Moons of Pluto - wikipedia Moons of Pluto Top : Styx ( left ) and Kerberos ( right ) Middle : Nix ( left ) and Hydra ( right ) Bottom : Pluto 's largest moon, Charon, with its dark Mordor Macula ( Images not to scale ) The dwarf planet Pluto has five moons down to a detection limit of about 1 km in diameter. In order of distance from Pluto, they are Charon, Styx, Nix, Kerberos, and Hydra. Charon, the largest of the five moons, is mutually tidally locked with Pluto, and is massive enough that Pluto -- Charon is sometimes considered a double dwarf planet. Contents 1 History 2 Charon 3 Small moons 4 Characteristics 4.1 Resonances 4.2 Rotation 5 Origin 6 List 6.1 Scale model of the Pluto system 7 Mutual events 8 Exploration 9 In science fiction 10 Notes 11 References 12 Sources 13 External links History The innermost and largest moon, Charon, was discovered by James Christy on 22 June 1978, nearly half a century after Pluto was discovered. This led to a substantial revision in estimates of Pluto 's size, which had previously assumed that the observed mass and reflected light of the system were all attributable to Pluto alone. Two additional moons were imaged by astronomers of the Pluto Companion Search Team preparing for the New Horizons mission and working with the Hubble Space Telescope on 15 May 2005, which received the provisional designations S / 2005 P 1 and S / 2005 P 2. The International Astronomical Union officially named these moons Nix ( or Pluto II, the inner of the two moons, formerly P 2 ) and Hydra ( Pluto III, the outer moon, formerly P 1 ), on 21 June 2006. Kerberos, announced on 20 July 2011, was discovered while searching for Plutonian rings. Styx, announced on 7 July 2012, was discovered while looking for potential hazards for New Horizons. Small moons of Pluto - studies suggest the moons were the result of merged bodies. Charon Pluto and Charon, to scale. Photo taken by New Horizons on approach. Main article : Charon ( moon ) Charon is about half the diameter of Pluto and is so massive ( nearly one eighth of the mass of Pluto ) that the system 's barycenter lies between them, approximately 960 km above Pluto 's surface. Charon and Pluto are also tidally locked, so that they always present the same face toward each other. The IAU General Assembly in August 2006 considered a proposal that Pluto and Charon be reclassified as a double planet, but the proposal was abandoned. Small moons Main articles : Styx ( moon ), Nix ( moon ), Kerberos ( moon ), and Hydra ( moon ) The Hubble discovery image of Nix and Hydra Discovery image of Styx, overlaid with orbits of the satellite system Pluto 's four small moons orbit Pluto at two to four times the distance of Charon, ranging from Styx at 42,700 kilometres to Hydra at 64,800 kilometres from the barycenter of the system. They have nearly circular prograde orbits in the same orbital plane as Charon. All are much smaller than Charon. Nix and Hydra, the two larger, are roughly 42 and 55 kilometers on their longest axis respectively, and Styx and Kerberos are 7 and 12 kilometers respectively. All four are irregularly shaped. Characteristics The relative masses of Pluto 's moons. Charon dominates the system. Nix and Hydra are barely visible and Styx and Kerberos are invisible at this scale. An oblique schematic view of the Pluto -- Charon system showing that Pluto orbits a point outside itself. Also visible is the mutual tidal locking between the two bodies. The Pluto system is highly compact and largely empty. Moons could potentially orbit Pluto at up to 53 % ( or 69 %, if retrograde ) of the Hill radius, the stable gravitational zone of Pluto 's influence. For example, Psamathe orbits Neptune at 40 % of