Moons of Jupiter

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A montage of Jupiter and its four largest moons (distance and sizes not to scale)
The orbit and motion of the Galilean moons around Jupiter, as captured by JunoCam aboard the Juno spacecraft.

There are 69 known moons of Jupiter.[1] This gives Jupiter the largest number of moons with reasonably stable orbits of any planet in the Solar System.[2] The most massive of the moons are the four Galilean moons, which were independently discovered in 1610 by Galileo Galilei and Simon Marius and were the first objects found to orbit a body that was neither Earth nor the Sun. From the end of the 19th century, dozens of much smaller Jovian moons have been discovered and have received the names of lovers, conquests, or daughters of the Roman god Jupiter or his Greek equivalent Zeus. The Galilean moons are by far the largest and most massive objects to orbit Jupiter, with the remaining 65 moons and its rings together comprising just 0.003% of the total orbiting mass.

Of Jupiter's moons, eight are regular satellites with prograde and nearly circular orbits that are not greatly inclined with respect to Jupiter's equatorial plane. The Galilean satellites are nearly spherical in shape due to their planetary mass, and so would be considered (dwarf) planets if they were in direct orbit around the Sun. The other four regular satellites are much smaller and closer to Jupiter; these serve as sources of the dust that makes up Jupiter's rings. The remainder of Jupiter's moons are irregular satellites whose prograde and retrograde orbits are much farther from Jupiter and have high inclinations and eccentricities. These moons were probably captured by Jupiter from solar orbits. Eighteen of the irregular satellites have not yet been named.

Characteristics

The physical and orbital characteristics of the moons vary widely. The four Galileans are all over 3,100 kilometres (1,900 mi) in diameter; the largest Galilean, Ganymede, is the ninth largest object in the Solar System, after the Sun and seven of the planets, Ganymede being larger than Mercury. All other Jovian moons are less than 250 kilometres (160 mi) in diameter, with most barely exceeding 5 kilometres (3.1 mi). Their orbital shapes range from nearly perfectly circular to highly eccentric and inclined, and many revolve in the direction opposite to Jupiter's spin (retrograde motion). Orbital periods range from seven hours (taking less time than Jupiter does to spin around its axis), to some three thousand times more (almost three Earth years).

Origin and evolution

Jupiter's regular satellites are believed to have formed from a circumplanetary disk, a ring of accreting gas and solid debris analogous to a protoplanetary disk.[3][4] They may be the remnants of a score of Galilean-mass satellites that formed early in Jupiter's history.[3][5]

The relative masses of the Jovian moons. Those smaller than Europa are not visible at this scale, and combined would only be visible at 100× magnification.

Simulations suggest that, while the disk had a relatively high mass at any given moment, over time a substantial fraction (several tenths of a percent) of the mass of Jupiter captured from the solar nebula was passed through it. However, only 2% the proto-disk mass of Jupiter is required to explain the existing satellites.[3] Thus there may have been several generations of Galilean-mass satellites in Jupiter's early history. Each generation of moons might have spiraled into Jupiter, because of drag from the disk, with new moons then forming from the new debris captured from the solar nebula.[3] By the time the present (possibly fifth) generation formed, the disk had thinned so that it no longer greatly interfered with the moons' orbits.[5] The current Galilean moons were still affected, falling into and being partially protected by an orbital resonance with each other, which still exists for Io, Europa, and Ganymede. Ganymede's larger mass means that it would have migrated inward at a faster rate than Europa or Io.[3]

The outer, irregular moons are thought to have originated from captured asteroids, whereas the protolunar disk was still massive enough to absorb much of their momentum and thus capture them into orbit. Many are believed to have broken up by mechanical stresses during capture, or afterward by collisions with other small bodies, producing the moons we see today.[6]

Discovery

Jupiter and the Galilean moons through a 25 cm (10 in) Meade LX200 telescope
The Galilean moons. From left to right, in order of increasing distance from Jupiter: Io, Europa, Ganymede, Callisto
The Galilean moons and their orbits around Jupiter

