As you know, it is the largest planet in the solar system with the largest mass. For this reason, Jupiter has more satellites than any other planet in the solar system. Jupiter is sometimes even called “A real star” because he has his own system of cosmic bodies of which he himself is the center. At the moment, 67 satellites are registered in orbits of Jupiter, but this is not the most accurate figure. To the question “How many satellites does Jupiter have,” scientists answer that there are at least 100 of them, but not all have been discovered yet. The number of satellites studied is only 60. The satellites of the planet Jupiter revolve around the planet both at close distances and at very large ones, due to the enormous gravity of the planet.
Satellites of the planet Jupiter or the Moon of Jupiter.
Typically, the satellites of Jupiter or the Moon of Jupiter are divided into three groups:
- Galileevs
- Domestic
- External
The Gallian satellites, as you might guess, were discovered by Galileo back in 1610. These satellites include the most famous satellites of Jupiter: Io, Europa, Callisto, Ganymede. These moons were the first to be discovered because they are closest to the planet and are large enough to be detected at that time. Other satellites were discovered a little later. is huge and allows the planet to hold a lot of satellites in its orbits.
And about
This satellite is known for its volcanic activity. Of all the Galilean satellites, it is the closest to the planet and, thanks to the same gravity of Jupiter, magma eruptions constantly occur on Io. Magma on Io comes in a range of colors, from yellow to brown and sometimes even black. The surface of Io is solid, unlike Io, and it is covered with its own frozen magma, so the color of the satellite’s surface is mainly yellow.
Europe
Europe is an even more interesting object. It has an interesting topography which consists of ice and unusual cracks in it. Scientists have been puzzling over the question of the origin of such a relief for quite some time. All the cracks in the huge block of ice covering the satellite form a grid that is located across the entire surface of Europa. There is an assumption that under this ice, closer to the core of the satellite, there is an ocean in which, perhaps, there is life.
Callisto
The second largest satellite in the Jupiter system. The surface of this satellite is completely covered with craters from impacts of various cosmic bodies on the satellite. This fact indicates that Callisto is older than the other satellites and also that there is no volcanic activity on Callisto.
Ganymede
The largest satellite in the Jupiter system. The surface of Ganymede, like Europa, is covered with a thick layer of ice and has an active molten metal core in its depths, which creates its own magnetic field for Ganymede. Presumably, closer to the core of the satellite, where the temperature allows water to exist, there is an ocean in which life can exist. If Ganymede were not a satellite of Jupiter, it could easily be classified as an independent planet.
There are also small satellites that orbit very close to the planet and are called internal. Here we could talk about 56 more studied satellites of Jupiter, but little is known about them yet. have their own mechanics of rotation around the planet, which is presented in the animation below.
The science
Currently, not much is known about Jupiter's moon Europa. The most important information information about this solar system object was obtained thanks to the approach of NASA spacecraft to it "Voyager 2" in 1979 and "Galileo" in the second half of the 1990s. Therefore, astronomers began to seriously think about sending to the object new devices soon.
Despite the fact that in the past, ships approached the satellite for a very short time, scientists were able to see it surface covered with cracks and ice with clear evidence of an ocean of liquid water beneath a solid crust.
This environment makes it possible to exist microbial life forms, scientists say. If astronomers ever send robotic craft to Europa, they will need to do a lot of preparation to understand what they need to take with them and what they should look for there.
It is believed that Jupiter's moon Europa is main contender for the existence of life in the solar system, and a mission to this object will be able to reveal all the secrets. For example, scientists have yet to figure out what red stripes and cracks cover the surface of the object, what is the chemical composition of the satellite, and does it contain organic molecules that are building blocks for living organisms?
First of all, scientists believe, the mission to Europe will be take samples of material at different depths(0.5-2 cm and 5-10 cm) so that conclusions can be drawn about the composition of the soil and its chemical composition, as well as the characteristics of salts, organic materials, and so on.
