers, at the Ph.D. level and beyond, active in professional research and education in astronomy...
(IAU): Calypso
Calypso (moon)
Calypso is a moon of Saturn. It was discovered in 1980, from ground-based observations, by Dan Pascu, P. Kenneth Seidelmann, William A. Baum, and Douglas G. Currie, and was provisionally designated ' . Several other apparitions of it were recorded in the following months: , , , and...
and asteroid 53 Kalypso
53 Kalypso
53 Kalypso is a large and very dark main belt asteroid. It was discovered by Robert Luther on April 4, 1858 at Düsseldorf. It is named after Calypso, a sea nymph in Greek mythology, a name it shares with Calypso, a moon of Saturn.- References :...
; and Helene
Helene (moon)
Helene is a moon of Saturn. It was discovered by Pierre Laques and Jean Lecacheux in 1980 from ground-based observations at Pic du Midi Observatory, and was designated . In 1988 it was officially named after Helen of Troy, who was the granddaughter of Cronus in Greek mythology...
and asteroid 101 Helena
101 Helena
101 Helena is a fairly small, rocky main-belt asteroid. It was discovered by J. C. Watson on August 15, 1868. It is named after Helen of Troy in Greek mythology....
.
Sizes
| Saturn's major satellites, compared to Earth's Moon Moon The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more... |
|||||
|---|---|---|---|---|---|
| Name |
Diameter (km) |
Mass (kg) |
Orbital radius (km) |
Orbital period (days) |
|
| Mimas Mimas (moon) Mimas is a moon of Saturn which was discovered in 1789 by William Herschel. It is named after Mimas, a son of Gaia in Greek mythology, and is also designated Saturn I.... |
396 (12% Moon) |
0.4×1020 (0.05% Moon) |
185,000 (50% Moon) |
0.9 (3% Moon) |
|
| Enceladus Enceladus (moon) Enceladus is the sixth-largest of the moons of Saturn. It was discovered in 1789 by William Herschel. Until the two Voyager spacecraft passed near it in the early 1980s very little was known about this small moon besides the identification of water ice on its surface... |
504 (14% Moon) |
1.1×1020 (0.2% Moon) |
238,000 (60% Moon) |
1.4 (5% Moon) |
|
| Tethys Tethys (moon) Tethys or Saturn III is a mid-sized moon of Saturn about across. It was discovered by G. D. Cassini in 1684 and is named after titan Tethys of Greek mythology. Tethys is pronounced |Odysseus]] is about 400 km in diameter, while the largest graben—Ithaca Chasma is about 100 km wide and... |
1,062 (30% Moon) |
6.2×1020 (0.8% Moon) |
295,000 (80% Moon) |
1.9 (7% Moon) |
|
| Dione Dione (moon) Dione is a moon of Saturn discovered by Cassini in 1684. It is named after the titan Dione of Greek mythology. It is also designated Saturn IV.- Name :... |
1,123 (32% Moon) |
11×1020 (1.5% Moon) |
377,000 (100% Moon) |
2.7 (10% Moon) |
|
| Rhea Rhea (moon) Rhea is the second-largest moon of Saturn and the ninth largest moon in the Solar System. It was discovered in 1672 by Giovanni Domenico Cassini.-Name:Rhea is named after the Titan Rhea of Greek mythology, "mother of the gods"... |
1,527 (44% Moon) |
23×1020 (3% Moon) |
527,000 (140% Moon) |
4.5 (20% Moon) |
|
| Titan Titan (moon) Titan , or Saturn VI, is the largest moon of Saturn, the only natural satellite known to have a dense atmosphere, and the only object other than Earth for which clear evidence of stable bodies of surface liquid has been found.... |
5,150 (148% Moon) (75% Mars) |
1,350×1020 (180% Moon) |
1,222,000 (320% Moon) |
16 (60% Moon) |
|
| Iapetus Iapetus (moon) Iapetus ), occasionally Japetus , is the third-largest moon of Saturn, and eleventh in the Solar System. It was discovered by Giovanni Domenico Cassini in 1671... |
1,470 (42% Moon) |
18×1020 (2.5% Moon) |
3,560,000 (930% Moon) |
79 (290% Moon) |
|
Orbital groups
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 PanPan (moon)
Pan is the innermost moon of Saturn. It is a walnut-shaped small moon about 35 kilometres across and 23 km high that orbits within the Encke Gap in Saturn's A Ring. Pan acts as a ring shepherd and is responsible for keeping the Encke Gap free of ring particles.It was discovered by Mark R...
and Daphnis
Daphnis (moon)
Daphnis is an inner satellite of Saturn. It is also known as '; its provisional designation was '. Daphnis is about 8 kilometres in diameter, and orbits the planet in the Keeler Gap within the A ring.- Naming :...
, 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
Iapetus (moon)
Iapetus ), occasionally Japetus , is the third-largest moon of Saturn, and eleventh in the Solar System. It was discovered by Giovanni Domenico Cassini in 1671...
, which has an inclination of 7.57 degrees) and small orbital eccentricities
Orbital eccentricity
The orbital eccentricity of an astronomical body is the amount by which its orbit deviates from a perfect circle, where 0 is perfectly circular, and 1.0 is a parabola, and no longer a closed orbit...
. 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.
Ring moonlets
Moonlet
Moonlet is an informal term for a particularly small natural satellite. In astronomical literature, it has been used in at least two situations:...
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
Propeller
A propeller is a type of fan that transmits power by converting rotational motion into thrust. A pressure difference is produced between the forward and rear surfaces of the airfoil-shaped blade, and a fluid is accelerated behind the blade. Propeller dynamics can be modeled by both Bernoulli's...
. 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 related to 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.
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 of the recently discovered moons, Aegaeon, resides within the bright arc of G Ring and is trapped in the 7:6 mean motion resonance
Orbital resonance
In celestial mechanics, an orbital resonance occurs when two orbiting bodies exert a regular, periodic gravitational influence on each other, usually due to their orbital periods being related by a ratio of two small integers. Orbital resonances greatly enhance the mutual gravitational influence of...
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.
Ring shepherds
Shepherd satellites are small moons that orbit within, or just beyond, a planet's ring systemPlanetary ring
A planetary ring is a ring of cosmic dust and other small particles orbiting around a planet in a flat disc-shaped region.The most notable planetary rings known in Earth's solar system are those around Saturn, but the other three gas giants of the solar system possess ring systems of their...
. 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), Atlas
Atlas (moon)
Atlas is an inner satellite of Saturn.Atlas was discovered by Richard Terrile in 1980 from Voyager photos and was designated '. In 1983 it was officially named after Atlas of Greek mythology, because it "holds the rings on its shoulders" like the Titan Atlas held the sky up above the Earth...
(A Ring), Prometheus
Prometheus (moon)
-Animations:-External links:* at ** anaglyph view of Prometheus...
(F Ring) and Pandora
Pandora (moon)
Pandora is an inner satellite of Saturn. It was discovered in 1980 from photos taken by the Voyager 1 probe, and was provisionally designated '. In late 1985 it was officially named after Pandora from Greek mythology. It is also designated as '.Pandora is the outer shepherd satellite of the F Ring...
(F Ring). These moons together with co-orbitals (see below) 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.
Co-orbitals
JanusJanus (moon)
Janus is an inner satellite of Saturn. It is also known as Saturn X . It is named after the mythological Janus.-Discovery and orbit:Janus occupies practically the same orbit as the moon Epimetheus...
and Epimetheus
Epimetheus (moon)
Epimetheus is an inner satellite of Saturn. It is also known as Saturn XI. It is named after the mythological Epimetheus, brother of Prometheus.-Discovery:Epimetheus occupies essentially the same orbit as the moon Janus...
are called co-orbital moons. They are of roughly equal size, with Janus being slightly larger than Epimetheus. Janus and Epimetheus have orbits with only a few kilometers difference in semi-major axis, 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.
