The Jovian system contains several smaller, irregular moons that we know very little about. These satellites of the planet Jupiter are extremely small, and many were not discovered until the Voyager and Galileo encounters with Jupiter or by astronomers using the Hubble space telescope. Because of their small size, it is possible that some of these moons may be captured asteroids or comets. These recent discoveries bring the total number of Jovian moons to 63. Below is a listing of some of the the largest of these moons in the order of their distance from Jupiter. Images that appear on this page are the best available at this time. You may access information on one of the moons directly by clicking on its name below.

Metis | Adrastea | Amalthea | Thebe | Leda | Himalia | Lysithea | Elara | Ananke | Carme | Pasiphae | Sinope

Metis

Metis [MEE-tis] is the innermost of Jupiter's moons. It was named after a Titaness who was the first wife of Jupiter in Roman Mythology (Zeus in Greek). Metis was discovered by Stephen Synnott in 1979 using data from the Voyager 1 spacecraft. It was one of the first two moons discovered by the Voyager project. Metis is one of two moons that orbit inside Jupiter's main ring. It is possible that these moons are the source of the material that forms the rings. Very little is known about Metis at this time, but it is probably composed of a mixture of ice and rock. Since Metis lies within the Roche limit, its orbit will eventually decay and it will crash into Jupiter.

Galileo Image of Metis

Galileo Image of Metis
(NASA / JPL)

Statistics for Metis

Discovered by

Year of Discovery

Approximate Diameter

Mean Distance from Jupiter

Rotational Period

Orbital Period

Orbital Eccentricity

Orbital Inclination

Apparent Magnitude

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Stephen Synnott

1979

27 miles (44 km)

79,598 miles (128,100 km)

unknown

0.29 days

0

0 degrees

17.5

Adrastea

Adrastea [a-DRAS-tee-uh] is the second innermost of Jupiter's moons. It is also one of the smallest moons in the Solar System. In Roman mythology, Adrastea was the daughter of Jupiter (Zeus) and Ananke and was the distributor of rewards and punishments. Adrastea was discovered by David Jewitt & E. Danielson in 1979 using data from the Voyager 1 spacecraft. It was one of the first two moons discovered by the Voyager project. Adrastea is one of two moons that orbit inside Jupiter's main ring. It is possible that these moons are the source of the material that forms the rings. Very little is known about Adrastea at this time, but it is probably composed of a mixture of ice and rock. Since Adrastea lies within the Roche limit, its orbit will eventually decay and it will crash into Jupiter.

Galileo Image of Adrastea

Galileo Image of Adrastea
(NASA / JPL)

Statistics for Adrastea

Discovered by

Year of Discovery

Approximate Diameter

Distance from Jupiter

Rotational Period

Orbital Period

Orbital Eccentricity

Orbital Inclination

Apparent Magnitude

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David Jewitt & E. Danielson

1979

10 miles (16 km)

80,095 miles (128,900 km)

unknown

0.298 days

0

0 degrees

19.1

Amalthea

Amalthea [am-al-THEE-uh] is the third of Jupiter's moons and is the fifth largest. It was named after the nymph who nursed the infant Jupiter (Zeus) with goat's milk in Roman mythology. Adrastea was discovered by Edward Emerson Barnard in 1892 using the 36-inch refractor telescope at Lick Observatory. It was the last moon in the Solar System to be discovered by direct visual observation. Amalthea is very irregular in shape and is covered with craters. Some of these are quite large when compared to the size of the moon itself. The largest of these craters is known as Pan and is 62 miles (100 km) in diameter. Another crater, Gaea, is 50 miles (80 km) in diameter. Amalthea's surface is dark red in color. It is, in fact, the reddest object in the Solar System. This red color is believed to be caused by sulfur ejected from Jupiter's moon, Io. Amalthea's orbit is synchronous, and it orbits with its long axis pointed towards Jupiter. The composition of this moon is believed to be similar to that of asteroids. Amalthea radiates more heat than it receives from the Sun. This is probably due to electrical currents produced by interaction with Jupiter's magnetic field.

