# Distances of moons of other planets

## September 2006

With the recent naming of 136199 Eris and its moon Dysnomia, I saw a question on a discussion list about astrologically separating their interpretations. This prompted me to dig out a few numbers to see how practical such an effort might be, not just for Eris and Dysnomia, but for any planets and moons in our solar system.

I suggest not making such an attempt because planets and their moons are always conjunct. Most are so closely conjunct that separate interpretations would be very difficult. Among the larger moons, the greatest possible separation is about 11 minutes of arc for Jupiter’s Callisto—the rest of the large moons are visually closer to their planets than that. The largest possible visual separation of any moon from its planet is about 3 degrees for Jupiter’s farthest-flung moons—most planet-moon separations are much smaller.

The main astrological technique that comes to mind immediately to allow separate interpretations would require a program that includes planets’ moons as separate points in lists of timed hits (progressions or transits). Then you would need a lot of well-timed events to check against the differing moments of planet and moon aspects. High-order harmonics are another possible technique.

I don’t know if any astrological software even offers positions of planetary moons, though it could exist (I don’t try to keep track of everything that is available). Accurate positions would certainly be a lot of work since orbital information for moons is in a variety of different forms.

You can easily make an estimate of how far apart a planet and moon could appear from Earth. (You can find most of the number you need in Wikipedia more conveniently than by hunting through reference books.) If your data sources give a mix of astronomical units and kilometers, convert all data to AU first. (1 AU = 149,597,870.7 km.)

Assume the moon’s orbit is angled so that its maximum planetocentric distance is perpendicular to the line of sight from Earth. (In most cases, the actual angle will reduce the maximum separation from the viewpoint of Earth, so this gives you an upper limit.)

Calculate the moon’s maximum planetocentric distance as moon’s semi-major axis times (1 + eccentricity).

Calculate the planet’s perihelion distance as planet’s semi-major axis times (1 - eccentricity).

Subtract the Earth’s aphelion distance from the planet’s perihelion distance to get the closest possible approach of the two planets. (This is another approximation of a limiting value. The two planets could only get this close if the Earth’s aphelion and the planets perihelion were aligned in space, which will rarely be the case.)

Calculate the circumference of a circle at the two-planet closest approach distance as distance * 2 * Pi.

Divide the moon’s maximum planetocentric distance by the two-planet closest approach circumference. (We are ignoring straight line vs. circle issues here as negligible in light of all the other simplifying assumptions.) This gives you the maximum angle an observer on Earth could see between the planet and the moon. Convert to degrees, minutes or seconds. Remember that this is an estimated maximum and that actual separations (which would require a LOT more calculations) will usually be less. Also remember that for some moons this separation will NOT be along the ecliptic, so the maximum separation in zodiacal longitude will be a smaller value.

 Visibile separation of planets and their moons 1 AU = 149,597,870.66 km Planet: Axis AU Eccentricity Perihelion Aphelion EarthMin AU Circumf AU Mercury 0.3870989 0.2056307 0.3074995 0.4666984 0.5165915 3.2458404 Venus 0.7233320 0.0067732 0.7184327 0.7282313 0.2550586 1.6025805 Earth 1.0000001 0.0167102 0.9832899 1.0167103 n/a n/a Mars 1.5236623 0.0934123 1.3813335 1.6659912 0.3646231 2.2909947 Jupiter 5.2033630 0.0483927 4.9515584 5.4551676 3.9682685 24.9333666 Saturn 9.5370703 0.0541506 9.0206322 10.0535084 8.0039219 50.2901245 Uranus 19.1912639 0.0471677 18.2860560 20.0964719 17.2693456 108.5064987 Neptune 30.0689635 0.0085859 29.8107953 30.3271317 28.7940849 180.9185714 Pluto 39.4816868 0.2488077 29.6583407 49.3050329 28.6416303 179.9606709 136199 Eris 67.6681000 0.4417700 37.7743635 97.5618365 36.7576531 230.9551461