Inner large moons
The innermost large moons of Saturn orbit within its tenuous E Ring, along with three smaller moons of the Alkyoniods group.- MimasMimas (moon)Mimas is a moon of Saturn which was discovered in 1789 by William Herschel. It is named after Mimas, a son of Gaia in Greek mythology, and is also designated Saturn I....
is the smallest and least massive of the inner round moons, although its mass is sufficient to alter the orbit of MethoneMethone (moon)Methone is a very small natural satellite of Saturn lying between the orbits of Mimas and Enceladus.It was first seen by the Cassini Imaging Team and given the temporary designation '. Methone is also named '....
. It is noticeably ovoid-shaped, having been made shorter at the poles and longer at the equator (by about 20 km) by the effects of Saturn's gravity. Mimas has a large impact craterImpact craterIn the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...
one-third its diameter, Herschel, situated on the moon's leading hemisphere. The moon has no known past or present geologic activity, and its surface is dominated by impact craters. The only tectonic features known are a few arcuate and linear troughTrough (geology)In geology, a trough generally refers to a linear structural depression that extends laterally over a distance, while being less steep than a trench.A trough can be a narrow basin or a geologic rift....
s, which probably formed when Mimas was shattered by the Herschel impact.
- EnceladusEnceladus (moon)Enceladus is the sixth-largest of the moons of Saturn. It was discovered in 1789 by William Herschel. Until the two Voyager spacecraft passed near it in the early 1980s very little was known about this small moon besides the identification of water ice on its surface...
is one of the smallest of Saturn's moons that is spherical in shape—only Mimas is smaller—yet is the only small Saturnian moon that is currently endogenously active, and the smallest known body in the Solar System that is geologically active today. The surface of the moon is morphologically diverse; it includes ancient heavily cratered terrain as well as younger smooth areas with few impact craters. Many plains on Enceladus are fractured and intersected by systems of lineamentLineamentSee also Line A lineament is a linear feature in a landscape which is an expression of an underlying geological structure such as a fault. Typically a lineament will comprise a fault-aligned valley, a series of fault or fold-aligned hills, a straight coastline or indeed a combination of these...
s. The area around the south pole of the moon was found by Cassini to be unusually warm and cut by a system of fractures about 130 km long called "tiger stripes", some of which emit jetJet (fluid)A jet is an efflux of fluid that is projected into a surrounding medium, usually from some kind of a nozzle, aperture or orifice. Jets can travel long distances without dissipating...
s of water vaporWater vaporWater vapor or water vapour , also aqueous vapor, is the gas phase of water. It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Under typical atmospheric conditions, water vapor is continuously...
and dustDustDust consists of particles in the atmosphere that arise from various sources such as soil dust lifted up by wind , volcanic eruptions, and pollution...
. These jets form a large plumePlume (hydrodynamics)In hydrodynamics, a plume is a column of one fluid or gas moving through another. Several effects control the motion of the fluid, including momentum, diffusion, and buoyancy...
off the south pole of the moon, which replenishes Saturn's E ring and serves as the main source of ionIonAn ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. The name was given by physicist Michael Faraday for the substances that allow a current to pass between electrodes in a...
s in the magnetosphere of Saturn. The gas and dust are released with a rate of more than 100 kg/s. Enceladus may have liquid water underneath the south-polar surface. The source of the energy for this cryovolcanism is thought to be a 2:1 mean motion resonanceOrbital resonanceIn celestial mechanics, an orbital resonance occurs when two orbiting bodies exert a regular, periodic gravitational influence on each other, usually due to their orbital periods being related by a ratio of two small integers. Orbital resonances greatly enhance the mutual gravitational influence of...
with Dione. The pure ice on the surface makes Enceladus one of the brightest known objects in the Solar System—its geometrical albedo is more than 140%. - TethysTethys (moon)Tethys or Saturn III is a mid-sized moon of Saturn about across. It was discovered by G. D. Cassini in 1684 and is named after titan Tethys of Greek mythology. Tethys is pronounced |Odysseus]] is about 400 km in diameter, while the largest graben—Ithaca Chasma is about 100 km wide and...
is the third largest of Saturn's inner moons. Its most prominent features are a large (400 km diameter) impact crater named OdysseusOdysseus (crater)Odysseus is the largest crater on Saturn's moon Tethys. It is 445 km across, more than 2/5 of the moon's diameter, and is one of the larger craters in the Solar System. It is situated in the western part of leading hemisphere of the moon—the latitude and longitude of its center are 32.8°N and...
on its leading hemisphere and a vast canyon system named Ithaca ChasmaIthaca ChasmaIthaca Chasma is a valley on Saturn's moon Tethys, named after the island of Ithaca, in Greece. It is on average 100 km wide, 3 to 5 km deep and 2,000 km long, running approximately three-quarters of the way around Tethys' circumference, making it one of the longer valleys in the...
extending at least 270° around the moon. The Ithaca Chasma is concentric with Odysseus, and these two features may be related. Tethys appears to have no current geological activity. A heavily cratered hilly terrain occupies the majority of its surface, while a smaller and smoother plains region lies on the hemisphere opposite to that of Odysseus. The plains contain fewer craters and are apparently younger. A sharp boundary separates them from the cratered terrain. There is also a system of extensional troughs radiating away from Odysseus. The density of Tethys (0.985 g/cm3) is less than that of water, indicating that the moon is made mainly of water ice with only a small fraction of rockRock (geology)In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...
. - DioneDione (moon)Dione is a moon of Saturn discovered by Cassini in 1684. It is named after the titan Dione of Greek mythology. It is also designated Saturn IV.- Name :...
is the second-largest inner moon of Saturn. It has a higher density than the geologically dead Rhea, the largest inner moon, but lower than that of active Enceladus. While the majority of Dione's surface is heavily cratered old terrain, this moon is also covered with an extensive network of troughs and lineaments, indicating that in the past it had global tectonic activity. The troughs and lineaments are especially prominent on the trailing hemisphere, where several intersecting sets of fractures form what is called "wispy terrain". The cratered plains have a few large impact craters reaching 250 km in diameter. Smooth plains with low impact crater counts are present as well on a small fraction of the moon's surface. They were probably tectonically resurfaced relatively later in the geological history of Dione. At two locations within smooth plains strange landforms (depressions) resembling oblong impact craters have been identified, both of which lie at the centers of radiating networks of cracks and troughs; these features may be cryovolcanic in origin. Dione may be geologically active even now, although on a scale much smaller than the cryovolcanism of Enceladus. This follows from Cassini magnetic measurements that show Dione is a net source of plasma in the magnetosphere of Saturn, much like Enceladus.
Alkyonides
Three small moons orbit between Mimas and Enceladus: MethoneMethone (moon)
Methone is a very small natural satellite of Saturn lying between the orbits of Mimas and Enceladus.It was first seen by the Cassini Imaging Team and given the temporary designation '. Methone is also named '....
, Anthe
Anthe (moon)
Anthe is a very small natural satellite of Saturn lying between the orbits of Mimas and Enceladus. It is also known as Saturn XLIX; its provisional designation was S/2007 S 4. It is named after one of the Alkyonides; the name means flowery. It is the sixtieth confirmed moon of Saturn.It was...
, and Pallene
Pallene (moon)
Pallene is a very small natural satellite of Saturn. It is one of three small moons known as the Alkyonides that lie between the orbits of the larger Mimas and Enceladus. It is also designated as '.-Discovery:...
. Named after the Alkyonides
Alkyonides
The Alkyonides were, in Greek mythology, the seven daughters of Alcyoneus. When their father was slain by Heracles, they threw themselves into the sea, and were transformed into halcyons by Amphitrite...
of Greek mythology, they are some of the smallest moons in the Saturn system. All Alkyonides possess very faint ring arcs along their orbits.
