Atmosphere of Jupiter
When the pressure of Jupiter's atmosphere reaches the pressure of the Earth's atmosphere, we will stop and look around. Above you can see the usual blue sky, with thick white clouds of condensed ammonia swirling around. At this altitude the air temperature reaches -100o C.
The reddish color of some of the Jovian clouds indicates that there are many complex chemical compounds here. Various chemical reactions in the atmosphere are initiated by ultraviolet radiation from the sun, powerful lightning strikes (a thunderstorm on Jupiter must be an impressive sight!), and heat coming from the planet's interior.
The atmosphere of Jupiter, in addition to hydrogen (87%) and helium (13%), contains small amounts of methane, ammonia, water vapor, phosphorine, propane and many other substances. It is difficult to determine what substances caused the Jovian atmosphere to turn orange.
The next layer of clouds consists of red-brown crystals of ammonium hydrosulfide at a temperature of -10°C. Water vapor and water crystals form a lower layer of clouds at a temperature of 20°C and a pressure of several atmospheres - almost above the very surface of Jupiter's ocean.
The thickness of the atmospheric layer in which all these amazing cloud structures arise is 1000 km.
Dark stripes and light zones parallel to the equator correspond to atmospheric currents of different directions (some lag behind the rotation of the planet, others advance it). The speed of these currents is up to 100 m/s. Giant vortices are formed at the border of multidirectional currents.
Particularly impressive is the Great Red Spot - a colossal atmospheric vortex of an elliptical shape measuring about 15 x 30 thousand kilometers. It is unknown when it arose, but it has been observed in ground-based telescopes for 300 years. This anticyclone sometimes almost disappears and then appears again. Obviously, it is a relative of terrestrial anticyclones, but due to its size it is much longer-lived.
The Voyagers sent to Jupiter conducted a thorough analysis of the clouds, which confirmed the already existing model of the internal structure of the planet. It became absolutely clear that Jupiter is a world of chaos: endless storms with thunder and lightning rage there, by the way, the Red Spot is part of this chaos. And on the night side of the planet, Voyagers recorded numerous lightning flashes.
Jovian Ocean
The Jovian ocean consists of the main element on the planet - hydrogen. At high enough pressure, hydrogen turns into a liquid. The entire surface of Jupiter under the atmosphere is a huge ocean of liquefied molecular hydrogen.
What waves arise in an ocean of liquid hydrogen with a super-dense wind at a speed of 100 m/s? It is unlikely that the surface of the hydrogen sea has a clear boundary: at high pressures, a gas-liquid hydrogen mixture forms on it. This looks like a continuous “boiling” of the entire surface of the Jovian ocean. The fall of a comet into it in 1994 caused a gigantic tsunami many kilometers high.
As Jupiter dives 20,000 kilometers into the ocean, pressure and temperature rapidly increase. At a distance of 46 thousand km. from the center of Jupiter, the pressure reaches 3 million atmospheres, the temperature is 11 thousand degrees. Hydrogen cannot withstand high pressure and turns into a liquid metallic state.
Core. Let's dive another 30 thousand km, into the second ocean of Jupiter. Closer to the center, the temperature reaches 30 thousand degrees, and the pressure is 100 million atmospheres: here is located a small (“only” 15 Earth masses!) core of the planet, which, unlike the ocean, consists of stone and metals. There is nothing surprising about this - after all, the Sun also contains impurities of heavy elements. The core was formed as a result of the adhesion of particles consisting of heavy chemical elements. It was with him that the formation of the planet began.
Moons of Jupiter and its ring
Information about Jupiter and its satellites has been significantly expanded thanks to the flight of several automatic spacecraft near the planet. The total number of known satellites jumped from 13 to 16. Two of them - Io and Europa - are the size of our Moon, and the other two - Ganymede and Callisto - are one and a half times larger in diameter.
Jupiter's domain is quite extensive: its eight outer moons are so distant from it that they could not be observed from the planet itself with the naked eye. The origin of the satellites is mysterious: half of them move around Jupiter in the opposite direction (compared to the rotation of the other 12 satellites and the direction of the daily rotation of the planet itself).
The satellites of Jupiter are the most interesting worlds, each with its own “face” and history, which were revealed to us only in the space age.
Thanks to the Pioneer space stations, the previous idea about the existence of a discharged gas-dust ring around Jupiter, similar to the famous ring of Saturn, was directly confirmed.
