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Jupiter Facts

Data and Comparison

5th planet from the Sun
Atmosphere Composition
hydrogen: 74.9% ; helium 23.8%
Average Orbit Velocity
47,002 km/h or 29,205 mph
Earth is more than double the velocity.
Density
1.326 g/cm3
Earth is about 4 times more dense.
Diameter (average)
139,822 km or 86,881 miles
About 11 times more than Earth.
Distance from Sun
778,340,821 km or 483,638,564 miles
About 5 times further than Earth.
Discovered Date
Unknown
Discovered by
Unknown
Equatorial Circumference
439,263.8 km or 272,945.9 miles
About 11 times larger than Earth.
Equatorial Inclination to Orbit (axial tilt)
3.1°
Galilean Moons
Io, Europa, Ganymede and Callisto
Discovered by Galileo Galilee in 1610.
Gas (Jovian) Planet
Great Red Spot
Giant storm which has been going on for hundreds of years.
About 3 times the size of Earth.
Largest moon
Ganymede
Larger than the planet Mercury.
Largest planet in the solar system
In terms of mass, diameter, volume and surface area
Mass
1.898130 x 1027 kg or 1,898,130,000,000,000,000,000,000,000 kg
About 318 times more than Earth.
Number of Moons
67
Planet Jupiter

Planet Jupiter

Number of Rings
3
Orbit Circumference
4,887,595,931 km or 3,037,011,311 miles
About 5 times larger than Earth.
Orbit Eccentricity
0.04838624
Almost 3 times more than Earth.
Orbit Inclination
1.304°
Surface Area
61,418,738,571 km2 or 23,713,907,537 mi2
About 120 times larger than Earth.
Surface Gravity
24.79 m/s2 or 81.3 ft/s2
If you weigh 150 pounds on Earth, then you would weigh 380 pounds on Jupiter.
Temperature
-148°C or -234°F
Several times more colder than the coldest parts of the Earth.
Time for 1 orbit around the Sun
4,332.82 Earth days
Almost 12 Earth years.
Time for 1 full rotation (day length)
9.92496 hours
Less than half an Earth day.
Volume
1,431,281,810,739,360 km3 or 343,382,767,518,322 mi3
About 1321 times larger than Earth.

General Information & History

Jupiter is the fifth planet from the Sun and the largest planet in the Solar System. The Jovian system is made up of Jupiter and the many moons orbiting it. To date, 67 of these satellites have been discovered.

Jupiter is one of five planets that can be seen by the naked eye (Mercury, Venus, Mars and Saturn are the other four); in fact, it is the second brightest planet after Venus. In terms of visibility, Jupiter is a night planet. It is best seen from dusk until the early morning. Its location however varies with the time of year, day and time. The best way to locate the planet is to determine its relative position from the constellations and stars. For example, in the beginning of 2013, Jupiter was visible in the southeastern night sky near the star Aldebaran in the constellation of Taurus where it can be seen until the end of May. The Sun's glare will mask Jupiter from late May until the middle of July, after which it will become visible again as it enters the constellation Gemini just north of Orion. Throughout the rest of 2013 and until mid-2014, Jupiter will travel through Gemini and can be observed southwest of its two brightest stars Castor and Pollux.

Jupiter appears brightest in the night sky when it reaches opposition to the Sun. It is also during this period when it is closest to the Earth. This happens, on average, every 398.9 days. The last time this occurred was on December 3, 2012.

It is unclear when Jupiter was first noticed by humans. The earliest record of the planet was found in ancient Babylonian texts from 800 to 700 BC in which Babylonian astronomers called it Marduk, after the Mesopotamian god and patron deity of the city of Babylon during the Hammurabi period (1800 BC). The planet was later referred to as Zeus by the ancient Greeks and Jupiter by the Romans.

On January 7, 1610, the astronomer Galileo Galilee trained his telescope on Jupiter and was the first person to observe the planet's four largest moons: Io, Europa, Ganymede and Callisto. These four moons are also called Galilean satellites after their discoverer. In 1664, the English physicist Robert Hooke was the first to notice a big red spot on Jupiter's surface. This spot later became known as the Great Red Spot and is still visible to this day, which makes it at least 350 years old.