The second objective of the mission will be to study geophysical features of Europe, seismology and magnetometry. It will also be necessary to penetrate the ice crust to the ocean.
Unfortunately, for now, a flight to Europe is just a far-reaching plan for NASA, since at present colossal budgets leave for other equally important missions.
Jupiter's total 67 satellites, however, most of them (about 50) are very small - less 10 kilometers in diameter. The number of satellites, however, changes periodically. Most of the moons were discovered starting in the 1970s, after various spacecraft began approaching Jupiter.
Jupiter owes its large number of satellites gigantic mass, thanks to gravitational stability, such a large number of objects, including relatively large ones, can be held in the planet’s orbit. The Earth, for example, has only one satellite, since its gravitational field does not allow keeping another satellite in orbit.
The moons orbit Jupiter at different speeds and over different periods of time: from 7 hours to 3 earth years.
Although Europe- one of the largest satellites of Jupiter, it is the smallest of the four Galilean satellites.
The Europa satellite is slightly smaller than the Moon.
The surface of Europa is very smooth, it is covered with thick ice about 100 kilometers, there are almost no craters on it, but there are stripes and cracks. Surface temperature approx. minus 150-190 degrees Celsius. Thanks to its crust of ice, Europa reflects light well, making it very bright. The surface of the satellite is relatively young - from 20 to 180 million years.
On the surface of Europa there are peculiar "freckles", darker spots that were formed due to the existence liquid ocean under a layer of ice, according to scientists.
Jupiter can rightfully be called the most “weighty” planet in the solar system, because if you add together all the other planets, including our Earth, then their total mass will be 2.5 times less than that of this giant. Jupiter has very powerful radiation, the level of which in the solar system is exceeded only by the Sun.
Everyone knows the rings of Saturn, but Jupiter also has a lot of satellites. To date, scientists know for sure 67 such satellites, of which 63 are well studied, but it is assumed that Jupiter has at least a hundred satellites, most of which were discovered in recent decades. Judge for yourself: at the end of the 70s of the 20th century, only 13 satellites were registered, and later new generation ground-based telescopes made it possible to discover more than 50 more.
Most of Jupiter's satellites have a small diameter - from 2 to 4 km. Astronomers divide them into Galilean, internal and external.
Galilean satellites
The largest moons of Jupiter: Io, Europa, Ganymede and Callisto were discovered by Galileo Galilei in 1610, and they got their name in honor of him. Their formation occurred after the formation of the planet, from the gas and dust that surrounded it.
And about
Io got her name in honor of Zeus’s beloved, so it would be more correct to talk about her in the feminine gender. It is the fifth satellite of Jupiter and is the most volcanically active body in the Solar System. Io is about the same age as Jupiter itself - 4.5 billion years. Like our Moon, Io is always turned to Jupiter with only one side, and its diameter is not much larger than that of the Moon (3642 km versus 3474 km for the Moon). The distance from Jupiter to Io is 350 thousand km. It is the fourth largest satellite in the solar system.
Volcanic activity is extremely rarely observed on the satellites of planets, and even on the planets of the Solar System themselves. Currently, only four cosmic bodies are known in the Solar System where it manifests itself. This is Earth, Neptune's satellite Triton, Saturn's satellite Enceladus and Io, which among these four is the undisputed leader in terms of volcanic activity.
The scale of the eruptions on Io is such that it is clearly visible from space. Suffice it to say that sulfur magma from volcanoes erupts to a height of up to 300 km (12 such volcanoes have already been discovered), and giant lava flows have covered the entire surface of the satellite, and of a wide variety of colors. And sulfur dioxide predominates in Io’s atmosphere, which is due to high volcanic activity.
Real picture!
Animation of the eruption at Tvashtara Patera, compiled from five images taken by the New Horizons spacecraft in 2007.