the Hill radius. In the case of Pluto, only the inner 3 % of the region where prograde orbits would be stable is occupied by satellites, and the region from Styx to Hydra is packed so tightly that there is little room for further moons with stable orbits. An intense search conducted by New Horizons confirmed that no moons larger than 4.5 km in diameter exist at the distances up to 180,000 km from Pluto ( for smaller distances, this threshold is still smaller ). The orbits of the moons are confirmed to be circular and coplanar, with inclinations differing less than 0.4 ° and eccentricities less than 0.005. The discovery of Nix and Hydra suggested that Pluto could have a ring system. Small - body impacts can create debris that can form into a ring system. However, data from a deep - optical survey by the Advanced Camera for Surveys on the Hubble Space Telescope, by occultation studies, and later by New Horizons, suggest that no ring system is present. Resonances Styx, Nix, and Hydra are thought to be in a 3 - body orbital resonance with orbital periods in a ratio of 18 : 22 : 33 ; the respective ratio of orbits is 11 : 9 : 6. The ratios should be exact when orbital precession is taken into account. Hydra and Nix are in a simple 2 : 3 resonance. Styx and Nix are in a 11 : 9 resonance, while the resonance between Styx and Hydra has a ratio of 11 : 6. This means that in a recurring cycle there are 11 orbits of Styx for every 9 of Nix and 6 of Hydra. The ratios of synodic periods are then such that there are 5 Styx -- Hydra conjunctions and 3 Nix -- Hydra conjunctions for every 2 conjunctions of Styx and Nix. If λ ( displaystyle lambda ) denotes the mean longitude and Φ ( displaystyle Phi ) the libration angle, then the resonance can be formulated as Φ = 3 ⋅ λ S t y x − 5 ⋅ λ N i x + 2 ⋅ λ H y d r a = 180 ∘ ( displaystyle Phi = 3 cdot lambda _ ( \rm ( Styx ) ) - 5 cdot lambda _ ( \rm ( Nix ) ) + 2 cdot lambda _ ( \rm ( Hydra ) ) = 180 ^ ( circ ) ). As with the Laplace resonance of the Galilean satellites of Jupiter, triple conjunctions never occur. Φ ( displaystyle Phi ) librates about 180 ° with an amplitude of at least 10 °. All of the outer circumbinary moons are also close to mean motion resonance with the Charon -- Pluto orbital period. Styx, Nix, Kerberos, and Hydra are in a 1 : 3 : 4 : 5 : 6 sequence of near resonances, with Styx approximately 5.4 % from its resonance, Nix approximately 2.7 %, Kerberos approximately 0.6 %, and Hydra approximately 0.3 %. It may be that these orbits originated as forced resonances when Charon was tidally boosted into its current synchronous orbit, and then released from resonance as Charon 's orbital eccentricity was tidally damped. The Pluto -- Charon pair creates strong tidal forces, with the gravitational field at the outer moons varying by 15 % peak to peak. However, it was calculated that a resonance with Charon could boost either Nix or Hydra into its current orbit, but not both : boosting Hydra would have required a near - zero Charonian eccentricity of 0.024, whereas boosting Nix would have required a larger eccentricity of at least 0.05. This suggests that Nix and Hydra were instead captured material, formed around Pluto -- Charon, and migrated inward until they were trapped in resonance with Charon. The existence of Kerberos and Styx may support this idea. Configurations of Hydra ( blue ), Nix ( red ) and Styx ( black ) over one quarter of the cycle of their mutual orbital resonance. Movements are counterclockwise and orbits completed are tallied at upper right of diagrams ( click on image to see the complete cycle ). Rotation Play media Rotations of the small moons of Pluto ( animation ; 01 : 00 ; released 10 