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Jupiter's natural satellites

Jupiter's natural satellites

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Jupiter
Jupiter
Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...

 has 64 confirmed moons
Natural satellite
A natural satellite or moon is a celestial body that orbits a planet or smaller body, which is called its primary. The two terms are used synonymously for non-artificial satellites of planets, of dwarf planets, and of minor planets....

, giving it the largest retinue of moons with "reasonably secure" orbits of any planet in the Solar System. The most massive of them, the four Galilean moons
Galilean moons
The Galilean moons are the four moons of Jupiter discovered by Galileo Galilei in January 1610. They are the largest of the many moons of Jupiter and derive their names from the lovers of Zeus: Io, Europa, Ganymede and Callisto. Ganymede, Europa and Io participate in a 1:2:4 orbital resonance...

, were discovered in 1610 by Galileo Galilei
Galileo Galilei
Galileo Galilei , was an Italian physicist, mathematician, astronomer, and philosopher who played a major role in the Scientific Revolution. His achievements include improvements to the telescope and consequent astronomical observations and support for Copernicanism...

 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
Roman mythology
Roman mythology is the body of traditional stories pertaining to ancient Rome's legendary origins and religious system, as represented in the literature and visual arts of the Romans...

 Jupiter
Jupiter (mythology)
In ancient Roman religion and myth, Jupiter or Jove is the king of the gods, and the god of the sky and thunder. He is the equivalent of Zeus in the Greek pantheon....

, or his Greek predecessor
Greek mythology
Greek mythology is the body of myths and legends belonging to the ancient Greeks, concerning their gods and heroes, the nature of the world, and the origins and significance of their own cult and ritual practices. They were a part of religion in ancient Greece...

, Zeus
Zeus
In the ancient Greek religion, Zeus was the "Father of Gods and men" who ruled the Olympians of Mount Olympus as a father ruled the family. He was the god of sky and thunder in Greek mythology. His Roman counterpart is Jupiter and his Etruscan counterpart is Tinia.Zeus was the child of Cronus...

. The Galilean moons are by far the largest objects in orbit around Jupiter, with the remaining 60 moons and the rings together comprising just 0.003 percent of the total orbiting mass.

Eight of Jupiter's moons are regular satellites, with prograde and nearly circular orbits that are not greatly inclined
Inclination
Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...

 with respect to Jupiter's equatorial plane. The Galilean satellites are spheroidal
Hydrostatic equilibrium
Hydrostatic equilibrium or hydrostatic balance is the condition in fluid mechanics where a volume of a fluid is at rest or at constant velocity. This occurs when compression due to gravity is balanced by a pressure gradient force...

 in shape, and so would be considered (dwarf) planets if they were in direct orbit about 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
Rings of Jupiter
The planet Jupiter has a system of rings, known as the rings of Jupiter or the Jovian ring system. It was the third ring system to be discovered in the Solar System, after those of Saturn and Uranus. It was first observed in 1979 by the Voyager 1 space probe and thoroughly investigated in the 1990s...

.

Jupiter's other 56 moons are irregular satellite
Irregular satellite
In astronomy, an irregular moon is a natural satellite following a distant, inclined, and often eccentric and retrograde orbit. They are believed to have been captured by their parent planet, unlike regular satellites, which form in situ....

s
, whose prograde and retrograde orbits are much farther from Jupiter and have high inclination
Inclination
Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...

s and eccentricities
Orbital eccentricity
The orbital eccentricity of an astronomical body is the amount by which its orbit deviates from a perfect circle, where 0 is perfectly circular, and 1.0 is a parabola, and no longer a closed orbit...

. These moons were probably captured by Jupiter from solar orbits
Minor planet
An asteroid group or minor-planet group is a population of minor planets that have a share broadly similar orbits. Members are generally unrelated to each other, unlike in an asteroid family, which often results from the break-up of a single asteroid...

. There are 14 recently discovered irregular satellites that have not yet been named.

Characteristics


The moons' physical and orbital characteristics vary widely. The four Galileans are all over 3100 kilometres (1,926.3 mi) in diameter; the largest Galilean, Ganymede
Ganymede (moon)
Ganymede is a satellite of Jupiter and the largest moon in the Solar System. It is the seventh moon and third Galilean satellite outward from Jupiter. Completing an orbit in roughly seven days, Ganymede participates in a 1:2:4 orbital resonance with the moons Europa and Io, respectively...

, is the ninth largest object in the Solar System
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...

, after the Sun and seven of the planet
Planet
A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...

s (Ganymede being larger than Mercury
Mercury (planet)
Mercury is the innermost and smallest planet in the Solar System, orbiting the Sun once every 87.969 Earth days. The orbit of Mercury has the highest eccentricity of all the Solar System planets, and it has the smallest axial tilt. It completes three rotations about its axis for every two orbits...

). All other Jovian moons are less than 250 kilometres (155.3 mi) in diameter, with most barely exceeding 5 kilometres (3.1 mi). Orbital shapes
Orbit
In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...

 range from nearly perfectly circular to highly eccentric and inclined
Inclination
Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...

, and many revolve in the direction opposite to Jupiter's spin (retrograde motion
Retrograde motion
Retrograde motion is motion in the direction opposite to the movement of something else, and is the contrary of direct or prograde motion. This motion can be the orbit of one body about another body or about some other point, or the rotation of a single body about its axis, or other phenomena such...

). Orbital period
Orbital period
The orbital period is the time taken for a given object to make one complete orbit about another object.When mentioned without further qualification in astronomy this refers to the sidereal period of an astronomical object, which is calculated with respect to the stars.There are several kinds of...

s 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
Protoplanetary disk
A protoplanetary disk is a rotating circumstellar disk of dense gas surrounding a young newly formed star, a T Tauri star, or Herbig Ae/Be star...

. They may be the remnants of a score of Galilean-mass satellites that formed early in Jupiter's history.

Simulations suggest that, while the disk had a relatively low mass at any given moment, over time a substantial fraction (several tens of a percent) of the mass of Jupiter captured from the Solar nebula was processed through it. However, the disk mass of only 2% that of Jupiter is required to explain the existing satellites. Thus there may have been several generations of Galilean-mass satellites in Jupiter's early history. Each generation of moons would have spiraled into Jupiter, due to drag from the disk, with new moons then forming from the new debris captured from the Solar nebula. By the time the present (possibly fifth) generation formed, the disk had thinned out to the point that it no longer greatly interfered with the moons' orbits. The current Galilean moons were still affected, falling into and being partially protected by an orbital resonance
Orbital resonance
In celestial mechanics, an orbital resonance occurs when two orbiting bodies exert a regular, periodic gravitational influence on each other, usually due to their orbital periods being related by a ratio of two small integers. Orbital resonances greatly enhance the mutual gravitational influence of...

 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.

The outer, irregular moons are thought to have originated from passing asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...

s while the protolunar disk was still massive enough to absorb much of their momentum and thus capture them into orbit. Many broke up by the stresses of capture, or afterward by collisions with other small bodies, producing the families we see today.