Trojan moons
Trojan moons are a unique feature not found outside 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, TelestoTelesto (moon)
Telesto is a moon of Saturn. It was discovered by Smith, Reitsema, Larson and Fountain in 1980 from ground-based observations, and was provisionally designated '. In the following months, several other apparitions were observed: , , and ....
(leading) and Calypso
Calypso (moon)
Calypso is a moon of Saturn. It was discovered in 1980, from ground-based observations, by Dan Pascu, P. Kenneth Seidelmann, William A. Baum, and Douglas G. Currie, and was provisionally designated ' . Several other apparitions of it were recorded in the following months: , , , and...
(trailing), and Dione also has two, Helene
Helene (moon)
Helene is a moon of Saturn. It was discovered by Pierre Laques and Jean Lecacheux in 1980 from ground-based observations at Pic du Midi Observatory, and was designated . In 1988 it was officially named after Helen of Troy, who was the granddaughter of Cronus in Greek mythology...
(leading) and Polydeuces
Polydeuces (moon)
Polydeuces is a very small natural satellite of Saturn that is co-orbital with Dione and librates around the trailing Lagrangian point . Its diameter is estimated to be about 3.5 km....
(trailing). Helene is by far the largest Trojan moon, while Polydeuces is the smallest and has the most chaotic orbit.
Outer large moons
These moons all orbit beyond the E Ring. They are:-- RheaRhea (moon)Rhea is the second-largest moon of Saturn and the ninth largest moon in the Solar System. It was discovered in 1672 by Giovanni Domenico Cassini.-Name:Rhea is named after the Titan Rhea of Greek mythology, "mother of the gods"...
is the second-largest of Saturn's moons. In 2005 Cassini detected a depletion of electrons in the plasma wakeWakeA wake is the region of recirculating flow immediately behind a moving or stationary solid body, caused by the flow of surrounding fluid around the body.-Fluid dynamics:...
of Rhea, which forms when the co-rotating plasma of Saturn's magnetosphere is absorbed by the moon. The depletion was hypothesized to be caused by the presence of dust-sized particles concentrated in a few faint equatorial ringsRings of RheaThe Saturnian moon Rhea may have a tenuous ring system consisting of three narrow, relatively dense bands within a particulate disk. This would be the first discovery of rings around a moon...
. Such a ring system would make Rhea the only moon in the solar System known to have rings. However, subsequent targeted observations of the putative ring plane from several angles by Cassinis narrow-angle camera turned up no evidence of the expected ring material, leaving the origin of the plasma observations unresolved. Otherwise Rhea has rather a typical heavily cratered surface, with the exceptions of a few large Dione-type fractures (wispy terrain) on the trailing hemisphere and a very faint "line" of material at the equator that may have been deposited by material deorbiting from present or former rings. Rhea also has two very large impact basins on its anti-Saturnian hemisphere, which are about 400 and 500 km across. The first, TirawaTirawa (crater)Tirawa basin is a large impact crater on Saturn's moon Rhea, at . It was glimpsed by Voyager 1 during its flyby of the moon and later photographed in greater detail by the Cassini orbiter....
, is roughly comparable to the Odysseus basin on Tethys. There is also a 48 km-diameter impact crater called Inktomi at 112°W that is prominent because of an extended system of bright rayRay systemA ray system comprises radial streaks of fine ejecta thrown out during the formation of an impact crater, looking a bit like many thin spokes coming from the hub of a wheel. The rays can extend for lengths up to several times the diameter of their originating crater, and are often accompanied by...
s, which may be one of the youngest craters on the inner moons of Saturn. No evidence of any endogenic activity has been discovered on the surface of Rhea. - TitanTitan (moon)Titan , or Saturn VI, is the largest moon of Saturn, the only natural satellite known to have a dense atmosphere, and the only object other than Earth for which clear evidence of stable bodies of surface liquid has been found....
, at 5,150 km diameter, is the second largest moon in the Solar System. Out of all the large moons, Titan is the only one with a dense (surface pressure of 1.5 atmAtmosphere (unit)The standard atmosphere is an international reference pressure defined as 101325 Pa and formerly used as unit of pressure. For practical purposes it has been replaced by the bar which is 105 Pa...
), cold atmosphere, primarily made of nitrogenNitrogenNitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...
with a small fraction of methaneMethaneMethane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...
. The dense atmosphere frequently produces bright white convective cloudCumulus cloudCumulus clouds are a type of cloud with noticeable vertical development and clearly defined edges. Cumulus means "heap" or "pile" in Latin. They are often described as "puffy" or "cotton-like" in appearance. Cumulus clouds may appear alone, in lines, or in clusters...
s, especially over the south pole region. The surface of Titan, which is difficult to observe due to persistent atmospheric hazeHazeHaze is traditionally an atmospheric phenomenon where dust, smoke and other dry particles obscure the clarity of the sky. The World Meteorological Organization manual of codes includes a classification of horizontal obscuration into categories of fog, ice fog, steam fog, mist, haze, smoke, volcanic...
, shows only a few impact craters and is probably very young. It contains a pattern of light and dark regions, flow channels and possibly cryovolcanoes. Some dark regions are covered by longitudinal dune fields shaped by tidal winds, where sand is made of frozen water or hydrocarbons. Titan is the only moon with large bodies of a liquid on its surface, in the form of methane/ethane lakesLakes of TitanThe Lakes of Titan, a moon of Saturn, are bodies of liquid ethane and methane that have been detected by the Cassini–Huygens space probe, and had been suspected long before. The large ones are known as maria and the small ones as lacūs .-History:The possibility that there were hydrocarbon seas on...
in Titan's north and south polar regions. The largest lake, Kraken MareKraken MareKraken Mare is the largest known body of liquid on the surface of Saturn's moon Titan. It was discovered in 2007 by the Cassini probe and was named in 2008 after the Kraken, a legendary sea monster....
, is larger than the Caspian SeaCaspian SeaThe Caspian Sea is the largest enclosed body of water on Earth by area, variously classed as the world's largest lake or a full-fledged sea. The sea has a surface area of and a volume of...
. Like Europa and Ganymede, it is believed that Titan has a subsurface ocean made of water mixed with ammoniaAmmoniaAmmonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...
, which can erupt to the surface of the moon and lead to cryovolcanism. - HyperionHyperion (moon)Hyperion , also known as Saturn VII, is a moon of Saturn discovered by William Cranch Bond, George Phillips Bond and William Lassell in 1848. It is distinguished by its irregular shape, its chaotic rotation, and its unexplained sponge-like appearance...
is Titan's nearest neighbor in the Saturn system. The two moons are locked in a 4:3 mean motion resonanceOrbital resonanceIn celestial mechanics, an orbital resonance occurs when two orbiting bodies exert a regular, periodic gravitational influence on each other, usually due to their orbital periods being related by a ratio of two small integers. Orbital resonances greatly enhance the mutual gravitational influence of...
with each other, meaning that while Titan makes four revolutions around Saturn, Hyperion makes exactly three. With an average diameter of about 270 km, Hyperion is smaller and lighter than Mimas. It has an extremely irregular shape, and a very odd, tan-colored icy surface resembling a sponge, though its interior may be partially porous as well. The average density of about 0.55 g/cm3 indicates that the porosity exceeds 40% even assuming it has a purely icy composition. The surface of Hyperion is covered with numerous impact craters—those with diameters 2–10 km are especially abundant. It is the only moon known to have a chaotic rotation, which means Hyperion has no well-defined poles or equator. While on short timescales the satellite approximately rotates around its long axis at a rate of 72–75° per day, on longer timescales its axis of rotation (spin vector) wanders chaotically across the sky. This makes the rotational behavior of Hyperion essentially unpredictable.
