Natural satellite - wikipedia Natural satellite `` Moons '' redirects here. For Earth 's natural satellite, see Moon. For other uses, see Moons ( disambiguation ). Most of the 178 known natural satellites are irregular moons, while only 19 are large enough to be round. Ganymede, followed by Titan, Callisto, Io and Earth 's Moon are the largest natural satellites in the Solar System ( see List of natural satellites § List ). A natural satellite or moon is, in the most common usage, an astronomical body that orbits a planet or minor planet ( or sometimes another small Solar System body ). In the Solar System there are six planetary satellite systems containing 178 known natural satellites. Four IAU - listed dwarf planets are also known to have natural satellites : Pluto, Haumea, Makemake, and Eris. As of October 2016, there are over 300 minor planets known to have moons. The Earth -- Moon system is unique in that the ratio of the mass of the Moon to the mass of Earth is much greater than that of any other natural - satellite -- planet ratio in the Solar System ( although there are minor - planet systems with even greater ratios, notably the Pluto -- Charon system ). At 3,474 km ( 2,158 miles ) across, Earth 's Moon is 0.27 times the diameter of Earth. Contents 1 Terminology 1.1 Definition of a moon 2 Origin and orbital characteristics 3 Tidal locking 4 Satellites of satellites 5 Trojan satellites 6 Asteroid satellites 7 Shape 8 Geological activity 9 Natural satellites of the Solar System 10 Visual summary 11 See also 11.1 Moons of planets 11.2 Moons of dwarf planets and small Solar System bodies 12 References 13 External links 13.1 All moons 13.2 Jupiter 's moons 13.3 Saturn 's moons Terminology The first known natural satellite was the Moon, but it was considered a `` planet '' until Copernicus ' introduction of heliocentrism in 1543. Until the discovery of the Galilean satellites in 1610, however, there was no opportunity for referring to such objects as a class. Galileo chose to refer to his discoveries as Planetæ ( `` planets '' ), but later discoverers chose other terms to distinguish them from the objects they orbited. The first to use of the term satellite to describe orbiting bodies was the German astronomer Johannes Kepler in his pamphlet Narratio de Observatis a se quatuor Iouis satellitibus erronibus ( `` Narration About Four Satellites of Jupiter Observed '' ) in 1610. He derived the term from the Latin word satelles, meaning `` guard '', `` attendant '', or `` companion '', because the satellites accompanied their primary planet in their journey through the heavens. The term satellite thus became the normal one for referring to an object orbiting a planet, as it avoided the ambiguity of `` moon ''. In 1957, however, the launching of the artificial object Sputnik created a need for new terminology. The terms man - made satellite and artificial moon were very quickly abandoned in favor of the simpler satellite, and as a consequence, the term has become linked primarily with artificial objects flown in space -- including, sometimes, even those not in orbit around a planet. Because of this shift in meaning, the term moon, which had continued to be used in a generic sense in works of popular science and in fiction, has regained respectability and is now used interchangeably with natural satellite, even in scientific articles. When it is necessary to avoid both the ambiguity of confusion with Earth 's natural satellite the Moon and the natural satellites of the other planets on the one hand, and artificial satellites on the other, the term natural satellite ( using `` natural '' in a sense opposed to `` artificial '' ) is used. To further avoid ambiguity, the convention is to capitalize the word Moon when referring to Earth 's natural satellite, but not when referring to other natural satellites. Many authors define `` satellite '' or `` natural satellite '' as orbiting some planet or minor