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 (km) |
Semi-major 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 |
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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 | | | | Ganymede (Jupiter III) | Characteristics | | | Apoapsis | 1 071 600 km | Periapsis | 1 069 200 km | Semi-major axis | 1 070 400 km |
Diameter | 5268 km | Axial tilt | 0-0.33° | Mass | 1.4819×1023 kg | Average orbital speed | 10.88 km/s | Eccentricity | 0.0013 | Orbital period | 7.15455296 d | Rotation period | synchronous | Inclination to Jupiter's equator | 0.20° | Discovered by | Galileo Galilei | Discovery date | January 7, 1610 |
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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 | | | Apoapsis | 423 000 km | Periapsis | 420 000 km | Semi-major axis | 421 700 km | Diameter | 3243.2 km | Mass | 8.931938×1022 kg | Average orbital speed | 17.334 km/s | Eccentricity | 0.0041 | Orbital period | 1.769137786 d | Rotation period | synchronous | Inclination to Jupiter's equator | 0.05° | Discovered by | Galileo Galilei | Discovery date | January 8, 1610 |
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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. | | 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. |