Io is quite close to Jupiter (by cosmic standards, of course) and is constantly experiencing the massive effects of its gravity. It is gravity that explains the enormous friction inside Io caused by tidal forces, as well as the constant deformation of the satellite, heating its interior and surface. On some parts of the satellite the temperature reaches 300°C. Along with Jupiter, Io is affected by gravitational forces from two other satellites - Ganymede and Europa, which mainly causes additional heating of Io.
The eruption of Mount Pele on Io, photographed by the Voyager 2 spacecraft.
Unlike volcanoes on Earth, which “sleep” most of the time and erupt only for a fairly short period of time, on hot Io volcanic activity is not interrupted, and peculiar rivers and lakes are formed from the flowing molten magma. The largest molten lake known today has a diameter of 20 km, and contains an island consisting of frozen sulfur.
However, the interaction between the planet and its satellite is not one-way. Although Jupiter, thanks to its powerful magnetic belts, takes up to 1000 kg of matter from Io every second, which almost doubles its magnetosphere. Io's movement through its magnetosphere generates such powerful electricity that severe thunderstorms rage in the planet's upper atmosphere.
Europe
Europe got its name in honor of another lover of Zeus - the daughter of the Phoenician king, whom he kidnapped in the form of a bull. This satellite is the sixth most distant from Jupiter, and is about the same age as it, that is, 4.5 billion years. However, the surface of Europa is much younger (about 100 million years old), so there are practically no meteorite craters on it that arose during the formation of Jupiter and its moons. Only five such craters with a diameter of 10 to 30 km were discovered.
Europa's orbital distance from Jupiter is 670,900 km. The diameter of Europa is smaller than that of Io and the Moon - only 3100 km, and it is also always turned to its planet with one side.
The maximum surface temperature at the equator of Europe is minus 160°C, and at the poles - minus 220°C. Although the entire surface of the satellite is covered with a layer of ice, scientists believe that it hides a liquid ocean. Moreover, researchers believe that some forms of life exist in this ocean thanks to thermal springs located next to underground volcanoes, that is, the same as on Earth. In terms of the amount of water, Europe is twice as large as the Earth.
Two models of the structure of Europe
The surface of Europa is riddled with cracks. The most common hypothesis attributes this to the effects of tidal forces on the ocean shore below the surface. It is likely that the rise of water under the ice above normal occurs as the satellite approaches Jupiter. If this is true, then the appearance of cracks on the surface is precisely caused by the constant rise and fall of the water level.
According to a number of scientists, sometimes the surface breaks through with water masses, like lava during a volcanic eruption, and then these masses freeze. This hypothesis is supported by icebergs that can be seen on the surface of the satellite.
In general, the surface of Europa does not have elevations higher than 100 m, so it is considered one of the smoothest bodies in the Solar System. Europa's thin atmosphere contains mainly molecular oxygen. Apparently, this is explained by the decomposition of ice into hydrogen and oxygen under the influence of solar radiation, as well as other hard radiation. As a result, molecular hydrogen from the surface of Europa quickly evaporates due to its lightness and the weakness of gravity on Europa.
Ganymede
The satellite got its name in honor of the beautiful young man whom Zeus transported to Olympus and made him a cupbearer at the feasts of the gods. Ganymede is the largest moon in the Solar System. Its diameter is 5268 km. If its orbit were not around Jupiter, but around the Sun, it would be considered a planet. The distance between Ganymede and Jupiter is about 1070 million km. It is the only satellite in the solar system that has its own magnetosphere.
About 60% of the satellite is occupied by strange bands of ice, the result of active geological processes that took place 3.5 billion years ago, and 40% is an ancient thick icy crust covered with many craters.
Possible internal structure of Ganymede
Ganymede's core and silicate mantle produce heat that makes the existence of an underground ocean possible. According to scientists, it is located below the surface at a depth of 200 km, while on Europa the large ocean is located closer to the surface.