planet, synonymous with `` moon '' -- by such a definition all natural satellites are moons, but Earth and other planets are not satellites. A few recent authors define `` moon '' as `` a satellite of a planet or minor planet '', and `` planet '' as `` a satellite of a star '' -- such authors consider Earth as a `` natural satellite of the sun ''. Definition of a moon Size comparison of Earth and the Moon There is no established lower limit on what is considered a `` moon ''. Every natural celestial body with an identified orbit around a planet of the Solar System, some as small as a kilometer across, has been considered a moon, though objects a tenth that size within Saturn 's rings, which have not been directly observed, have been called moonlets. Small asteroid moons ( natural satellites of asteroids ), such as Dactyl, have also been called moonlets. The upper limit is also vague. Two orbiting bodies are sometimes described as a double body rather than primary and satellite. Asteroids such as 90 Antiope are considered double asteroids, but they have not forced a clear definition of what constitutes a moon. Some authors consider the Pluto -- Charon system to be a double ( dwarf ) planet. The most common dividing line on what is considered a moon rests upon whether the barycentre is below the surface of the larger body, though this is somewhat arbitrary, because it depends on distance as well as relative mass. Origin and orbital characteristics Two moons : Saturn 's natural satellite Dione occults Enceladus The natural satellites orbiting relatively close to the planet on prograde, uninclined circular orbits ( regular satellites ) are generally thought to have been formed out of the same collapsing region of the protoplanetary disk that created its primary. In contrast, irregular satellites ( generally orbiting on distant, inclined, eccentric and / or retrograde orbits ) are thought to be captured asteroids possibly further fragmented by collisions. Most of the major natural satellites of the Solar System have regular orbits, while most of the small natural satellites have irregular orbits. The Moon and possibly Charon are exceptions among large bodies in that they are thought to have originated by the collision of two large proto - planetary objects ( see the giant impact hypothesis ). The material that would have been placed in orbit around the central body is predicted to have reaccreted to form one or more orbiting natural satellites. As opposed to planetary - sized bodies, asteroid moons are thought to commonly form by this process. Triton is another exception ; although large and in a close, circular orbit, its motion is retrograde and it is thought to be a captured dwarf planet. Tidal locking Main article : Tidal locking Most regular moons ( natural satellites following relatively close and prograde orbits with small orbital inclination and eccentricity ) in the Solar System are tidally locked to their respective primaries, meaning that the same side of the natural satellite always faces its planet. The only known exception is Saturn 's natural satellite Hyperion, which rotates chaotically because of the gravitational influence of Titan. In contrast, the outer natural satellites of the giant planets ( irregular satellites ) are too far away to have become locked. For example, Jupiter 's Himalia, Saturn 's Phoebe, and Neptune 's Nereid have rotation periods in the range of ten hours, whereas their orbital periods are hundreds of days. Satellites of satellites Artist impression of Rhea 's proposed rings No `` moons of moons '' ( natural satellites that orbit a natural satellite of a planet ) are currently known as of 2017. In most cases, the tidal effects of the planet would make such a system unstable. However, calculations performed after the recent detection of a possible ring system around Saturn 's moon Rhea indicate that satellites orbiting Rhea could have stable orbits. Furthermore, the suspected