Nothing more was learned about Jupiter until The United States' National Aeronautics and Space Administration (NASA) launched several spacecraft missions to the planet and beyond starting in the 1970s. Its first mission to Jupiter was launched in March 1972 with the spacecraft Pioneer 10. Pioneer 10 was the first man-made object to cross the asteroid belt and also the first one to take images of Jupiter, which it accomplished on November 6, 1973. In April 1973, NASA launched Pioneer 11, which arrived in Jupiter's vicinity on September 1979. The spacecraft sent back the first detailed and close-up photographs of Jupiter's Great Red Spot. In 1977, two spacecrafts were launched to study Jupiter and its many moons: Voyager 2 in August followed by Voyager 1 in September. The two missions sent back photographs that revealed that, among other things, the Great Red Spot was actually a complex storm of gases and that the Jovian moon Io had many active volcanos on its surface. The Voyager 1 spacecraft also discovered faint rings surrounding the planet. In December 1995, the spacecraft Galileo arrived in Jupiter. Unlike its predecessors, which only orbited the planet, Galileo had a probe as well as being an orbiter. The probe was dropped into Jupiter to study its atmosphere while the orbiter continued research into Jupiter's moons. Galileo was also the only spacecraft that had a direct view of Jupiter when the comet Shoemaker-Levy crashed into the planet in 1994. The spacecraft's mission was concluded in September 2003. NASA's latest mission to Jupiter, named Juno, was launched in August 2011. It will study how the planet formed by investigating its atmospheric structure and measuring its gravity field and magnetic field. The spacecraft is expected to arrive at its destination in July 2016.

Discovery

Jupiter and Venus from Earth
Jupiter and Venus from Earth

It is unknown who discovered Jupiter. This is because Jupiter at times can be seen by the naked eye (no telescope needed). Jupiter is the 2nd brightest planet in the night sky (Venus is 1st).

The earliest record of the planet was found in ancient Babylonian texts from 800 to 700 BC in which Babylonian astronomers called it Marduk, after the Mesopotamian god and patron deity of the city of Babylon during the Hammurabi period (1800 BC). The planet was later referred to as Zeus by the ancient Greeks and Jupiter by the Romans.

On January 7, 1610, the astronomer Galileo Galilee trained his telescope on Jupiter and was the first person to observe the planet's four largest moons: Io, Europa, Ganymede and Callisto. These four moons are also called Galilean satellites after their discoverer. In 1664, the English physicist Robert Hooke was the first to notice a big red spot on Jupiter's surface. This spot later became known as the Great Red Spot and is still visible to this day, which makes it at least 350 years old.

The image on the right was taken by Marek Nikodem on March 18, 2012 outside Szubin, Poland. In the photo, Jupiter is at the left hand and Venus is at the right hand of the person.

Gravity

Comet Shoemaker-Levy 9 collision with Jupiter
Brown spots show the collision
from Comet Shoemaker-Levy 9

Jupiter’s surface gravity is 24.79 m/s2 or 81.3 ft/s2. It is 2.4 times more than Earth’s, so if you weigh 100 pounds on Earth then you would weigh 240 pounds on Jupiter. Its gravity is so strong that the escape velocity is 216,720 km/h or 134,664 mph (5.38 times more than Earth’s).

Jupiter being the most massive with the highest gravity than any other planet in our solar system helps give it the reputation as being the “vacuum cleaner” of our solar system. This is because space objects like comets and asteroids that are unstable which could even collide with Earth or other planets can get a change in direction or even pulled into Jupiter due to its great mass and gravitational pull. A matter of fact for about 7 days from July 16 through July 22, 1994, at least 21 pieces with diameters of about 2 km of an object known as “Comet Shoemaker-Levy 9” collided with Jupiter from its superior gravitational pull.





Mass & Size

Jupiter's size can be described in four different ways: by mass, diameter, volume and surface area. Any one of this would still make Jupiter the largest planet in the Solar System. At 1.43 x 1015 km3 (3.43 x 1014 mi3), its volume is 1321 times that of the Earth. Its surface area 6.14 x 1010 km2 or 2.37 x 1010 mi2 is 120.4 times larger than the Earth and its diameter at the equator (142,984 km or 88,846 mi) is 11 times wider than the Earth; in fact, the Great Red Spot alone is three times the diameter of the Earth. Jupiter is also the heaviest planet in the Solar System with a mass of 1.898 x 1027 kg, which is about 318 times greater than the Earth. If the masses of all the other planets in the Solar System were added up, Jupiter would still be 2.5 times heavier.