November 2015 ) Nix, Hydra, Styx, and Kerberos rotate chaotically. According to Mark R. Showalter, `` Nix can flip its entire pole. It could actually be possible to spend a day on Nix in which the sun rises in the east and sets in the north. It is almost random - looking in the way it rotates. '' This is because they are in a dynamically changing gravitational field caused by Pluto and Charon orbiting each other. The variable gravitational field creates torques that make Nix and Hydra tumble. The torques are increased because the moons are elongated and not spherical. Only one other moon, Saturn 's moon Hyperion, is known to tumble, though it is likely that Haumea 's moons do so as well. Origin Formation of Pluto 's moons. 1 : a Kuiper belt object approaches Pluto ; 2 : it impacts Pluto ; 3 : a dust ring forms around Pluto ; 4 : the debris aggregates to form Charon ; 5 : Pluto and Charon relax into spherical bodies. It is suspected that Pluto 's satellite system was created by a massive collision, similar to the `` big whack '' thought to have created the Moon. In both cases, the high angular momenta of the moons can only be explained by such a scenario. The nearly circular orbits of the smaller moons suggests that they were also formed in this collision, rather than being captured Kuiper Belt objects. This and their near orbital resonances with Charon ( see below ) suggest that they formed closer to Pluto than they are at present and migrated outward as Charon reached its current orbit. Their grey color is different from that of Pluto, one of the reddest bodies in the Solar System. This is thought to be due to a loss of volatiles during the impact or subsequent coalescence, leaving the surfaces of the moons dominated by water ice. However, such an impact should have created additional debris ( more moons ), yet no moons or rings were discovered by New Horizons, ruling out any more moons of significant size orbiting Pluto. List Pluto 's moons are listed here by orbital period, from shortest to longest. Charon, which is massive enough to have collapsed into a spheroid at some point in its history, is highlighted in light purple. Pluto has been added for comparison. Name ( pronunciation ) Image Diameter ( km ) Mass ( × 10 kg ) Semi-major axis ( km ) Orbital period ( days ) Orbital period ( relative to Charon ) Eccentricity Inclination ( ° ) ( to Pluto 's equator ) Magnitude ( mean ) Discovery date Pluto / ˈpluːtoʊ / 7003237200000000000 ♠ 2372 ± 4 7003130500000000000 ♠ 1305 ± 7 7003203500000000000 ♠ 2035 6.387230 1 : 1 0.0022 0.001 15.1 1930 / 02 / 18 Pluto I Charon / ˈʃærən /, / ˈkɛərən / 7003120800000000000 ♠ 1208 ± 3 7002158700000000000 ♠ 158.7 ± 1.5 7004175360000000000 ♠ 17 536 ± 3 * 6.387230 1 : 1 0.0022 0.001 16.8 1978 / 06 / 22 Pluto V Styx / ˈstɪks / 7001160000000000000 ♠ 16 × 9 × 8 ± ? 0.00075 7004426560000000000 ♠ 42 656 ± 78 7001201615499999999 ♠ 20.161 55 ± 0.000 27 1 : 3.16 0.0058 ± 0.0011 0.81 ± 0.16 27 2012 / 06 / 26 Pluto II Nix / ˈnɪks / 7001500000000000000 ♠ 50 × 35 × 33 ± ? 0.005 ± 0.004 7004486940000000000 ♠ 48 694 ± 3 7001248546300000000 ♠ 24.854 63 ± 0.000 03 1 : 3.89 0.002036 ± 0.000050 0.133 ± 0.008 23.7 2005 / 06 / 15 Pluto IV Kerberos / ˈkɜːrbərəs / / ˈkɜːrbəroʊs / 7001190000000000000 ♠ 19 × 10 × 9 0.0016 ± 0.0009 7004577830000000000 ♠ 57 783 ± 19 7001321675600000000 ♠ 32.167 56 ± 0.000 14 1 : 5.04 0.00328 ± 0.00020 0.389 ± 0.037 26 2011 / 06 / 28 Pluto III Hydra / ˈhaɪdrə / 65 x 45 x 25 ± ? 