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The first claimed observation of one of Jupiter's moons is that of Chinese astronomer Gan De around 364 BC.[7] However, the first certain observations of Jupiter's satellites were those of Galileo Galilei in 1609.[8] By January 1610, he had sighted the four massive Galilean moons with his 30× magnification telescope, and he published his results in March 1610.[9] Simon Marius had independently discovered them one day after Galileo, though he did not publish his book on the subject until 1614, and the names Marius assigned are used today: Ganymede, Callisto, Io, and Europa.[10] No additional satellites were discovered until E. E. Barnard observed Amalthea in 1892.[11] With the aid of telescopic photography, further discoveries followed quickly over the course of the twentieth century. Himalia was discovered in 1904,[12] Elara in 1905,[13] Pasiphae in 1908,[14] Sinope in 1914,[15] Lysithea and Carme in 1938,[16] Ananke in 1951,[17] and Leda in 1974.[18] By the time that Voyager space probes reached Jupiter around 1979, 13 moons had been discovered, not including Themisto which had been observed in 1975,[19] but was lost until 2000 due to insufficient initial observation data. The Voyager spacecraft discovered an additional three inner moons in 1979: Metis, Adrastea, and Thebe.[20]

No additional moons were discovered for two decades but, between October 1999 and February 2003, researchers found and later named another 34 moons using sensitive ground-based detectors.[21] These are tiny moons, in long, eccentric, generally retrograde orbits, and averaging 3 km (1.9 mi) in diameter, with the largest being just 9 km (5.6 mi) across. All of these moons are thought to have been captured asteroidal or perhaps comet bodies, possibly fragmented into several pieces;[22] but very little is known about them. Since 2003, 18 additional moons have been discovered but not yet named,[23] bringing the total number of known moons of Jupiter to 69.[1] As of 2017, this is the most of any planet in the Solar System; but additional undiscovered, tiny moons may exist.

Some of the 69 known satellites of Jupiter are considered lost because they have not been observed since their discovery and hence their orbits are not well-known enough to pinpoint their current locations. Work has been done to recover many of them in surveys from 2009 onwards (in which some new moons were also discovered), but six – S/2003 J 12, S/2003 J 10, S/2003 J 19, S/2003 J 4, S/2003 J 2, and S/2011 J 1 – still remain lost today.[24][25][26] Follow-up observations in 2018 are planned to secure their orbits and perhaps find new moons.[27]

Naming

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The Galilean moons of Jupiter (Io, Europa, Ganymede, and Callisto) were named by Simon Marius soon after their discovery in 1610.[28] However, these names fell out of favor until the 20th century. The astronomical literature instead simply referred to "Jupiter I", "Jupiter II", etc., or "the first satellite of Jupiter", "Jupiter's second satellite", and so on.[28] The names Io, Europa, Ganymede, and Callisto became popular in the 20th century, whereas the rest of the moons remained unnamed and were usually numbered in Roman numerals V (5) to XII (12).[29] Jupiter V was discovered in 1892 and given the name Amalthea by a popular though unofficial convention, a name first used by French astronomer Camille Flammarion.[21]

The other moons were simply labeled by their Roman numeral (e.g. Jupiter IX) in the majority of astronomical literature until the 1970s.[30] In 1975, the International Astronomical Union's (IAU) Task Group for Outer Solar System Nomenclature granted names to satellites V–XIII,[31] and provided for a formal naming process for future satellites still to be discovered.[31] The practice was to name newly discovered moons of Jupiter after lovers and favorites of the god Jupiter (Zeus) and, since 2004, also after their descendants.[32] All of Jupiter's satellites from XXXIV (Euporie) are named after daughters of Jupiter or Zeus.[32] Names ending with "a" or "o" are used for prograde irregular satellites (the latter for highly inclined satellites), and names ending with "e" are used for retrograde irregulars.[33]

Some asteroids share the same names as moons of Jupiter: 9 Metis, 38 Leda, 52 Europa, 85 Io, 113 Amalthea, 239 Adrastea. Two more asteroids previously shared the names of Jovian moons until spelling differences were made permanent by the IAU: Ganymede and asteroid 1036 Ganymed; and Callisto and asteroid 204 Kallisto.

Groups

The orbits of Jupiter's irregular satellites, and how they cluster into groups: by semi-major axis (the horizontal axis in Gm); by orbital inclination (the vertical axis); and orbital eccentricity (the yellow lines). The relative sizes are indicated by the circles.