- IapetusIapetus (moon)Iapetus ), occasionally Japetus , is the third-largest moon of Saturn, and eleventh in the Solar System. It was discovered by Giovanni Domenico Cassini in 1671...
is the third-largest of Saturn's moons. Orbiting the planet at km, it is by far the most distant of Saturn's large moons, and also possesses the greatest orbital inclinationInclinationInclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...
, at 14.72 degrees. Iapetus has long been known for its unusual two-toned surface; its leading hemisphere is pitch-black and its trailing hemisphere is almost as bright as fresh snow. Cassini images showed that the dark material is confined to a large near equatorial area on the leading hemisphere called Cassini RegioCassini RegioCassini Regio is the enigmatic dark area that covers half of Saturn's moon Iapetus. It is named after Giovanni Cassini, the discoverer of Iapetus; 'Regio' is a term used in planetary geology for a large area that is strongly differentiated in colour or albedo from its surroundings...
, which extends approximately from 40°N to 40°S. The pole regions of Iapetus are as bright as its trailing hemisphere. Cassini also discovered a 20 km tall equatorial ridge, which spans nearly the moon's entire equator. Otherwise both dark and bright surfaces of Iapetus are old and heavily cratered. The images revealed at least four large impact basins with diameters from 380 to 550 km and numerous smaller impact craters. No evidence of any endogenic activity has been discovered. A clue to the origin of the dark material covering part of Iapetus' starkly dichromaticDichroismDichroism has two related but distinct meanings in optics. A dichroic material is either one which causes visible light to be split up into distinct beams of different wavelengths , or one in which light rays having different polarizations are absorbed by different amounts.The original meaning of...
surface may have been found in 2009, when NASA's Spitzer Space TelescopeSpitzer Space TelescopeThe Spitzer Space Telescope , formerly the Space Infrared Telescope Facility is an infrared space observatory launched in 2003...
discovered a vast, nearly invisible disk around Saturn, just inside the orbit of the moon Phoebe—the Phoebe ring. Scientists believe that the disk originates from dust and ice particles kicked up by impacts on Phoebe. Because the disk particles, like Phoebe itself, orbit in the opposite direction to Iapetus, Iapetus collides with them as they drift in the direction of Saturn, darkening its leading hemisphere slightly. Once a difference in albedo, and hence in average temperature, was established between different regions of Iapetus, a thermal runawayThermal runawayThermal runaway refers to a situation where an increase in temperature changes the conditions in a way that causes a further increase in temperature, often leading to a destructive result...
process of water ice sublimation from warmer regions and deposition of water vapor onto colder regions ensued. Iapetus' present two-toned appearance results from the contrast between the bright, primarily ice-coated areas and regions of dark lag, the residue left behind after the loss of surface ice.
Irregular moons
Irregular moons are small satellites with large-radii, inclined, and frequently retrogradeRetrograde and direct motion
Apparent retrograde motion is the motion of a planetary body in a direction opposite to that of other bodies within its system as observed from a particular vantage point...
orbits, believed to have been acquired by the parent planet through a capture process. They often occur as collisional families
Collisional family
In astronomy, a collisional family is a group of objects that are thought to have a common origin in an impact . They have similar compositions, and most share similar orbital elements....
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
C-type asteroid
C-type asteroids are carbonaceous asteroids. They are the most common variety, forming around 75% of known asteroids, and an even higher percentage in the outer part of the asteroid belt beyond 2.7 AU, which is dominated by this asteroid type...
, P-type
P-type asteroid
P-type asteroids have low albedo and a featureless reddish electromagnetic spectrum. It has been suggested that they have a composition of organic rich silicates, carbon and anhydrous silicates, possibly with water ice in their interior...
, or D-type asteroid
D-type asteroid
D-type asteroids have a very low albedo and a featureless reddish electromagnetic spectrum. It has been suggested that they have a composition of organic rich silicates, carbon and anhydrous silicates, possibly with water ice in their interiors...
s, though they are much less red than Kuiper Belt objects.
Inuit group
The Inuit group includes five prograde outer moons that are similar enough in their distances from the planet (186–297 radii of Saturn), their orbital inclinations (45–50°) and their colors that they can be considered a group. The moons are IjiraqIjiraq (moon)
Ijiraq , or Saturn XXII , is small prograde irregular satellite of Saturn. It was discovered by the team ofBrett Gladman, John J. Kavelaars, et al. in 2000, and given the temporary designation '...
, Kiviuq
Kiviuq (moon)
Kiviuq is a prograde irregular satellite of Saturn. It was discovered by Brett J. Gladman in 2000, and given the temporary designation S/2000 S 5. It was named after Kiviuq, a hero of Inuit mythology....
, Paaliaq
Paaliaq (moon)
Paaliaq is a prograde irregular satellite of Saturn. It was discovered by Brett J. Gladman, John J. Kavelaars, Jean-Marc Petit, Hans Scholl, Matthew J. Holman, Brian G. Marsden, Philip D. Nicholson and Joseph A. Burns in early October 2000, and given the temporary designation S/2000 S 2...
, Siarnaq
Siarnaq (moon)
Siarnaq , or Saturn XXIX, is a prograde irregular satellite of Saturn. It was discovered by Brett J. Gladman, et al. in 2000, and given the temporary designation S/2000 S 3....
, and Tarqeq
Tarqeq (moon)
Tarqeq , also known as Saturn LII is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on April 13, 2007, from observations taken between January 5, 2006, and March 22, 2007...
. The largest among them is Siarnaq with an estimated size of about 40 km.
Gallic group
The Gallic group are four prograde outer moons that are similar enough in their distance from the planet (207–302 radii of Saturn), their orbital inclination (35–40°) and their color that they can be considered a group. They are AlbiorixAlbiorix (moon)
Albiorix is a prograde irregular satellite of Saturn. It was discovered by Holman, et al. in 2000, and given the temporary designation S/2000 S 11.Albiorix is the largest member of the Gallic group of irregular satellites....
, Bebhionn, Erriapus, and Tarvos
Tarvos (moon)
Tarvos , or Saturn XXI, is a prograde irregular satellite of Saturn. It was discovered by John J. Kavelaars et al. on September 23, 2000, and given the temporary designation S/2000 S 4...
. Tarvos, as of 2009, is the most distant of Saturn's moons with a prograde orbit. The largest among these moons is Albiorix with an estimated size of about 32 km.
Norse group
The Norse (or Phoebe) group consists of 29 retrogradeRetrograde motion
Retrograde motion is motion in the direction opposite to the movement of something else, and is the contrary of direct or prograde motion. This motion can be the orbit of one body about another body or about some other point, or the rotation of a single body about its axis, or other phenomena such...
outer moons. They are Aegir, Bergelmir, Bestla, Farbauti, Fenrir, Fornjot, Greip, Hati, Hyrrokkin, Jarnsaxa, Kari, Loge, Mundilfari
Mundilfari (moon)
Mundilfari , or Saturn XXV, is a natural satellite of Saturn. It was discovered by Brett J. Gladman, et al. in 2000, and given the temporary designation S/2000 S 9....
, Narvi
Narvi (moon)
Narvi , or Saturn XXXI, is a natural satellite of Saturn. It was discovered by a team of astronomers led by Scott S. Sheppard in 2003, and given the temporary designation S/2003 S 1.- Description :...
, Phoebe
Phoebe (moon)
Phoebe is an irregular satellite of Saturn. It was discovered by William Henry Pickering on 17 March 1899 from photographic plates that had been taken starting on 16 August 1898 at the Boyden Observatory near Arequipa, Peru, by DeLisle Stewart...
, Skathi
Skathi (moon)
Skathi , or Saturn XXVII, is a natural satellite of Saturn. It was discovered by Brett Gladman, Kavelaars, et al. in 2000, and given the temporary designation S/2000 S 8....
, Skoll, Surtur, Suttungr
Suttungr (moon)
Suttungr , or Saturn XXIII, is a natural satellite of Saturn. It was discovered by Brett J. Gladman, et al. in 2000, and given the temporary designation S/2000 S 12...