0.005 ± 0.004 7004647380000000000 ♠ 64 738 ± 3 7001382017700000000 ♠ 38.201 77 ± 0.000 03 1 : 5.98 0.005862 ± 0.000025 0.242 ± 0.005 23.3 2005 / 06 / 15 ( * ) All elements are with respect to the Pluto - Charon barycenter. The maximum distance between the centers of Pluto and Charon is 19,571 ± 4 km. Scale model of the Pluto system Pluto and its five moons, including the location of the system 's barycenter. Sizes, distances and relative brightness of the bodies are to scale ( click on image for detail ). The small moons to approximate scale, compared to Charon Mutual events Simulated view of Charon transiting Pluto on 25 February 1989. Transits occur when one of Pluto 's moons passes between Pluto and the Sun. This occurs when one of the satellites ' orbital nodes ( the points where their orbits cross Pluto 's ecliptic ) lines up with Pluto and the Sun. This can only occur at two points in Pluto 's orbit ; coincidentally, these points are near Pluto 's perihelion and aphelion. Occultations occur when Pluto passes in front of and blocks one of Pluto 's satellites. Charon has an angular diameter of 4 degrees of arc as seen from the surface of Pluto ; the Sun appears much smaller, only 39 to 65 arcseconds. Charon 's proximity further ensures that a large proportion of Pluto 's surface can experience an eclipse. Because Pluto always presents the same face towards Charon due to tidal locking, only the Charon - facing hemisphere experiences solar eclipses by Charon. The smaller moons can cast shadows elsewhere. The angular diameters of the four smaller moons ( as seen from Pluto ) are uncertain. Nix 's is 3 -- 9 minutes of arc and Hydra 's is 2 -- 7 minutes. These are much larger than the Sun 's angular diameter, so total solar eclipses are caused by these moons. Eclipses by Styx and Kerberos are more difficult to estimate, as both moons are very irregular, with angular dimensions of 76.9 x 38.5 to 77.8 x 38.9 arcseconds for Styx, and 67.6 x 32.0 to 68.0 x 32.2 for Kerberos. As such, Styx has no annular eclipses, its widest axis being more than 10 arcseconds larger than the Sun at its largest. However, Kerberos, although slightly larger, can not make total eclipses as its largest minor axis is a mere 32 arcseconds. Eclipses by Kerberos and Styx will entirely consist of partial and hybrid eclipses, with total eclipses being extremely rare. The next period of mutual events due to Charon will begin in October 2103, peak in 2110, and end in January 2117. During this period, solar eclipses will occur once each Plutonian day, with a maximum duration of 90 minutes. Exploration The Pluto system was visited by the New Horizons spacecraft in July 2015. Images with resolutions of up to 330 meters per pixel were returned of Nix and up to 1.1 kilometers per pixel of Hydra. Lower - resolution images were returned of Styx and Kerberos. In science. fiction Author Edmond Hamilton referred to three moons of Pluto in his 1940 novel Calling Captain Future, naming them Charon, Styx, and Cerberus. Charon was listed as the largest of them. All three moons would not be discovered until the year 1970, according to Hamilton. The real Charon was discovered in 1978. Notes Jump up ^ `` P1P2_motion. avi ''. Archived from the original ( AVI ) on 4 November 2005. and barycenter for animations Jump up ^ The ratio of 18 : 22 : 33 in the 3 - body resonance corresponds to a 2 - body resonance with ratio 2 : 3 between Hydra and Nix. Jump up ^ The ratio of 18 : 22 : 33 in the 3 - body resonance corresponds to a 2 - body resonance with ratio 9 : 11 between Nix and Styx. In analogy, the ratio of 18 : 22 : 33 in the 3 - body resonance corresponds to a 2 - body resonance with ratio 6 : 11 between Hydra and Styx. Jump up ^ This is calculated as follows : For every 1 ( displaystyle 1 ) orbit of Hydra there are 33 22 = 3 2 ( displaystyle ( \frac ( 33 ) ( 22 ) ) = ( \frac ( 3 ) ( 2 ) ) ) orbits of Nix and 33 18 = 11 6 ( displaystyle ( \frac ( 33 ) ( 18 ) ) = ( \frac ( 11 ) ( 6 ) ) ) orbits of Styx. The conjunctions then occur at a relative rate of 11 6 − 1 = 5 6 ( displaystyle ( \frac ( 11 ) ( 6 ) ) - 1 = ( \frac ( 5 ) ( 6 ) ) ) for Styx - Hydra, 3 2 − 1 = 1 2 ( displaystyle ( \frac ( 3 ) ( 2 ) ) - 1 = ( \frac ( 1 ) ( 2 ) ) ) for Nix - Hydra and 11 6 − 3 2 = 1 3 ( displaystyle ( \frac ( 11 ) ( 6 ) ) - ( \frac ( 3 ) ( 2 ) ) = ( \frac ( 1 ) ( 3 ) ) ) for Styx - Nix. Multiplying all three rates by 6 ( displaystyle 6 ) ( to make them integers ) yields that there are 5 ( displaystyle 5 ) Styx - Hydra conjunctions and 3 ( displaystyle 3 ) Nix - Hydra conjunctions for every 2 ( displaystyle 2 ) Styx - Nix conjunctions. ^ Jump up to : Orbital eccentricity and inclination of Pluto and Charon are equal because they refer to the same two - body problem ( the gravitational influence of the smaller satellites is neglected here ). Jump up ^ Many astronomers use this, Christy 's pronunciation, rather than the classical / ˈkɛərɒn /, but both are acceptable. References Jump up ^ `` Moons dance around Pluto ''. Smithsonian Institution. 9 June 2015. Retrieved 9 April 2016. Jump up ^ Green, Daniel W.E. ( 21 June 2006 ). `` Satellites of Pluto ''. IAU Circular. 8723. Retrieved 26 November 2011. `` NASA 's Hubble Discovers Another Moon Around Pluto ''. NASA. 20 July 2011. Retrieved 20 July 2011. Jump up ^ `` Hubble Discovers a Fifth Moon Orbiting Pluto ''. hubblesite.org. 29 July 2012. Retrieved 2015 - 07 - 29. Jump up ^ Staff ( 30 January 2014 ). `` Barycenter ''. Education.com. Retrieved 4 June 2015. Jump up ^ `` The IAU draft definition of `` planet '' and `` plutons '' ``. International Astronomical Union. 16 August 2006. Retrieved 4 June 2015. Jump up ^ `` New Horizons ' Captures ' Two of Pluto 's Smaller Moons ''. New Horizons. Retrieved 2015 - 07 - 29. Jump up ^ New Horizons Picks Up Styx Jump up ^ Last of Pluto 's Moons -- Mysterious Kerberos -- Revealed by New Horizons ^ Jump up to : Stern, S. Alan ; Weaver, Harold A., Jr. ; Steffl, Andrew J. ; et al. ( 2005 ). `` Characteristics and Origin of the Quadruple System at Pluto ''. Submitted to Nature. arXiv : astro - ph / 0512599. Bibcode : 2005astro. ph. 12599S. Jump up ^ Steffl, A.J. ; Mutchler, M.J. ; Weaver, H.A. ; Stern, S.A. ; Durda, D.D. ; Terrell, D. ; Merline, W.J. ; Young, L.A. ; Young, E.F. ; Buie, M.W. ; Spencer, J.R. ( 2006 ). `` New Constraints on Additional Satellites of the Pluto System ''. The Astronomical Journal. 132 ( 2 ) : 614 -- 619. arXiv : astro - ph / 0511837. Bibcode : 2006AJ... 132... 614S. doi : 10.1086 / 505424. Jump up ^ Kenyon, S.J. ( 2015 - 06 - 03 ). `` Astronomy : Pluto leads the way in planet formation ''. Nature. 522 ( 7554 ) : 40 -- 41. Bibcode : 2015Natur. 522... 40K. doi : 10.1038 / 522040a. PMID 26040888. Jump up ^ Stern, S.A. ; Bagenal, F. ; Ennico, K. ; et al. ( 2015 ). `` The Pluto system : Initial results from its exploration by New Horizons '' ( PDF ). Science. 350 ( 6258 ) : aad1815. arXiv : 1510.07704. Bibcode : 2015Sci... 350.1815 S. doi : 10.1126 / science. aad1815. PMID 26472913. ( Supplements ) Jump up ^ `` Orbits of 4 Bodies in Pluto System about Barycenter as Seen from Earth ''. Hubblesite. Retrieved 21 June 2006. Jump up ^ Pasachoff, Jay M. ; Babcock, Bryce A. ; Souza, Steven P. ; et al. ( 2006 ). `` A Search for Rings, Moons, or Debris in the Pluto System during the 2006 July 12 Occultation ''. Bulletin of the American Astronomical Society. 38 ( 3 ) : 523. Bibcode : 2006DPS... 38.2502 P. ^ Jump up to : Showalter, M.R. ; Hamilton, D.P. ( 3 June 2015 ). `` Resonant interactions and chaotic rotation of Pluto 's small moons ''. Nature. 522 ( 7554 ) : 45 -- 49. Bibcode : 2015Natur. 522... 