Discovery






The first claimed observation of one of Jupiter's moons is that of the Chinese astronomer Gan De
Gan De
Gan De was a Chinese astronomer/astrologer born in the State of Qi also known as the Lord Gan . Along with Shi Shen, he is believed to be the first in history known by name to compile a star catalogue, preceded by the anonymous authors of the early Babylonian star catalogues and followed by the...

 around 364 BC. However, the first certain observations of Jupiter's satellites were those of Galileo Galilei
Galileo Galilei
Galileo Galilei , was an Italian physicist, mathematician, astronomer, and philosopher who played a major role in the Scientific Revolution. His achievements include improvements to the telescope and consequent astronomical observations and support for Copernicanism...

 in 1609. By March 1610, he had sighted the four massive Galilean moons
Galilean moons
The Galilean moons are the four moons of Jupiter discovered by Galileo Galilei in January 1610. They are the largest of the many moons of Jupiter and derive their names from the lovers of Zeus: Io, Europa, Ganymede and Callisto. Ganymede, Europa and Io participate in a 1:2:4 orbital resonance...

 with his 30x magnification
Magnification
Magnification is the process of enlarging something only in appearance, not in physical size. This enlargement is quantified by a calculated number also called "magnification"...

 telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...

: Ganymede
Ganymede (moon)
Ganymede is a satellite of Jupiter and the largest moon in the Solar System. It is the seventh moon and third Galilean satellite outward from Jupiter. Completing an orbit in roughly seven days, Ganymede participates in a 1:2:4 orbital resonance with the moons Europa and Io, respectively...

, Callisto
Callisto (moon)
Callisto named after the Greek mythological figure of Callisto) is a moon of the planet Jupiter. It was discovered in 1610 by Galileo Galilei. It is the third-largest moon in the Solar System and the second largest in the Jovian system, after Ganymede. Callisto has about 99% the diameter of the...

, Io
Io (moon)
Io ) is the innermost of the four Galilean moons of the planet Jupiter and, with a diameter of , the fourth-largest moon in the Solar System. It was named after the mythological character of Io, a priestess of Hera who became one of the lovers of Zeus....

, and Europa
Europa (moon)
Europa Slightly smaller than Earth's Moon, Europa is primarily made of silicate rock and probably has an iron core. It has a tenuous atmosphere composed primarily of oxygen. Its surface is composed of ice and is one of the smoothest in the Solar System. This surface is striated by cracks and...

. No additional satellites were discovered until E.E. Barnard observed Amalthea
Amalthea (moon)
Amalthea is the third moon of Jupiter in order of distance from the planet. It was discovered on September 9, 1892, by Edward Emerson Barnard and named after Amalthea, a nymph in Greek mythology. It is also known as '....

 in 1892. With the aid of telescopic photography, further discoveries followed quickly over the course of the twentieth century. Himalia
Himalia (moon)
Himalia is the largest irregular satellite of Jupiter, the sixth largest overall in size, and the fifth largest in mass. It was discovered by Charles Dillon Perrine at the Lick Observatory on 3 December 1904 and is named after the nymph Himalia, who bore three sons of Zeus .- Discovery...

 was discovered in 1904, Elara
Elara (moon)
Elara is a prograde irregular satellite of Jupiter. It was discovered by Charles Dillon Perrine at Lick Observatory in 1905. It is the eighth largest moon of Jupiter and is named after the mother by Zeus of the giant Tityus....

 in 1905, Pasiphaë
Pasiphaë (moon)
Pasiphaë is a retrograde irregular satellite of Jupiter. It was discovered in 1908 by Philibert Jacques Melotte and later named after the mythological Pasiphaë, wife of Minos and mother of the Minotaur from Greek legend....

 in 1908, Sinope
Sinope (moon)
Sinope is a retrograde irregular satellite of Jupiter discovered by Seth Barnes Nicholson at Lick Observatory in 1914, and is named after Sinope of Greek mythology....

 in 1914, Lysithea
Lysithea (moon)
Lysithea is a prograde irregular satellite of Jupiter. It was discovered by Seth Barnes Nicholson in 1938 at Mount Wilson Observatory and is named after the mythological Lysithea, daughter of Oceanus and one of Zeus' lovers....

 and Carme
Carme (moon)
Carme is a retrograde irregular satellite of Jupiter. It was discovered by Seth Barnes Nicholson at Mount Wilson Observatory in California in July 1938. It is named after the mythological Carme, mother by Zeus of Britomartis, a Cretan goddess....

 in 1938, Ananke
Ananke (moon)
Ananke is a retrograde irregular satellite of Jupiter. It was discovered by Seth Barnes Nicholson at Mount Wilson Observatory in 1951 and is named after the mythological Ananke, the personification of Necessity, and the mother of the Moirae by Zeus...

 in 1951, and Leda
Leda (moon)
Leda , also known as ', is a prograde irregular satellite of Jupiter. It was discovered by Charles T. Kowal at the Mount Palomar Observatory on September 14, 1974, after three nights' worth of photographic plates had been taken...

 in 1974. By the time Voyager space probes
Voyager program
The Voyager program is a U.S program that launched two unmanned space missions, scientific probes Voyager 1 and Voyager 2. They were launched in 1977 to take advantage of a favorable planetary alignment of the late 1970s...

 reached Jupiter around 1979, 13 moons had been discovered; while Themisto
Themisto (moon)
Themisto , also known as ', is a small prograde irregular satellite of Jupiter. It was discovered in 1975, lost, and then rediscovered in 2000.- Discovery and naming :...

 was observed in 1975, but due to insufficient initial observation data, it was lost until 2000. The Voyager missions discovered an additional three inner moons in 1979: Metis
Metis (moon)
Metis , also known as ', is the innermost moon of Jupiter. It was discovered in 1979 in images taken by Voyager 1, and was named in 1983 after the first wife of Zeus, Metis...

, Adrastea
Adrastea (moon)
Adrastea , also known as ', is the second by distance, and the smallest of the four inner moons of Jupiter. It was discovered in Voyager 2 probe photographs taken in 1979, making it the first natural satellite to be discovered from images taken by an interplanetary spacecraft, rather than...

, and Thebe
Thebe (moon)
Thebe also known as ', is the fourth of Jupiter's moons by distance from the planet. It was discovered by Stephen P. Synnott in images from the Voyager 1 space probe taken on March 5, 1979, while orbiting around Jupiter...

.

For two decades no additional moons were discovered; but between October 1999 and February 2003, researchers using sensitive ground-based detectors found another 32 moons, most of which were discovered by a team led by Scott S. Sheppard
Scott S. Sheppard
Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and...

 and David C. Jewitt
David C. Jewitt
David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in...

. These are tiny moons, in long, eccentric, generally retrograde orbits, and average of 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 be captured asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...

al or perhaps comet
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...

ary bodies, possibly fragmented into several pieces, but very little is actually known about them. A number of 14 additional moons were discovered since then, but not yet confirmed, bringing the total number of observed moons of Jupiter at 63. As of 2008, this is the most of any planet in the Solar System, but additional undiscovered, tiny moons
Moonlet
Moonlet is an informal term for a particularly small natural satellite. In astronomical literature, it has been used in at least two situations:...

 may exist.

Naming



The Galilean moons of Jupiter (Io
Io (moon)
Io ) is the innermost of the four Galilean moons of the planet Jupiter and, with a diameter of , the fourth-largest moon in the Solar System. It was named after the mythological character of Io, a priestess of Hera who became one of the lovers of Zeus....

, Europa
Europa (moon)
Europa Slightly smaller than Earth's Moon, Europa is primarily made of silicate rock and probably has an iron core. It has a tenuous atmosphere composed primarily of oxygen. Its surface is composed of ice and is one of the smoothest in the Solar System. This surface is striated by cracks and...

