Planetary Satellite Discovery Circumstances The tables below show the discovery circumstances of planetary satellites and satellites of Pluto officially recognized by the International Astronomical Union (IAU). A total of 209 planetary satellites (including those of Pluto but not Earth) are represented below. References are listed where known. These data were last updated 2019-Oct-08. IAU

number IAU

name provisional

designation year

discovered discoverer(s)/spacecraft mission references Satellites of Mars: 2 I Phobos 1877 A. Hall II Deimos 1877 A. Hall Satellites of Jupiter: 79 I Io 1610 Galileo II Europa 1610 Galileo III Ganymede 1610 Galileo IV Callisto 1610 Galileo V Amalthea 1892 E.E. Barnard VI Himalia 1904 C. Perrine VII Elara 1905 C. Perrine VIII Pasiphae 1908 P. Melotte IX Sinope 1914 S.B. Nicholson X Lysithea 1938 S.B. Nicholson XI Carme 1938 S.B. Nicholson XII Ananke 1951 S.B. Nicholson XIII Leda 1974 C. Kowal XIV Thebe S/1979 J2 1980 Voyager Science Team XV Adrastea S/1979 J1 1979 Voyager Science Team XVI Metis S/1979 J3 1980 Voyager Science Team XVII Callirrhoe S/1999 J1 1999 J.V. Scotti, T.B. Spahr, R.S. McMillan, J.A. Larsen, J. Montani, A.E. Gleason, T. Gehrels IAUC 7460 XVIII Themisto S/1975 J1

S/2000 J1 2000 S.S. Sheppard, D.C. Jewitt, Y. Fernandez, G. Magnier IAUC 7525 XIX Megaclite S/2000 J8 2000 S.S. Sheppard, D.C. Jewitt, Y. Fernandez, G. Magnier IAUC 7555 XX Taygete S/2000 J9 2000 S.S. Sheppard, D.C. Jewitt, Y. Fernandez, G. Magnier IAUC 7555 XXI Chaldene S/2000 J10 2000 S.S. Sheppard, D.C. Jewitt, Y. Fernandez, G. Magnier IAUC 7555 XXII Harpalyke S/2000 J5 2000 S.S. Sheppard, D.C. Jewitt, Y. Fernandez, G. Magnier IAUC 7555 XXIII Kalyke S/2000 J2 2000 S.S. Sheppard, D.C. Jewitt, Y. Fernandez, G. Magnier IAUC 7555 XXIV Iocaste S/2000 J3 2000 S.S. Sheppard, D.C. Jewitt, Y. Fernandez, G. Magnier IAUC 7555 XXV Erinome S/2000 J4 2000 S.S. Sheppard, D.C. Jewitt, Y. Fernandez, G. Magnier IAUC 7555 XXVI Isonoe S/2000 J6 2000 S.S. Sheppard, D.C. Jewitt, Y. Fernandez, G. Magnier IAUC 7555 XXVII Praxidike S/2000 J7 2000 S.S. Sheppard, D.C. Jewitt, Y. Fernandez, G. Magnier IAUC 7555 XXVIII Autonoe S/2001 J1 2001 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2002-J54 XXIX Thyone S/2001 J2 2001 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2002-J54 XXX Hermippe S/2001 J3 2001 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2002-J54 XXXI Aitne S/2001 J11 2001 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2002-J54 XXXII Eurydome S/2001 J4 2001 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2002-J54 XXXIII Euanthe S/2001 J7 2001 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2002-J54 XXXIV Euporie S/2001 J10 2001 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2002-J54 XXXV Orthosie S/2001 