45S. doi : 10.1038 / nature14469. PMID 26040889. Jump up ^ Codex Regius ( 2016 ). Pluto & Charon. XinXii. p. 197. ISBN 9781534633520. Retrieved 13 March 2018. Jump up ^ Witze, Alexandra ( 2015 ). `` Pluto 's moons move in synchrony ''. Nature. doi : 10.1038 / nature. 2015.17681. Jump up ^ Matson, J. ( 11 July 2012 ). `` New Moon for Pluto : Hubble Telescope Spots a 5th Plutonian Satellite ''. Scientific American web site. Retrieved 12 July 2012. Jump up ^ Lithwick, Y. ; Y. Wu ( 2008 ). `` On the Origin of Pluto 's Minor Moons, Nix and Hydra ''. arXiv : 0802.2951 ( astro - ph ). Jump up ^ Chang, Kenneth ( 3 June 2015 ). `` Astronomers Describe the Chaotic Dance of Pluto 's Moons ''. New York Times. Retrieved 4 June 2015. Jump up ^ `` NASA 's Hubble Finds Pluto 's Moons Tumbling in Absolute Chaos ''. Retrieved 3 June 2015. Jump up ^ `` Hubble Finds Two Chaotically Tumbling Pluto Moons ''. hubblesite.org. 3 June 2015. Retrieved 3 June 2015. ^ Jump up to : Drake, Nadia ; 03, National Geographic Published June. `` Pluto 's Moons Dance to a Random Beat ''. National Geographic News. Retrieved 4 June 2015. Jump up ^ Ragozzine, Darin ( 17 October 2016 ). `` Rapidly Rotating Regular Satellites and Tides ''. Planetary Society. Retrieved 12 September 2017. Jump up ^ Canup, R.M. ( 8 January 2005 ). `` A Giant Impact Origin of Pluto - Charon ''. Science. 307 ( 5709 ) : 546 -- 550. Bibcode : 2005Sci... 307... 546C. doi : 10.1126 / science. 1106818. PMID 15681378. Retrieved 2011 - 07 - 20. Jump up ^ Stern, S.A. ; Weaver, H.A. ; Steff, A.J. ; Mutchler, M.J. ; Merline, W.J. ; Buie, M.W. ; Young, E.F. ; Young, L.A. ; Spencer, J.R. ( 23 February 2006 ). `` A giant impact origin for Pluto 's small moons and satellite multiplicity in the Kuiper belt '' ( PDF ). Nature. 439 ( 7079 ) : 946 -- 948. Bibcode : 2006Natur. 439... 946S. doi : 10.1038 / nature04548. PMID 16495992. Archived from the original ( PDF ) on 19 January 2012. Retrieved 20 July 2011. Jump up ^ Orbital elements of small satellites from Showalter and Hamilton, 2015 ; mass and magnitude from Buie & Grundy, 2006 Jump up ^ `` ( 134340 ) Pluto, Charon, Nix, Hydra, Kerberos, and Styx ''. www.johnstonsarchive.net. Retrieved 2018 - 06 - 22. Jump up ^ Pluto data from D.R. Williams ( 7 September 2006 ). `` Pluto Fact Sheet ''. NASA. Retrieved 24 March 2007... ^ Jump up to : Weaver et al. ( 2016 ) Jump up ^ `` Start of Eclipse ''. JPL Solar System Simulator. 12 December 1987. Retrieved 2014 - 07 - 29. ( Pluto as seen from the Sun during mid-eclipse ) Jump up ^ `` End of Eclipse ''. JPL Solar System Simulator. 12 December 1987. Retrieved 2014 - 07 - 29. Jump up ^ New Horizons flyby timeline Jump up ^ Codex Regius ( 2016 ). Pluto & Charon. CreateSpace Independent Publishing Platform. ISBN 978 - 1534960749. Sources S.A. Stern, H.A. Weaver, A.J. Steffl, M.J. Mutchler, W.J. Merline, M.W. Buie, E.F. Young, L.A. Young, & J.R. Spencer ( 2006 ), Characteristics and Origin of the Quadruple System at Pluto, Nature, submitted ( preprint ) Steffl, A.J. ; Mutchler, M.J. ; Weaver, H.A. ; Stern, S.A. ; Durda, D.D. ; Terrell, D. ; Merline, W.J. ; Young, L.A. ; Young, E.F. ; Buie, M.W. ; Spencer, J.R. ( 2006 ). `` New Constraints on Additional Satellites of the Pluto System ''. The Astronomical Journal. 132 ( 2 ) : 614 -- 619. arXiv : astro - ph / 0511837. Bibcode : 2006AJ... 132... 614S. doi : 10.1086 / 505424. Buie M.W., Grundy W.M., Young, E.F., Young L.A., Stern S.A. ( 2005 ), Orbits and photometry of Pluto 's satellites : Charon, S / 2005 P1 and S / 2005 P2, submitted ( preprint ) Brozovic, M., Showalter, M.R., Jacobson, R.A., & Buie, M.W. ( 2015 ), The orbits and masses of satellites of Pluto, Icarus, 246, 317. doi : 10.1016 / j. icarus. 2014.03. 