, Ganymede
Ganymede (moon)
Ganymede is a satellite of Jupiter and the largest moon in the Solar System. It is the seventh moon and third Galilean satellite outward from Jupiter. Completing an orbit in roughly seven days, Ganymede participates in a 1:2:4 orbital resonance with the moons Europa and Io, respectively...

 and Callisto
Callisto (moon)
Callisto named after the Greek mythological figure of Callisto) is a moon of the planet Jupiter. It was discovered in 1610 by Galileo Galilei. It is the third-largest moon in the Solar System and the second largest in the Jovian system, after Ganymede. Callisto has about 99% the diameter of the...

) were named by Simon Marius
Simon Marius
Simon Marius was a German astronomer. He was born in Gunzenhausen, near Nuremberg, but he spent most of his life in the city of Ansbach....

 soon after their discovery in 1610. However, until the 20th century these fell out of favor, and instead they were referred to in the astronomical literature simply as "Jupiter I", "Jupiter II", etc., or as "the first satellite of Jupiter", "Jupiter's second satellite", and so on. The names Io, Europa, Ganymede, and Callisto became popular in the 20th century, while the rest of the moons, usually numbered in Roman numerals V (5) through XII (12), remained unnamed. By a popular though unofficial convention, Jupiter V, discovered in 1892, was given the name Amalthea, first used by the French astronomer Camille Flammarion
Camille Flammarion
Nicolas Camille Flammarion was a French astronomer and author. He was a prolific author of more than fifty titles, including popular science works about astronomy, several notable early science fiction novels, and several works about Spiritism and related topics. He also published the magazine...

.

The other moons, in the majority of astronomical literature, were simply labeled by their Roman numeral (i.e. Jupiter IX) until the 1970s. In 1975, the International Astronomical Union
International Astronomical Union
The International Astronomical Union IAU is a collection of professional astronomers, at the Ph.D. level and beyond, active in professional research and education in astronomy...

's (IAU) Task Group for Outer Solar System Nomenclature granted names to satellites V–XIII, and provided for a formal naming process for future satellites to be discovered. The practice was to name newly discovered moons of Jupiter after lovers and favorites of the god Jupiter (Zeus
Zeus
In the ancient Greek religion, Zeus was the "Father of Gods and men" who ruled the Olympians of Mount Olympus as a father ruled the family. He was the god of sky and thunder in Greek mythology. His Roman counterpart is Jupiter and his Etruscan counterpart is Tinia.Zeus was the child of Cronus...

), and since 2004, after their descendants also. All of Jupiter's satellites from XXXIV (Euporie
Euporie (moon)
Euporie , also known as ', is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

) are named after daughters of Jupiter or Zeus.

Some asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...

s share the same names
Name conflicts of Solar System objects
Although in principle every named body in the Solar System ought to have a distinct name, due to a variety of circumstances, there are several real or apparent name conflicts between different Solar System bodies. Most of these conflicts are between asteroids and natural satellites of planets,...

 as moons of Jupiter: 9 Metis
9 Metis
9 Metis is one of the larger main-belt asteroids. It is composed of silicates and metallic nickel-iron, and may be the core remnant of a large asteroid that was destroyed by an ancient collision...

, 38 Leda
38 Leda
38 Leda is a large, dark main-belt asteroid.It was discovered by J. Chacornac on January 12, 1856, and named after Leda, the mother of Helen of Troy in Greek mythology.Leda is also the name of a satellite of Jupiter and a catalogue of galaxies....

, 52 Europa
52 Europa
52 Europa is one of the larger asteroids in the asteroid belt, having a diameter of 300 km. It was discovered on February 4, 1858, by Hermann Goldschmidt from his balcony in Paris...

, 85 Io
85 Io
85 Io is a large, dark main-belt asteroid of the C spectral class. It is probably a primitive body composed of carbonates. Like 70 Panopaea it orbits within the Eunomia asteroid family but it is not related to the shattered parent body....

, 113 Amalthea
113 Amalthea
113 Amalthea is a fairly typical rocky main-belt asteroid orbiting in the inner regions of the belt. It was discovered by R. Luther on March 12, 1871....

, 239 Adrastea
239 Adrastea
239 Adrastea is a typical main belt asteroid.It was discovered by Johann Palisa on August 18, 1884 in Vienna. It is named after the Greek nymph Adrasteia.- References :*[ftp://ftp.lowell.edu/pub/elgb/astorb.html The Asteroid Orbital Elements Database]*...

. Two more asteroids previously shared the names of Jovian moons until spelling differences were made permanent by the IAU: Ganymede
Ganymede (moon)
Ganymede is a satellite of Jupiter and the largest moon in the Solar System. It is the seventh moon and third Galilean satellite outward from Jupiter. Completing an orbit in roughly seven days, Ganymede participates in a 1:2:4 orbital resonance with the moons Europa and Io, respectively...

 and asteroid 1036 Ganymed
1036 Ganymed
1036 Ganymed is the largest Amor asteroid, at about 32 km in diameter. It was discovered by Walter Baade on October 23, 1924, and is named after Ganymede, the Trojan prince turned god whom Zeus designated the cupbearer to the Greek gods...

; and Callisto
Callisto (moon)
Callisto named after the Greek mythological figure of Callisto) is a moon of the planet Jupiter. It was discovered in 1610 by Galileo Galilei. It is the third-largest moon in the Solar System and the second largest in the Jovian system, after Ganymede. Callisto has about 99% the diameter of the...

 and asteroid 204 Kallisto
204 Kallisto
204 Kallisto is a fairly typical, although sizeable Main belt asteroid. It is classified as an S-type asteroid. Like other asteroids of its type, it is light in colour.It was discovered by Johann Palisa on October 8, 1879 in Pola....

.

Groups



Regular satellites


These are split into two groups:
  • Inner satellites or Amalthea group: Metis
    Metis (moon)
    Metis , also known as ', is the innermost moon of Jupiter. It was discovered in 1979 in images taken by Voyager 1, and was named in 1983 after the first wife of Zeus, Metis...

    , Adrastea
    Adrastea (moon)
    Adrastea , also known as ', is the second by distance, and the smallest of the four inner moons of Jupiter. It was discovered in Voyager 2 probe photographs taken in 1979, making it the first natural satellite to be discovered from images taken by an interplanetary spacecraft, rather than...

    , Amalthea
    Amalthea (moon)
    Amalthea is the third moon of Jupiter in order of distance from the planet. It was discovered on September 9, 1892, by Edward Emerson Barnard and named after Amalthea, a nymph in Greek mythology. It is also known as '....

    , and Thebe
    Thebe (moon)
    Thebe also known as ', is the fourth of Jupiter's moons by distance from the planet. It was discovered by Stephen P. Synnott in images from the Voyager 1 space probe taken on March 5, 1979, while orbiting around Jupiter...

    . 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. These moons, along with a number of as-yet-unseen inner moonlets, replenish and maintain Jupiter's faint ring system
    Rings of Jupiter
    The planet Jupiter has a system of rings, known as the rings of Jupiter or the Jovian ring system. It was the third ring system to be discovered in the Solar System, after those of Saturn and Uranus. It was first observed in 1979 by the Voyager 1 space probe and thoroughly investigated in the 1990s...

    . Metis and Adrastea help to maintain Jupiter's main ring, while Amalthea and Thebe each maintain their own faint outer rings.

  • Main group or Galilean moons
    Galilean moons
    The Galilean moons are the four moons of Jupiter discovered by Galileo Galilei in January 1610. They are the largest of the many moons of Jupiter and derive their names from the lovers of Zeus: Io, Europa, Ganymede and Callisto. Ganymede, Europa and Io participate in a 1:2:4 orbital resonance...