Jupiter compared to Earth
Jupiter compared to Earth

Because of its composition (mainly hydrogen), Jupiter would be considered a star, not a planet, if it were 80 times larger than it is now. That's because it would need to be that much more massive to be able to compress and produce enough heat to ignite hydrogen fusion, which is the nuclear fusion process that generates a star's energy. Compared to the Sun, the Solar System's star, Jupiter is only one-tenth its diameter and 0.001 times its mass. It is, however, only 30% smaller than the smallest red dwarf, which is a kind of star that has a very low mass. Because of these similarities, Jupiter can actually be considered as either a very large planet or a star that failed to form.

Despite its massive size, Jupiter is actually shrinking by 2 cm (0.78 in) each year. In fact, its diameter is currently half what it was when it first formed. Jupiter generates a lot of internal heat that is believed to come from residual heat left by the collapse of the primordial nebula when the Solar System formed. The planet radiates 1.6 times more energy than it receives from the Sun. Although the amount of interior heat it generates is equal to the amount of heat it receives from the Sun, additional heat is believed to be radiated by a process known as the Kelvin–Helmholtz mechanism. This mechanism explains what occurs when the surface of a planet or a star cools. As the temperature goes down, the pressure also drops, which causes the planet to contract as a result. This compression, in turn, causes the planet's core to heat up. Jupiter and Saturn are two planets that exhibit the Kelvin–Helmholtz mechanism, but it is believed that Jupiter radiates more heat through this mechanism than it receives from the Sun, whereas the same may not be true of Saturn. Brown dwarfs, which are astronomical objects whose masses are too small to be a star and whose core temperatures are not high enough to sustain hydrogen fusion, also exhibit the Kelvin–Helmholtz mechanism.

Jupiter's size is believed to be as big as it can possibly be in terms of diameter based on its composition and the history of its formation. If the planet were heavier than it is now, it would shrink considerably. This is because the additional mass would result in an increase in gravitational force that would cause the interior to become much more compressed. This compression would result in a decrease in the planet's volume, even with the additional mass.

Jupiter is not the largest planet known to exist. That distinction goes to WASP-17b, which can be found orbiting the star WASP-17 in the constellation Scorpius 1,000 light years from Earth. The discovery of this extrasolar planet (meaning it lies outside the Solar System) was announced in 2009. Although its radius is about twice as wide, its mass is only half that of Jupiter.

Diameter/Radius of Jupiter

Jupiter Diameter Compared To Earth
Jupiter Diameter Compared To Earth

The average diameter of Jupiter is 139,822 km or 86,881 miles (radius 69,911 km or 43,440 miles). The reason why it is an average is because the diameter/radius is not exactly the same when measured from all end points. The diameter of Jupiter’s equator is 142,984 km or 88,846 miles (radius 71,492 km or 44,423 miles). The diameter when measured from pole to pole is 133,708 or 83,082 miles (radius 66,854 km or 41,541 miles). It is the quick rotation of Jupiter (9 hours and 55 and half minutes for full rotation) which causes this widening at the equator.

When compared to the Earth’s average diameter (12,742 km or 7,917 miles), Jupiter’s average diameter/radius is 10.97 times larger. Jupiter’s equator diameter is 11.21 times larger than Earth’s equator diameter (12,756.2 km or 7,926 miles). Jupiter’s pole to pole diameter is 10.52 times larger than Earth’s pole to pole diameter (12,713.6 km or 7,900 miles).

Atmosphere & Interior

Despite its massive size, Jupiter is called a gas giant because it is made up primarily of gases. Jupiter's atmosphere is comprised mostly of hydrogen and helium—similar to the Sun and at roughly the same proportions of 74.9% and 23.8%, respectively. Small amounts of methane (0.3%), ammonia (0.03%), hydrogen sulfide and water have also been detected. Spectroscopic studies have also revealed traces of hydrogen deuteride (HD), ethane (C2H6), ethyne (C2H2) phosphine (PH3), carbon monoxide (CO) and germane (GeH4).

Surface

An illustration of what Jupiter's surface may look like
An illustration if Jupiter's surface looked like an ocean

Although Jupiter’s surface area is a massive 61,418,738,571 km2 or 23,713,907,537 mi2 (120.414 times Earth’s surface area), Jupiter does not have a firm surface as we are accustomed to here on Earth. So where would you stand? Maybe the question should be where would you fly or swim? This is because the colors we see when observing Jupiter are its clouds (upper gaseous layers) which are mainly composed of Hydrogen. But then as you probe beneath the clouds you would reach liquid hydrogen. And if you probe further you would get to metallic hydrogen. Then lastly you would reach the core which may be solid (rocky). But good luck getting there since the enormous pressure and temperature (cold and hot) would be unbearable for any living organism.