Galileo Image of Amalthea

Galileo Image of Amalthea
(NASA / JPL)

Statistics for Amalthea

Discovered by

Year of Discovery

Approximate Diameter

Distance from Jupiter

Rotational Period

Orbital Period

Orbital Eccentricity

Orbital Inclination

Apparent Magnitude

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Edward Emerson Barnard

1892

104 miles (168 km)

112,717 miles (181,400 km)

0.498 days

0.498 days

0.003

0.4 degrees

14.1

Thebe

Thebe [THEE-bee] is the fourth of Jupiter's moons. It was named after a nymph who was the daughter of the river god Asophus. Thebe was discovered in 1979 by Stephen Synnott using data from the Voyager 1 spacecraft. Very little is known about Thebe. What we do know is that its orbit around Jupiter is synchronous, and its leading side shows four large craters.

Galileo Image of Thebe

Galileo Image of Thebe
(NASA / JPL)

Statistics for Thebe

Discovered by

Year of Discovery

Approximate Diameter

Distance from Jupiter

Rotational Period

Orbital Period

Orbital Eccentricity

Orbital Inclination

Apparent Magnitude

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Stephen Synnott

1979

61 miles (98 km)

137,882 miles (221,900 km)

0.675 days

0.675 days

0

1.065 degrees

15.7

Leda

Leda [LEE-duh] is the ninth of Jupiter's moons and is the smallest. It is also the smallest known moon in the Solar System. Leda was named after the queen of Sparta and mother of Hellen and Pollux. It was discovered by Charles Kowal in 1974 and was the last Jovian moon to be discovered from Earth. Very little is known about Leda except that it is one of the smallest moons in the Solar System, and its orbit is highly inclined to Jupiter's equator. Some astronomers believe it may be one of four moons that could be the remnants of an asteroid that was captured by Jupiter and broken up by its gravitational forces.

Voyager Image of Leda

Voyager Image of Leda
(NASA / JPL)

Statistics for Leda

Discovered by

Year of Discovery

Approximate Diameter

Distance from Jupiter

Rotational Period

Orbital Period

Orbital Eccentricity

Orbital Inclination

Apparent Magnitude

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Charles Kowal

1974

11 miles (18 km)

6,937,609 miles (11,165,000 km)

unknown

238.72 days

0.147

26.07 degrees

20.2

Himalia

Himalia [him-MAH-lee-uh] is the tenth of Jupiter's moons. It was named after a nymph who bore three sons to Zeus (Jupiter) in Greek mythology. It was discovered in 1904 by the Argentine-American astronomer Charles Dillon Perrine at Lick Observatory. Very little is known about Himalia except that its orbit is significantly inclined to Jupiter's equator by almost 28 degrees. Some astronomers believe it may be one of four moons that could be the remnants of an asteroid that was captured by Jupiter and broken up by its gravitational forces.

Voyager Image of Himalia

Voyager Image of Himalia
(NASA / JPL)

Statistics for Himalia

Discovered by

Year of Discovery

Approximate Diameter

Distance from Jupiter

Rotational Period

Orbital Period

Orbital Eccentricity

Orbital Inclination

Apparent Magnitude

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Charles Dillon Perrine

1904

114 miles (184 km)

7,121,535 miles (11,461,000 km)

0.4 days

250.56 days

0.158

27.63 degrees

14.84

Lysithea

Lysithea [ly-SITH-ee-uh] is the eleventh of Jupiter's moons. It was named after a daughter of Oceanus who was one of Zeus' lovers. Lysithea was discovered by Seth Barnes Nicholson in 1938. Very little is known about Lysithea at this time except that it has a highly inclined orbit. Some astronomers believe it may be one of four moons that could be the remnants of an asteroid that was captured by Jupiter and broken up by its gravitational forces.

Statistics for Lysithea

Discovered by

Year of Discovery

Approximate Diameter

Distance from Jupiter

Rotational Period

Orbital Period

Orbital Eccentricity

Orbital Inclination

Apparent Magnitude

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Seth Barnes Nicholson

1938

24 miles (38 km)

7,280,606 miles (11,717,000 km)

unknown

259.22 days

0.107

29.02 degrees

18.4

Elara

Elara [ee-LAH-ruh] is the twelfth of Jupiter's moons. In Greek mythology, Elara and Zeus (Jupiter) were the parents of the giant, Titys. Elara was discovered in 1905 Charles Dillon Perrine at Lick Observatory. Very little is known about Elara except that is has a highly inclined orbit. Some astronomers believe it may be one of four moons that could be the remnants of an asteroid that was captured by Jupiter and broken up by its gravitational forces.