    : Io
    Io (moon)
    Io ) is the innermost of the four Galilean moons of the planet Jupiter and, with a diameter of , the fourth-largest moon in the Solar System. It was named after the mythological character of Io, a priestess of Hera who became one of the lovers of Zeus....

    , Europa
    Europa (moon)
    Europa Slightly smaller than Earth's Moon, Europa is primarily made of silicate rock and probably has an iron core. It has a tenuous atmosphere composed primarily of oxygen. Its surface is composed of ice and is one of the smoothest in the Solar System. This surface is striated by cracks and...

    , Ganymede
    Ganymede (moon)
    Ganymede is a satellite of Jupiter and the largest moon in the Solar System. It is the seventh moon and third Galilean satellite outward from Jupiter. Completing an orbit in roughly seven days, Ganymede participates in a 1:2:4 orbital resonance with the moons Europa and Io, respectively...

     and Callisto
    Callisto (moon)
    Callisto named after the Greek mythological figure of Callisto) is a moon of the planet Jupiter. It was discovered in 1610 by Galileo Galilei. It is the third-largest moon in the Solar System and the second largest in the Jovian system, after Ganymede. Callisto has about 99% the diameter of the...

    . With radii that are larger than any of the dwarf planet
    Dwarf planet
    A dwarf planet, as defined by the International Astronomical Union , is a celestial body orbiting the Sun that is massive enough to be spherical as a result of its own gravity but has not cleared its neighboring region of planetesimals and is not a satellite...

    s, they are some of the largest objects in the Solar System
    Solar System
    The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...

     outside the Sun
    Sun
    The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...

     and the eight planets in terms of mass, and Ganymede exceeds the planet Mercury
    Mercury (planet)
    Mercury is the innermost and smallest planet in the Solar System, orbiting the Sun once every 87.969 Earth days. The orbit of Mercury has the highest eccentricity of all the Solar System planets, and it has the smallest axial tilt. It completes three rotations about its axis for every two orbits...

     in diameter. Respectively the fourth, sixth, first and third largest natural satellites in the Solar System, they contain almost 99.999% of the total mass in orbit around Jupiter. Jupiter is almost 5,000 times more massive than the Galilean moons. The inner moons also participate in a 1:2:4 orbital resonance
    Orbital resonance
    In celestial mechanics, an orbital resonance occurs when two orbiting bodies exert a regular, periodic gravitational influence on each other, usually due to their orbital periods being related by a ratio of two small integers. Orbital resonances greatly enhance the mutual gravitational influence of...

    . Models suggest that they formed by slow accretion
    Accretion (astrophysics)
    In astrophysics, the term accretion is used for at least two distinct processes.The first and most common is the growth of a massive object by gravitationally attracting more matter, typically gaseous matter in an accretion disc. Accretion discs are common around smaller stars or stellar remnants...

     in the low-density Jovian subnebula
    Solar nebula
    In cosmogony, the nebular hypothesis is the most widely accepted model explaining the formation and evolution of the Solar System. There is evidence that it was first proposed in 1734 by Emanuel Swedenborg. Originally applied only to our own Solar System, this method of planetary system formation...

    —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.

Irregular satellites




The irregular satellites are substantially smaller objects with more distant and eccentric orbits. They form families with shared similarities in orbit (semi-major axis
Semi-major axis
The major axis of an ellipse is its longest diameter, a line that runs through the centre and both foci, its ends being at the widest points of the shape...

, inclination
Inclination
Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...

, eccentricity
Orbital eccentricity
The orbital eccentricity of an astronomical body is the amount by which its orbit deviates from a perfect circle, where 0 is perfectly circular, and 1.0 is a parabola, and no longer a closed orbit...

) and composition; it is believed that these are at least partially collisional families
Collisional family
In astronomy, a collisional family is a group of objects that are thought to have a common origin in an impact . They have similar compositions, and most share similar orbital elements....

 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:
  • Prograde satellites:
  • Themisto
    Themisto (moon)
    Themisto , also known as ', is a small prograde irregular satellite of Jupiter. It was discovered in 1975, lost, and then rediscovered in 2000.- Discovery and naming :...

     is the innermost irregular moon and not part of a known family.

  • The Himalia group
    Himalia group
    The Himalia group is a group of prograde irregular satellites of Jupiter that follow similar orbits to Himalia and are thought to have a common origin.The known members of the group are :* Leda...

    is spread over barely 1.4 Gm in semi-major axis
    Semi-major axis
    The major axis of an ellipse is its longest diameter, a line that runs through the centre and both foci, its ends being at the widest points of the shape...

    , 1.6° in inclination (27.5 ± 0.8°), and eccentricities between 0.11 and 0.25. It has been suggested that the group could be a remnant of the break-up of an asteroid from the main asteroid belt
    Asteroid belt
    The asteroid belt is the region of the Solar System located roughly between the orbits of the planets Mars and Jupiter. It is occupied by numerous irregularly shaped bodies called asteroids or minor planets...

    .

  • Carpo
    Carpo (moon)
    Carpo , also ', is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

     is the outermost prograde moon and not part of a known family.


  • Retrograde
    Retrograde motion
    Retrograde motion is motion in the direction opposite to the movement of something else, and is the contrary of direct or prograde motion. This motion can be the orbit of one body about another body or about some other point, or the rotation of a single body about its axis, or other phenomena such...

     satellites:
  • S/2003 J 12
    S/2003 J 12
    ' is a natural satellite of Jupiter, and is the smallest known satellite in the Solar System. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

     is the innermost of the retrograde moons, and is not part of a known family.

  • The Carme group
    Carme group
    The Carme group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Carme and are thought to have a common origin....

    is spread over only 1.2 Gm in semi-major axis
    Semi-major axis
    The major axis of an ellipse is its longest diameter, a line that runs through the centre and both foci, its ends being at the widest points of the shape...

    , 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
    D-type asteroid
    D-type asteroids have a very low albedo and a featureless reddish electromagnetic spectrum. It has been suggested that they have a composition of organic rich silicates, carbon and anhydrous silicates, possibly with water ice in their interiors...

     progenitor, possibly a Jupiter Trojan.

  • The Ananke group
    Ananke group
    The Ananke group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Ananke and are thought to have a common origin....

    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.

  • The Pasiphae group
    Pasiphaë group
    The Pasiphaë group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Pasiphaë and are thought to have a common origin....

    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. The colors also vary significantly, from red to grey, which might be the result of multiple collisions. Sinope
    Sinope (moon)
    Sinope is a retrograde irregular satellite of Jupiter discovered by Seth Barnes Nicholson at Lick Observatory in 1914, and is named after Sinope of Greek mythology....

    , sometimes included in the Pasiphae group, is red and, given the difference in inclination, it could have been captured independently; Pasiphae and Sinope are also trapped in secular resonance
    Secular resonance
    A secular resonance is a type of orbital resonance.Secular resonances occur when the precession of two orbits is synchronised . A small body in secular resonance with a much larger one will precess at the same rate as the large body...

    s with Jupiter.

  • S/2003 J 2
    S/2003 J 2
    ' is a retrograde irregular satellite of Jupiter. The discovery, by a team of astronomers from the University of Hawaii led by Scott S. Sheppard and David C. Jewitt, was announced on March 4, 2003...

     is the outermost moon of Jupiter, and is not part of a known family.