Some believe underneath the clouds, Jupiter’s surface may look like a giant ocean with violent storms. The image on the right is an illustration.



Temperature

Temperature of Jupiter from core to the upper atmosphere
Temperature range of Jupiter.

The temperature of Jupiter is -148°C or -234°F in its upper atmosphere (top of the clouds). However the temperature increases as you approach the core of the planet. As you start moving below the clouds and hit a point where the atmospheric temperature is 10 times Earth’s, the temperature increases to 70°F or 21°C (similar to room temperature for us on Earth). As you move further in and reach the core, the temperature can be as high 43,000°F or 23,871°C (more than 4 times Earth’s core temperature).












Orbit & Rotation

Jupiter Orbit compared to Earth
Jupiter Orbit compared to Earth.

It was Claudius Ptolemy, the Greco-Roman astronomer that lived the 2nd century AD, who first calculated Jupiter's orbital period. In his astronomical and mathematical treatise Almagest, Ptolemy determined that Jupiter took 11.86 years (or 4,332.38 days) to orbit around the Earth. Ptolemy was a proponent of the geocentric model in astronomy, which held the view that the Earth was the center of the universe and all celestial bodies orbited around it. Aryabhata, an Indian mathematician and astronomer, also calculated Jupiter's orbital period at 11.86 years (or 4,332.27 days) in 499 AD using the geocentric model. It was not until the 16th century when the geocentric model was challenged by Nicolaus Copernicus, who presented a mathematical model of a heliocentric system in which the Sun was the center of the Solar System and the Earth and other planets orbited it. Regardless of this change in view, Ptolemy's calculation of Jupiter's orbital period were later proven accurate, although this time it would be the Sun that Jupiter orbited.

Jupiter orbits the sun at an average velocity of 47,002 km/h (29,205 mi/h). This makes it less than half (0.438 times) the Earth's orbital velocity. So the Earth actually overtakes Jupiter every 399 days. Jupiter's orbit size around the Sun is a little over 778 million kilometers wide (483 million miles), which makes it 5.2 times wider than the Earth's. Its orbital circumference is 4.88 billion kilometers (3.03 billion miles) long, 5.2 times longer than the Earth's. Along this orbital path, the closest that Jupiter comes to the Sun (perihelion) is at a distance of 740, 679, 835 km (460, 236, 112 mi), while its farthest distance (aphelion) is 816,001,807 km (507,040,015 miles).

Jupiter's rotational axis tilts at an angle of 3.13°. This is relatively small compared to the Earth's 23.44°, which is the reason why there are no significant changes in Jupiter's seasons compared to the seasonal changes experienced by Earth or even Mars.

Jupiter completes one rotation on its axis in 9.925 h or 9h 55m 29.71s, the fastest of all planets in the Solar System and despite its large size. This value is based on a calculation of Jupiter's interior rotation, which is based on the rotation of its magnetic field. Its atmospheric cloud, on the other hand, rotates faster than the interior. Because Jupiter is a gaseous planet, its atmosphere exhibits differential rotation, that is, the rate of rotation varies with latitude. Toward the poles, the planet completes one rotation in 9h 55m 40.6s, whereas along the equator the rate of rotation is 9h 50m 30s. These differing rotations are designated as Systems I, II and III. System I applies to the equatorial rotation at latitudes from 10°N to 10°S; System II applies to latitudes outside of System I including at the poles; and System III applies to the interior rotation (9h 55m 29.71s), which is designated as the official rotation of Jupiter.

As a result of its very rapid rotation, Jupiter's shape is noticeably flat at the poles and bulging at the equator resulting in an oblate spheroidal planet. This can be seen even with a simple telescope. Jupiter's diameter at the equator of 142,984 km (88,846 mi) is 6% larger than the polar diameter (diameter from pole to pole).

Differential rotation does not occur on terrestrial planets such as the Earth, but it is normal in gaseous or fluid objects like Jupiter. Jupiter's atmosphere is comprised mostly of hydrogen and some helium. However, very little is known about the planet's composition beneath the atmosphere. Jupiter's equatorial bulge reveals one important clue: if the planet's interior were composed of only hydrogen and helium (gases), then the planet would have a greater bulge along the equator and more flattened poles. Because this is not the case, then it is probable that Jupiter has a dense and rocky core that could be 10 to 20 times the mass of the Earth.