 Moon: Axis in km Axis in AU Eccentricity Peri Ap Fract. Of Circ AsDegrees AsMinutes AsSeconds 1 AU Elong ElongSecs Moons of Mars I Phobos 9,377 0.0000627 0.0150 0.0000617 0.0000636 0.0000278 0.0100 0.60 36.0 II Deimos 23,460 0.0001568 0.0004 0.0001568 0.0001569 0.0000685 0.0247 1.48 88.7 Moons of Jupiter XVI Metis 127,690 0.0008536 0.0012 0.0008525 0.0008546 0.0000343 0.0123 0.74 44.4 XV Adrastea 128,690 0.0008602 0.0018 0.0008587 0.0008618 0.0000346 0.0124 0.75 44.8 V Amalthea 181,170 0.0012110 0.0031 0.0012073 0.0012148 0.0000487 0.0175 1.05 63.1 249.55 62.9 XIV Thebe 221,700 0.0014820 0.0177 0.0014557 0.0015082 0.0000605 0.0218 1.31 78.4 305.95 77.1 I Io 421,700 0.0028189 0.0041 0.0028073 0.0028304 0.0001135 0.0409 2.45 147.1 II Europa 671,034 0.0044856 0.0094 0.0044434 0.0045277 0.0001816 0.0654 3.92 235.3 III Ganymede 1,070,412 0.0071553 0.0011 0.0071474 0.0071631 0.0002873 0.1034 6.21 372.3 IV Callisto 1,882,709 0.0125851 0.0074 0.0124920 0.0126783 0.0005085 0.1831 10.98 659.0 Themisto 7,393,200 0.0494205 0.2116 0.0389631 0.0598779 0.0024015 0.8645 51.87 3112.4 Leda 11,097,245 0.0741805 0.1854 0.0604274 0.0879336 0.0035267 1.2696 76.18 4570.7 Himalia 11,432,435 0.0764211 0.1443 0.0653935 0.0874487 0.0035073 1.2626 75.76 4545.5 Lysithia 11,653,225 0.0778970 0.1132 0.0690791 0.0867149 0.0034779 1.2520 75.12 4507.3 Elara 11,683,115 0.0780968 0.1723 0.0646407 0.0915529 0.0036719 1.3219 79.31 4758.8 Carpo 17,144,875 0.1146064 0.2736 0.0832501 0.1459627 0.0058541 2.1075 126.45 7586.9 Euporie 19,088,435 0.1275983 0.0960 0.1153489 0.1398477 0.0056089 2.0192 121.15 7269.1 Thelxinoe 20,453,755 0.1367249 0.2685 0.1000143 0.1734355 0.0069560 2.5041 150.25 9014.9 Euanthe 20,464,855 0.1367991 0.2000 0.1094393 0.1641589 0.0065839 2.3702 142.21 8532.7 Helike 20,540,265 0.1373032 0.1375 0.1184240 0.1561824 0.0062640 2.2550 135.30 8118.1 Orthosie 20,567,970 0.1374884 0.2433 0.1040375 0.1709393 0.0068558 2.4681 148.09 8885.2 Iocaste 20,722,565 0.1385218 0.2874 0.0987106 0.1783330 0.0071524 2.5749 154.49 9269.5 Ananke 20,815,225 0.1391412 0.3963 0.0839995 0.1942828 0.0077921 2.8051 168.31 10098.5 Praxidike 20,823,950 0.1391995 0.1840 0.1135868 0.1648122 0.0066101 2.3796 142.78 8566.7 Harpalyke 21,063,815 0.1408029 0.2441 0.1064329 0.1751729 0.0070256 2.5292 151.75 9105.2 Hermippe 21,182,085 0.1415935 0.2290 0.1091686 0.1740184 0.0069793 2.5126 150.75 9045.2 Thyone 21,405,570 0.1430874 0.2526 0.1069435 0.1792313 0.0071884 2.5878 155.27 9316.2 Mneme 21,427,110 0.1432314 0.2214 0.1115200 0.1749428 0.0070164 2.5259 151.55 9093.3 Aitne 22,285,160 0.1489671 0.3927 0.0904677 0.2074665 0.0083208 2.9955 179.73 10783.8 Kale 22,409,210 0.1497963 0.2011 0.1196723 0.1799204 0.0072160 2.5978 155.87 9352.0 Taygete 22,438,650 0.1499931 0.3678 0.0948256 0.2051606 0.0082284 2.9622 177.73 10663.9 Chaldene 22,713,445 0.1518300 0.2916 0.1075564 0.1961036 0.0078651 2.8314 