Table


The moons of Jupiter are listed below by orbital period. Moons massive enough for their surfaces to have collapsed
Gravitational collapse
Gravitational collapse is the inward fall of a body due to the influence of its own gravity. In any stable body, this gravitational force is counterbalanced by the internal pressure of the body, in the opposite direction to the force of gravity...

 into a spheroid
Spheroid
A spheroid, or ellipsoid of revolution is a quadric surface obtained by rotating an ellipse about one of its principal axes; in other words, an ellipsoid with two equal semi-diameters....

 are highlighted in bold. These are the four Galilean moons
Galilean moons
The Galilean moons are the four moons of Jupiter discovered by Galileo Galilei in January 1610. They are the largest of the many moons of Jupiter and derive their names from the lovers of Zeus: Io, Europa, Ganymede and Callisto. Ganymede, Europa and Io participate in a 1:2:4 orbital resonance...

, which are comparable in size to Earth's Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

. The four inner moons are much smaller. The irregular
Irregular satellite
In astronomy, an irregular moon is a natural satellite following a distant, inclined, and often eccentric and retrograde orbit. They are believed to have been captured by their parent planet, unlike regular satellites, which form in situ....

 captured moons are shaded light gray when prograde and dark gray when retrograde
Retrograde motion
Retrograde motion is motion in the direction opposite to the movement of something else, and is the contrary of direct or prograde motion. This motion can be the orbit of one body about another body or about some other point, or the rotation of a single body about its axis, or other phenomena such...

.

Order
Order refers to the position among other moons with respect to their average distance from Jupiter.
Label
Label refers to the Roman numeral attributed to each moon in order of their discovery.
Name
Pronunciation
(key)
Image Diameter
(km)Diameters with multiple entries such as "60×40×34" reflect that the body is not a perfect spheroid
Spheroid
A spheroid, or ellipsoid of revolution is a quadric surface obtained by rotating an ellipse about one of its principal axes; in other words, an ellipsoid with two equal semi-diameters....

 and that each of its dimensions have been measured well enough.
( kg
Kilogram
The kilogram or kilogramme , also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram , which is almost exactly equal to the mass of one liter of water...

)
Semi-major axis
Semi-major axis
The major axis of an ellipse is its longest diameter, a line that runs through the centre and both foci, its ends being at the widest points of the shape...


(km)
Orbital period
Orbital period
The orbital period is the time taken for a given object to make one complete orbit about another object.When mentioned without further qualification in astronomy this refers to the sidereal period of an astronomical object, which is calculated with respect to the stars.There are several kinds of...


(d
Day
A day is a unit of time, commonly defined as an interval equal to 24 hours. It also can mean that portion of the full day during which a location is illuminated by the light of the sun...

)Periods with negative values are retrograde.
Inclination
Inclination
Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...


(°
Degree (angle)
A degree , usually denoted by ° , is a measurement of plane angle, representing 1⁄360 of a full rotation; one degree is equivalent to π/180 radians...

)
Eccentricity
Orbital eccentricity
The orbital eccentricity of an astronomical body is the amount by which its orbit deviates from a perfect circle, where 0 is perfectly circular, and 1.0 is a parabola, and no longer a closed orbit...


Discovery year
Discoverer
Group
"?" refers to group assignments that are not considered sure yet.
1 Metis
Metis (moon)
Metis , also known as ', is the innermost moon of Jupiter. It was discovered in 1979 in images taken by Voyager 1, and was named in 1983 after the first wife of Zeus, Metis...

 
ˈmiːtɨs
0.000 02 1979 Synnott
Stephen P. Synnott
Stephen P. Synnott is an American astronomer Voyager scientist who discovered several moons of Jupiter, Saturn, Uranus, and Neptune.He discovered Metis, Puck, Larissa , Proteus, and Thebe.-References:...


(Voyager 1
Voyager 1
The Voyager 1 spacecraft is a 722-kilogram space probe launched by NASA in 1977, to study the outer Solar System and eventually interstellar space. Operating for as of today , the spacecraft receives routine commands and transmits data back to the Deep Space Network. At a distance of as of...

)
Inner
2 Adrastea
Adrastea (moon)
Adrastea , also known as ', is the second by distance, and the smallest of the four inner moons of Jupiter. It was discovered in Voyager 2 probe photographs taken in 1979, making it the first natural satellite to be discovered from images taken by an interplanetary spacecraft, rather than...

 
ˌædrəˈstiːə
0.0015 1979 Jewitt
David C. Jewitt
David C. Jewitt is a professor of astronomy formerly at the University of Hawaii Institute for Astronomy, now at UCLA. He was born in 1958 in England, and is a 1979 graduate of the University of London. Jewitt received an M.Sc. and a Ph.D. in astronomy at the California Institute of Technology in...


(Voyager 2
Voyager 2
The Voyager 2 spacecraft is a 722-kilogram space probe launched by NASA on August 20, 1977 to study the outer Solar System and eventually interstellar space...

)
Inner
3 Amalthea
Amalthea (moon)
Amalthea is the third moon of Jupiter in order of distance from the planet. It was discovered on September 9, 1892, by Edward Emerson Barnard and named after Amalthea, a nymph in Greek mythology. It is also known as '....

 
ˌæməlˈθiːə
0.0032 1892 Barnard  Inner
4 Thebe
Thebe (moon)
Thebe also known as ', is the fourth of Jupiter's moons by distance from the planet. It was discovered by Stephen P. Synnott in images from the Voyager 1 space probe taken on March 5, 1979, while orbiting around Jupiter...

 
ˈθiːbiː
0.0175 1979 Synnott
(Voyager 1)
Inner
5 Io
Io (moon)
Io ) is the innermost of the four Galilean moons of the planet Jupiter and, with a diameter of , the fourth-largest moon in the Solar System. It was named after the mythological character of Io, a priestess of Hera who became one of the lovers of Zeus....

ˈaɪ.oʊ
0.0041 1610 Galilei
Galileo Galilei
Galileo Galilei , was an Italian physicist, mathematician, astronomer, and philosopher who played a major role in the Scientific Revolution. His achievements include improvements to the telescope and consequent astronomical observations and support for Copernicanism...

 
Galilean
6 Europa
Europa (moon)
Europa Slightly smaller than Earth's Moon, Europa is primarily made of silicate rock and probably has an iron core. It has a tenuous atmosphere composed primarily of oxygen. Its surface is composed of ice and is one of the smoothest in the Solar System. This surface is striated by cracks and...

jʊˈroʊpə
0.0094 1610 Galilei Galilean
7 Ganymede
Ganymede (moon)
Ganymede is a satellite of Jupiter and the largest moon in the Solar System. It is the seventh moon and third Galilean satellite outward from Jupiter. Completing an orbit in roughly seven days, Ganymede participates in a 1:2:4 orbital resonance with the moons Europa and Io, respectively...

ˈɡænɨmiːd 0.0011 1610 Galilei Galilean
8 Callisto
Callisto (moon)
Callisto named after the Greek mythological figure of Callisto) is a moon of the planet Jupiter. It was discovered in 1610 by Galileo Galilei. It is the third-largest moon in the Solar System and the second largest in the Jovian system, after Ganymede. Callisto has about 99% the diameter of the...

kəˈlɪstoʊ
0.0074 1610 Galilei Galilean
9 Themisto
Themisto (moon)
Themisto , also known as ', is a small prograde irregular satellite of Jupiter. It was discovered in 1975, lost, and then rediscovered in 2000.- Discovery and naming :...