Moons

Since the discovery of Jupiter's four largest moons (satellites) in 1610 by Galileo Galilee, the number of discovered moons orbiting Jupiter has continued to increase. When an astronomer discovers a new moon orbiting Jupiter, it is reported to the International Astronomical Union, which gives it a temporary name until its orbit is confirmed. Once confirmed, the moon is given an appropriate name and added to the list of officially recognized moons. There are currently 50 of such officially named moons (satellites) with another 17 "temporary" moons (satellites) awaiting orbit confirmation.

An illustration of Jupiter's 4 Galilean moons.
An illustration of the 4 Galilean moons.

Jupiter's four largest moons are Io, Europa, Ganymede and Callisto. Their discovery provided the crucial evidence that planets in the Solar System orbit the Sun rather than the Earth. It was also the first time that a moon was discovered orbiting a planet other than the Earth.

Galileo's journal discovering the 4 moons
Galileo's journal








IO

Jupiter's moon IO
Jupiter's moon IO

IO was discovered on January 8, 1610 by Galileo Galilei. Galileo originally named IO “Jupiter l” (number 1) since he just used numerical values 1 to 4 for the moons. It wasn’t until about 250 years later that the moon “Jupiter l” was named IO, which was named from Greek mythology.

IO’s distinctive characteristic in our solar system is its volcanic activity. Just to give you a sense of how volatile it is, imagine the Earth’s ocean with waves as high as 100m (328 ft), but wait, imagine that happening with a solid surface. That is what is occurring on IO due to the moons Europa and Ganymede causing IO to orbit in an irregular orbit around Jupiter.

IO is the 3rd largest moon of Jupiter with a diameter of 3,643.2 km (2,264 mi) which is 1.05 times larger than Earth’s moon. The volume is 25,319,064,907 km3 (6,074,366,681 mi3) which is 1.15 times more than Earth’s moon. The surface area is 41,698,064.74 km2 (16,099,712.8 mi2) which is 1.1 times more than Earth’s moon. The mass is 8.9319 x 1022 kg which is 1.22 times more than Earth’s moon.

IO Moon's area Tvashtar Catena
IO's Tvashtar Catena area

IO is the 5th moon from Jupiter with an average orbit distance of 421,800 km (262,094 miles) which is 1.1 times farther than Earth and its moon. The closest (Perigee) point during IO’s orbit is 420,071 km (261,020 miles) and farthest (Apogee) is 423,529 km (263,169 miles). The orbit inclination to ecliptic (orbit angle relative to Jupiter’s equator) is 0.036° with an orbit eccentricity (amount of deviation from a perfect circle) of 0.0041. IO’s orbital period (time for 1 trip around Jupiter) is 1.769 Earth days travelling at a velocity of 62,423.1 km/h (38788 mph) and has the exact same rotation period (time for 1 rotation) of 1.769 Earth days. This is the reason why the same side of IO always faces Jupiter. To visualize this, just hold your arm straight in front of you with a ball in your hand and make a full turn in 1 spot. Obviously the same side of ball will always be facing you since for every degree you turn, then so does the ball. It must also be noted that during IO’s orbit is crosses Jupiter’s powerful magnetic force in that time 66 tons of IO’s material is stripped away every minute. Some of this material goes to Jupiter and creates auroras.

IO has a surface gravity of 1.796 m/s2 (5.89 ft/s2) which is slightly more than Earth’s Moon surface gravity. That means it would take about 5.8 seconds to drop a solid ball from a 10 story building, where on Earth it would be about 2.5 seconds. IO’s escape velocity is 8,552 km/h (5,314 mph) which is the same as Earth’s moon escape velocity.

IO has a great variance of temperature depending where you are. If you are near the volcanic areas then you will enjoy 1,649°C (3000°F) of heat. However if you are anywhere else you will enjoy a chilling temperature of -130°C (-202°F). This range of temperature is a reason why the atmosphere is Sulfur Dioxide. As you go deeper the outer shell of IO is silicate and the core is iron, which may give it a magnetic field of its own, but that is still a mystery.