015 Bibcode : 2015Icar... 246... 317B Codex Regius ( 2016 ), Pluto & Charon, CreateSpace Independent Publishing Platform ISBN 978 - 1534960749 IAU Circular No. 8625, describing the discovery of 2005 P1 and P2 IAU Circular No. 8686, reporting a more neutral color for 2005 P2 IAU Circular No. 8723 announcing the names of Nix and Hydra Background Information Regarding Our Two Newly Discovered Satellites of Pluto -- The website of the discoverers of Nix and Hydra External links Wikimedia Commons has media related to Moons of Pluto. Pluto 's Known Satellites Animation of the Plutonian system Hubble Spots Possible New Moons Around Pluto ( NASA ) Two More Moons Discovered Orbiting Pluto ( SPACE.com ) New Horizons Mission Site Pluto Geography ( features ) Regions `` Brass Knuckles '' Krun Ala Balrog Vucub - Came Hun - Came Meng - p'o Cadejo Cthulhu Hayabusa Lowell Morgoth Pioneer Tombaugh Venera Viking Voyager Mountains Challenger Colles Coleta de Dados Colles Hillary Montes Tenzing Montes Plains Sputnik Planitia Valleys and depressions Quidlivun Cavus Lineae Luna Linea General Atmosphere Geology Moons Charon ( features ) Regions Gallifrey Mordor Vulcan Mountains Kubrick Mons Chasms Nostromo Chasma Craters Ripley Crater Vader Crater Geology Geology Other moons Styx Nix Kerberos Hydra Astronomy Definition Alan Stern Definition of planet Double planet Dwarf planet IAU definition of planet International Astronomical Union Michael E. Brown Neil deGrasse Tyson Planet Plutino Plutoid Trans - Neptunian object Discovery Clyde Tombaugh James W. Christy Lowell Observatory Percival Lowell Planet X Roger Putnam Eclipses Solar eclipses on Pluto General Kuiper belt Exploration Current Hubble Space Telescope Former New Horizons Cancelled Pluto Fast Flyby / Pluto Kuiper Express Mariner Mark II Old proposals Voyager 1 TAU Related Fiction Mythology Moons of dwarf planets Official 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 Makemakean Eridian 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 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. 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 Haumean Moons Terrestrial Moon other near - Earth objects Martian Phobos Deimos Jovian Ganymede Callisto Io Europa all 69 Saturnian Titan Rhea Iapetus Dione Tethys Enceladus Mimas Hyperion Phoebe all 62 Uranian Titania Oberon Umbriel Ariel Miranda all 27 Neptunian Triton Proteus Nereid all 14 Plutonian Charon Nix Hydra Kerberos Styx Haumean Hiʻiaka Namaka Makemakean S / 2015 ( 136472 ) 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 List of crewed spacecraft 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 → Observable universe → Universe Each arrow ( → ) may be read as `` within '' or `` part of ''. Retrieved from `` https://en.wikipedia.org/w/index.php?title=Moons_of_Pluto&oldid=848469877 '' Categories : Moons of Pluto Lists of moons Hidden categories : Use dmy dates from June 2015 All articles with unsourced statements Articles with unsourced statements from June 2015 Articles containing video clips Talk Contents About Wikipedia Afrikaans Avañe'ẽ Azərbaycanca تۆرکجه Bân - lâm - gú Беларуская Беларуская ( тарашкевіца ) ‎ Català Čeština Dansk Ελληνικά Español Esperanto Euskara فارسی Français Galego 한국어 Հայերեն हिन्दी Ido Bahasa Indonesia Italiano Latviešu Lietuvių मराठी მარგალური Bahasa Melayu Nāhuatl Nederlands 日本 語 Norsk Norsk nynorsk Polski Português Română Русский Simple English Slovenčina Slovenščina Српски / srpski Suomi Svenska Tagalog ไทย Türkçe Українська Tiếng Việt 粵語 中文 42 more Edit links This page was last edited on 2 July 2018, at 03 : 10 ( UTC ). Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: what are the names of pluto's moons
Answer: Charon