 
θɨˈmɪstoʊ +129.87 0.2115 1975/2000 Kowal
Charles T. Kowal
Charles Thomas Kowal was an American astronomer.He discovered two moons of Jupiter: Leda in 1974 and Themisto in 1975, although the latter was lost and not rediscovered until 2000....

 & Roemer
Elizabeth Roemer
Elizabeth Roemer is an American astronomer whose research interests center on comets and asteroids.She discovered the asteroids 1930 Lucifer and 1983 Bok...

/
Sheppard
Scott S. Sheppard
Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and...

 et al.
Themisto
10 Leda
Leda (moon)
Leda , also known as ', is a prograde irregular satellite of Jupiter. It was discovered by Charles T. Kowal at the Mount Palomar Observatory on September 14, 1974, after three nights' worth of photographic plates had been taken...

 
ˈliːdə
11,187,781 +241.75 0.1673 1974 Kowal
Charles T. Kowal
Charles Thomas Kowal was an American astronomer.He discovered two moons of Jupiter: Leda in 1974 and Themisto in 1975, although the latter was lost and not rediscovered until 2000....

 
Himalia
Himalia group
The Himalia group is a group of prograde irregular satellites of Jupiter that follow similar orbits to Himalia and are thought to have a common origin.The known members of the group are :* Leda...

11 Himalia
Himalia (moon)
Himalia is the largest irregular satellite of Jupiter, the sixth largest overall in size, and the fifth largest in mass. It was discovered by Charles Dillon Perrine at the Lick Observatory on 3 December 1904 and is named after the nymph Himalia, who bore three sons of Zeus .- Discovery...

 
haɪˈmeɪliə
11,451,971 +250.37 0.1513 1904 Perrine
Charles Dillon Perrine
Charles Dillon Perrine was an American astronomer living in Argentina.Born in Steubenville, Ohio, a son of Peter and Elizabeth McCauley Perrine, and a descendant of Daniel Perrin, "The Huguenot", he worked at Lick Observatory from 1893 to 1909 and then was director of the Argentine National...

 
Himalia
Himalia group
The Himalia group is a group of prograde irregular satellites of Jupiter that follow similar orbits to Himalia and are thought to have a common origin.The known members of the group are :* Leda...

12 Lysithea
Lysithea (moon)
Lysithea is a prograde irregular satellite of Jupiter. It was discovered by Seth Barnes Nicholson in 1938 at Mount Wilson Observatory and is named after the mythological Lysithea, daughter of Oceanus and one of Zeus' lovers....

 
laɪˈsɪθiːə 11,740,560 +259.89 0.1322 1938 Nicholson
Seth Barnes Nicholson
Seth Barnes Nicholson was an American astronomer.Nicholson was born in Springfield, Illinois and was raised in rural Illinois...

 
Himalia
Himalia group
The Himalia group is a group of prograde irregular satellites of Jupiter that follow similar orbits to Himalia and are thought to have a common origin.The known members of the group are :* Leda...

13 Elara
Elara (moon)
Elara is a prograde irregular satellite of Jupiter. It was discovered by Charles Dillon Perrine at Lick Observatory in 1905. It is the eighth largest moon of Jupiter and is named after the mother by Zeus of the giant Tityus....

 
ˈɛlərə 11,778,034 +261.14 0.1948 1905 Perrine Himalia
Himalia group
The Himalia group is a group of prograde irregular satellites of Jupiter that follow similar orbits to Himalia and are thought to have a common origin.The known members of the group are :* Leda...

14 Carpo
Carpo (moon)
Carpo , also ', is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
ˈkɑrpoʊ 17,144,873 +458.62 0.2735 2003 Sheppard et al. Carpo
15 S/2003 J 12
S/2003 J 12
' is a natural satellite of Jupiter, and is the smallest known satellite in the Solar System. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
17,739,539 −482.69 142.680° 0.4449 2003 Sheppard et al. ?
16 Euporie
Euporie (moon)
Euporie , also known as ', is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
juːˈpɒrɨ.iː 19,088,434 −538.78 144.694° 0.0960 2002 Sheppard et al. Ananke
Ananke group
The Ananke group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Ananke and are thought to have a common origin....

17 S/2003 J 3
S/2003 J 3
' is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2003. is about 2 kilometres in diameter, and orbits Jupiter at an average distance of 19,622 Mm in 561.518 days, at an inclination of 146° to the ecliptic , in a...

 
19,621,780 −561.52 146.363° 0.2507 2003 Sheppard et al. Ananke
Ananke group
The Ananke group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Ananke and are thought to have a common origin....

18 S/2003 J 18
S/2003 J 18
' is a natural satellite of Jupiter. It was discovered by a team of astronomers led by Brett J. Gladman in 2003. is about 2 kilometres in diameter, and orbits Jupiter at an average distance of 19,813 Mm in 569.728 days, at an inclination of 147° to the ecliptic , in a retrograde direction and with...

 
19,812,577 −569.73 147.401° 0.1569 2003 Gladman et al. Ananke
Ananke group
The Ananke group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Ananke and are thought to have a common origin....

19 S/2010 J 2
S/2010 J 2
' is a natural satellite of Jupiter. It was discovered by Christian Veillet in 2010....

 
20,307,150 −588.1 150.4° 0.307 2010 Veillet Ananke
Ananke group
The Ananke group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Ananke and are thought to have a common origin....

?
20 Thelxinoe
Thelxinoe (moon)
Thelxinoe , also known as ', is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
θɛlkˈsɪnɵʊiː 20,453,753 −597.61 151.292° 0.2684 2003 Sheppard et al. Ananke
Ananke group
The Ananke group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Ananke and are thought to have a common origin....

21 Euanthe
Euanthe (moon)
Euanthe , also known as ', is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
juːˈænθiː 20,464,854 −598.09 143.409° 0.2000 2002 Sheppard et al. Ananke
Ananke group
The Ananke group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Ananke and are thought to have a common origin....

22 Helike
Helike (moon)
Helike , also known as ', is a moon of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2003, and given the temporary designation '....

 
ˈhɛlɨkiː 20,540,266 −601.40 154.586° 0.1374 2003 Sheppard et al. Ananke
Ananke group
The Ananke group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Ananke and are thought to have a common origin....

23 Orthosie
Orthosie (moon)
Orthosie , also known as ', is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
ɔrˈθɒsɨ.iː 20,567,971 −602.62 142.366° 0.2433 2002 Sheppard et al. Ananke
Ananke group
The Ananke group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Ananke and are thought to have a common origin....

24 Iocaste
Iocaste (moon)
Iocaste , also known as ', is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
ˌaɪ.ɵˈkæstiː 20,722,566 −609.43 147.248° 0.2874 2001 Sheppard et al. Ananke
Ananke group
The Ananke group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Ananke and are thought to have a common origin....

25 S/2003 J 16
S/2003 J 16
' is a natural satellite of Jupiter. It was discovered by a team of astronomers led by Brett J. Gladman in 2003. is about 2 kilometres in diameter, and orbits Jupiter at an average distance of 20,744 Mm in 610.362 days, at an inclination of 151° to the ecliptic , in a retrograde direction and with...

 
20,743,779 −610.36 150.769° 0.3184 2003 Gladman et al. Ananke
Ananke group
The Ananke group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Ananke and are thought to have a common origin....