Ganymede

Ganymede was discovered on January 7, 1610 by Galileo Galilei. Galileo originally named Ganymede “Jupiter lll” (number 3) since he just used numerical values 1 to 4 for the moons. It wasn’t until about 250 years later that the moon “Jupiter lll” was named Ganymede, which was named from Greek mythology after a boy who was carried to Olympus by Zeus to become the cupbearer of the Olympian Gods.

Jupiter's moon Ganymede
Jupiter's moon Ganymede

Ganymede is the largest moon in our solar system with a diameter of 5,262.4 km (3,270 mi) which is 1.51 times larger than Earth’s moon. The volume is 76,304,506,998 km3 (18,306,424,688 mi3) which is 3.47 times more than Earth’s moon. The surface area is 86,999,665.93 km2 (33,590,758.81 mi2) which is 2.29 times more than Earth’s moon. The mass is 1.4819 x 1023 kg which is 2.02 times more than Earth’s moon. Ganymede is so large that if it orbited the Sun it would be classified as a planet, a matter of fact it is larger than the planet Mercury.

Ganymede is the 7th moon from Jupiter with an average orbit distance of 1,070,400 km (665,116 miles) which is 2.78 times farther than Earth and its moon. The closest (Perigee) point during Ganymede’s orbit is 1,069,008 km (664,251 miles) and farthest (Apogee) is 1,071,792 km (665,981 miles). The orbit inclination to ecliptic (orbit angle relative to Jupiter’s equator) is 0.177° with an orbit eccentricity (amount of deviation from a perfect circle) of 0.0013. Ganymede’s orbital period (time for 1 trip around Jupiter) is 7.155 Earth days travelling at a velocity of 39,165.6 km/h (24,336 mph) and has a rotation period (time for 1 rotation) of 171.7 hours.

Ganymede has a surface gravity of 1.428 m/s2 (4.68 ft/s2) which is slightly less than Earth’s Moon surface gravity. That means it would take about 6.5 seconds to drop a solid ball from a 10 story building, where on Earth it would be about 2.5 seconds. Ganymede’s escape velocity is 9,869 km/h (6,133 mph) which is a little higher than Earth’s moon escape velocity.

Ganymede’s surface temperature ranges from -297°F (-183°C) to -171°F (-112°C), which is much colder than any place on Earth. The reason why it is so cold is because it receives such little sunlight and has no thick atmosphere (very thin composed of Oxygen) to hold in heat. The night time temperatures which can drop down to -315°F (-193deg;C). The coldest parts on Ganymede are near the North and South Poles.

Ganymede is the only moon in our solar system that has a magnetosphere. Some have argued this is just from Jupiter’s magnetic field; however Ganymede’s magnetic fields are much stronger than Jupiter’s magnetic fields from its distance, a matter of fact it is 3 times stronger than Mercury’s magnetic field with a moment value of 1.3 × 1013 T·m3.

Ganymede is generally made up of 3 layers. The first layer is the core which is made of metallic iron. The second layer is mantle (rock). The third layer is mainly ice which can be up to 800 km (497 miles) thick. About 60% of Ganymede’s surface is covered by a light grooved terrain and remaining 40% is covered by a dark grooved terrain. The dark regions are generally old and may be the original crust of Ganymede. The groove ridges can run for thousands of kilometers and can be up to 700 m (2,297 feet) high.

Europa

Europa is the smallest of the four Galilean moons and is sixth in orbit from the planet. Its diameter of 3,121.6 km is slightly smaller than the Earth's moon. Europa's unique feature is its surface of water ice. There is also evidence to suggest that this icy surface may be covering an ocean of either water or slush beneath it. Europa's watery condition is important information because it could possibly support some life forms. Europa orbits Jupiter once every 3.55 days.

Callisto

Callisto is the farthest of the Galilean moons. It is roughly the size of Mercury (4,820.6 km vs. 4,879.4 km) but is only one third of the planet's mass. Callisto's ancient and heavily crated surface is a mixture of unknown rocky material and water ice in approximately equal parts. Callisto completes one orbit around Jupiter in 16.68 days.