, Thrymr, Ymir
Ymir (moon)
Ymir , or Saturn XIX, is a retrograde irregular moon of Saturn. It was discovered by Brett J. Gladman, et al. in 2000, and given the temporary designation S/2000 S 1...
, S/2004 S 7
S/2004 S 7
S/2004 S 7 is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on May 4, 2005 from observations taken between December 12, 2004 and March 8, 2005....
, S/2004 S 12
S/2004 S 12
S/2004 S 12 is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on May 4, 2005 from observations taken between December 12, 2004 and March 9, 2005....
, S/2004 S 13
S/2004 S 13
S/2004 S 13 is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on May 4, 2005 from observations taken between December 12, 2004 and March 9, 2005....
, S/2004 S 17
S/2004 S 17
S/2004 S 17 is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on May 4, 2005 from observations taken between December 13, 2004 and March 5, 2005....
, S/2006 S 1
S/2006 S 1
S/2006 S 1 is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on June 26, 2006 from observations taken between January 4 and April 30, 2006....
, S/2006 S 3
S/2006 S 3
S/2006 S 3 is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on June 26, 2006 from observations taken between January and April 2006....
, S/2007 S 2
S/2007 S 2
S/2007 S 2 is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on May 1, 2007, from observations taken between January 18 and April 19, 2007....
, and S/2007 S 3
S/2007 S 3
S/2007 S 3 is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on May 1, 2007 from observations taken between January 18 and April 19, 2007....
. After Phoebe, Ymir is the largest of the known retrograde irregular moons, with an estimated diameter of only 18 km. The Norse group may itself consist of several smaller subgroups.
- PhoebePhoebe (moon)Phoebe is an irregular satellite of Saturn. It was discovered by William Henry Pickering on 17 March 1899 from photographic plates that had been taken starting on 16 August 1898 at the Boyden Observatory near Arequipa, Peru, by DeLisle Stewart...
, at 214 km in diameter, is by far the largest of Saturn's irregular satellites. It has a retrograde orbit and rotates on its axis every 9.3 hours. Phoebe was the first moon of Saturn to be studied in detail by Cassini, in ; during this encounter Cassini was able to map nearly 90% of the moon's surface. Phoebe has a nearly spherical shape and a relatively high density of about 1.6 g/cm3. Cassini images revealed a dark surface scarred by numerous impacts—there are about 130 craters with diameters exceeding 10 km. Spectroscopic measurement showed that the surface is made of water ice, carbon dioxideCarbon dioxideCarbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
, phyllosilicates, organics and possibly iron bearing minerals. Phoebe is believed to be a captured Kuiper Belt object or centaur. It also serves as a source of material for the largest known ring of Saturn, which darkens the leading hemisphere of Iapetus (see above).
Confirmed moons
| Order |
Name |
Pronunciation (key) | Image | ( kg Kilogram The kilogram or kilogramme , also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram , which is almost exactly equal to the mass of one liter of water... ) |
Orbital period (d Day A day is a unit of time, commonly defined as an interval equal to 24 hours. It also can mean that portion of the full day during which a location is illuminated by the light of the sun... )Negative orbital periods indicate a retrograde orbit around Saturn (opposite to the planet's rotation). |
Inclination To Saturn's equator |
Eccentricity Orbital eccentricity The orbital eccentricity of an astronomical body is the amount by which its orbit deviates from a perfect circle, where 0 is perfectly circular, and 1.0 is a parabola, and no longer a closed orbit... |
Position | Discovery year |
Discoverer |
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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| S/2009 S 1 S/2009 S 1 S/2009 S 1 is a 'propeller moonlet' of Saturn orbiting at a distance of about , in the outer part of Saturn's B Ring, and with an approximate diameter of . It was discovered by the Cassini Imaging Team on July 26, 2009. The moon was noticed during the 2009 equinox event by an approximately long... |
— | outer B Ring | 2009 | Cassini–Huygens | |||||||||
| (moonlets) | — | .jpg) |
Three 1000 km bands within A Ring | 2006 | Cassini–Huygens | ||||||||
| Pan Pan (moon) Pan is the innermost moon of Saturn. It is a walnut-shaped small moon about 35 kilometres across and 23 km high that orbits within the Encke Gap in Saturn's A Ring. Pan acts as a ring shepherd and is responsible for keeping the Encke Gap free of ring particles.It was discovered by Mark R... |
ˈpæn |  |
in Encke Division | 1990 | M. Showalter | ||||||||
| Daphnis Daphnis (moon) Daphnis is an inner satellite of Saturn. It is also known as '; its provisional designation was '. Daphnis is about 8 kilometres in diameter, and orbits the planet in the Keeler Gap within the A ring.- Naming :... |
ˈdæfnɨs |  |
in Keeler Gap | 2005 | Cassini–Huygens | ||||||||
| Atlas Atlas (moon) Atlas is an inner satellite of Saturn.Atlas was discovered by Richard Terrile in 1980 from Voyager photos and was designated '. In 1983 it was officially named after Atlas of Greek mythology, because it "holds the rings on its shoulders" like the Titan Atlas held the sky up above the Earth... |
ˈætləs |  |
outer A Ring shepherd | 1980 | Voyager 2 Voyager 2 The Voyager 2 spacecraft is a 722-kilogram space probe launched by NASA on August 20, 1977 to study the outer Solar System and eventually interstellar space... |
||||||||
| Prometheus Prometheus (moon) -Animations:-External links:* at ** anaglyph view of Prometheus... |
proʊˈmiːθiːəs | inner F Ring shepherd | 1980 | Voyager 2 Voyager 2 The Voyager 2 spacecraft is a 722-kilogram space probe launched by NASA on August 20, 1977 to study the outer Solar System and eventually interstellar space... |
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| Pandora Pandora (moon) Pandora is an inner satellite of Saturn. It was discovered in 1980 from photos taken by the Voyager 1 probe, and was provisionally designated '. In late 1985 it was officially named after Pandora from Greek mythology. It is also designated as '.Pandora is the outer shepherd satellite of the F Ring... |
pænˈdɔərə |  |
outer F Ring Shepherd | 1980 | Voyager 2 Voyager 2 The Voyager 2 spacecraft is a 722-kilogram space probe launched by NASA on August 20, 1977 to study the outer Solar System and eventually interstellar space... |
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| Epimetheus Epimetheus (moon) Epimetheus is an inner satellite of Saturn. It is also known as Saturn XI. It is named after the mythological Epimetheus, brother of Prometheus.-Discovery:Epimetheus occupies essentially the same orbit as the moon Janus... |
ˌɛpɨˈmiːθiːəs |  |
co-orbital with Janus | 1977 | J. Fountain, and S. Larson | ||||||||
| Janus Janus (moon) Janus is an inner satellite of Saturn. It is also known as Saturn X . It is named after the mythological Janus.-Discovery and orbit:Janus occupies practically the same orbit as the moon Epimetheus... |
ˈdʒeɪnəs | co-orbital with Epimetheus | 1966 | A. Dollfus Audouin Dollfus Audouin Charles Dollfus was a French astronomer and aeronaut, specialist in studies of the solar system and discoverer of Janus, a moon of Saturn.-Astronomical Career and Research:... |
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| Aegaeon | iːˈdʒiːən | .jpg) |
| | G Ring moonlet | 2008 | Cassini–Huygens | |||||||
| †Mimas Mimas (moon) Mimas is a moon of Saturn which was discovered in 1789 by William Herschel. It is named after Mimas, a son of Gaia in Greek mythology, and is also designated Saturn I.... |
ˈmaɪməs |  |
1789 | W. Herschel William Herschel Sir Frederick William Herschel, KH, FRS, German: Friedrich Wilhelm Herschel was a German-born British astronomer, technical expert, and composer. Born in Hanover, Wilhelm first followed his father into the Military Band of Hanover, but emigrated to Britain at age 19... |
