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Moons of Jupiter

Satellites of Jupiter

 Automatic translation  Automatic translation Updated June 01, 2013

Jupiter, the largest planet in our solar system is surrounded by more than 60 moons.
The moons of Jupiter were first discovered in 1610. Galileo Galilei discovered at that time the four largest Jovian System satellites Io, Europa, Ganymede and Callisto. These Galilean moons called for, were the first to be observed except that of the Earth.
Today, thanks to space probes, we have a more complete view of Jovian system. This series of Voyager has lifted the veil on the Jovian system (1979: Metis, Adrastea and Thebe).
Before the space age, astronomers have discovered: Amalthea (1892), Himalia (1904), Elara (1905), Pasiphae (1908), Sinope (1914), Lysithea Carme and (1938), Ananke (1951), Leda ( 1974) and Themisto (1975.
Between 1979 and 1999, no new satellite of Jupiter was discovered and it was not until October 6, 1999, to Spacewatch program discovers a new moon to Jupiter, Callirrhoe.


The observations in 2000 revealed ten new moons, bringing the number of satellites to 28 after the rediscovery of Themisto, Kalyke, Jocasta, Erinome, Harpalyke, Isono, Praxidike, Megaclite, Taygete, Chaldene and S/2000 J 11.
The following year, eleven other moons were discovered, bringing the total to 39, Hermippe, Eurydome, Sponde, Kale, Autonoe, Thyone, Pasithee, Euanthe, orthoclase, Euporie and Aitne. In 2002, one moon, Archy, was discovered. In 2003 there is the discovery of 23 new satellites, Eukélade, S/2003 J 2, S/2003 J 3 S/2003 J 4, S/2003 J 5, Helice, Aoede, Hegemone, S/2003 J 9, S / 2003 J 10, Kallichore, S/2003 J 12, Cyllene, S/2003 J 14 S/2003 J 15 S/2003 J 16 S/2003 J 17 S/2003 J 18 S/2003 J 19 , Carpo, Mneme, Thelxinoé and S/2003 J 23. Most of the 47 satellites discovered after the 2000s are small moons of a few kilometers in diameter, the largest reaching only 9 km. In 2006, 63 known moons of Jupiter, the record of the solar system.

Moons of Jupiter Diameter
axis (km)
Ganymede (Jupiter III) 5262 1 070 400
Callisto (Jupiter IV) 4821 1 882 700
Io (Jupiter I) 3643 421 800
Europa (Jupiter II) 3122 671 100
Amalthea (Jupiter V) 262x146x134 181 365
Himalia (Jupiter VI) 170 11 493 550
Thebe (Jupiter XIV) 110x90 221 889
Elara (Jupiter VII) 86 11 676 677
Pasiphae (Jupiter VIII) 60 23 912 238
Carme (Jupiter XI) 46 24 097 020
Sinope (Jupiter IX) 38 23 368 614
Lysithea (Jupiter X) 36 11 665 380
Ananke (Jupiter XII) 28 20 439 111
Adrastea (Jupiter XV) 26×20×16 129 000
Leda (Jupiter XIII) 16 11 098 480
Callirrhoe (Jupiter XVII) 9 24 103 000



Ganymede is the largest moon of Jupiter, but also the solar system. It is bigger than Mercury. Ganymede has roughly half the mass of Mercury.
It was discovered in 1610 by Galileo Galilei and Simon Marius, who named it in honor of Ganymede, the Trojan prince of great beauty, abducted by Zeus, an eagle, while he was tending his flock on Mount Ida in Troad.
Ganymede is composed of silicate and water ice based on a liquid mantle could contain liquid water.
Like our own moon, Ganymede always presents the same face toward the planet Jupiter.

Image: Ganymede has an area dotted with craters brilliant. In this detailed mosaic taken by the Galileo spacecraft around Jupiter from 1995 to 2003, the colors of the moon were very different.
Credit: Galileo Project, DLR, JPL, NASA

 ganymède lune de jupiter vue par galileo  
Ganymede (Jupiter III)Characteristics
Apoapsis1 071 600 km
Periapsis1 069 200 km
Semi-major axis1 070 400 km
Diameter5268 km
Axial tilt0-0.33°
Mass1.4819×1023 kg
Average orbital speed10.88 km/s
Orbital period7.15455296 d
Rotation periodsynchronous
Inclination to Jupiter's equator0.20°
Discovered byGalileo Galilei
Discovery dateJanuary 7, 1610



Callisto was discovered in 1610 by Galilee and Simon Marius.
This last one so named it in honor of Callisto, a nymph of a very big beauty, a following one of Artemis and loving conquest of Zeus, of which she had Arcas.
Callisto has a surface intensely craterised. Its size in fact the third biggest moon of the system solar and comparable to Mercury.
Callisto an enormous ice floe of several kilometers in thickness under which exists probably a liquid ocean.

Image: photography taken by the probe Galileo.