rings are thought to be narrow, a phenomenon normally associated with shepherd moons. However, targeted images taken by the Cassini spacecraft failed to detect rings around Rhea. It has also been proposed that Saturn 's moon Iapetus had a satellite in the past ; this is one of several hypotheses that have been put forward to account for its equatorial ridge. Trojan satellites Two natural satellites are known to have small companions at both their L and L Lagrangian points, sixty degrees ahead and behind the body in its orbit. These companions are called trojan moons, as their orbits are analogous to the trojan asteroids of Jupiter. The trojan moons are Telesto and Calypso, which are the leading and following companions, respectively, of the Saturnian moon Tethys ; and Helene and Polydeuces, the leading and following companions of the Saturnian moon Dione. Asteroid satellites Main article : Asteroid moon The discovery of 243 Ida 's natural satellite Dactyl in the early 1990s confirmed that some asteroids have natural satellites ; indeed, 87 Sylvia has two. Some, such as 90 Antiope, are double asteroids with two comparably sized components. Shape The relative masses of the natural satellites of the Solar System. Mimas, Enceladus, and Miranda are too small to be visible at this scale. All the irregularly shaped natural satellites, even added together, would also be too small to be visible. Neptune 's moon Proteus is the largest irregularly shaped natural satellite. All other known natural satellites that are at least the size of Uranus 's Miranda have lapsed into rounded ellipsoids under hydrostatic equilibrium, i.e. are `` round / rounded satellites ''. The larger natural satellites, being tidally locked, tend toward ovoid ( egg - like ) shapes : squat at their poles and with longer equatorial axes in the direction of their primaries ( their planets ) than in the direction of their motion. Saturn 's moon Mimas, for example, has a major axis 9 % greater than its polar axis and 5 % greater than its other equatorial axis. Methone, another of Saturn 's moons, is only around 3 km in diameter and visibly egg - shaped. The effect is smaller on the largest natural satellites, where their own gravity is greater relative to the effects of tidal distortion, especially those that orbit less massive planets or, as in the case of the Moon, at greater distances. Name Satellite of Difference in axes km % of mean diameter Mimas Saturn 33.4 ( 20.4 / 13.0 ) 8.4 ( 5.1 / 3.3 ) Enceladus Saturn 16.6 3.3 Miranda Uranus 14.2 3.0 Tethys Saturn 25.8 2.4 Io Jupiter 29.4 0.8 The Moon Earth 4.3 0.1 Geological activity This section does not cite any sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. ( December 2013 ) Of the nineteen known natural satellites in the Solar System that are massive enough to have lapsed into hydrostatic equilibrium, several remain geologically active today. Io is the most volcanically active body in the Solar System, while Europa, Enceladus, Titan and Triton display evidence of ongoing tectonic activity and cryovolcanism. In the first three cases, the geological activity is powered by the tidal heating resulting from having eccentric orbits close to their giant - planet primaries. ( This mechanism would have also operated on Triton in the past, before its orbit was circularized. ) Many other natural satellites, such as Earth 's Moon, Ganymede, Tethys and Miranda, show evidence of past geological activity, resulting from energy sources such as the decay of their primordial radioisotopes, greater past orbital eccentricities ( due in some cases to past orbital resonances ), or the differentiation or freezing of their interiors. Enceladus and Triton both have active features resembling geysers, although in the case of Triton solar heating appears to provide the energy. Titan and Triton have significant atmospheres ; Titan also has hydrocarbon lakes. Four of the largest natural satellites, Europa, Ganymede, Callisto, and