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| 10 | Methone Methone (moon) Methone is a very small natural satellite of Saturn lying between the orbits of Mimas and Enceladus.It was first seen by the Cassini Imaging Team and given the temporary designation '. Methone is also named '.... |
mɨˈθoʊniː | .jpg) |
| | Alkyonides Alkyonides The Alkyonides were, in Greek mythology, the seven daughters of Alcyoneus. When their father was slain by Heracles, they threw themselves into the sea, and were transformed into halcyons by Amphitrite... |
2004 | Cassini–Huygens | ||||||
| 11 | Anthe Anthe (moon) Anthe is a very small natural satellite of Saturn lying between the orbits of Mimas and Enceladus. It is also known as Saturn XLIX; its provisional designation was S/2007 S 4. It is named after one of the Alkyonides; the name means flowery. It is the sixtieth confirmed moon of Saturn.It was... |
ˈænθiː |  |
| | Alkyonides | 2007 | Cassini–Huygens | ||||||
| 12 | Pallene Pallene (moon) Pallene is a very small natural satellite of Saturn. It is one of three small moons known as the Alkyonides that lie between the orbits of the larger Mimas and Enceladus. It is also designated as '.-Discovery:... |
pəˈliːniː |  |
| | Alkyonides | 2004 | Cassini–Huygens | ||||||
| 13 | †Enceladus Enceladus (moon) Enceladus is the sixth-largest of the moons of Saturn. It was discovered in 1789 by William Herschel. Until the two Voyager spacecraft passed near it in the early 1980s very little was known about this small moon besides the identification of water ice on its surface... |
ɛnˈsɛlədəs | Generates the E ring | 1789 | W. Herschel William Herschel Sir Frederick William Herschel, KH, FRS, German: Friedrich Wilhelm Herschel was a German-born British astronomer, technical expert, and composer. Born in Hanover, Wilhelm first followed his father into the Military Band of Hanover, but emigrated to Britain at age 19... |
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| 14 | †Tethys Tethys (moon) Tethys or Saturn III is a mid-sized moon of Saturn about across. It was discovered by G. D. Cassini in 1684 and is named after titan Tethys of Greek mythology. Tethys is pronounced |Odysseus]] is about 400 km in diameter, while the largest graben—Ithaca Chasma is about 100 km wide and... |
ˈtiːθɨs |  |
1684 | G. Cassini Giovanni Domenico Cassini This article is about the Italian-born astronomer. For his French-born great-grandson, see Jean-Dominique Cassini.Giovanni Domenico Cassini was an Italian/French mathematician, astronomer, engineer, and astrologer... |
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| Telesto Telesto (moon) Telesto is a moon of Saturn. It was discovered by Smith, Reitsema, Larson and Fountain in 1980 from ground-based observations, and was provisionally designated '. In the following months, several other apparitions were observed: , , and .... |
tɨˈlɛstoʊ |  |
leading Tethys Trojan | 1980 | B. Smith, H. Reitsema, S. Larson, and J. Fountain | ||||||||
| Calypso Calypso (moon) Calypso is a moon of Saturn. It was discovered in 1980, from ground-based observations, by Dan Pascu, P. Kenneth Seidelmann, William A. Baum, and Douglas G. Currie, and was provisionally designated ' . Several other apparitions of it were recorded in the following months: , , , and... |
kəˈlɪpsoʊ | trailing Tethys Trojan | 1980 | D. Pascu, P. Seidelmann, W. Baum, and D. Currie | |||||||||
| 17 | †Dione Dione (moon) Dione is a moon of Saturn discovered by Cassini in 1684. It is named after the titan Dione of Greek mythology. It is also designated Saturn IV.- Name :... |
daɪˈoʊniː |  |
1684 | G. Cassini Giovanni Domenico Cassini This article is about the Italian-born astronomer. For his French-born great-grandson, see Jean-Dominique Cassini.Giovanni Domenico Cassini was an Italian/French mathematician, astronomer, engineer, and astrologer... |
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| Helene Helene (moon) Helene is a moon of Saturn. It was discovered by Pierre Laques and Jean Lecacheux in 1980 from ground-based observations at Pic du Midi Observatory, and was designated . In 1988 it was officially named after Helen of Troy, who was the granddaughter of Cronus in Greek mythology... |
ˈhɛlɨniː | leading Dione Trojan | 1980 | P. Laques and J. Lecacheux | |||||||||
| Polydeuces Polydeuces (moon) Polydeuces is a very small natural satellite of Saturn that is co-orbital with Dione and librates around the trailing Lagrangian point . Its diameter is estimated to be about 3.5 km.... |
ˌpɒliˈdjuːsiːz |  |
trailing Dione Trojan | 2004 | Cassini–Huygens | ||||||||
| 20 | †Rhea Rhea (moon) Rhea is the second-largest moon of Saturn and the ninth largest moon in the Solar System. It was discovered in 1672 by Giovanni Domenico Cassini.-Name:Rhea is named after the Titan Rhea of Greek mythology, "mother of the gods"... |
ˈriːə |  |
1672 | G. Cassini Giovanni Domenico Cassini This article is about the Italian-born astronomer. For his French-born great-grandson, see Jean-Dominique Cassini.Giovanni Domenico Cassini was an Italian/French mathematician, astronomer, engineer, and astrologer... |
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| 21 | ♠Titan Titan (moon) Titan , or Saturn VI, is the largest moon of Saturn, the only natural satellite known to have a dense atmosphere, and the only object other than Earth for which clear evidence of stable bodies of surface liquid has been found.... |
ˈtaɪtən |  |
1655 | C. Huygens | ||||||||
| 22 | †Hyperion Hyperion (moon) Hyperion , also known as Saturn VII, is a moon of Saturn discovered by William Cranch Bond, George Phillips Bond and William Lassell in 1848. It is distinguished by its irregular shape, its chaotic rotation, and its unexplained sponge-like appearance... |
haɪˈpɪəriən |  |
in 4:3 resonance with Titan | 1848 | W. Bond William Cranch Bond William Cranch Bond was an American astronomer, and the first director of Harvard College Observatory.- Upbringing :William Cranch Bond was born in Falmouth, Maine on September 9, 1789... G. Bond George Phillips Bond George Phillips Bond was an American astronomer. He was the son of William Cranch Bond. Some sources give his year of birth as 1826.... W. Lassell William Lassell William Lassell FRS was an English merchant and astronomer.Born in Bolton and educated in Rochdale after the death of his father, he was apprenticed from 1814 to 1821 to a merchant in Liverpool. He then made his fortune as a beer brewer, which enabled him to indulge his interest in astronomy... |
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| 23 | †Iapetus Iapetus (moon) Iapetus ), occasionally Japetus , is the third-largest moon of Saturn, and eleventh in the Solar System. It was discovered by Giovanni Domenico Cassini in 1671... |
aɪˈæpɨtəs |  |
1671 | G. Cassini Giovanni Domenico Cassini This article is about the Italian-born astronomer. For his French-born great-grandson, see Jean-Dominique Cassini.Giovanni Domenico Cassini was an Italian/French mathematician, astronomer, engineer, and astrologer... |
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| 24 | ‡Kiviuq Kiviuq (moon) Kiviuq is a prograde irregular satellite of Saturn. It was discovered by Brett J. Gladman in 2000, and given the temporary designation S/2000 S 5. It was named after Kiviuq, a hero of Inuit mythology.... |
ˈkɪviək | Inuit group | 2000 | B. Gladman Brett J. Gladman Brett J. Gladman is a Canadian astronomer and a full professor at the University of British Columbia's Department of Physics and Astronomy in Vancouver, British Columbia. He holds the Canada Research Chair in Planetary Astronomy.-Career:... , J. Kavelaars John J. Kavelaars John J. Kavelaars, better known as JJ Kavelaars, is a Canadian astronomer who was part of a team that discovered several moons of Jupiter, Saturn, Uranus, and Neptune.... , et al. |
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| 25 | ‡Ijiraq Ijiraq (moon) Ijiraq , or Saturn XXII , is small prograde irregular satellite of Saturn. It was discovered by the team ofBrett Gladman, John J. Kavelaars, et al. in 2000, and given the temporary designation '... |