169.89 10193.2 Erinome 22,986,265 0.1536537 0.2552 0.1144413 0.1928661 0.0077353 2.7847 167.08 10024.9 Aoede 23,044,175 0.1540408 0.6012 0.0614315 0.2466501 0.0098924 3.5613 213.68 12820.5 Kallichore 23,111,825 0.1544930 0.2042 0.1229455 0.1860405 0.0074615 2.6861 161.17 9670.1 Kalyke 23,180,775 0.1549539 0.2140 0.1217938 0.1881140 0.0075447 2.7161 162.96 9777.9 Eurydome 23,230,860 0.1552887 0.3770 0.0967449 0.2138326 0.0085762 3.0874 185.25 11114.7 Pasithee 23,307,320 0.1557998 0.3289 0.1045573 0.2070424 0.0083038 2.9894 179.36 10761.8 Cyllene 23,396,270 0.1563944 0.4116 0.0920225 0.2207663 0.0088543 3.1875 191.25 11475.1 Eukelade 23,483,695 0.1569788 0.2829 0.1125695 0.2013881 0.0080771 2.9077 174.46 10467.9 Hegemone 23,702,510 0.1584415 0.4077 0.0938449 0.2230381 0.0089454 3.2203 193.22 11593.2 Arche 23,717,050 0.1585387 0.1492 0.1348847 0.1821927 0.0073072 2.6306 157.84 9470.1 Carme 23,734,465 0.1586551 0.3122 0.1091230 0.2081872 0.0083497 3.0059 180.35 10821.3 Isonoe 23,832,630 0.1593113 0.1665 0.1327860 0.1858366 0.0074533 2.6832 160.99 9659.5 Pasiphaë 24,094,770 0.1610636 0.2953 0.1135015 0.2086257 0.0083673 3.0122 180.73 10844.1 Sinope 24,214,390 0.1618632 0.2468 0.1219154 0.2018110 0.0080940 2.9138 174.83 10489.8 Sponde 24,252,625 0.1621188 0.4432 0.0902677 0.2339698 0.0093838 3.3782 202.69 12161.4 Autonoe 24,264,445 0.1621978 0.3690 0.1023468 0.2220488 0.0089057 3.2060 192.36 11541.8 Callirrhoe 24,356,030 0.1628100 0.2644 0.1197630 0.2058570 0.0082563 2.9723 178.34 10700.1 Megaclite 24,687,240 0.1650240 0.3078 0.1142296 0.2158184 0.0086558 3.1161 186.97 11217.9 Skipped several unnamed moons. S/2003 J 2 30,290,845 0.2024818 0.1882 0.1643747 0.2405889 0.0096493 3.4737 208.42 12505.5 Moons of Saturn XVIII Pan 133,584 0.0008930 0.0000 0.0008929 0.0008930 0.0000178 0.0064 0.38 23.0 XXXV Daphnis 136,505 0.0009125 0.0000 0.0009125 0.0009125 0.0000181 0.0065 0.39 23.5 XV Atlas 137,670 0.0009203 0.0012 0.0009192 0.0009214 0.0000183 0.0066 0.40 23.7 XVII Prometheus 139,380 0.0009317 0.0022 0.0009296 0.0009337 0.0000186 0.0067 0.40 24.1 XVII Pandora 141,720 0.0009473 0.0042 0.0009434 0.0009513 0.0000189 0.0068 0.41 24.5 XI Epimetheus 151,422 0.0010122 0.0098 0.0010023 0.0010221 0.0000203 0.0073 0.44 26.3 X Janus 151,472 0.0010125 0.0068 0.0010056 0.0010194 0.0000203 0.0073 0.44 26.3 I Mimas 185,404 0.0012393 0.0202 0.0012143 0.0012644 0.0000251 0.0091 0.54 32.6 XXXII Methone 194,440 0.0012998 0.0001 0.0012996 0.0012999 0.0000258 0.0093 0.56 33.5 XXXIII Pallene 212,280 0.0014190 0.0040 0.0014133 0.0014247 0.0000283 0.0102 0.61 36.7 II Enceladus 237,950 0.0015906 0.0047 0.0015831 0.0015981 0.0000318 0.0114 0.69 41.2 III Tethys 294,619 0.0019694 0.0000 0.0019694 0.0019694 0.0000392 0.0141 0.85 50.8 XIII Telesto 294,619 0.0019694 0.0000 0.0019694 0.0019694 0.0000392 0.0141 0.85 50.8 XIV Calypso 294,619 0.0019694 0.0000 0.0019694 0.0019694 0.0000392 