Statistics for Elara

Discovered by

Year of Discovery

Approximate Diameter

Distance from Jupiter

Rotational Period

Orbital Period

Orbital Eccentricity

Orbital Inclination

Apparent Magnitude

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Charles Dillon Perrine

1905

48 miles (78 km)

11,741,000 miles (11,741,000 km)

0.5 days

259.65 days

0.207

24.77 degrees

16.77

Ananke

Ananke [a-NANG-kee] is the thirteenth of Jupiter's moons. In Greek mythology, Ananke and Zeus (Jupiter) were the parents of Adrastea. Ananke was discovered by Seth Barnes Nicholson in 1951 with the reflector telescope at Mount Wilson. Very little is known about Ananke except that its orbit is extremely inclined at 147 degrees, and it is one of the four moons that orbit Jupiter in a retrograde motion.

Statistics for Ananke

Discovered by

Year of Discovery

Approximate Diameter

Distance from Jupiter

Rotational Period

Orbital Period

Orbital Eccentricity

Orbital Inclination

Apparent Magnitude

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Seth Barnes Nicholson

1951

17 miles (28 km)

13,220,293 miles (21,276,000 km)

unknown

-631 days

0.169

147 degrees

18.9


Carme

Elara [KAR-mee] is the fourteenth of Jupiter's moons. In Greek mythology, Carme was the mother, by Zeus, of a Cretan goddess named Britomartis. It was discovered in 1938 by Seth Barnes Nicholson with the reflector telescope at Mount Wilson. Very little is known about Carme except that its orbit is extremely inclined at 163 degrees, and it is one of the four moons that orbit Jupiter in a retrograde motion.

Statistics for Carme

Discovered by

Year of Discovery

Approximate Diameter

Distance from Jupiter

Rotational Period

Orbital Period

Orbital Eccentricity

Orbital Inclination

Apparent Magnitude

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......

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Seth Barnes Nicholson

1938

29 miles (46 km)

14,542,571 miles (23,404,000 km)

unknown

-692 days

0.207

163 degrees

18.0

Pasiphae

Pasiphae [pah-SIF-ah-ee] is the fifteenth of Jupiter's moons. In Greek mythology, Pasiphae was the wife of Minos and mother, by a white bull, of the Minotaur. It was discovered in 1908 by P. J. Melotta in Greenwich, England. Very little is known about Pasiphae except that its orbit is extremely inclined at 147 degrees, and it is one of the four moons that orbit Jupiter in a retrograde motion.

Statistics for Pasiphae

Discovered by

Year of Discovery

Approximate Diameter

Distance from Jupiter

Rotational Period

Orbital Period

Orbital Eccentricity

Orbital Inclination

Apparent Magnitude

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P. J. Melotta

1908

37 miles (60 km)

14,679,273 miles (23,624,000 km)

unknown

-735 days

0.378

147 degrees

17.03

Sinope

Sinope [sah-NOH-pee] is the sixteenth and outermost of Jupiter's moons. It was named after a woman in Greek mythology who was unsuccessfully courted by Zeus (Jupiter). It was discovered by Seth Barnes Nicholson in 1914 with the reflector telescope at Mount Wilson. Very little is known about Sinope except that its orbit is extremely inclined at 153 degrees, and it is one of the four moons that orbit Jupiter in a retrograde motion.

Statistics for Sinope

Discovered by

Year of Discovery

Approximate Diameter

Distance from Jupiter

Rotational Period

Orbital Period

Orbital Eccentricity

Orbital Inclination

Apparent Magnitude

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......

......

......

......

......

......

......

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Seth Barnes Nicholson

1914

24 miles (38 km)

14,875,004 miles (23,939,000 km)

unknown

-758 days

0.275

153 degrees

18.3

 

 

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