J9 2001 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2002-J54 XXXVI Sponde S/2001 J5 2001 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2002-J54 XXXVII Kale S/2001 J8 2001 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2002-J54 XXXVIII Pasithee S/2001 J6 2001 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2002-J54 XXXIX Hegemone S/2003 J8 2003 S.S. Sheppard IAUC 8088 XL Mneme S/2003 J21 2003 S.S. Sheppard, B. Gladman IAUC 8138 XLI Aoede S/2003 J7 2003 S.S. Sheppard IAUC 8087 XLII Thelxinoe S/2003 J22 2003 S.S. Sheppard, B. Gladman IAUC 8276 XLIII Arche S/2002 J1 2003 S.S. Sheppard IAUC 8035 XLIV Kallichore S/2003 J11 2003 S.S. Sheppard IAUC 8089 XLV Helike S/2003 J6 2003 S.S. Sheppard IAUC 8087 XLVI Carpo S/2003 J20 2003 S.S. Sheppard IAUC 8125 XLVII Eukelade S/2003 J1 2003 S.S. Sheppard IAUC 8087 XLVIII Cyllene S/2003 J13 2003 S.S. Sheppard IAUC 8116 XLIX Kore S/2003 J14 2003 S.S. Sheppard IAUC 8116 L Herse S/2003 J17 2003 B. Gladman IAUC 8116 LI S/2010 J1 2010 R. Jacobson, M. Brozovic, et al. IAUC 9222 LII S/2010 J2 2010 C. Veillet IAUC 9222 LIII Dia S/2000 J11 2000 S.S. Sheppard, D.C. Jewitt, Y. Fernandez, G. Magnier IAUC 7555 LIV S/2016 J1 2016 S.S. Sheppard MPEC 2017-L08 LV S/2003 J18 2003 B. Gladman IAUC 8116 LVI S/2011 J2 2011 S.S. Sheppard CBET 3002/IAUC 9252 LVII Eirene S/2003 J5 2003 S.S. Sheppard IAUC 8087 LVIII Philophrosyne S/2003 J15 2003 S.S. Sheppard IAUC 8116 LIX S/2017 J1 2017 S.S. Sheppard MPEC 2017-L47 LX Eupheme S/2003 J3 2003 S.S. Sheppard IAUC 8087 LXI S/2003 J19 2003 B. Gladman IAUC 8125 LXII S/2016 J2 2016 S.S. Sheppard MPEC 2018-O09 LXIII S/2017 J2 2017 S.S. Sheppard MPEC 2018-O10 LXIV S/2017 J3 2017 S.S. Sheppard MPEC 2018-O11 LXV Pandia S/2017 J4 2017 S.S. Sheppard MPEC 2018-O12 LXVI S/2017 J5 2017 S.S. Sheppard MPEC 2018-O13 LXVII S/2017 J6 2017 S.S. Sheppard MPEC 2018-O14 LXVIII S/2017 J7 2017 S.S. Sheppard MPEC 2018-O15 LXIX S/2017 J8 2017 S.S. Sheppard MPEC 2018-O16 LXX S/2017 J9 2017 S.S. Sheppard MPEC 2018-O17 LXXI Ersa S/2018 J1 2018 S.S. Sheppard MPEC 2018-O18 LXXII S/2011 J1 2011 S.S. Sheppard CBET 3002/IAUC 9252 S/2003 J2 2003 S.S. Sheppard IAUC 8087 S/2003 J4 2003 S.S. Sheppard IAUC 8087 S/2003 J9 2003 S.S. Sheppard IAUC 8089 S/2003 J10 2003 S.S. Sheppard IAUC 8089 S/2003 J12 2003 S.S. Sheppard IAUC 8089 S/2003 J16 2003 B. Gladman IAUC 8116 S/2003 J23 2003 S.S. Sheppard IAUC 8281 Satellites of Saturn: 82 I Mimas 1789 W. Herschel II Enceladus 1789 W. Herschel III Tethys 1684 G.D. Cassini IV Dione 1684 G.D. Cassini V Rhea 1672 G.D. Cassini VI Titan 1655 C. Huygens VII Hyperion 1848 W. Bond, W. Lassell VIII Iapetus 1671 G.D. Cassini IX Phoebe 1898 W. Pickering X Janus S/1980 S1 1966 A. Dollfus XI Epimetheus S/1980 S3 1980 J. Fountain, S. Larson, H. Reitsema, B. Smith/Voyager 1 