0.0141 0.85 50.8 IV Dione 377,396 0.0025227 0.0022 0.0025172 0.0025283 0.0000503 0.0181 1.09 65.2 XII Helene 377,396 0.0025227 0.0022 0.0025172 0.0025283 0.0000503 0.0181 1.09 65.2 XXXIV Polydeuces 377,396 0.0025227 0.0192 0.0024743 0.0025712 0.0000511 0.0184 1.10 66.3 V Rhea 527,108 0.0035235 0.0013 0.0035191 0.0035279 0.0000702 0.0253 1.52 90.9 VI Titan 1,221,931 0.0081681 0.0289 0.0079322 0.0084040 0.0001671 0.0602 3.61 216.6 VII Hyperion 1,481,010 0.0098999 0.1230 0.0086822 0.0111177 0.0002211 0.0796 4.78 286.5 VIII Iapetus 3,560,820 0.0238026 0.0286 0.0231216 0.0244837 0.0004868 0.1753 10.52 631.0 XXIV Kiviuq 11,333,200 0.0757578 0.1560 0.0639396 0.0875760 0.0017414 0.6269 37.61 2256.9 XXII Ijiraq 11,372,000 0.0760171 0.3430 0.0499433 0.1020910 0.0020300 0.7308 43.85 2630.9 XI Pheobe 12,955,759 0.0866039 0.1562 0.0730728 0.1001350 0.0019911 0.7168 43.01 2580.5 XX Paaliaq 14,923,800 0.0997594 0.4330 0.0565636 0.1429553 0.0028426 1.0233 61.40 3684.0 XXVII Skathi 15,576,200 0.1041205 0.2460 0.0785068 0.1297341 0.0025797 0.9287 55.72 3343.3 XXVI Albiorix 16,401,600 0.1096379 0.5210 0.0525166 0.1667593 0.0033159 1.1937 71.62 4297.5 XXVIII Erriapo 17,408,700 0.1163700 0.5340 0.0542284 0.1785115 0.0035496 1.2779 76.67 4600.3 XXIX Siarnaq 17,905,700 0.1196922 0.4790 0.0623596 0.1770248 0.0035201 1.2672 76.03 4562.0 XXI Tarvos 18,160,200 0.1213934 0.5470 0.0549912 0.1877957 0.0037342 1.3443 80.66 4839.6 XXV Mundilfari 18,360,100 0.1227297 0.1980 0.0984292 0.1470302 0.0029236 1.0525 63.15 3789.0 XXXI Narvi 19,370,700 0.1294851 0.3200 0.0880499 0.1709204 0.0033987 1.2235 73.41 4404.7 XXIII Suttungr 19,666,700 0.1314638 0.1310 0.1142420 0.1486855 0.0029566 1.0644 63.86 3831.7 XXX Thrymr 20,810,300 0.1391083 0.4530 0.0760922 0.2021243 0.0040192 1.4469 86.81 5208.8 XIX Ymir 23,174,600 0.1549126 0.3580 0.0994539 0.2103714 0.0041832 1.5059 90.36 5421.4 Skipped several unnamed moons. S/2004 S 8 23,608,900 0.1578157 0.1860 0.1284620 0.1871695 0.0037218 1.3398 80.39 4823.4 Moons of Uranus VI Cordelia 49,752 0.0003326 0.0005 0.0003324 0.0003327 0.0000031 0.0011 0.07 4.0 VII Ophelia 53,764 0.0003594 0.0101 0.0003558 0.0003630 0.0000033 0.0012 0.07 4.3 VIII Bianca 59,165 0.0003955 0.0009 0.0003951 0.0003958 0.0000036 0.0013 0.08 4.7 IX Cressida 61,767 0.0004129 0.0002 0.0004128 0.0004130 0.0000038 0.0014 0.08 4.9 X Desdemona 62,659 0.0004188 0.0002 0.0004188 0.0004189 0.0000039 0.0014 0.08 5.0 XI Juliet 64,358 0.0004302 0.0006 0.0004300 0.0004305 0.0000040 0.0014 0.09 5.1 XII Portia 66,097 0.0004418 0.0001 0.0004418 0.0004419 0.0000041 0.0015 0.09 5.3 XIII Rosalind 69,927 0.0004674 0.0001 0.0004674 0.0004675 0.0000043 0.0016 0.09 5.6 XXVII Cupid 74,392 0.0004973 0.0013 0.0004966 0.0004979 0.0000046 0.0017 0.10 5.9 XIV Belinda 75,255 0.0005030 0.0001 0.0005030 0.0005031 0.0000046 0.0017 0.10 6.0 XXV Perdita 76,416 0.0005108 0.0030 0.0005093 0.0005123 