The main ring of Jupiter is one radius from the planet and extends 6 thousand km in width. and has a thickness of 1 km. One of the satellites orbits along the outer edge of this ring. However, even closer to the planet, almost reaching its cloud layer, is a system of much less dense “inner” rings of Jupiter.
It is practically impossible to see the ring of Jupiter from Earth: it is very thin and is constantly turned edge-on towards the observer due to the small inclination of the axis of rotation of Jupiter to the plane of its orbit.
> > > Atmosphere of Jupiter
Compound Jupiter's atmosphere- gas giant of the solar system. Description of the structure, structure of the atmosphere, the Great Red Spot, photo, density, pressure.
In fact, it is stupid to determine the presence of an atmosphere of Jupiter, because this is the entire planet, since it does not have a solid crust. This is a solid mass of hydrogen and helium with admixtures of other gases and air. Let's see what Jupiter's atmosphere looks like and what chemical elements it contains.
Atmospheric composition of Jupiter
Before you is a huge accumulation of hydrogen (90%). The remaining 10% is helium, as well as small amounts of methane, ammonia, sulfur and water vapor. The atmospheric structure of Jupiter is shown in the photo.
If you move from the outer layers to the inner ones, you feel an increase in temperature and pressure. This is why gases are divided into layers. In the depths, hydrogen transforms from gas to liquid and can also become metallic.
Atmospheric layers of Jupiter
Scientists have calculated that at the atmospheric surface the pressure is equal to one bar, which corresponds to the situation on the earth's surface. Next comes the troposphere (50 km). It is represented by ammonia, ammonium hydrosulfide and water, forming attractive and noticeable red and white lines. The white (colder) ones are called zones (gas rises), and the red ones are called belts (gases fall).
Most often these areas are separated by wind currents, but sometimes frozen cloud structures overlap the red stripes and obscure them for a certain period of time. Scientists even managed to record the periodic erasure of the southern stripe, but the northern one does not change. Dense water clouds also influence the dynamics. If you rise higher, you will feel a sharp drop in temperature: from -160°C to -100°C.
Next comes the stratosphere (320 km), containing hydrocarbon haze. Here the temperature can reach -100°C. The stratosphere resembles the troposphere because it is heated by the sun's rays and the internal heat of the planet. The higher the temperature, the greater the speed of movement. The layer ends at a point where the pressure exceeds the earth's pressure a thousand times.
Above it is the thermosphere (1000 km above the surface) with a temperature of 725°C. It is here at the poles that auroras occur. In addition, the thermosphere is capable of creating a faint glow, which prevents the night sky from completely plunging into darkness. The layer is heated by particles from the magnetosphere, as well as by the Sun.
At the very top is the exosphere, in which gas particles spread into cosmic space. It has no clear division.
Great Red Spot in Jupiter's atmosphere
Thanks to its red and white stripes, Jupiter is striking in its beauty. The outstanding feature is the Great Red Spot. It was discovered back in the 1600s. It is a powerful storm located on the southern side of the equatorial line. These hurricanes can be seen through telescopes.
It takes 6 days for a cyclone to rotate. It is so huge that two Earths could easily fit in there. However, recent studies say that it may be declining.
Since the Great Red Spot is cooler than the streak, it must be higher in the atmosphere of the planet Jupiter. There is no exact data yet on the reason for the appearance of the red light.
After traveling a third of the way to the planet, hydrogen becomes metallic, which produces electrical charges. This helps control the strong magnetic field. Jupiter rotates extremely quickly around its axis (once every 9.9 hours), so it easily feeds the field with electricity.
Jupiter's magnetic field is 20 times greater than Earth's. Moreover, radio amateurs can hear electromagnetic storms. Sometimes these signals are even stronger than the sun.
The fifth and largest planet in the solar system, known since ancient times, is Jupiter. The gas giant was named in honor of the ancient Roman god Jupiter, similar to Zeus the Thunderer among the Greeks. Jupiter is located beyond the asteroid belt and consists almost entirely of gases, mainly hydrogen and helium. The mass of Jupiter is so huge (M = 1.9∙1027 kg) that it is almost 2.5 times the mass of all the planets of the solar system combined. Around its axis, Jupiter rotates at a speed of 9 hours 55 minutes, and its orbital speed is 13 km/s. The sidereal period (period of rotation in its orbit) is 11.87 years.