Titan, are thought to have subsurface oceans of liquid water, while smaller Enceladus may have localized subsurface liquid water. Natural satellites of the Solar System Euler diagram showing the types of bodies in the Solar System. Of the objects within our Solar System known to have natural satellites, there are 76 in the asteroid belt ( five with two each ), four Jupiter trojans, 39 near - Earth objects ( two with two satellites each ), and 14 Mars - crossers. There are also 84 known natural satellites of trans - Neptunian objects. Some 150 additional small bodies have been observed within the rings of Saturn, but only a few were tracked long enough to establish orbits. Planets around other stars are likely to have satellites as well, and although numerous candidates have been detected to date, none have yet been confirmed. Of the inner planets, Mercury and Venus have no natural satellites ; Earth has one large natural satellite, known as the Moon ; and Mars has two tiny natural satellites, Phobos and Deimos. The giant planets have extensive systems of natural satellites, including half a dozen comparable in size to Earth 's Moon : the four Galilean moons, Saturn 's Titan, and Neptune 's Triton. Saturn has an additional six mid-sized natural satellites massive enough to have achieved hydrostatic equilibrium, and Uranus has five. It has been suggested that some satellites may potentially harbour life. Among the identified dwarf planets, Ceres has no known natural satellites. Pluto has the relatively large natural satellite Charon and four smaller natural satellites ; Styx, Nix, Kerberos, and Hydra. Haumea has two natural satellites, and Eris and Makemake have one each. The Pluto -- Charon system is unusual in that the center of mass lies in open space between the two, a characteristic sometimes associated with a double - planet system. The seven largest natural satellites in the Solar System ( those bigger than 2,500 km across ) are Jupiter 's Galilean moons ( Ganymede, Callisto, Io, and Europa ), Saturn 's moon Titan, Earth 's moon, and Neptune 's captured natural satellite Triton. Triton, the smallest of these, has more mass than all smaller natural satellites together. Similarly in the next size group of nine natural satellites, between 1,000 km and 1,600 km across, Titania, Oberon, Rhea, Iapetus, Charon, Ariel, Umbriel, Dione, and Tethys, the smallest, Tethys, has more mass than all smaller natural satellites together. As well as the natural satellites of the various planets, there are also over 80 known natural satellites of the dwarf planets, minor planets and other small Solar System bodies. Some studies estimate that up to 15 % of all trans - Neptunian objects could have satellites. The following is a comparative table classifying the natural satellites in the Solar System by diameter. The column on the right includes some notable planets, dwarf planets, asteroids, and trans - Neptunian objects for comparison. The natural satellites of the planets are named after mythological figures. These are predominantly Greek, except for the Uranian natural satellites, which are named after Shakespearean characters. The nineteen bodies massive enough to have achieved hydrostatic equilibrium are in bold in the table below. Minor planets and satellites suspected but not proven to have achieved a hydrostatic equilibrium are italicized in the table below. Mean diameter ( km ) Satellites of planets Satellites of dwarf planets Satellites of other minor planets Non-satellites for comparison Earth Mars Jupiter Saturn Uranus Neptune Pluto Makemake Haumea Eris 4,000 -- 6,000 Ganymede Callisto Titan Mercury 3,000 -- 4,000 Moon Io Europa 2,000 -- 3,000 Triton Eris Pluto 1,000 -- 2,000 Rhea Iapetus Dione Tethys Titania Oberon Umbriel Ariel Charon Makemake Haumea 2007 OR, Quaoar 500 -- 1,000 Enceladus Dysnomia Sedna, Ceres, Salacia, Orcus, Pallas, Vesta many more TNOs 250 -- 500 Mimas Hyperion Miranda