0.0000047 0.0017 0.10 6.1 XV Puck 86,004 0.0005749 0.0001 0.0005749 0.0005749 0.0000053 0.0019 0.11 6.9 XXVI Mab 97,736 0.0006533 0.0025 0.0006517 0.0006550 0.0000060 0.0022 0.13 7.8 V Miranda 129,390 0.0008649 0.0013 0.0008638 0.0008660 0.0000080 0.0029 0.17 10.3 I Ariel 191,020 0.0012769 0.0012 0.0012754 0.0012784 0.0000118 0.0042 0.25 15.3 II Umbriel 266,000 0.0017781 0.0039 0.0017712 0.0017850 0.0000165 0.0059 0.36 21.3 III Titania 435,910 0.0029139 0.0011 0.0029107 0.0029171 0.0000269 0.0097 0.58 34.8 IV Oberon 583,520 0.0039006 0.0014 0.0038951 0.0039061 0.0000360 0.0130 0.78 46.7 XXII Francisco 4,276,000 0.0285833 0.1459 0.0244130 0.0327536 0.0003019 0.1087 6.52 391.2 XVI Caliban 7,231,000 0.0483362 0.1588 0.0406605 0.0560120 0.0005162 0.1858 11.15 669.0 XX Stephano 8,004,000 0.0535034 0.2295 0.0412244 0.0657825 0.0006063 0.2183 13.10 785.7 XXI Trinculo 8,578,000 0.0573404 0.2079 0.0454193 0.0692615 0.0006383 0.2298 13.79 827.3 XVII Sycorax 12,179,000 0.0814116 0.5224 0.0388822 0.1239410 0.0011422 0.4112 24.67 1480.3 XXIII Margaret 14,345,000 0.0958904 0.6608 0.0325260 0.1592548 0.0014677 0.5284 31.70 1902.1 XVIII Prospero 16,243,000 0.1085777 0.4431 0.0604669 0.1566885 0.0014440 0.5199 31.19 1871.5 XIX Setebos 17,501,000 0.1169870 0.5843 0.0486315 0.1853424 0.0017081 0.6149 36.90 2213.7 XXIV Ferdinand 20,901,000 0.1397146 0.3682 0.0882717 0.1911575 0.0017617 0.6342 38.05 2283.2 Moons of Neptune III Naiad 48,227 0.0003224 0.0004 0.0003222 0.0003225 0.0000018 0.0006 0.04 2.3 IV Thalassa 50,075 0.0003347 0.0002 0.0003347 0.0003348 0.0000019 0.0007 0.04 2.4 V Despina 52,526 0.0003511 0.0002 0.0003510 0.0003512 0.0000019 0.0007 0.04 2.5 VI Galatea 61,953 0.0004141 0.0000 0.0004141 0.0004141 0.0000023 0.0008 0.05 3.0 VII Larissa 73,548 0.0004916 0.0014 0.0004910 0.0004923 0.0000027 0.0010 0.06 3.5 VIII Proteus 117,647 0.0007864 0.0005 0.0007860 0.0007868 0.0000043 0.0016 0.09 5.6 I Triton 354,800 0.0023717 0.0000 0.0023717 0.0023717 0.0000131 0.0047 0.28 17.0 488.49 17.0 II Nereid 5,513,400 0.0368548 0.7512 0.0091695 0.0645401 0.0003567 0.1284 7.71 462.3 S/2002 N 1 15,728,000 0.1051352 0.5711 0.0450925 0.1651779 0.0009130 0.3287 19.72 1183.2 S/2002 N 2 22,422,000 0.1498818 0.2931 0.1059515 0.1938122 0.0010713 0.3857 23.14 1388.4 S/2002 N 3 23,571,000 0.1575624 0.4237 0.0908032 0.2243216 0.0012399 0.4464 26.78 1606.9 X Psamathe 46,695,000 0.3121368 0.4499 0.1717065 0.4525671 0.0025015 0.9005 54.03 3241.9 S/2002 N 4 48,387,000 0.3234471 0.4945 0.1635025 0.4833917 0.0026719 0.9619 57.71 3462.7 Moons of Pluto I Charon 19,571 0.0001308 0.0000 0.0001308 0.0001308 0.0000007 0.0003 0.02 0.9 0 0.000004 II Nix 48,675 0.0003254 0.0020 0.0003247 0.0003260 0.0000018 0.0007 0.04 2.3 III Hydra 64,780 0.0004330 0.0050 0.0004309 0.0004352 0.0000024 0.0009 0.05 3.1 Moons of Eris Dysnomia 36,000 0.0002406 0.0000 0.0002406 0.0002406 0.0000010 0.0004 0.02 1.4