XII Helene S/1980 S6 1980 P. Laques and J. Lecacheux XIII Telesto S/1980 S13 1980 B. Smith, H. Reitsema, S. Larson, J. Fountain/Voyager 1 XIV Calypso S/1980 S25 1980 D. Pascu, K. Seidelmann, W. Baum, D. Currie XV Atlas S/1980 S28 1980 Voyager Science Team XVI Prometheus S/1980 S27 1980 Voyager Science Team XVII Pandora S/1980 S26 1980 Voyager Science Team XVIII Pan S/1981 S13 1990 M. Showalter/Voyager 2 XIX Ymir S/2000 S1 2000 B. Gladman IAUC 7512 XX Paaliaq S/2000 S2 2000 B. Gladman IAUC 7512 XXI Tarvos S/2000 S4 2000 J.J. Kavelaars, B. Gladman IAUC 7513 XXII Ijiraq S/2000 S6 2000 J.J. Kavelaars, B. Gladman IAUC 7521 XXIII Suttungr S/2000 S12 2000 B. Gladman, J.J. Kavelaars IAUC 7548 XXIV Kiviuq S/2000 S5 2000 B. Gladman IAUC 7521 XXV Mundilfari S/2000 S9 2000 B. Gladman, J.J. Kavelaars IAUC 7538 XXVI Albiorix S/2000 S11 2000 M. Holman, T.B. Spahr IAUC 7545 XXVII Skathi S/2000 S8 2000 J.J. Kavelaars, B. Gladman IAUC 7538 XXVIII Erriapus S/2000 S10 2000 J.J. Kavelaars, B. Gladman IAUC 7539 XXIX Siarnaq S/2000 S3 2000 B. Gladman, J.J. Kavelaars IAUC 7513 XXX Thrymr S/2000 S7 2000 B. Gladman, J.J. Kavelaars IAUC 7538 XXXI Narvi S/2003 S1 2003 S.S. Sheppard IAUC 8116 XXXII Methone S/2004 S1 2004 Cassini Imaging Science Team IAUC 8389 XXXIII Pallene S/2004 S2 2004 Cassini Imaging Science Team IAUC 8389 XXXIV Polydeuces S/2004 S5 2004 Cassini Imaging Science Team IAUC 8432 XXXV Daphnis S/2005 S1 2005 Cassini Imaging Science Team IAUC 8524 XXXVI Aegir S/2004 S10 2005 D. Jewitt, S. Sheppard, J. Kleyna IAUC 8523 XXXVII Bebhionn S/2004 S11 2005 D. Jewitt, S. Sheppard, J. Kleyna IAUC 8523 XXXVIII Bergelmir S/2004 S15 2005 D. Jewitt, S. Sheppard, J. Kleyna IAUC 8523 XXXIX Bestla S/2004 S18 2005 D. Jewitt, S. Sheppard, J. Kleyna IAUC 8523 XL Farbauti S/2004 S9 2005 D. Jewitt, S. Sheppard, J. Kleyna IAUC 8523 XLI Fenrir S/2004 S16 2005 D. Jewitt, S. Sheppard, J. Kleyna IAUC 8523 XLII Fornjot S/2004 S8 2005 D. Jewitt, S. Sheppard, J. Kleyna IAUC 8523 XLIII Hati S/2004 S14 2005 D. Jewitt, S. Sheppard, J. Kleyna IAUC 8523 XLIV Hyrrokkin S/2004 S19 2006 S. Sheppard, D. Jewitt, J. Kleyna IAUC 8727 XLV Kari S/2006 S2 2006 S. Sheppard, D. Jewitt, J. Kleyna IAUC 8727 XLVI Loge S/2006 S5 2006 S. Sheppard, D. Jewitt, J. Kleyna IAUC 8727 XLVII Skoll S/2006 S8 2006 S. Sheppard, D. Jewitt, J. Kleyna IAUC 8727 XLVIII Surtur S/2006 S7 2006 S. Sheppard, D. Jewitt, J. Kleyna IAUC 8727 XLIX Anthe S/2007 S4 2007 Cassini Imaging Science Team IAUC 8857 L Jarnsaxa S/2006 S6 2006 S. Sheppard, D. Jewitt, J. Kleyna IAUC 8727 LI Greip S/2006 S4 2006 S. Sheppard, D. Jewitt, J. Kleyna IAUC 8727 LII Tarqeq S/2007 S1 2007 S. Sheppard, D. Jewitt, J. Kleyna IAUC 8836 LIII Aegaeon S/2008 S1 2008 Cassini Imaging Science Team IAUC 9023 S/2004 S7 2005 D. Jewitt, S. Sheppard, J. Kleyna IAUC 