26 Praxidike
Praxidike (moon)
Praxidike , also known as ', is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
prækˈsɪdɨkiː 20,823,948 −613.90 144.205° 0.1840 2001 Sheppard et al. Ananke
Ananke group
The Ananke group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Ananke and are thought to have a common origin....

27 Harpalyke
Harpalyke (moon)
Harpalyke , also known as ', is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2000, and given the temporary designation '...

 
hɑrˈpælɨkiː 21,063,814 −624.54 147.223° 0.2440 2001 Sheppard et al. Ananke
Ananke group
The Ananke group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Ananke and are thought to have a common origin....

28 Mneme
Mneme (moon)
Mneme , also known as ', is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard, et al...

 
ˈniːmiː 21,129,786 −627.48 149.732° 0.3169 2003 Gladman
Brett J. Gladman
Brett J. Gladman is a Canadian astronomer and a full professor at the University of British Columbia's Department of Physics and Astronomy in Vancouver, British Columbia. He holds the Canada Research Chair in Planetary Astronomy.-Career:...

 et al.
Ananke
Ananke group
The Ananke group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Ananke and are thought to have a common origin....

29 Hermippe
Hermippe (moon)
Hermippe , or ', is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
hərˈmɪpiː 21,182,086 −629.81 151.242° 0.2290 2002 Sheppard et al. Ananke
Ananke group
The Ananke group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Ananke and are thought to have a common origin....

?
30 Thyone
Thyone (moon)
Thyone , also known as ', is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard, et al...

 
θaɪˈoʊniː 21,405,570 −639.80 147.276° 0.2525 2002 Sheppard et al. Ananke
Ananke group
The Ananke group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Ananke and are thought to have a common origin....

31 Ananke
Ananke (moon)
Ananke is a retrograde irregular satellite of Jupiter. It was discovered by Seth Barnes Nicholson at Mount Wilson Observatory in 1951 and is named after the mythological Ananke, the personification of Necessity, and the mother of the Moirae by Zeus...

 
əˈnæŋkiː 21,454,952 −642.02 151.564° 0.3445 1951 Nicholson Ananke
Ananke group
The Ananke group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Ananke and are thought to have a common origin....

32 Herse  ˈhɜrsiː 22,134,306 −672.75 162.490° 0.2379 2003 Gladman et al. Carme
Carme group
The Carme group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Carme and are thought to have a common origin....

33 Aitne
Aitne (moon)
Aitne , also known as ', is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard, et al. in 2001, and given the temporary designation '...

 
ˈaɪtniː 22,285,161 −679.64 165.562° 0.3927 2002 Sheppard et al. Carme
Carme group
The Carme group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Carme and are thought to have a common origin....

34 Kale
Kale (moon)
Kale , also known as ', is a retrograde irregular satellite of Jupiter. It was discovered in 2001 by astronomers S. Sheppard, D. Jewitt, and J...

 
ˈkeɪliː 22,409,207 −685.32 165.378° 0.2011 2002 Sheppard et al. Carme
Carme group
The Carme group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Carme and are thought to have a common origin....

35 Taygete
Taygete (moon)
Taygete , also known as ', is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
teɪˈɪdʒɨtiː 22,438,648 −686.67 164.890° 0.3678 2001 Sheppard et al. Carme
Carme group
The Carme group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Carme and are thought to have a common origin....

36 S/2003 J 19
S/2003 J 19
' is a natural satellite of Jupiter. It was discovered by a team of astronomers led by Brett J. Gladman, et al. in 2003. is about 2 kilometres in diameter, and orbits Jupiter at an average distance of 22,709 Mm in 699.125 days, at an inclination of 165° to the ecliptic , in a retrograde direction...

 
22,709,061 −699.12 164.727° 0.1961 2003 Gladman et al. Carme
Carme group
The Carme group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Carme and are thought to have a common origin....

37 Chaldene
Chaldene (moon)
Chaldene , also known as ', is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
kælˈdiːniː 22,713,444 −699.33 167.070° 0.2916 2001 Sheppard et al. Carme
Carme group
The Carme group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Carme and are thought to have a common origin....

38 S/2003 J 15
S/2003 J 15
' is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard, et al. in 2003....

 
22,720,999 −699.68 141.812° 0.0932 2003 Sheppard et al. Ananke
Ananke group
The Ananke group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Ananke and are thought to have a common origin....

?
39 S/2003 J 10
S/2003 J 10
' is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard et al. in 2003....

 
22,730,813 −700.13 163.813° 0.3438 2003 Sheppard et al. Carme
Carme group
The Carme group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Carme and are thought to have a common origin....

?
40 S/2003 J 23
S/2003 J 23
' is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard et al. in 2004 from pictures taken in 2003....

 
22,739,654 −700.54 148.849° 0.3930 2004 Sheppard et al. Pasiphaë
Pasiphaë group
The Pasiphaë group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Pasiphaë and are thought to have a common origin....

41 Erinome
Erinome (moon)
Erinome , also known as ', is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
ɨˈrɪnɵmiː 22,986,266 −711.96 163.737° 0.2552 2001 Sheppard et al. Carme
Carme group
The Carme group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Carme and are thought to have a common origin....

42 Aoede
Aoede (moon)
Aoede , also known as ', is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2003...

 
eɪˈiːdiː 23,044,175 −714.66 160.482° 0.6011 2003 Sheppard et al. Pasiphaë
Pasiphaë group
The Pasiphaë group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Pasiphaë and are thought to have a common origin....

43 Kallichore
Kallichore (moon)
Kallichore , also known as ', is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard, et al. in 2003...

 
kəˈlɪkɵriː 23,111,823 −717.81 164.605° 0.2041 2003 Sheppard et al. Carme
Carme group
The Carme group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Carme and are thought to have a common origin....

?
44 Kalyke
Kalyke (moon)
Kalyke , also known as ', is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
ˈkælɨkiː 23,180,773 −721.02 165.505° 0.2139 2001 Sheppard et al. Carme
Carme group
The Carme group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Carme and are thought to have a common origin....

45 Carme
Carme (moon)
Carme is a retrograde irregular satellite of Jupiter. It was discovered by Seth Barnes Nicholson at Mount Wilson Observatory in California in July 1938. It is named after the mythological Carme, mother by Zeus of Britomartis, a Cretan goddess....

 
ˈkɑrmiː 23,197,992 −721.82 165.047° 0.2342 1938 Nicholson Carme
Carme group
The Carme group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Carme and are thought to have a common origin....

46 Callirrhoe
Callirrhoe (moon)
Callirrhoe , also known as ' , is one of Jupiter's outermost named natural satellites. It is an irregular moon that orbits in a retrograde direction. Callirrhoe was imaged by Spacewatch at Kitt Peak National Observatory from October 6 through November 4, 1999, and originally designated as asteroid...

 
kəˈlɪrɵʊiː 23,214,986 −722.62 139.849° 0.2582 2000 Spahr, Scotti Pasiphaë
Pasiphaë group
The Pasiphaë group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Pasiphaë and are thought to have a common origin....

47 Eurydome
Eurydome (moon)
Eurydome , also known as ', is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
jʊˈrɪdəmiː 23,230,858 −723.36 149.324° 0.3769 2002 Sheppard et al. Pasiphaë
Pasiphaë group
The Pasiphaë group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Pasiphaë and are thought to have a common origin....