Most of the columns in the above table should be self-explanatory. AsDegrees, AsMinutes and AsSeconds are the answers to look at (mostly AsSeconds). “1 AU Elong” is a value I found in the Explanatory Supplement for a few moons and “ElongSecs” is that value converted to seconds of arc at the planet’s minimum distance from Earth. I included it as a cross-check of the calculations described (with all their simplifying assumptions).

For anyone who wants to plug in other values, here are two sample lines showing the calculations in the spreadsheet:

Mars 1.52366231 0.09341233 =B6*(1-C6) =B6*(1+C6) =D6-E5 =F6*2*3.14159265358979

I Phobos 9377 =B16/G1 0.015 =C16*(1-D16) =C16*(1+D16) =F16/G6 =G16*360 =H16*60 =I16*60

As you can see from the tables, the maximum possible separation between 136199 Eris and Dysnomia is only 1.4 seconds of arc. Given the angles and the current uncertainty of the Dysnomia data, the actual ecliptic separation is almost certainly less. This is EXTREMELY close for any astrological work. It is more than the mean error in tests of my Eris ephemeris against observations but less than my maximum error, so even if the orbital elements needed to calculate Dysnomia were available I would be VERY skeptical of any positions I could produce.

Pluto and Charon are a special case—really a double planet. The barycenter of the Pluto-Charon orbit is NOT below the surface of Pluto the way the Earth-Moon barycenter is below the surface of the Earth. If I read one value right in an astronomical reference book, the maximum visual separation of Pluto and Charon can’t exceed 0.000004 seconds of arc, so the point called Pluto in charts is really Pluto-Charon.

For practical purposes, if one is going to think about planetary moons at all, one should think of the astrological interpretation of the planet as actually interpreting the planet plus its moons. Thus, what astrologers really work with is:

Mars + Phobos + Deimos

Jupiter + Metis + Adrastea + Amalthea + Thebe + Io + Europa + Ganymede + Callisto + Themisto + Leda + Himalia + Lysithia + Elara + Carpo + Euporie + Thelxinoe + Euanthe + Helike + Orthosie + Iocaste + Ananke + Praxidike + Harpalyke + Hermippe + Thyone + Mneme + Aitne + Kale + Taygete + Chaldene + Erinome + Aoede + Kallichore + Kalyke + Eurydome + Pasithee + Cyllene + Eukelade + Hegemone + Arche + Carme + Isonoe + Pasiphaë + Sinope + Sponde + Autonoe + Callirrhoe + Megaclite + moons yet to be named

Saturn + Pan + Daphnis + Atlas + Prometheus + Pandora + Epimetheus + Janus + Mimas + Methone + Pallene + Enceladus + Tethys + Telesto + Calypso + Dione + Helene + Polydeuces + Rhea + Titan + Hyperion + Iapetus + Kiviuq + Ijiraq + Pheobe + Paaliaq + Skathi + Albiorix + Erriapo + Siarnaq + Tarvos + Mundilfari + Narvi + Suttungr + Thrymr + Ymir + moons yet to be named

Uranus + Cordelia + Ophelia + Bianca + Cressida + Desdemona + Juliet + Portia + Rosalind + Cupid + Belinda + Perdita + Puck + Mab + Miranda + Ariel + Umbriel + Titania + Oberon + Francisco + Caliban + Stephano + Trinculo + Sycorax + Margaret + Prospero + Setebos + Ferdinand

Neptune + Naiad + Thalassa + Despina + Galatea + Larissa + Proteus + Triton + Nereid + Psamathe + moons yet to be named

Pluto + Charon + Nix + Hydra

Eris + Dysnomia

2019 note: more moons have been discovered and/or named since I wrote this, but I won't expand the 2006 list, since the basic point won't be changed by more examples.