In terms of illumination, not counting the Sun, Jupiter is second only to Venus, and therefore is an excellent object for observation. It glows with white light with an albedo of 0.52. In good weather, even with the simplest telescope, you can see not only the planet itself, but also the four largest satellites.
The formation of the Sun and other planets began billions of years ago from a common cloud of gas and dust. So Jupiter got 2/3 of the mass of all the planets in the solar system. But, since the planet is 80 times lighter than the smallest star, thermonuclear reactions never began. However, the planet emits 1.5 times more energy than it receives from the Sun. Its own heat source is associated primarily with radioactive decays of energy and matter that is released during the compression process. The thing is that Jupiter is not a solid body, but a gaseous planet. Therefore, the speed of rotation at different latitudes is not the same. At the poles, the planet has a strong compression due to rapid rotation around its axis. Wind speeds exceed 600 km/h.
Modern science believes that the mass of Jupiter's core is currently 10 times the mass of the Earth, or 4% of the total mass of the planet, and its size is 1.5 times its diameter. It is rocky, with traces of ice.
The composition of Jupiter's atmosphere is 89.8% hydrogen (H2) and 10% helium (He). Less than 1% consists of methane, ammonium, ethane, water and other components. Under this crown of the giant planet there are 3 layers of clouds. The top layer is glaciated ammonia with a pressure of about 1 atm, the middle layer contains crystals of methane and ammonium, and the bottom layer consists of water ice or tiny liquid drops of water. The orange color of Jupiter's atmosphere comes from a combination of sulfur and phosphorus. It contains acetylene and ammonia, so this composition of the atmosphere is harmful to people.
The stripes that stretch along the equator of Jupiter have been known to everyone for a long time. But no one has yet been able to really explain their origin. The main theory was the theory of convection - the lowering of colder gases to the surface, and the rise of warmer ones. But in 2010, it was suggested that the satellites (moons) of Jupiter influence the formation of the stripes. Allegedly, by their attraction they formed certain “columns” of substances, which also rotate and are visible as stripes. The theory has been confirmed in laboratory conditions, experimentally and now seems most probable.
Perhaps the most mysterious and lengthy observation described in the characteristics of the planet can be considered the famous Great Red Spot on Jupiter. It was discovered by Robert Hooke in 1664, hence it has been observed for almost 350 years. This is a huge formation, constantly changing in size. Most likely, this is a long-lived, gigantic atmospheric vortex, its dimensions are 15x30 thousand km; for comparison, the diameter of the Earth is about 12.6 thousand km.
Jupiter's magnetic field
Jupiter's magnetic field is so huge that it even extends beyond the orbit of Saturn and is about 650,000,000 km. It exceeds the Earth's by almost 12 times, and the inclination of the magnetic axis is 11° relative to the axis of rotation. Metallic hydrogen, present in the bowels of the planet, explains the presence of such a powerful magnetic field. It is an excellent conductor and, rotating at tremendous speed, creates magnetic fields. On Jupiter, like on Earth, there are also 2 magnetic inverted poles. But the compass needle on the gaseous giant always points south.
Today, in the description of Jupiter, you can find about 70 satellites, although presumably there are about a hundred of them. The first and largest moons of Jupiter - Io, Europa, Ganymede and Callisto - were discovered by Galileo Galilei back in 1610.
The satellite Europa attracts the most attention from scientists. In terms of the possibility of life, it follows Saturn's moon Enceladus and ranks second. They believe there may be life on it. First of all, due to the presence of a deep (up to 90 km) subglacial ocean, the volume of which exceeds even the Earth’s ocean!
Ganymede is simply the largest moon in the solar system. So far, interest in its structure and characteristics is minimal.
Io is a volcanically active moon, with much of its surface covered in volcanoes and lava.
Presumably, the moon Callisto also has an ocean. Most likely it is located under the surface, as evidenced by its magnetic field.
The density of Galium satellites is determined by their distance from the planet. For example: the density of the most distant of the large satellites - Callisto p = 1.83 g/cm³, then as you get closer, the density increases: for Ganymede p = 1.94 g/cm³, for Europa p = 2.99 g/cm³, for Io p = 3.53 g/cm³. All large satellites always face one side towards Jupiter and rotate synchronously.
The rest were opened much later. Some of them rotate in the opposite direction, in comparison with the majority, and represent some kind of meteorite bodies of various shapes.