List of Jupiter's 67 Moons

Name Distance from Jupiter (km) Days for 1 full Orbit around Jupiter Diameter (km) Year Discovered Group
Metis128,1000.3441979Amalthea
Adrastea128,9000.3161979Amalthea
Amalthea181,4000.51681892Amalthea
Thebe221,9000.7981979Amalthea
Io421,8001.83,6431610Galilean
Europa671,1003.63,1221610Galilean
Ganymede1,070,4007.25,2621610Galilean
Callisto1,882,70016.74,8211610Galilean
Themisto7,507,000130.092000Themisto
Leda11,165,000240.9181974Himalia
Himalia11,461,000250.61601904Himalia
Lysithea11,717,000259.2381938Himalia
Elara11,741,000259.6781905Himalia
S/2000 J1112,555,000287.042000Himalia
Carpo16,989,000456.132003Carpo
Euporie19,302,000550.722001Ananke
Orthosie20,721,000622.622001Ananke
Euanthe20,799,000620.632001Ananke
Thyone20,940,000627.342001Ananke
Mneme21,069,000620.022003Ananke
Harpalyke21,105,000623.342000Ananke
Hermippe21,131,000633.942001Ananke
Praxidike21,147,000625.372000Ananke
Thelxinoe21,162,000628.122003Ananke
Iocaste21,269,000631.552000Ananke
Ananke21,276,000610.5281951Ananke
Arche22,931,000723.932002Carme
Pasithee23,096,000719.522001Carme
Herse23,097,000715.422003Carme
Chaldene23,179,000723.842000Carme
Kale23,217,000729.522001Carme
Isonoe23,217,000725.542000Carme
Aitne23,231,000730.232001Carme
Erinome23,279,000728.332000Carme
Taygete23,360,000732.252000Carme
Carme23,404,000702.3461938Carme
Kalyke23,583,000743.052000Carme
Eukelade23,661,000746.442003Carme
Kallichor24,043,000764.722003Carme
Helike21,263,000634.842003Pasiphae
Eurydome22,865,000717.332001Pasiphae
Autonoe23,039,000762.742001Pasiphae
Sponde23,487,000748.322001Pasiphae
Pasiphae23,624,000708.0581908Pasiphae
Megaclite23,806,000752.862000Pasiphae
Sinope23,939,000724.5381914Pasiphae
Hegemone23,947,000739.632003Pasiphae
Aoede23,981,000761.542003Pasiphae
Callirrho24,102,000758.871999Pasiphae
Cyllene24,349,000737.822003Pasiphae
Kore24,543,000779.222003Pasiphae
S/2003 J228,570,410982.522003No Group
S/2003 J318,339,885504.022003No Group
S/2003 J423,257,920723.222003No Group
S/2003 J524,084,180759.742003No Group
S/2003 J922,441,680683.012003No Group
S/2003 J1024,249,600767.022003No Group
S/2003 J1219,002,480533.312003No Group
S/2003 J1522,000,000668.422003No Group
S/2003 J1621,000,000595.422003No Group
S/2003 J1820,700,000606.322003No Group
S/2003 J1922,800,000701.322003No Group
S/2003 J2324,055,500759.722003No Group
S/2010 J123,314,335723.222010No Group
S/2010 J220,307,150588.112010No Group
S/2011 J120,155,290580.712011No Group
S/2011 J223,329,710726.812011No Group

Rings

Rings of Jupiter
Rings of Jupiter

Jupiter's ring system was first detected by the orbiter Voyager 1. Voyager 2 and Galileo were then tasked to take more detailed images of the ring. The ring system of Jupiter is composed of three parts: the "Main" ring, the "Halo" and the "Gossamer" ring. They are made up of micrometer-sized dust particles kicked up by Jupiter's inner moons.

The Halo is the innermost ring (closest to Jupiter) and is about 30,000 km wide and about 20,000 km thick. Its inner boundary extends to the tops of Jupiter's clouds, while its outer boundary extends halfway through the Main ring. It is characterized as being broad and faint. The Main ring is the brightest of the ring components and encloses the orbits of Adrastea and Metis, two small moons that may be a source of dust particles that comprises most of the ring. This ring is 7,000 km wide and abruptly ends at a boundary of 129,130 km from the center of Jupiter. The outermost ring component is made up of two Gossamer rings that are both wide but faint. They are named Amalthea and Thebe after the two inner Jovian moons whose orbit they enclose. The Amalthea Gossamer ring stretches from Amalthea's orbit 182,000 km away from the center of Jupiter to about 129,000 km, just within the Main ring. The Thebe Gossamer ring is the faintest of the ring system and overlaps with the Amalthea Gossamer ring. Its outer boundary just encloses the orbit of Thebe 226,000 km from Jupiter's center and stretches inward to 129,000 km from the center of Jupiter.