?
48 Pasithee
Pasithee (moon)
Pasithee , also known as ', is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
pəˈsɪθɨ.iː 23,307,318 −726.93 165.759° 0.3288 2002 Sheppard et al. Carme
Carme group
The Carme group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Carme and are thought to have a common origin....

49 S/2010 J 1
S/2010 J 1
' is a natural satellite of Jupiter. It was discovered by R. Jacobson, M. Brozovic, B. Gladman, and M. Alexandersen in 2010....

 
23,314,335 −723.2 163.2° 0.320 2010 Jacobson et al. Pasiphaë
Pasiphaë group
The Pasiphaë group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Pasiphaë and are thought to have a common origin....

?
50 Kore  ˈkɔəriː 23,345,093 −776.02 137.371° 0.1951 2003 Sheppard et al. Pasiphaë
Pasiphaë group
The Pasiphaë group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Pasiphaë and are thought to have a common origin....

51 Cyllene
Cyllene (moon)
Cyllene , also known as ', is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
sɨˈliːniː 23,396,269 −731.10 140.148° 0.4115 2003 Sheppard et al. Pasiphaë
Pasiphaë group
The Pasiphaë group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Pasiphaë and are thought to have a common origin....

52 Eukelade
Eukelade (moon)
Eukelade , also known as ', is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
juːˈkɛlədiː 23,483,694 −735.20 163.996° 0.2828 2003 Sheppard et al. Carme
Carme group
The Carme group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Carme and are thought to have a common origin....

53 S/2003 J 4
S/2003 J 4
' is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2003. is about 2 km in diameter, and orbits Jupiter at an average distance of 23,571 Mm in 739.294 days, at an inclination of 147° to the ecliptic , in a...

 
23,570,790 −739.29 147.175° 0.3003 2003 Sheppard et al. Pasiphaë
Pasiphaë group
The Pasiphaë group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Pasiphaë and are thought to have a common origin....

54 Pasiphaë
Pasiphaë (moon)
Pasiphaë is a retrograde irregular satellite of Jupiter. It was discovered in 1908 by Philibert Jacques Melotte and later named after the mythological Pasiphaë, wife of Minos and mother of the Minotaur from Greek legend....

 
pəˈsɪfeɪ.iː 23,609,042 −741.09 141.803° 0.3743 1908 Melotte
Philibert Jacques Melotte
Philibert Jacques Melotte was a British astronomer whose parents immigrated from Belgium.In 1908 he discovered a moon of Jupiter, today known as Pasiphaë. It was simply designated "Jupiter VIII" and was not given its present name until 1975.The asteroid 676 Melitta, the only one he discovered, is...

 
Pasiphaë
Pasiphaë group
The Pasiphaë group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Pasiphaë and are thought to have a common origin....

55 Hegemone
Hegemone (moon)
Hegemone , also known as ', is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
hɨˈdʒɛməniː 23,702,511 −745.50 152.506° 0.4077 2003 Sheppard et al. Pasiphaë
Pasiphaë group
The Pasiphaë group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Pasiphaë and are thought to have a common origin....

56 Arche
Arche (moon)
Arche , also known as ', is a moon of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2002, and received the temporary designation '....

 
ˈɑrkiː 23,717,051 −746.19 164.587° 0.1492 2002 Sheppard et al. Carme
Carme group
The Carme group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Carme and are thought to have a common origin....

57 Isonoe
Isonoe (moon)
Isonoe , also known as ', is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
aɪˈsɒnɵʊiː 23,800,647 −750.13 165.127° 0.1775 2001 Sheppard et al. Carme
Carme group
The Carme group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Carme and are thought to have a common origin....

58 S/2003 J 9
S/2003 J 9
' is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2003....

 
23,857,808 −752.84 164.980° 0.2761 2003 Sheppard et al. Carme
Carme group
The Carme group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Carme and are thought to have a common origin....

59 S/2003 J 5
S/2003 J 5
' is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2003....

 
23,973,926 −758.34 165.549° 0.3070 2003 Sheppard et al. Carme
Carme group
The Carme group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Carme and are thought to have a common origin....

60 Sinope
Sinope (moon)
Sinope is a retrograde irregular satellite of Jupiter discovered by Seth Barnes Nicholson at Lick Observatory in 1914, and is named after Sinope of Greek mythology....

 
sɨˈnoʊpiː 24,057,865 −762.33 153.778° 0.2750 1914 Nicholson Pasiphaë
Pasiphaë group
The Pasiphaë group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Pasiphaë and are thought to have a common origin....

61 Sponde
Sponde (moon)
Sponde , also known as ', is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
ˈspɒndiː 24,252,627 −771.60 154.372° 0.4431 2002 Sheppard et al. Pasiphaë
Pasiphaë group
The Pasiphaë group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Pasiphaë and are thought to have a common origin....

62 Autonoe
Autonoe (moon)
Autonoe , also known as ', is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
ɔːˈtɒnɵʊiː 24,264,445 −772.17 151.058° 0.3690 2002 Sheppard et al. Pasiphaë
Pasiphaë group
The Pasiphaë group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Pasiphaë and are thought to have a common origin....

63 Megaclite
Megaclite (moon)
Megaclite , also known as ', is a natural satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S...

 
ˌmɛɡəˈklaɪtiː 24,687,239 −792.44 150.398° 0.3077 2001 Sheppard et al. Pasiphaë
Pasiphaë group
The Pasiphaë group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Pasiphaë and are thought to have a common origin....

64 S/2003 J 2
S/2003 J 2
' is a retrograde irregular satellite of Jupiter. The discovery, by a team of astronomers from the University of Hawaii led by Scott S. Sheppard and David C. Jewitt, was announced on March 4, 2003...

 
30,290,846 153.521° 0.1882 2003 Sheppard et al. ?


Another moon-like object, S/2000 J 11
S/2000 J 11
S/2000 J 11 was an object believed to be the second-outermost prograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2000....

, was discovered in 2000 by Sheppard et al., but it has gone missing and is now no longer considered a moon candidate.
Name
Diameter
(km)
( kg
Kilogram
The kilogram or kilogramme , also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram , which is almost exactly equal to the mass of one liter of water...

)
Semi-major axis
Semi-major axis
The major axis of an ellipse is its longest diameter, a line that runs through the centre and both foci, its ends being at the widest points of the shape...


(km)
Orbital period
Orbital period
The orbital period is the time taken for a given object to make one complete orbit about another object.When mentioned without further qualification in astronomy this refers to the sidereal period of an astronomical object, which is calculated with respect to the stars.There are several kinds of...


(d
Day
A day is a unit of time, commonly defined as an interval equal to 24 hours. It also can mean that portion of the full day during which a location is illuminated by the light of the sun...

)
Inclination
Inclination
Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...


(°
Degree (angle)
A degree , usually denoted by ° , is a measurement of plane angle, representing 1⁄360 of a full rotation; one degree is equivalent to π/180 radians...

)
Eccentricity
Orbital eccentricity
The orbital eccentricity of an astronomical body is the amount by which its orbit deviates from a perfect circle, where 0 is perfectly circular, and 1.0 is a parabola, and no longer a closed orbit...


Discovery year
Discoverer
Group
S/2000 J 11
S/2000 J 11
S/2000 J 11 was an object believed to be the second-outermost prograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2000....

 
12 570 424 +287.93 0.2058 2001 Sheppard et al. Himalia
Himalia group
The Himalia group is a group of prograde irregular satellites of Jupiter that follow similar orbits to Himalia and are thought to have a common origin.The known members of the group are :* Leda...

?

External links