Regular satellites

These have prograde and nearly circular orbits of low inclination and are split into two groups:

  • Inner satellites or Amalthea group: Metis, Adrastea, Amalthea, and Thebe. These orbit very close to Jupiter; the innermost two orbit in less than a Jovian day. The latter two are respectively the fifth and seventh largest moons in the Jovian system. Observations suggest that at least the largest member, Amalthea, did not form on its present orbit, but farther from the planet, or that it is a captured Solar System body.[34] These moons, along with a number of as-yet-unseen inner moonlets, replenish and maintain Jupiter's faint ring system. Metis and Adrastea help to maintain Jupiter's main ring, whereas Amalthea and Thebe each maintain their own faint outer rings.[35][36]
  • Main group or Galilean moons: Io, Europa, Ganymede and Callisto. They are some of the largest objects in the Solar System outside the Sun and the eight planets in terms of mass and are larger than any known dwarf planet. Ganymede exceeds even the planet Mercury in diameter. They are respectively the fourth-, sixth-, first-, and third-largest natural satellites in the Solar System, containing approximately 99.997% of the total mass in orbit around Jupiter, while Jupiter is almost 5,000 times more massive than the Galilean moons.[note 1] The inner moons are in a 1:2:4 orbital resonance. Models suggest that they formed by slow accretion in the low-density Jovian subnebula—a disc of the gas and dust that existed around Jupiter after its formation—which lasted up to 10 million years in the case of Callisto.[37] Several are suspected of having subsurface oceans.

Irregular satellites

Jupiter's outer moons and their highly inclined orbits

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The irregular satellites are substantially smaller objects with more distant and eccentric orbits. They form families with shared similarities in orbit (semi-major axis, inclination, eccentricity) and composition; it is believed that these are at least partially collisional families that were created when larger (but still small) parent bodies were shattered by impacts from asteroids captured by Jupiter's gravitational field. These families bear the names of their largest members. The identification of satellite families is tentative, but the following are typically listed:[23][38][39]

  • Themisto[38] is the innermost irregular moon and not part of a known family.[23]
  • Carpo is the outermost prograde moon and not part of a known family.[23]
Retrograde satellites: inclinations (°) vs. eccentricities, with Carme's (orange) and Ananke's (yellow) groups identified
  • S/2003 J 12 and S/2011 J 1 are the innermost of the retrograde moons, and are not part of any known family.
  • The Carme group is spread over only 1.2 Gm in semi-major axis, 1.6° in inclination (165.7 ± 0.8°), and eccentricities between 0.23 and 0.27. It is very homogeneous in color (light red) and is believed to have originated from a D-type asteroid progenitor, possibly a Jupiter Trojan.[22]
  • The Ananke group has a relatively wider spread than the previous groups, over 2.4 Gm in semi-major axis, 8.1° in inclination (between 145.7° and 154.8°), and eccentricities between 0.02 and 0.28. Most of the members appear gray, and are believed to have formed from the breakup of a captured asteroid.[22]
  • The Pasiphae group is quite dispersed, with a spread over 1.3 Gm, inclinations between 144.5° and 158.3°, and eccentricities between 0.25 and 0.43.[22] The colors also vary significantly, from red to grey, which might be the result of multiple collisions. Sinope, sometimes included in the Pasiphae group,[22] is red and, given the difference in inclination, it could have been captured independently;[38] Pasiphae and Sinope are also trapped in secular resonances with Jupiter.[40]
  • S/2003 J 2 is the outermost moon of Jupiter, and is not part of a known family.

List

The moons of Jupiter are listed below by orbital period. Moons massive enough for their surfaces to have collapsed into a spheroid are highlighted in bold. These are the four Galilean moons, which are comparable in size to the Moon. The four inner moons are much smaller, the fourth most massive being more than 7000 times more massive than the fifth-most. The irregular captured moons are shaded light gray when prograde and dark gray when retrograde.

Order
[note 2]
Label
[note 3]
Name
Pronunciation
(key)
Image Diameter
(km)[note 4]
Mass
(×1016 kg)
Semi-major
axis