Proteus Nereid Hiʻiaka Orcus I Vanth Salacia I Actaea 10 Hygiea 704 Interamnia 87 Sylvia and many others 100 -- 250 Amalthea Himalia Thebe Phoebe Janus Epimetheus Sycorax Puck Portia Larissa Galatea Despina S / 2015 ( 136472 ) 1 Namaka S / 2005 ( 82075 ) 1 Sila -- Nunam I Ceto I Phorcys Patroclus I Menoetius ~ 21 more moons of TNOs 3 Juno 1992 QB 5 Astraea 42355 Typhon and many others 50 -- 100 Elara Pasiphae Prometheus Pandora Caliban Juliet Belinda Cressida Rosalind Desdemona Bianca Thalassa Halimede Neso Naiad Quaoar I Weywot 90 Antiope I Typhon I Echidna Logos I Zoe 5 more moons of TNOs 90 Antiope 58534 Logos 253 Mathilde and many others 25 -- 50 Carme Metis Sinope Lysithea Ananke Siarnaq Helene Albiorix Atlas Pan Ophelia Cordelia Setebos Prospero Perdita Stephano Sao Laomedeia Psamathe Hydra Nix Kalliope I Linus 1036 Ganymed 243 Ida and many others 10 -- 25 Phobos Deimos Leda Adrastea Telesto Paaliaq Calypso Ymir Kiviuq Tarvos Ijiraq Erriapus Mab Cupid Francisco Ferdinand Margaret Trinculo S / 2004 N 1 Kerberos Styx 762 Pulcova I Sylvia I Romulus 624 Hektor I Skamandrios Eugenia I Petit - Prince 121 Hermione I 283 Emma I 1313 Berna I 107 Camilla I 433 Eros 1313 Berna and many others < 10 53 moons 36 moons Sylvia II Remus Ida I Dactyl and many others many Visual summary Solar System moons Ganymede ( moon of Jupiter ) Titan ( moon of Saturn ) Callisto ( moon of Jupiter ) Io ( moon of Jupiter ) Moon ( moon of Earth ) Europa ( moon of Jupiter ) Triton ( moon of Neptune ) Titania ( moon of Uranus ) Rhea ( moon of Saturn ) Oberon ( moon of Uranus ) Iapetus ( moon of Saturn ) Charon ( moon of Pluto ) Umbriel ( moon of Uranus ) Ariel ( moon of Uranus ) Dione ( moon of Saturn ) Tethys ( moon of Saturn ) Enceladus ( moon of Saturn ) Miranda ( moon of Uranus ) Proteus ( moon of Neptune ) Mimas ( moon of Saturn ) Hyperion ( moon of Saturn ) Phoebe ( moon of Saturn ) Janus ( moon of Saturn ) Amalthea ( moon of Jupiter ) Epimetheus ( moon of Saturn ) Thebe ( moon of Jupiter ) Prometheus ( moon of Saturn ) Pandora ( moon of Saturn ) Hydra ( moon of Pluto ) Helene ( moon of Saturn ) Nix ( moon of Pluto ) Atlas ( moon of Saturn ) Telesto ( moon of Saturn ) Calypso ( moon of Saturn ) Phobos ( moon of Mars ) Deimos ( moon of Mars ) Methone ( moon of Saturn ) Dactyl ( moon of Ida ) This box : view talk edit Comparison of ( a part of ) Jupiter and its four largest natural satellites See also Co-orbital moon Exomoon Inner moon Irregular moon List of natural satellites Naming of moons Quasi-satellite Subsatellite Timeline of discovery of Solar System planets and their moons Trojan moon Tug of war ( astronomy ) Moons of planets The Moon, Earth 's natural satellite Moons of Mars Moons of Jupiter Moons of Saturn Moons of Uranus Moons of Neptune Moons of dwarf planets and small Solar System bodies Minor - planet moon Moons of Pluto Dysnomia, Eris 's natural satellite Moons of Haumea S / 2015 ( 136472 ) 1, Makemake 's natural satellite References Jump up ^ Sheppard, Scott S. `` The Giant Planet Satellite and Moon Page ''. Departament of Terrestrial Magnetism at Carniege Institution for science. Retrieved 2012 - 09 - 11. Jump up ^ `` How Many Solar System Bodies ''. NASA / JPL Solar System Dynamics. Retrieved 2012 - 01 - 26. Jump up ^ `` Planet and Satellite Names and Discoverers ''. International Astronomical Union ( IAU ) Working Group for Planetary System Nomenclature ( WGPSN ). Retrieved 2012 - 01 - 27. Jump up ^ `` Asteroids with satellites ''. www.johnstonsarchive.net. Retrieved 2017 - 09 - 13. Jump up ^ Glenday, Craig ( 2014 ). Guinness World Records 2014. p. 186. ISBN 9781908843159. Jump up ^ Kenneth R. Lang. `` The Cambridge Guide to the Solar System ''. 2011. p. 15. quote : `` Any object that orbits a planet is now called a satellite, and a natural satellite is also now called a moon. '' Jump up ^ Therese Encrenaz, et. al. `` The Solar System ''. 2004. p. 30. Jump up ^ Tilman Spohn, Doris Breuer, Torrence Johnson. `` Encyclopedia of the Solar System ''. 