Callisto (Jupiter IV)Characteristics
Apoapsis1 897 000 km
Periapsis1 869 000 km
Semi-major axis1 882 700 km
Diameter4820.3 km
Axial tilt
Mass1.075938×1023 kg
Average orbital speed8.204 km/s
Orbital period16.6890184 d
Rotation periodsynchronous
Inclination to Jupiter's equator0.192°
Discovered byGalileo Galilei
Discovery dateJanuary 7, 1610



Io is one of four Galilean moons of Jupiter, the closest to the planet. it pulls its name of Io, loving conquest of Zeus persecuted by the wife of this last one, Hera, whose a priestess she had been. Io is especially remarkable for its active, observed volcanism that on the Earth, Triton and Enceladus.
The energy necessary for this activity results probably from interactions of tide between Io, Europe, Ganymede and Jupiter. Although Io always presents the same in front of Jupiter, the presence of Europe and Ganymede makes it vacillate a little.
This interaction deforms the surface of Io which lifts up itself and falls up to 100 meters and produces of the heat by internal friction.

Io (Jupiter I)Characteristics
Apoapsis423 000 km
Periapsis420 000 km
Semi-major axis421 700 km
Diameter3243.2 km
Mass8.931938×1022 kg
Average orbital speed17.334 km/s
Orbital period1.769137786 d
Rotation periodsynchronous
Inclination to Jupiter's equator0.05°
Discovered byGalileo Galilei
Discovery dateJanuary 8, 1610



Europa is one of four Galilean moons, discovered by Galilee and Simon Marius who so named it in honor of Europa, princess Phoenician, delighted on a beach of Sidon by Zeus transformed in white bull. Of their union were born Minos, Rhadamanthe and Sarpedon.
Europe is subjected to the strong gravitational strengths of Jupiter.
The Galileo probe revealed the presence on its surface of crystals of sulfate of magnesium, which on Earth are in the dried up lakes.
The ice of surface of several kilometers in thickness ache a maintained liquid ocean by the heating produced by the strengths of tide due to the nearness with Jupiter.

Image: photography taken by the probe Galileo.

Europa (Jupiter II)Characteristics
Diameter3 126.6 km
Apoapsis676 938 km
Periapsis664 862 km
Semi-major axis670 900 km
Diameter3121.6 km
Mass4.799844×1022 kg
Surface gravity1.314 m/s2
Escape velocity2.025 km/s
Average orbital speed13.74 km/s
Orbital period3.551181 d
Rotation periodsynchronous
Inclination to Jupiter's equator0.47°
Discovered byGalileo Galilei,
Simon Marius
Discovery dateJanuary 8, 1610



Amalthea was discovered in 1892 by the American astronomer Edward Emerson Barnard using the 91 cm telescope at Lick Observatory.
This is the first satellite of Jupiter discovered since the Galilean moons in 1610.
The surface of Amalthea is very red, its reflectivity increases with wavelength from the green to the infrared.
The period of revolution of Amalthea is 12 days.
The rotation around its axis is synchronous, ie, 12 days.
Its surface is cratered. Its craters are very large compared to the size of Amalthea. Amalthea is made of ice and debris very porous.
Pan crater, the largest, measuring 100 km in diameter and is deep at least 8 km.
The crater, Gaea, measuring 80 km, it is about twice as deep as Pan. Amalthea has two mountains, and Mons Ida Mons Lyctas. Amalthea orbits Jupiter at a distance of 181,000 km. The orbit of Amalthea is very close to the outer edge of the ring Gossamer. This ring is composed of dust ejected from the satellite. Amalthea is not to be confused with the asteroid (113) Amalthea. Name Amalthea comes from the nymph feeds Jupiter.

 Amalthée satellite de Jupiter

Image: photograph taken in 1999 by the Galileo spacecraft

Amalthea (Jupiter V) Characteristics
Dimensions 262x146x134 km
Mass 2,1x1018 kg
Axial tilt 0
Periapsis 181 150 km
Apoapsis 182 840 km
Eccentricity  0.00319
Escape velocity ≈ 0.0581 km/s
Orbital period 0.49817943 d
Rotation period synchronous
discovered date September 9, 1892
discovered by Edward Emerson Barnard

NB: November 5, 2002, the Galileo spacecraft flew past Amalthea at 160 km altitude. During the close flyby, no picture of Amalthea, was published, the only published views of the Jovian satellite fifth, lack of sharpness.



Himalia is an irregular satellite of Jupiter which revolves in 11 443 000 km of the planet. it was discovered in 1904 by Charles Dillon Perrine to the look-out observatory Lick in California.
It is the biggest moon of the group Himalia. Himalia was a nymph who carried three sons of Zeus (Jupiter) in the Greek mythology.


Image: photography taken in 2000 by the probe Cassini-Huygens.

Himalia (Jupiter VI)Characteristics
Apoapsis13 082 000 km
Periapsis9 782 900 km
Semi-major axis11 460 000 km
Diameter≈170 km
Mass6.7×1018 kg
Average orbital speed3.312 km/s
Orbital period250.56 d
Inclination to Jupiter's equator29.59°
Discovered byC. D. Perrine
Discovery dateDecember 3, 1904



Thebe is the moon 100 km in diameter on average.
It revolves on an orbit in 222 000 km of Jupiter.
1 in 1980 were discovered by Stephen Synott from the data of Voyager.

Image: photography taken in 2000 by the probe Galileo.

 Jupiter's moon Thebe  
Thebe (Jupiter XIV)Characteristics
Apoapsis226 000 km
Periapsis218 000 km
Semi-major axis221 889 km
Diameter≈100 km
Mass4.3×1017 kg
Orbital period0.674 536 d
Inclination to Jupiter's equator1.076°
Discovered byStephen P. Synnott
Discovery dateMarch 5, 1979

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