(km)[41]
Orbital period
(d)[41][note 5]
Inclination
(°)[41]
Eccentr.
[23]
Discovery
year
[21]
Discoverer[21] Group
[note 6]
1 XVI Metis /ˈmts/
Metis.jpg
60 × 40 × 34 ≈ 3.6 127690 +7h 4m 29s 0.06[42] 0.0002 1979 Synnott
(Voyager 1)
Inner
2 XV Adrastea /əˈdræstiə/
Adrastea.jpg
20 × 16 × 14 ≈ 0.2 128690 +7h 9m 30s 0.03[42] 0.0015 1979 Jewitt
(Voyager 2)
Inner
3 V Amalthea /əˈmælθiə/[43]
Amalthea Voyager-1.png
250 × 146 × 128
(167±4.0)
208 181366 +11h 57m 23s 0.374[42] 0.0032 1892 Barnard Inner
4 XIV Thebe /ˈθb/
Thebe.jpg
116 × 98 × 84 ≈ 43 221889 +16h 11m 17s 1.076[42] 0.0175 1979 Synnott
(Voyager 1)
Inner
5 I Io /ˈ/
Io highest resolution true color.jpg
3660.0
× 3637.4
× 3630.6
8931900 421700 +1.7691 0.050[42] 0.0041 1610 Galilei Galilean
6 II Europa /ˌjʊərˈpə/[44]
Europa-moon.jpg
3121.6 4800000 671034 +3.5512 0.471[42] 0.0094 1610 Galilei Galilean
7 III Ganymede /ˈɡænɪˌmd/[45][46]
Ganymede g1 true-edit1.jpg
5262.4 14819000 1070412 +7.1546 0.204[42] 0.0011 1610 Galilei Galilean
8 IV Callisto /kəˈlɪst/
Callisto.jpg
4820.6 10759000 1882709 +16.689 0.205[42] 0.0074 1610 Galilei Galilean
9 XVIII Themisto /θˈmɪst/ S 2000 J 1.jpg 8 0.069 7393216 +129.87 45.762 0.2115 1975/2000 Kowal & Roemer/
Sheppard et al.
Themisto
10 XIII Leda /ˈldə/
Leda2(moon).jpg
16 0.6 11187781 +240.82 27.562 0.1673 1974 Kowal Himalia
11 VI Himalia /hˈmliə/
Himalia from New Horizons.jpg
170 670 11451971 +250.23 30.486 0.1513 1904 Perrine Himalia
12 X Lysithea /lˈsɪθiə/ Lysithea2.jpg 36 6.3 11740560 +259.89 27.006 0.1322 1938 Nicholson Himalia
13 VII Elara /ˈɛlərə/
Elara2-LB1-mag17.jpg
86 87 11778034 +257.62 29.691 0.1948 1905 Perrine Himalia
14 LIII Dia /ˈdə/ 4 0.0090 12570424 +287.93 27.584 0.2058 2001 Sheppard et al. Himalia
15 XLVI Carpo /ˈkɑːrp/ 3 0.0045 17144873 +458.62 56.001 0.2735 2003 Sheppard et al. Carpo
16 S/2003 J 12 1 0.00015 17739539 −482.69 142.680 0.4449 2003 Sheppard et al. ?
17 XXXIV Euporie /jˈpɒr/ 2 0.0015 19088434 −538.78 144.694 0.0960 2002 Sheppard et al. Pasiphae
18 S/2003 J 3 2 0.0015 19621780 −561.52 146.363 0.2507 2003 Sheppard et al. Ananke?
19 S/2011 J 1 1 20155290 −582.22 162.8 0.2963 2011 Sheppard et al. ?
20 LV S/2003 J 18 2 0.0015 20219648 −587.38 146.376 0.1048 2003 Gladman et al. Pasiphae
21 LII S/2010 J 2 1 20307150 −588.36 150.4 0.307 2010 Veillet Ananke
22 XLII Thelxinoe /θɛlkˈsɪn/ 2 0.0015 20453753 −597.61 151.292 0.2684 2003 Sheppard et al. Ananke
23 XXXIII Euanthe /jˈænθ/ 3 0.0045 20464854 −598.09 143.409 0.2000 2002 Sheppard et al. Ananke
24 XLV Helike /ˈhɛlk/ 4 0.0090 20540266 −601.40 154.586 0.1374 2003 Sheppard et al. Pasiphae
25 XXXV Orthosie /ɔːrˈθɒs/ 2 0.0015 20567971 −602.62 142.366 0.2433 2002 Sheppard et al. Pasiphae
26 LIV S/2016 J 1 3 0.0015 20595483 −603.83 139.839 0.1377 2016 Sheppard et al. Pasiphae
27 XXIV Iocaste /ˈkæst/ 5 0.019 20722566 −609.43 147.248 0.2874 2001 Sheppard et al. Ananke
28 S/2003 J 16 2 0.0015 20743779 −610.36 150.769 0.3184 2003 Gladman et al. Ananke
29 XXVII Praxidike /prækˈsɪdk/ 7 0.043 20823948 −613.90 144.205 0.1840 2001 Sheppard et al. Ananke
30 XXII Harpalyke /hɑːrˈpælk/ 4 0.012 21063814 −624.54 147.223 0.2440 2001 Sheppard et al. Ananke
31 XL Mneme /ˈnm/ 2 0.0015 21129786 −627.48 149.732 0.3169 2003 Gladman et al. Ananke
32 XXX Hermippe /hərˈmɪp/ Ερμίππη.gif 4 0.0090 21182086 −629.81 151.242 0.2290 2002 Sheppard et al. Ananke