2014. p. 18. Jump up ^ David Andrew Weintraub. `` Is Pluto a Planet ? : A Historical Journey Through the Solar System ''. p. 65 quote : '... the general concept of a `` moon '' as a satellite of a planet and `` planet '' as a satellite of a star. '' Jump up ^ `` Satellite ''. wwww.meriam-webster.com. Merriam Webster. Retrieved 16 November 2015. Jump up ^ Stillman, Dan. `` What Is a Satellite ? ''. www.nasa.gov. NASA. Retrieved 16 November 2015. Jump up ^ F. Marchis, et al. ( 2005 ). `` Discovery of the triple asteroidal system 87 Sylvia ''. Nature. 436 ( 7052 ) : 822 -- 4. Bibcode : 2005Natur. 436... 822M. PMID 16094362. doi : 10.1038 / nature04018. Jump up ^ Canup, Robin M. ; Ward, William R. ( 2008 - 12 - 30 ). Origin of Europa and the Galilean Satellites. University of Arizona Press. p. 59. Bibcode : 2009euro. book... 59C. ISBN 978 - 0 - 8165 - 2844 - 8. arXiv : 0812.4995. Jump up ^ D'Angelo, G. ; Podolak, M. ( 2015 ). `` Capture and Evolution of Planetesimals in Circumjovian Disks ''. The Astrophysical Journal. 806 ( 1 ) : 29pp. Bibcode : 2015ApJ... 806... 203D. arXiv : 1504.04364. doi : 10.1088 / 0004 - 637X / 806 / 2 / 203. Jump up ^ Encyclopedia of the Solar System, page 366, Academic Press, 2007, Lucy - Ann Adams McFadden, Paul Robert Weissman, Torrence V. Johnson Jump up ^ Canup, RM & Asphaug, E ( 2001 ). `` Origin of the Moon in a giant impact near the end of the Earth 's formation ''. Nature. 412 ( 6848 ) : 708 -- 712. Bibcode : 2001Natur. 412... 708C. PMID 11507633. doi : 10.1038 / 35089010. Jump up ^ Stern, SA ; Weaver, HA ; Steffl, AJ ; Mutchler, MJ ; et al. ( 2006 ). `` A giant impact origin for Pluto 's small natural satellites and satellite multiplicity in the Kuiper belt ''. Nature. 439 ( 7079 ) : 946 -- 949. Bibcode : 2006Natur. 439... 946S. PMID 16495992. doi : 10.1038 / nature04548. Jump up ^ `` The Dust Halo of Saturn 's Largest Icy Moon, Rhea -- Jones et al. 319 ( 5868 ) : 1380 -- Science ''. Retrieved 2008 - 03 - 06. Jump up ^ `` Saturn satellite reveals first moon rings -- 06 March 2008 -- New Scientist ''. Retrieved 2008 - 03 - 06. Jump up ^ `` Cassini imaging search rules out rings around Rhea -- Tiscareno -- 2010 -- Geophysical Research Letters -- Wiley Online Library ''. Agu.org. Retrieved 2013 - 10 - 29. Jump up ^ `` How Iapetus, Saturn 's outermost moon, got its ridge ''. Retrieved 2010 - 12 - 18. ^ Jump up to : Wm. Robert Johnston ( 2012 - 01 - 11 ). `` Asteroids with Satellites ''. Johnston 's Archive. Retrieved 2012 - 01 - 26. Jump up ^ Woo, Marcus ( 27 January 2015 ). `` Why We 're Looking for Alien Life on Moons, Not Just Planets ''. Wired. Retrieved 27 January 2015. Jump up ^ `` Hubble Discovers New Pluto Moon ''. ESA / Hubble Press Release. Retrieved 13 July 2012. Jump up ^ `` How Big Is Pluto ? New Horizons Settles Decades - Long Debate ''. NASA. External links Wikimedia Commons has media related to Natural satellites. All moons Natural Satellite Physical Parameters ( JPL - NASA, with refs -- last updated July 2006 ) Moons of the Solar System ( The Planetary Society, as of March 2009 ) JPL 's Solar System Dynamics page USGS list of named moons Upper size limit for moons explained Asteroids with Satellites Images of planets and major moons ( not to scale ) The Planetary Society -- Moon Montage ( s ) Jupiter 's moons Scott Sheppard 's page Jupiter 's new moons ( discovered in 2002 ) Jupiter 's new moons ( discovered in 2003 ) Saturn 's moons Saturn 's new moons ( discovered in 2000 ) Saturn 's new moon ( discovered in 2003 ) Natural satellites of the Solar System Moons of Earth, Mars and the Asteroids Earth Mars Asteroid moons The Moon Phobos Deimos Binaries List Moons of Jupiter Listed in approximately increasing distance from Jupiter. Provisional designations in italics. Inner moons Metis Adrastea Amalthea Thebe Galilean moons Io Europa Ganymede Callisto Themisto group Themisto Himalia group Leda Himalia Lysithea Elara Dia Carpo