ˈiː.ɨrɒk | Inuit group | 2000 | B. Gladman Brett J. Gladman Brett J. Gladman is a Canadian astronomer and a full professor at the University of British Columbia's Department of Physics and Astronomy in Vancouver, British Columbia. He holds the Canada Research Chair in Planetary Astronomy.-Career:... , J. Kavelaars John J. Kavelaars John J. Kavelaars, better known as JJ Kavelaars, is a Canadian astronomer who was part of a team that discovered several moons of Jupiter, Saturn, Uranus, and Neptune.... , et al. |
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| 26 | ♣†Phoebe Phoebe (moon) Phoebe is an irregular satellite of Saturn. It was discovered by William Henry Pickering on 17 March 1899 from photographic plates that had been taken starting on 16 August 1898 at the Boyden Observatory near Arequipa, Peru, by DeLisle Stewart... |
ˈfiːbiː |  |
Norse group | 1899 | W. Pickering William Henry Pickering William Henry Pickering was an American astronomer, brother of Edward Charles Pickering. He was elected a Fellow of the American Academy of Arts and Sciences in 1883.-Work:... |
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| 27 | ‡Paaliaq Paaliaq (moon) Paaliaq is a prograde irregular satellite of Saturn. It was discovered by Brett J. Gladman, John J. Kavelaars, Jean-Marc Petit, Hans Scholl, Matthew J. Holman, Brian G. Marsden, Philip D. Nicholson and Joseph A. Burns in early October 2000, and given the temporary designation S/2000 S 2... |
ˈpɑːliɒk | Inuit group | 2000 | B. Gladman Brett J. Gladman Brett J. Gladman is a Canadian astronomer and a full professor at the University of British Columbia's Department of Physics and Astronomy in Vancouver, British Columbia. He holds the Canada Research Chair in Planetary Astronomy.-Career:... , J. Kavelaars John J. Kavelaars John J. Kavelaars, better known as JJ Kavelaars, is a Canadian astronomer who was part of a team that discovered several moons of Jupiter, Saturn, Uranus, and Neptune.... , et al. |
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| 28 | ♣Skathi Skathi (moon) Skathi , or Saturn XXVII, is a natural satellite of Saturn. It was discovered by Brett Gladman, Kavelaars, et al. in 2000, and given the temporary designation S/2000 S 8.... |
ˈskɒði | Norse (Skathi) Group | 2000 | B. Gladman Brett J. Gladman Brett J. Gladman is a Canadian astronomer and a full professor at the University of British Columbia's Department of Physics and Astronomy in Vancouver, British Columbia. He holds the Canada Research Chair in Planetary Astronomy.-Career:... , J. Kavelaars John J. Kavelaars John J. Kavelaars, better known as JJ Kavelaars, is a Canadian astronomer who was part of a team that discovered several moons of Jupiter, Saturn, Uranus, and Neptune.... , et al. |
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| 29 | ♦Albiorix Albiorix (moon) Albiorix is a prograde irregular satellite of Saturn. It was discovered by Holman, et al. in 2000, and given the temporary designation S/2000 S 11.Albiorix is the largest member of the Gallic group of irregular satellites.... |
ˌælbiˈɒrɪks | Gallic group | 2000 | M. Holman Matthew J. Holman Matthew J. Holman is a Smithsonian Astrophysicist and lecturer at Harvard University. Holman studied at MIT, where he received his bachelor's degree in mathematics in 1989 and his PhD in planetary science in 1994.... |
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| 30 | ♣S/2007 S 2 S/2007 S 2 S/2007 S 2 is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on May 1, 2007, from observations taken between January 18 and April 19, 2007.... |
— | Norse group | 2007 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... , B. Marsden Brian G. Marsden Brian Geoffrey Marsden was a British astronomer born in Cambridge, England, and educated at The Perse School in Cambridge, New College, Oxford and Yale University. Dr... |
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| 31 | ♦Bebhionn | bɛˈviːn, ˈvɪvi.ɒn | Gallic group | 2004 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 32 | ♦Erriapus | ˌɛriˈæpəs | Gallic group | 2000 | B. Gladman Brett J. Gladman Brett J. Gladman is a Canadian astronomer and a full professor at the University of British Columbia's Department of Physics and Astronomy in Vancouver, British Columbia. He holds the Canada Research Chair in Planetary Astronomy.-Career:... , J. Kavelaars John J. Kavelaars John J. Kavelaars, better known as JJ Kavelaars, is a Canadian astronomer who was part of a team that discovered several moons of Jupiter, Saturn, Uranus, and Neptune.... , et al. |
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| 33 | ♣Skoll | ˈskɒl, ˈskɜːl | Norse (Skathi) group | 2006 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 34 | ‡Siarnaq Siarnaq (moon) Siarnaq , or Saturn XXIX, is a prograde irregular satellite of Saturn. It was discovered by Brett J. Gladman, et al. in 2000, and given the temporary designation S/2000 S 3.... |
ˈsiːɑrnək | Inuit group | 2000 | B. Gladman Brett J. Gladman Brett J. Gladman is a Canadian astronomer and a full professor at the University of British Columbia's Department of Physics and Astronomy in Vancouver, British Columbia. He holds the Canada Research Chair in Planetary Astronomy.-Career:... , J. Kavelaars John J. Kavelaars John J. Kavelaars, better known as JJ Kavelaars, is a Canadian astronomer who was part of a team that discovered several moons of Jupiter, Saturn, Uranus, and Neptune.... , et al. |
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| 35 | ‡Tarqeq Tarqeq (moon) Tarqeq , also known as Saturn LII is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on April 13, 2007, from observations taken between January 5, 2006, and March 22, 2007... |
ˈtɑrkeɪk | Inuit group | 2007 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 36 | ♣S/2004 S 13 S/2004 S 13 S/2004 S 13 is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on May 4, 2005 from observations taken between December 12, 2004 and March 9, 2005.... |
— | Norse group | 2004 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 37 | ♣Greip | ˈɡreɪp | Norse group | 2006 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 38 | ♣Hyrrokkin | hɪˈrɒkɨn | Norse (Skathi) group | 2006 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 39 | ♣Jarnsaxa | jɑrnˈsæksə | Norse group | 2006 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 40 | ♦Tarvos Tarvos (moon) Tarvos , or Saturn XXI, is a prograde irregular satellite of Saturn. It was discovered by John J. Kavelaars et al. on September 23, 2000, and given the temporary designation S/2000 S 4... |
ˈtɑrvɵs | Gallic group | 2000 | B. Gladman Brett J. Gladman Brett J. Gladman is a Canadian astronomer and a full professor at the University of British Columbia's Department of Physics and Astronomy in Vancouver, British Columbia. He holds the Canada Research Chair in Planetary Astronomy.-Career:... , J. Kavelaars John J. Kavelaars John J. Kavelaars, better known as JJ Kavelaars, is a Canadian astronomer who was part of a team that discovered several moons of Jupiter, Saturn, Uranus, and Neptune.... , et al. |
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| 41 | ♣Mundilfari Mundilfari (moon) Mundilfari , or Saturn XXV, is a natural satellite of Saturn. It was discovered by Brett J. Gladman, et al. in 2000, and given the temporary designation S/2000 S 9.... |
ˌmʊndəlˈvɛri | Norse group | 2000 | B. Gladman Brett J. Gladman Brett J. Gladman is a Canadian astronomer and a full professor at the University of British Columbia's Department of Physics and Astronomy in Vancouver, British Columbia. He holds the Canada Research Chair in Planetary Astronomy.-Career:... , J. Kavelaars John J. Kavelaars John J. Kavelaars, better known as JJ Kavelaars, is a Canadian astronomer who was part of a team that discovered several moons of Jupiter, Saturn, Uranus, and Neptune.... , et al. |
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| 42 | ♣S/2006 S 1 S/2006 S 1 S/2006 S 1 is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on June 26, 2006 from observations taken between January 4 and April 30, 2006.... |