But the thin layer of Ganymede's atmosphere, consisting of oxygen, is similar to the atmosphere discovered on Europa. Compared to other moons of Jupiter, the flat craters on Ganymede have virtually no elevation and do not have a depression in the center, like craters on the Moon. This appears to be due to the slow, gradual movement of the soft ice surface.
Callisto
The satellite Callisto got its name in honor of another lover of Zeus. With a diameter of 4,820 km, it is the third largest moon in the solar system, with it being approximately 99% of the diameter of Mercury, while the mass of the satellite is three times less than that of the planet.
Callisto, like Jupiter itself and other Galilean satellites, is also about 4.5 billion years old, but its distance to Jupiter compared to other satellites is significantly greater, almost 1.9 million kilometers. Thanks to this, the hard radiation field of the gas giant does not affect it.
The surface of Callisto is one of the oldest surfaces in the solar system - it is about 4 billion years old. Craters cover it all, so over time, each meteorite necessarily fell into an existing crater. There is no violent tectonic activity on Callisto; its surface does not heat up after its formation, so it has retained its ancient appearance.
According to many scientists, Callisto is covered by a thick layer of ice, under which there is an ocean, and the center of the satellite contains rocks and iron. Its thin atmosphere consists of carbon dioxide.
The Valhalla crater with a total diameter of about 3800 km deserves special attention on Callisto. It consists of a bright central region with a diameter of 360 km, surrounded by ridged concentric rings with a radius of up to 1900 kilometers. This whole picture resembles ripples in the water caused by a stone thrown into it, only in this case the role of the “stone” was played by a large asteroid 10-20 km in size. Valhalla is considered the largest formation around an impact crater in the Solar System, although the crater itself is only 13th in size.
Valhalla - impact pool on the moon Callisto
As already mentioned, Callisto is located outside the hard radiation field of Jupiter, so it is considered as the most suitable object (after the Moon and Mars) for constructing a space base. Ice can serve as a source of water, and from Callisto itself it will be convenient to explore another satellite of Jupiter - Europa.
A flight to Callisto will take from 2 to 5 years. The first manned mission is scheduled to launch no earlier than 2040, although the flight could begin later.
Model of the internal structure of Callisto
Shown are an icy crust, a possible water ocean, and a core of rocks and ice.
Inner satellites of Jupiter
Jupiter's inner moons are so named because of their orbits that pass very close to the planet and are within the orbit of Io, which is the closest Galilean moon to Jupiter. There are four inner satellites: Metis, Amalthea, Adrastea and Thebe.
Amalthea, 3D model
Jupiter's faint ring system is replenished and supported not only by its inner satellites, but also by small inner moons that are not yet visible. Jupiter's main ring is supported by Metis and Adrastea, while Amalthea and Thebe have to support their own weak outer rings.
Of all the inner satellites, Amalthea with its dark red surface is of greatest interest. The fact is that there is no analogue to this in the solar system. There is a hypothesis that this surface color is explained by inclusions of minerals and sulfur-containing substances in the ice, but this does not clarify the reason for this color. It is more likely that Jupiter's capture of this satellite occurred from the outside, as regularly happens with comets.
Outer satellites of Jupiter
The outer group consists of small satellites with a diameter of 1 to 170 km, which move in elongated orbits with a strong inclination towards Jupiter's equator. To date, 59 such external satellites are known. Unlike the inner satellites, which move in their own orbits in the direction of Jupiter's rotation, most of the outer satellites move in their orbits in the opposite direction.
Orbits of Jupiter's moons
Since some of the small satellites have almost identical orbits, they are believed to be the remnants of larger satellites destroyed by Jupiter's gravitational force. In photographs taken from spacecraft flying past, they look like shapeless blocks. Apparently, Jupiter's gravitational field captured some of them during their free flight in space.
Rings of Jupiter
Along with its satellites, Jupiter also has its own system, like other gas giants in the Solar System: Saturn, Uranus and Neptune. The rings of Saturn, discovered by Galileo in 1610, look much more spectacular and noticeable, since they consist of shiny ice, while for Jupiter it is just a slight dusty structure. This explains their late discovery when spacecraft first reached the Jupiter system in the 1970s.