8523 S/2004 S12 2005 D. Jewitt, S. Sheppard, J. Kleyna IAUC 8523 S/2004 S13 2005 D. Jewitt, S. Sheppard, J. Kleyna IAUC 8523 S/2004 S17 2005 D. Jewitt, S. Sheppard, J. Kleyna IAUC 8523 S/2004 S20 2004 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2019-T126 S/2004 S21 2004 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2019-T127 S/2004 S22 2004 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2019-T128 S/2004 S23 2004 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2019-T129 S/2004 S24 2004 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2019-T131 S/2004 S25 2004 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2019-T132 S/2004 S26 2004 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2019-T133 S/2004 S27 2004 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2019-T134 S/2004 S28 2004 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2019-T135 S/2004 S29 2004 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2019-T136 S/2004 S30 2004 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2019-T137 S/2004 S31 2004 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2019-T153 S/2004 S32 2004 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2019-T154 S/2004 S33 2004 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2019-T155 S/2004 S34 2004 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2019-T156 S/2004 S35 2004 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2019-T157 S/2004 S36 2004 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2019-T158 S/2004 S37 2004 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2019-T159 S/2004 S38 2004 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2019-T160 S/2004 S39 2004 S.S. Sheppard, D.C. Jewitt, J. Kleyna MPEC 2019-T161 S/2006 S1 2006 S. Sheppard, D. Jewitt, J. Kleyna IAUC 8727 S/2006 S3 2006 S. Sheppard, D. Jewitt, J. Kleyna IAUC 8727 S/2007 S2 2007 S. Sheppard, D. Jewitt, J. Kleyna IAUC 8836 S/2007 S3 2007 S. Sheppard, D. Jewitt, J. Kleyna IAUC 8836 S/2009 S1 2009 Cassini Imaging Science Team IAUC 9091 Satellites of Uranus: 27 I Ariel 1851 W. Lassell II Umbriel 1851 W. Lassell III Titania 1787 W. Herschel IV Oberon 1787 W. Herschel V Miranda 1948 G. Kuiper VI Cordelia S/1986 U7 1986 Voyager Science Team VII Ophelia S/1986 U8 1986 Voyager Science Team VIII Bianca S/1986 U9 1986 Voyager Science Team IX Cressida S/1986 U3 1986 Voyager Science Team X Desdemona S/1986 U6 1986 Voyager Science Team XI Juliet S/1986 U2 1986 Voyager Science Team XII Portia S/1986 U1 1986 Voyager Science Team XIII Rosalind S/1986 U4 1986 Voyager Science Team XIV Belinda S/1986 U5 1986 Voyager Science Team XV Puck S/1985 U1 1985 Voyager Science Team XVI Caliban S/1997 U1 1997 B.J. Gladman, P.D. Nicholson, J.A. Burns, J.J. Kavelaars XVII Sycorax S/1997 U2 1997 P.D. Nicholson, B.J. Gladman, J.A. Burns, J.J. Kavelaars XVIII Prospero S/1999 U3 1999 M. Holman, J.J. Kavelaars, B. Gladman, J.