— | Norse (Skathi) group | 2006 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D.C. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 43 | ♣S/2004 S 17 S/2004 S 17 S/2004 S 17 is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on May 4, 2005 from observations taken between December 13, 2004 and March 5, 2005.... |
— | Norse group | 2004 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 44 | ♣Bergelmir | bɛərˈjɛlmɪər | Norse (Skathi) group | 2004 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 45 | ♣Narvi Narvi (moon) Narvi , or Saturn XXXI, is a natural satellite of Saturn. It was discovered by a team of astronomers led by Scott S. Sheppard in 2003, and given the temporary designation S/2003 S 1.- Description :... |
ˈnɑrvi | Norse (Narvi) group | 2003 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 46 | ♣Suttungr Suttungr (moon) Suttungr , or Saturn XXIII, is a natural satellite of Saturn. It was discovered by Brett J. Gladman, et al. in 2000, and given the temporary designation S/2000 S 12... |
ˈsʊtʊŋɡər | Norse group | 2000 | B. Gladman Brett J. Gladman Brett J. Gladman is a Canadian astronomer and a full professor at the University of British Columbia's Department of Physics and Astronomy in Vancouver, British Columbia. He holds the Canada Research Chair in Planetary Astronomy.-Career:... , J. Kavelaars John J. Kavelaars John J. Kavelaars, better known as JJ Kavelaars, is a Canadian astronomer who was part of a team that discovered several moons of Jupiter, Saturn, Uranus, and Neptune.... , et al. |
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| 47 | ♣Hati | ˈhɑːti | Norse group | 2004 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 48 | ♣S/2004 S 12 S/2004 S 12 S/2004 S 12 is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on May 4, 2005 from observations taken between December 12, 2004 and March 9, 2005.... |
— | Norse group | 2004 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 49 | ♣Farbauti | fɑrˈbaʊti | Norse (Skathi) group | 2004 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 50 | ♣Thrymr | ˈθrɪmər | Norse group | 2000 | B. Gladman Brett J. Gladman Brett J. Gladman is a Canadian astronomer and a full professor at the University of British Columbia's Department of Physics and Astronomy in Vancouver, British Columbia. He holds the Canada Research Chair in Planetary Astronomy.-Career:... , J. Kavelaars John J. Kavelaars John J. Kavelaars, better known as JJ Kavelaars, is a Canadian astronomer who was part of a team that discovered several moons of Jupiter, Saturn, Uranus, and Neptune.... , et al. |
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| 51 | ♣Aegir | ˈaɪ.ɪər | Norse group | 2004 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 52 | ♣S/2007 S 3 S/2007 S 3 S/2007 S 3 is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on May 1, 2007 from observations taken between January 18 and April 19, 2007.... |
— | Norse group | 2007 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 53 | ♣Bestla | ˈbɛstlə | Norse (Narvi) group | 2004 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 54 | ♣S/2004 S 7 S/2004 S 7 S/2004 S 7 is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on May 4, 2005 from observations taken between December 12, 2004 and March 8, 2005.... |
— | Norse group | 2004 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 55 | ♣S/2006 S 3 S/2006 S 3 S/2006 S 3 is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on June 26, 2006 from observations taken between January and April 2006.... |
— | Norse (Skathi) group | 2006 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 56 | ♣Fenrir | ˈfɛnrɪər | Norse group | 2004 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 57 | ♣Surtur | ˈsɜrtər | Norse group | 2006 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 58 | ♣Kari | ˈkɑri | Norse (Skathi) group | 2006 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 59 | ♣Ymir Ymir (moon) Ymir , or Saturn XIX, is a retrograde irregular moon of Saturn. It was discovered by Brett J. Gladman, et al. in 2000, and given the temporary designation S/2000 S 1... |
ˈɪmɪər | Norse group | 2000 | B. Gladman Brett J. Gladman Brett J. Gladman is a Canadian astronomer and a full professor at the University of British Columbia's Department of Physics and Astronomy in Vancouver, British Columbia. He holds the Canada Research Chair in Planetary Astronomy.-Career:... , J. Kavelaars John J. Kavelaars John J. Kavelaars, better known as JJ Kavelaars, is a Canadian astronomer who was part of a team that discovered several moons of Jupiter, Saturn, Uranus, and Neptune.... , et al. |
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| 60 | ♣Loge | ˈlɔɪ.eɪ | Norse group | 2006 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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| 61 | ♣Fornjot | ˈfɔrnjɒt | Norse group | 2004 | S. Sheppard Scott S. Sheppard Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and... , D. Jewitt David C. Jewitt David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in... , J. Kleyna Jan Kleyna Jan Kleyna is a postdoctoral astronomy researcher at the University of Hawaii Institute for Astronomy. His area of interest is galaxy dynamics, and he has worked to develop codes for the real-time detection of moving objects such as Jovian satellites. He has also co-discovered several of... |
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 Day A day is a unit of time, commonly defined as an interval equal to 24 hours. It also can mean that portion of the full day during which a location is illuminated by the light of the sun... ) |
Position | Discovery year |
|---|---|---|---|---|---|---|
| S/2004 S 6 |  |
≈ 3–5 | ≈ 140,130 | +0.61801 | uncertain objects around the F Ring | 2004 |
| S/2004 S 3/S 4 S/2004 S 4 ' is the provisional designation of an unconfirmed object seen orbiting Saturn within the inner strand of the F ring on June 21, 2004. It was spotted while J. N. Spitale was trying to confirm the orbit of another provisional object, that was seen 5 hours earlier just exterior to the F ring... |
 |
≈ 3−5 | ≈ 140,300 | ≈ +0.619 | 2004 |
Hypothetical moons
Two moons were claimed to be discovered by different astronomers but never seen again. Both moons were said to orbit between TitanTitan (moon)
Titan , or Saturn VI, is the largest moon of Saturn, the only natural satellite known to have a dense atmosphere, and the only object other than Earth for which clear evidence of stable bodies of surface liquid has been found....
and Hyperion
Hyperion (moon)
Hyperion , also known as Saturn VII, is a moon of Saturn discovered by William Cranch Bond, George Phillips Bond and William Lassell in 1848. It is distinguished by its irregular shape, its chaotic rotation, and its unexplained sponge-like appearance...
.
- ChironChiron (hypothetical moon)Chiron is the name given to a supposed moon of Saturn sighted by Hermann Goldschmidt in 1861. It has since been determined that no such moon exists....
which was supposedly sighted by Hermann Goldschmidt in 1861, but never observed by anyone else. - ThemisThemis (hypothetical moon)On April 28, 1905, William H. Pickering, who had seven years earlier discovered Phoebe, announced the discovery of a tenth satellite of Saturn, which he promptly named Themis. The photographic plates on which it supposedly appeared, thirteen in all, spanned a period between April 17 and July 8, 1904...
was allegedly discovered in 1905 by astronomer William PickeringWilliam Henry PickeringWilliam Henry Pickering was an American astronomer, brother of Edward Charles Pickering. He was elected a Fellow of the American Academy of Arts and Sciences in 1883.-Work:...
, but never seen again. Nevertheless it was included in numerous almanacAlmanacAn almanac is an annual publication that includes information such as weather forecasts, farmers' planting dates, and tide tables, containing tabular information in a particular field or fields often arranged according to the calendar etc...
s and astronomy books until the 1960s.