group Carpo S / 2003 J 12 S / 2011 J 1 Ananke group Core Euanthe Iocaste Praxidike Harpalyke Thyone Ananke Peripheral S / 2003 J 3 ( ? ) Jupiter LII Thelxinoe S / 2003 J 16 Mneme Hermippe Carme group Herse Kale Aitne Taygete S / 2003 J 19 ( ? ) Chaldene Erinome Kallichore Kalyke Carme Pasithee Jupiter LI Eukelade Arche Isonoe S / 2003 J 9 ( ? ) Jupiter LVII Pasiphae group Euporie Jupiter LV Helike Orthosie Jupiter LIV Jupiter LVIII S / 2003 J 10 ( ? ) S / 2003 J 23 ( ? ) Aoede Callirrhoe Eurydome Kore Cyllene Jupiter LVI Jupiter LIX S / 2003 J 4 ( ? ) Pasiphae Hegemone Sinope Sponde Autonoe Megaclite S / 2003 J 2 Rings of Jupiter In fiction Moons of Saturn Listed in approximately increasing distance from Saturn. Temporary names in italics. Ring shepherds S / 2009 S 1 Ring moonlets Pan Daphnis Atlas Prometheus Pandora Co-orbitals Epimetheus Janus G Ring Aegaeon Mimas and Alkyonides Mimas Methone Anthe Pallene Inner large ( with trojans ) Enceladus Tethys Telesto Calypso Dione Helene Polydeuces Outer large Rhea Titan Hyperion Iapetus Inuit group Kiviuq Ijiraq Paaliaq Siarnaq Tarqeq Norse group Phoebe Skathi S / 2007 S 2 ( ? ) Skoll S / 2004 S 13 ( ? ) Greip Hyrrokkin Jarnsaxa Mundilfari S / 2006 S 1 ( ? ) S / 2004 S 17 ( ? ) Bergelmir Narvi Suttungr Hati S / 2004 S 12 ( ? ) Farbauti Thrymr Aegir S / 2007 S 3 ( ? ) Bestla S / 2004 S 7 ( ? ) S / 2006 S 3 Fenrir Surtur Kari Ymir Loge Fornjot Gallic group Albiorix Bebhionn Erriapus Tarvos Rings of Saturn Cassini -- Huygens Themis Chiron S / 2004 S 6 S / 2004 S 4 S / 2004 S 3 In fiction Moons of Uranus Generally listed in increasing distance from Uranus Inner Rings of Uranus Cordelia Ophelia Bianca Cressida Desdemona Juliet Portia Rosalind Cupid Belinda Perdita Puck Mab Major ( spheroid ) Miranda Ariel Umbriel Titania Oberon Outer ( irregular ) Francisco Caliban Stephano Trinculo Sycorax Margaret Prospero Setebos Ferdinand Geological features Arielian Kachina Chasmata Yangoor Mirandian Verona Rupes Oberonian Hamlet Mommur Chasma Puckian Titanian Gertrude Messina Chasma Ursula Rousillon Rupes Umbrielian Wunda Vuver Skynd Moons of Neptune Generally listed in increasing distance from Neptune Regular ( inner ) Naiad Thalassa Despina Galatea Larissa S / 2004 N 1 Proteus Triton Triton ( Atmosphere Geological features Sky ) Irregular Nereid Halimede Sao Laomedeia Psamathe Neso See also Neptune trojans Rings of Neptune Book Portal Moons of dwarf planets Identified dwarf planets Pluto Haumea Makemake Eris Charon Styx Nix Kerberos Hydra Namaka Hiʻiaka S / 2015 ( 136472 ) 1 Dysnomia Likely dwarf planets Orcus Quaoar ( 55637 ) 2002 UX 25 ( 229762 ) 2007 UK 126 ( 208996 ) 2003 AZ 84 Salacia Varda Huya Vanth Weywot S / 2007 ( 55637 ) 1 S / 2008 ( 229762 ) 1 S / 2005 ( 208996 ) 1 ( unrecovered ) Actaea Ilmarë S / 2012 ( 38628 ) 1 Natural satellites of the Solar System Planetary satellites Terrestrial Martian Jovian Saturnian Uranian Neptunian Other satellites Minor - planet moons Plutonian Haumean Eridian Makemakean Largest satellites ( mean radius ≥ 100 km ) size Ganymede largest / 2634 km / 0.413 Earths Titan Callisto Io Moon Europa Triton Titania Rhea Oberon Iapetus Charon Umbriel Ariel Dione Tethys ( Dysnomia ) Enceladus Miranda Proteus Mimas ( Hi'iaka ) Nereid Hyperion Phoebe smallest / 106 km / 0.017 Earths abc 's Ariel Callisto Charon Dione ( Dysnomia ) Enceladus Europa Ganymede ( Hi'iaka ) Hyperion Iapetus Io Mimas Miranda Moon Nereid Oberon Phoebe Proteus Rhea Tethys Titan Titania Triton Umbriel Discovery timeline Inner moons Irregular moons List Naming Regular moons Trojan moons NOTE : Italicized moons are not close to being in hydrostatic equilibrium ; ( bracketed ) moons may or may not be close to being in hydrostatic equilibrium. Regular moons Inner moons Irregular moons Trojan moons Discovery timeline List Naming The Solar System The Sun Mercury Venus Earth Mars Ceres Jupiter Saturn Uranus Neptune Pluto Haumea Makemake Eris Planets Terrestrial planets Mercury