-M. Petit, H. Scholl IAUC 7248 XIX Setebos S/1999 U1 1999 J.J. Kavelaars, B. Gladman, M. Holman, J.-M. Petit, H. Scholl IAUC 7230 XX Stephano S/1999 U2 1999 B. Gladman, M. Holman, J.J. Kavelaars, J.-M. Petit, H. Scholl IAUC 7230 XXI Trinculo S/2001 U1 2001 M. Holman, J.J. Kavelaars, D. Milisavljevic IAUC 7980 XXII Francisco S/2001 U3 2001 J.J. Kavelaars, M. Holman, D. Milisavljevic, T. Grav IAUC 8216, IAUC 7980 XXIII Margaret S/2003 U3 2003 D.C. Jewitt, S.S. Sheppard IAUC 8217 XXIV Ferdinand S/2001 U2 2001 D. Milisavljevic, M. Holman, J.J. Kavelaars, T. Grav IAUC 8213 XXV Perdita S/1986 U10 1999 E. Karkoschka/Voyager 2 IAUC 7171 XXVI Mab S/2003 U1 2003 M. R. Showalter, J. J. Lissauer IAUC 8209 XXVII Cupid S/2003 U2 2003 M. R. Showalter, J. J. Lissauer IAUC 8209 Satellites of Neptune: 14 I Triton 1846 W. Lassell II Nereid 1949 G. Kuiper III Naiad S/1989 N6 1989 Voyager Science Team IV Thalassa S/1989 N5 1989 Voyager Science Team V Despina S/1989 N3 1989 Voyager Science Team VI Galatea S/1989 N4 1989 Voyager Science Team VII Larissa S/1989 N2 1989 Voyager Science Team VIII Proteus S/1989 N1 1989 Voyager Science Team IX Halimede S/2002 N1 2002 M. Holman, J.J. Kavelaars, T. Grav, W. Fraser, D. Milisavljevic IAUC 8047 X Psamathe S/2003 N1 2003 D.C. Jewitt, J. Kleyna, S.S. Sheppard IAUC 8193 XI Sao S/2002 N2 2002 M. Holman, J.J. Kavelaars, T. Grav, W. Fraser, D. Milisavljevic IAUC 8047 XII Laomedeia S/2002 N3 2002 M. Holman, J.J. Kavelaars, T. Grav, W. Fraser, D. Milisavljevic IAUC 8047 XIII Neso S/2002 N4 2002 M. Holman et al., B. Gladman et al. IAUC 8213 XIV Hippocamp S/2004 N1 2013 M.R. Showalter, I. de Pater, J.J. Lissauer, R.S. French CBET 3586 Satellites of Pluto: 5 I Charon S/1978 P1 1978 J. Christy II Nix S/2005 P2 2005 H.A. Weaver, S.A. Stern, et al. IAUC 8625 III Hydra S/2005 P1 2005 H.A. Weaver, S.A. Stern, et al. IAUC 8625 IV Kerberos S/2011 (134340) 1 2011 M.R. Showalter, D.P. Hamilton, et al. IAUC 9221 V Styx S/2012 (134340) 1 2012 M.R. Showalter, H.A. Weaver, et al. IAUC 9253

Notes: • A number of IAUCs listed individuals associated with discoveries from data obtained by missions such as Voyager and Cassini. It has come to our attention (2007-Apr-23) that the IAU working group on Planetary System Nomenclature (WGPSN, see the entry on this IAU page) has changed such cases to list only the project team as the discoverer (e.g. "Cassini Imaging Science Team"). The reference for these revised discovery data is a web-page pointed to (indirectly) by the IAU WGPSN at the USGS, http://planetarynames.wr.usgs.gov/append7.html. • Earth's moon is not included since we were unable to contact the Neanderthal who first saw it.