33 XXIX Thyone /θˈn/ 4 0.0090 21405570 −639.80 147.276 0.2525 2002 Sheppard et al. Ananke
34 XII Ananke /əˈnæŋk/ Ananké.jpg 28 3.0 21454952 −640.38 151.564 0.3445 1951 Nicholson Ananke
35 L Herse /ˈhɜːrs/ 2 0.0015 22134306 −672.75 162.490 0.2379 2003 Gladman et al. Carme
36 XXXI Aitne /ˈtn/ 3 0.0045 22285161 −679.64 165.562 0.3927 2002 Sheppard et al. Carme
37 XXXVII Kale /ˈkl/ 2 0.0015 22409207 −685.32 165.378 0.2011 2002 Sheppard et al. Carme
38 XX Taygete /tˈɪdʒt/ 5 0.016 22438648 −686.67 164.890 0.3678 2001 Sheppard et al. Carme
39 S/2003 J 19 2 0.0015 22709061 −699.12 164.727 0.1961 2003 Gladman et al. Carme?
40 XXI Chaldene /kælˈdn/ 4 0.0075 22713444 −699.33 167.070 0.2916 2001 Sheppard et al. Carme
41 LVIII S/2003 J 15 2 0.0015 22720999 −699.68 141.812 0.0932 2003 Sheppard et al. Pasiphae
42 S/2003 J 10 2 0.0015 22730813 −700.13 163.813 0.3438 2003 Sheppard et al. Carme?
43 S/2003 J 23 S2003j23ccircle.gif 2 0.0015 22739654 −700.54 148.849 0.3930 2004 Sheppard et al. Pasiphae?
44 XXV Erinome /ˈrɪnm/ 3 0.0045 22986266 −711.96 163.737 0.2552 2001 Sheppard et al. Carme
45 XLI Aoede /ˈd/ 4 0.0090 23044175 −714.66 160.482 0.4311 2003 Sheppard et al. Pasiphae
46 XLIV Kallichore /kəˈlɪkr/ 2 0.0015 23111823 −717.81 164.605 0.2041 2003 Sheppard et al. Carme
47 XXIII Kalyke /ˈkælk/ 5 0.019 23180773 −721.02 165.505 0.2139 2001 Sheppard et al. Carme
48 XI Carme /ˈkɑːrm/ Carmé.jpg 46 13 23197992 −763.95 165.047 0.2342 1938 Nicholson Carme
49 XVII Callirrhoe /kəˈlɪr/
S1999j1.jpg
9 0.087 23214986 −727.11 139.849 0.2582 2000 Spahr, Scotti Pasiphae
50 XXXII Eurydome /jʊərˈɪdəm/ 3 0.0045 23230858 −723.36 149.324 0.3769 2002 Sheppard et al. Pasiphae
51 XXXVIII Pasithee /pəˈsɪθ/ 2 0.0015 23307318 −726.93 165.759 0.3288 2002 Sheppard et al. Carme
52 LI S/2010 J 1 2 23314335 −722.83 163.2 0.320 2010 Jacobson et al. Carme
53 XLIX Kore /ˈkɔər/ 2 0.0015 23345093 −776.02 137.371 0.1951 2003 Sheppard et al. Pasiphae
54 XLVIII Cyllene /sˈln/ 2 0.0015 23396269 −731.10 140.148 0.4115 2003 Sheppard et al. Pasiphae
55 LVI S/2011 J 2 1 23400981 −731.32 148.77 0.3321 2011 Sheppard et al. Pasiphae
56 XLVII Eukelade /jˈkɛləd/ 4 0.0090 23483694 −735.20 163.996 0.2828 2003 Sheppard et al. Carme
57 LIX S/2017 J 1 2 0.0015 23483978 -734.15 149.197 0.3969 2017 Sheppard et al. Pasiphae
58 S/2003 J 4 2 0.0015 23570790 −739.29 147.175 0.3003 2003 Sheppard et al. Pasiphae?
59 VIII Pasiphae /pəˈsɪf/ Pasiphaé.jpg 60 30 23609042 −739.80 141.803 0.3743 1908 Melotte Pasiphae
60 XXXIX Hegemone /hˈɛmən/ 3 0.0045 23702511 −745.50 152.506 0.4077 2003 Sheppard et al. Pasiphae
61 XLIII Arche /ˈɑːrk/ Bigs2002j1barrow.png 3 0.0045 23717051 −746.19 164.587 0.1492 2002 Sheppard et al. Carme
62 XXVI Isonoe /ˈsɒn/ 4 0.0075 23800647 −750.13 165.127 0.1775 2001 Sheppard et al. Carme
63 S/2003 J 9 1 0.00015 23857808 −752.84 164.980 0.2761 2003 Sheppard et al. Carme?
64 LVII S/2003 J 5 4 0.0090 23973926 −758.34 165.549 0.3070 2003 Sheppard et al. Carme
65 IX Sinope /sˈnp/ Sinopé.jpg 38 7.5 24057865 −739.33 153.778 0.2750 1914 Nicholson Pasiphae
66 XXXVI Sponde /ˈspɒnd/ 2 0.0015 24252627 −771.60 154.372 0.4431 2002 Sheppard et al. Pasiphae
67 XXVIII Autonoe /ɔːˈtɒn/ 4 0.0090 24264445 −772.17 151.058 0.3690 2002 Sheppard et al. Pasiphae
68 XIX Megaclite /mɛɡəˈklt/ 5 0.021 24687239 −792.44 150.398 0.3077 2001 Sheppard et al. Pasiphae
69 S/2003 J 2 2 0.0015 28570410 −981.55 153.521 0.4074 2003 Sheppard et al. ?

