Io and a Volcano

Ganymede Europa Callisto

The Satellites of Jupiter

Details about Jupiter's 63 moons


Name
Diameter(s)
(km)
Mean Distance
From Planet
(×103 km)
Rotational
Period
(days)
Orbital
Period
(days)
Orbital
Inclination
Orbital
Eccentricity
Albedo
(%)
The Small Inner Regular Satellites
Metis 44 127.96 0.294780 0.294780 0.021° 0.001 5
Adrastea 26 × 20 × 16 128.98 0.29826 0.29826 0.027° 0.002 5
Amalthea 262 × 146 × 134 181.3 0.498179 0.498179 0.389° 0.003 7
Thebe 110 × 90 221.90   0.6745 1.070° 0.018 4
The Galilean Satellites
Io 3,642.6 421.8 1.769138 1.769138 0.036° 0.004 63
Europa 3,122 671.1 3.551181 3.551181 0.467° 0.009 67
Ganymede 5,262 1,070.4 7.154553 7.154553 0.172° 0.001 44
Callisto 4,821 1,882.7 16.689018 16.689018 0.307° 0.007 20
Themisto (A Sole Direct Satellite)
Themisto 9 7,507.0   130 43.08° 0.242  
The Himalia Group of Direct Satellites
Leda 18 11,165   240.9 27.46° 0.164 7
Himalia 184 11,461 0.4 250.5662 27.63° 0.162 3
Lysithea 38 11,717   259.22 28.30° 0.112 6
Elara 78 11,741 0.5 259.6528 26.63° 0.217 3
S/2000 J11 4 12,555   287.0 28.30° 0.248  
Carpo (A Sole Direct Satellite)
Carpo 3 16,989   456.1 51.4° 0.430  
The Ananke Group of Retrograde Satellites
S/2003 J3 2 18,340   -504.0 143.7° 0.241  
S/2003 J12 1 19,002   -533.3 145.8° 0.376  
Euporie 2 19,302   -550.7 145.8° 0.144  
S/2003 J18 2 20,700   -606.3 146.5° 0.119  
Orthosie 2 20,721   -622.6 145.9° 0.281  
Euanthe 3 20,799   -620.6 148.9° 0.232  
Thyone 4 20,940   -627.3 148.5° 0.229  
S/2003 J16 2 21,000   -595.4 148.6° 0.270  
Mneme 2 21,069   -620.0 148.6° 0.227  
Harpalyke 4 21,105   -623.3 148.6° 0.226  
Hermippe 4 21,131   -623.9 150.7° 0.210  
Praxidike 7 21,147   -625.3 149.0° 0.230  
Thelxinoe 2 21,162   -628.1 151.4° 0.221  
Iocaste 5 21,269   -631.5 149.4° 0.216  
Ananke 28 21,276   -610.5 148.9° 0.244 6
The Carme Group of Retrograde Satellites
S/2003 J17 2 22,000   -690.3 163.7° 0.190  
S/2003 J9 1 22,442   -683.0 164.5° 0.269  
S/2003 J19 2 22,800   -701.3 162.9° 0.334  
Arche 3 22,931   -723.9 165.0° 0.259  
Pasithee 2 23,096   -719.5 165.1° 0.267  
Chaldene 4 23,179   -723.8 165.2° 0.251  
Kale 2 23,217   -729.5 165.0° 0.260  
Isonoe 4 23,217   -725.5 165.2° 0.246  
Aitne 3 23,231   -730.2 165.1° 0.264  
Erinome 3 23,279   -728.3 164.9° 0.266  
Taygete 5 23,360   -732.2 165.2° 0.252  
Carme 46 23,404   -702.3 164.9° 0.253 6
Kalyke 5 23,583   -743.0 165.2° 0.245  
Eukelade 4 23,661   -746.4 165.5° 0.272  
Kallichore 2 24,043   -764.7 165.5° 0.264  
S/2003 J5 4 24,084   -759.7 165.0° 0.210  
S/2003 J10 2 24,250   -767.0 164.1° 0.214  
The Pasiphae Group of Retrograde Satellites
Helike 4 21,263   -634.8 154.8° 0.156  
Eurydome 3 22,865   -717.3 150.3° 0.276  
Autonoe 4 23,039   -762.7 152.9° 0.334  
Sponde 2 23,487   -748.3 151.0° 0.312  
Pasiphae 58 23,624   -708.0 151.4° 0.409 10
Megaclite 6 23,806   -752.8 152.8° 0.421  
Sinope 38 23,939   -724.5 158.1° 0.250 5
Hegemone 3 23,947   -739.6 155.2° 0.328  
Aoede 4 23,981   -761.5 158.3° 0.432  
S/2003 J23 2 24,056   -759.7 149.2° 0.309  
Callirrhoe 7 24,102   -758.8 147.1° 0.283  
Cyllene 2 24,349   -737.8 149.3° 0.319  
Unallocated Retrograde Satellites
S/2003 J15 2 22,000   -668.4 140.8° 0.110  
S/2003 J4 2 23,258   -723.2 144.9° 0.204  
S/2003 J14 2 25,000   -807.8 140.9° 0.222  
S/2003 J2 2 28,570   -982.5 151.8° 0.380  

Name

The satellites of Jupiter have names associated with Jupiter, the king of the gods. For example, Leda and Ganymede are characters seduced by Jupiter.

Un-named satellites are in blue.

Diameter

Io, Europa, Ganymede and Callisto are the Galilean Satellites, discovered by Galileo in 1610. These are amongst the largest satellites in the Solar System. Io, Ganymede and Callisto are larger than the Moon; Ganymede is actually larger than the planet Mercury. The other satellites are small, irregularly shaped bodies.

Mean Distance From Planet

The satellites of Jupiter orbit as six main groups.

The first group is the four small inner satellites. Of these, Metis and Adrastea orbit the planet faster than it rotates on its axis. The second group are the four large Galilean satellites. These are evenly spaced out. The inner satellites have almost circular orbits

Themisto is an isolated satellite not part of any group. Further out is the third group of five orbiting between 11 and 12 million kilometres. Carpo is another isolated satellite.

The fourth, fifth and sixth groups of 15, 17 and 12 satellites respectively. These orbit the planet between 19 and 25 million kilometres.

Recently a small outer satellite has been discovered. A few newly discovered satellites are yet to be classified.

Rotational and Orbital Periods

Most of Jupiter's satellites rotate in the same period as they revolve around the planet. This is caused by the strong tidal forces exerted by the planet on the satellite. The outer satellites are less affected by tidal forces.

As seen from above the north pole of the Earth, most of the planets and satellites revolve in an anticlockwise direction. This is called Direct or Prograde Motion.

Some satellites revolve in a clockwise sense. This is called Retrograde Motion and is shown by the presence of a minus sign on the orbital period. Jupiter's outer satellites orbit in a retrograde sense. They are probably captured asteroids.

Orbital Inclination

This is the angle of inclination of the satellite orbits compared to the planet's equatorial plane. Jupiter's inner satellites orbit close to the planet's equator. The middle satellites are inclined to Jupiter's equator by about 25°. The outer satellites have orbits that are inclined very steeply.

Orbital Eccentricity

The orbits of Jupiter's inner satellites are nearly circular. The distant satellites orbit in more elliptical paths.

Albedo

This is the percentage of sunlight that is reflected by the satellites. The smaller bodies are very dark.

Ice-covered Europa and volcanically sulphurous Io are very reflective.


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