Galileo's image of the Main Ring using forward-scattered light
Jupiter's ring system consists of four main components:
A halo is a thick torus of particles resembling a donut or disk with a hole in appearance;
The main ring is very thin and quite bright;
Two outer rings, wide but weak, called “arachnoid rings”.
The halo and Main Ring consist mainly of dust from Metis, Adrastea, and probably several other smaller moons. The halo has a width of approximately 20 to 40 thousand km, although the main component of its mass is located no further than several hundred kilometers from the plane of the ring. The shape of the halo, according to a common hypothesis, is due to the influence of electromagnetic forces inside Jupiter's magnetosphere on dust particles in the ring.
The arachnoid rings are very thin and transparent, like a cobweb, and are named after the material of the satellites of Jupiter, Amalthea and Thebe that form them. The outer edges of the Main Ring are outlined by the satellites Adrastea and Metis.
Jupiter's rings and inner moons
The largest satellite in the solar system - How the satellite Ganymede was discovered - The atmosphere and magnetosphere of Ganymede - The size, landscape and surface composition of Ganymede - Prospects for the colonization of the satellite of Jupiter
Satellite of Jupiter Ganymede- the largest satellite not only of this planet, but also in the entire solar system. It is so large that it exceeds the size of the planet, and is also the only one of the planetary satellites that can boast of the presence of a magnetosphere and, albeit weak, but still an oxygen atmosphere!
Ganymede is Jupiter's largest moon
How the moon Ganymede was discovered
"Officially" Ganymede was discovered Galileo Galilei On January 7, 1610, and discovered purely by chance - while observing, the astronomer drew attention to four small “stars” next to him, and, noticing their shift the next night, made the correct assumption that in front of him were not stars, but the moons of Jupiter. Galileo did not bother with names and christened all the newly discovered celestial bodies (Callisto, Europa, Io, Ganymede) simply: Jupiter 1, 2, 3 and 4.
Ganymede appeared on this list as "Jupiter 3".
However, here a German astronomer came onto the scene Simon Mari, who claimed that he observed the satellites of Jupiter back in 1609, and in advance decided to give them much more sonorous and interesting names. That's how the name came about Ganymede- in Greek myths this name was borne by the son of the Trojan king cable, raised by Zeus (Jupiter) to heaven and included in his retinue.
However, this name came into widespread use only in the 20th century.
Dimensions, terrain and surface composition of Ganymede
Ganymede is the largest moon in the Solar System, with a diameter of 5268 kilometers and a record mass for planetary satellites of 1.4619 x 1023 (2 of our Moons). Judging by the density characteristics of the substance that makes up its mass, Ganymede consists of approximately equal parts of rock and water ice. The poles have ice caps made of water ice.
Ganymede orbits Jupiter in 7 days and 3 hours, and the average distance from Jupiter for this satellite is 1,070,400 kilometers.
Inside, the satellite has a liquid iron core, a silicate mantle and a shell of ice. The core has a radius of 500 km, and its temperature is 1500-1700 K with a pressure of 10 Pa.
The mantle is represented by chondrites and iron. The outer ice crust of Ganymede is up to 800 km thick, and it is highly likely that a liquid ocean is located under the surface of this satellite of Jupiter.
There are two distinct types of relief on the surface of the satellite. The first is ancient areas covered with craters (dark) occupying 1/3 of the surface, the second is young territories with ridges and “ravines” (light).
The young landscape was formed by tectonics, but, of course, of a different nature than on Earth. The formation of mountain ranges and chasms on Ganymede is caused by cryovolcanism (the eruption of ice volcanoes) and tidal heating.
The abundance of craters on the “ancient” flat areas of the planet dates back to the period 3.5-4 billion years ago, when Ganymede was subjected to a powerful asteroid attack.