Exploration

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The first spacecraft to visit Jupiter were Pioneer 10 in 1973, and Pioneer 11 a year later, taking low-resolution images of the four Galilean moons.[47] The Voyager 1 and Voyager 2 probes visited Jupiter in 1979, discovering the volcanic activity on Io and the presence of water ice on the surface of Europa. The Cassini probe to Saturn flew by Jupiter in 2000 and collected data on interactions of the Galilean moons with Jupiter's extended atmosphere. The New Horizons spacecraft flew by Jupiter in 2007 and made improved measurements of its satellites' orbital parameters.

The Galileo spacecraft was the first to enter orbit around Jupiter, arriving in 1995 and studying it until 2003. During this period, Galileo gathered a large amount of information about the Jovian system, making close approaches to all of the Galilean moons and finding evidence for thin atmospheres on three of them, as well as the possibility of liquid water beneath the surfaces of Europa, Ganymede, and Callisto. It also discovered a magnetic field around Ganymede.

In 2016, the Juno spacecraft imaged the Galilean moons from above their orbital plane as it approached Jupiter orbit insertion, creating a time-lapse movie of their motion.[48]

See also

Notes

  1. Jupiter Mass of 1.8986 × 1027 kg / Mass of Galilean moons 3.93 × 1023 kg = 4,828
  2. Order refers to the position among other moons with respect to their average distance from Jupiter.
  3. Label refers to the Roman numeral attributed to each moon in order of their naming.
  4. Diameters with multiple entries such as "60 × 40 × 34" reflect that the body is not a perfect spheroid and that each of its dimensions have been measured well enough.
  5. Periods with negative values are retrograde.
  6. "?" refers to group assignments that are not considered sure yet.

References

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  32. 32.0 32.1 Gazetteer of Planetary Nomenclature Planet and Satellite Names and Discoverers International Astronomical Union (IAU)
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  38. 38.0 38.1 38.2 38.3 Lua error in package.lua at line 80: module 'strict' not found.
  39. Lua error in package.lua at line 80: module 'strict' not found.
  40. Lua error in package.lua at line 80: module 'strict' not found.
  41. 41.0 41.1 41.2 Lua error in package.lua at line 80: module 'strict' not found.
  42. 42.0 42.1 42.2 42.3 42.4 42.5 42.6 42.7 Lua error in package.lua at line 80: module 'strict' not found.
  43. Lua error in package.lua at line 80: module 'strict' not found.
  44. Lua error in package.lua at line 80: module 'strict' not found.
  45. Lua error in package.lua at line 80: module 'strict' not found.
  46. Merriam-Webster Dictionary Ganymede
  47. File:Pioneer-10 jupiter moons.jpg
  48. Juno Approach Movie of Jupiter and the Galilean Moons, NASA, July 2016

External links