Venus Earth Mars Giant planets Jupiter Saturn Uranus Neptune Dwarf planets Ceres Pluto Haumea Makemake Eris Rings Jovian Saturnian ( Rhean ) Charikloan Chironean Uranian Neptunian Moons 1 Terrestrial ( Moon ) Other near - Earth objects 2 Martian Phobos Deimos 69 Jovian Ganymede Callisto Io Europa all 62 Saturnian Titan Rhea Iapetus Dione Tethys Enceladus Mimas Hyperion Phoebe all 27 Uranian Titania Oberon Umbriel Ariel Miranda all 14 Neptunian Triton Proteus Nereid all 5 Plutonian Charon Nix Hydra Kerberos Styx 2 Haumean Hiʻiaka Namaka 1 Makemakean ( S / 2015 ( 136472 ) 1 ) 1 Eridian ( Dysnomia ) Lists Solar System objects By size By discovery date Minor planets Gravitationally rounded objects Possible dwarf planets Natural satellites Comets Small Solar System bodies Meteoroids Minor planets moons Comets Damocloids Mercury - crossers Venus - crossers Venus trojans Near - Earth objects Earth - crossers Earth trojans Mars - crossers Mars trojans Asteroid belt Asteroids first discovered : Ceres Pallas Juno Vesta Families Notable asteroids Kirkwood gap Main - belt comets Jupiter trojans Jupiter - crossers Centaurs Saturn - crossers Uranus trojans Uranus - crossers Neptune trojans Cis - Neptunian objects Trans - Neptunian objects Neptune - crossers Plutoids Kuiper belt Plutinos Cubewanos Scattered disc Detached objects Sednoids Hills cloud Oort cloud Hypothetical objects Vulcan Vulcanoids Phaeton Planet V Theia Fifth giant Planets beyond Neptune Tyche Nemesis Planet Nine Exploration ( outline ) Discovery Astronomy Timeline Spaceflight Robotic spacecraft Human spaceflight Colonization List of probes Timeline Mercury Venus Moon Mars Ceres Asteroids Mining Comets Jupiter Saturn Uranus Neptune Pluto Deep space Outline of the Solar System Portals Solar System Astronomy Earth sciences Mars Jupiter Uranus Cosmology Solar System → Local Interstellar Cloud → Local Bubble → Gould Belt → Orion Arm → Milky Way → Milky Way subgroup → Local Group → Virgo Supercluster → Laniakea Supercluster → Pisces -- Cetus Supercluster Complex → Observable universe → Universe Each arrow ( → ) may be read as `` within '' or `` part of ''. GND : 4179141 - 1 NDL : 00561855 Retrieved from `` https://en.wikipedia.org/w/index.php?title=Natural_satellite&oldid=800504165 '' Categories : Moons Hidden categories : Articles containing potentially dated statements from October 2016 All articles containing potentially dated statements All articles with unsourced statements Articles with unsourced statements from November 2016 Articles with unsourced statements from January 2017 Articles with unsourced statements from January 2012 Articles needing additional references from December 2013 All articles needing additional references Use dmy dates from April 2011 Wikipedia articles with GND identifiers Talk Contents About Wikipedia Afrikaans Alemannisch Asturianu Avañe'ẽ Azərbaycanca تۆرکجه বাংলা Bân - lâm - gú Беларуская Беларуская ( тарашкевіца ) ‎ भोजपुरी Български Boarisch Bosanski Brezhoneg Català Čeština Dansk Deutsch Eesti Ελληνικά Español Esperanto Euskara فارسی Français Gaeilge Gàidhlig Galego 贛 語 한국어 Հայերեն हिन्दी Hrvatski Bahasa Indonesia Interlingua Íslenska Italiano עברית Basa Jawa ಕನ್ನಡ ქართული Kreyòl ayisyen Kurdî Кыргызча Latina Latviešu Lëtzebuergesch Lietuvių Limburgs Magyar Македонски മലയാളം मराठी მარგალური Bahasa Melayu Mìng - dĕ̤ng - ngṳ̄ Mirandés Nederlands 日本 語 Norsk Norsk nynorsk Occitan Oʻzbekcha / ўзбекча ਪੰਜਾਬੀ Patois Plattdüütsch Polski Português Ripoarisch Română Runa Simi Русский Scots Seeltersk Shqip Sicilianu Simple English سنڌي Slovenčina Slovenščina Soomaaliga کوردی Српски / srpski Srpskohrvatski / српскохрватски Suomi Svenska Tagalog தமிழ் Татарча / tatarça తెలుగు ไทย ᏣᎳᎩ Türkçe Українська اردو Vèneto Tiếng Việt 文言 ייִדיש 粵語 中文 Edit links This page was last edited on 13 September 2017, at 23 : 45. 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Question: what is the natural satellite of the earth
Answer: the Moon