The landscape of Ganymede is quite bizarre, here and there it is crossed by wide stripes, as if a giant ice skating rink had passed through them. In fact, these are areas of compression-tension of the surface
Atmosphere and magnetosphere of Ganymede
As already noted, it is Ganymede that has something that not all planets in the Solar System can boast of - a highly rarefied, but still oxygen atmosphere. Oxygen appears in it due to the presence on the surface of the satellite of deposits of water ice, which, under the influence of ultraviolet radiation, decomposes into hydrogen and oxygen. Moreover, since ozone was also found in Ganymede’s atmosphere, we can most likely talk about the presence of an ionosphere on the satellite.
The presence of an atmosphere (or rather the presence of atomic hydrogen in it) leads to airbrush effect– weak light radiation appearing at the poles of the planet.
However, although the phrase “oxygen atmosphere” sounds very nice and makes us think of colonization and extraterrestrial intelligence, it is worth remembering that the pressure of Ganymede’s atmosphere is only 0.1 Pa, that is, a tiny fraction of that on Earth.
An even more interesting feature of this Jovian moon is its magnetosphere. Yes, Ganymede has a magnetosphere, the value of a stable magnetic moment of which reaches – 1.3 x 10 3 T m 3 (i.e. 3 times higher than that of Mercury). The strength of the magnetic field reaches 719 Tesla, and the diameter of the magnetosphere reaches 13,156 km. Closed field lines are located below 30° latitude, where charged particles are captured and form a radiation belt. Among the ions, the most common is single ionized oxygen.
When the magnetosphere of Ganymede comes into contact with the plasma of Jupiter, a situation very similar to the contact of the solar wind and the Earth's magnetosphere is observed. However, it must be admitted that the satellite’s magnetic field is too weak and is not able to contain the radiation flows emitted by Jupiter, so if we were on the surface of Ganymede, despite the presence of a magnetosphere, we would not be happy.
The structure of the largest moon of Jupiter - Ganymede
Research of Ganymede in our time and prospects for the colonization of the satellite of Jupiter
In recent times, several research probes have been sent to Jupiter, so we have fairly detailed data not only about the giant planet, but also about its satellites.
The Pioneer 10 (1973) and Pioneer 11 (1974) spacecraft gave us insight into the physical characteristics of the moons of Jupiter, Voyager 1 and Voyager 2 (1979) provided photographs and “ atmospheric samples,” but these devices rather asked questions...
The Galileo probe, which studied Ganymede from 1996-2000, began to provide answers. It was he who managed to detect the magnetic field, the internal ocean and provide many spectral images. And in 2007, we received not only spectra, but also a topographic map of this satellite made by the New Horizons probe.
At the moment, there are still a lot of unresolved questions regarding the satellites of Jupiter, their suitability for colonization and the potential for life. However, neither NASA, nor Roscosmos, nor the European Union yet have money for new expeditions.
However, perhaps in the near future everything will change.
Words about the colonization of Ganymede are not just words. The fact is that this satellite, despite all its shortcomings (remoteness, radiation, etc.), has many advantages as an “intermediate base” on the way to “deep space.” Water reserves, some kind of magnetic shield, gravity allowing you to spend less energy on takeoff - all this makes Ganymede not the worst candidate, in any case, this satellite of Jupiter offers better starting conditions than the same one or ours.
A satellite is a dense natural object that orbits a planet. No specific scientific explanation provides a satisfactory answer to the question of how moons came to be, although several theories exist. The Moon was considered the only satellite, but after the invention of the telescope, satellites of others were discovered. Each planet has one or more satellites, except Mercury and Venus. Jupiter has the largest number of satellites - 67. Technological advances have allowed man to discover and even send spacecraft on expeditions to other planets and their satellites.
The largest moons in our solar system are:
Ganymede
Ganymede is the largest moon in our system, orbiting Jupiter. Its diameter is 5,262 km. The moon is larger than Mercury and Pluto, and could easily be called a planet if it were orbiting the Sun. Ganymede has its own magnetic field. Its discovery was made by the Italian astronomer Galileo Galilei on January 7, 1610. The satellite's orbit is about 1,070,400 km from Jupiter and it takes 7.1 Earth days to complete its orbit. The surface of Ganymede has two main types of landscapes. It has lighter and younger regions, as well as a darker crater area. The satellite's atmosphere is thin and contains oxygen in dispersed molecules. Ganymede is primarily composed of water ice and rock, and is believed to have underground oceans. The name of the satellite comes from the name of a prince in ancient Greek mythology.
Titanium
Titan is a satellite of Saturn with a diameter of 5,150 km, making it the second largest moon in the Solar System. It was discovered by the Dutch astronomer Christiaan Huygens in 1655. The satellite has a dense atmosphere similar to that of Earth. 90% of the atmosphere consists of nitrogen, and the remaining 10% consists of methane, small amounts of ammonia, argon and ethane. Titan makes a complete revolution around Saturn in 16 days. On the surface of the satellite there are seas and lakes filled with liquid hydrocarbons. This is the only cosmic body in the solar system, besides the Earth, that has water bodies. The name of the satellite is taken from ancient Greek mythology, in honor of the ancient gods called the Titans. Ice and rock make up the bulk of Titan's mass.
Callisto
Callisto is the second largest satellite of Jupiter and the third largest satellite in the Solar System. It has a diameter of 4821 km and is estimated by scientists to be about 4.5 billion years old; its surface is mostly dotted with craters. Callisto was discovered by Galileo Galilei on January 7, 1610. The satellite received its name in honor of a nymph from ancient Greek mythology. Callisto orbits Jupiter at a distance of about 1,882,700 km, and completes its orbit in 16.7 Earth days. It is the most distant moon from Jupiter, meaning it was not significantly exposed to the planet's powerful magnetosphere. Water ice, as well as other materials such as magnesium and hydrated silicates, make up most of the moon's mass. Callisto has a dark surface and is thought to have a salt sea underneath.
And about
Io is the third largest moon of Jupiter and the fourth in the Solar System. Its diameter is 3,643 km. The satellite was first discovered by Galileo Galilei in 1610. This is the most volcanically active cosmic body along with the Earth. Its surface mainly consists of floodplains of liquid rocks and lava lakes. Io is located approximately 422,000 km from Jupiter, and orbits the planet in 1.77 Earth days. The satellite has a mottled appearance with dominant colors of white, red, yellow, black and orange. Io's atmosphere is dominated by sulfur dioxide. The moon was named after a nymph from ancient Greek mythology who was seduced by Zeus. Beneath Io's surface is an iron core and an outer layer of silicates.
Other large satellites
Other large satellites of the Solar System include: the Moon (3,475 km), Earth; Europa (3,122 km), Jupiter; Triton (2,707 km), Neptune; Titania (1,578 km), Uranus; Rhea (1,529 km), Saturn and Oberon (1,523 km), Uranus. Most observations of these satellites are made from Earth. Advances in technology make it possible for scientists to send spacecraft to different parts of the solar system to obtain more information about the planets and their satellites.
Table: TOP 10 largest satellites in the solar system
| Place in the ranking | Satellite, Planet | Average diameter |
| 1 | Ganymede, Jupiter | 5,262 km |
| 2 | Titan, Saturn | 5,150 km |
| 3 | Callisto, Jupiter | 4,821 km |
| 4 | Io, Jupiter | 3,643 km |
| 5 | Moon, Earth | 3,475 km |
| 6 | Europa, Jupiter | 3,122 km |
| 7 | Triton, Neptune | 2,707 km |
| 8 | Titania, Uranus | 1,578 km |
| 9 | Rhea, Saturn | 1,529 km |
| 10 | Oberon, Uranus | 1,523 km |