Characteristics of Jupiter
Mass: 1.9*1027 kg (318 times the mass of the Earth)
Diameter at equator: 142,984 km (11.3 times the diameter of Earth)
Diameter at the pole: 133708 km
Axis tilt: 3.1°
Density: 1.33 g/cm3
Temperature of the upper layers: about –160 °C
Period of rotation around the axis (days): 9.93 hours
Distance from the Sun (average): 5.203 a. e. or 778 million km
Orbital period around the Sun (year): 11.86 years
Orbital speed: 13.1 km/s
Orbital eccentricity: e = 0.049
Orbital inclination to the ecliptic: i = 1°
Gravity acceleration: 24.8 m/s2
Satellites: there are 70pcs
Cloud tiers: when the pressure of Jupiter's atmosphere reaches the pressure of the earth's atmosphere, we will stop and look around. Above you can see the usual blue sky, with thick white clouds of condensed ammonia swirling around. Its smell is unpleasant for humans, so there is no point in ventilating our observation point; Besides, it’s frosty outside: - 100° C.
The reddish color of some of the Jovian clouds indicates that there are many complex chemical compounds here. Various chemical reactions in the atmosphere are initiated by ultraviolet radiation from the sun, powerful lightning strikes (a thunderstorm on Jupiter must be an impressive sight!), and heat coming from the planet's interior. The atmosphere of Jupiter, in addition to hydrogen (81%) and a small fraction of helium (18%), contains small amounts of methane, ammonia and water vapor. Scientists also found traces of acetylene, ethane, carbon monoxide, hydrocyanic acid, germanium hydride, phosphine and propane. From this chemical “porridge” it is difficult to choose the main candidates for the role of the orange dye of the atmosphere: these could be compounds of phosphorus, sulfur or organic compounds.
The next tier of clouds consists of red-brown crystals of ammonium hydrosulfide at a temperature of - 10 ° C. Water vapor and water crystals form a lower tier of clouds at a temperature of 20 ° C and a pressure of several atmospheres - almost above the very surface of Jupiter's ocean. (Although some models allow for the presence of a fourth tier of clouds - made of liquid ammonia.)
The thickness of the atmospheric layer in which all these amazing cloud structures arise is 1000 km. Dark stripes and light zones parallel to the equator correspond to atmospheric currents of different directions (some lag behind the rotation of the planet, others advance it). The speed of these currents is up to 100 m/s. Giant vortices are formed at the border of multidirectional currents. Particularly impressive is the Great Red Spot - a colossal atmospheric vortex. It is unknown when it arose, but it has been observed in telescopes for 300 years.
Recent studies show that the further a planet is from the Sun, the less turbulent its atmosphere is, the less intense heat exchange between neighboring regions occurs and the less energy is dissipated. In the atmosphere of large planets, physical processes are such that energy from individual small areas is transferred to larger ones and then accumulates in global air structures - zonal flows. These streams are cloud belts that can be seen even with a small telescope. Neighboring streams move in opposite directions. Their color may vary slightly depending on the chemical composition. Colored clouds are found in the highest layers of Jupiter (their depth is about 0.1-0.3% of the planet's radius). The origin of their color remains a mystery, although, apparently, it can be argued that it is associated with trace components of the atmosphere and indicates complex chemical processes occurring in it. Based on a study at the end of 2000 by the Cassini probe, it was found that the light stripes and the Great Red Spot (a giant storm with a major axis of about 35 thousand km and a minor axis of 14 thousand km) are associated with downdrafts (vertical circulation of atmospheric masses) ; The clouds here are higher and the temperature is lower than in other areas. The color of the clouds correlates with altitude: blue structures are the highest, brown ones lie below them, then white ones. Red structures are the lowest. The planet's reddish hue is attributed mainly to the presence of red phosphorus in the atmosphere and possibly organic matter produced by electrical discharges. In the area where the pressure is about 100 kPa, the temperature is about 160 K. Thunderstorms have been observed in the atmosphere of Jupiter. The temperature of the upper clouds is - 130°C. Jupiter releases 60% more energy than it receives from the Sun. The atmosphere reflects 45% of incident sunlight. The presence of an ionosphere has also been established, the length of which in height is about 3000 km.
Great Red Spot: The surface of Jupiter cannot be observed directly due to a dense layer of clouds, presenting a pattern of alternating dark stripes and bright zones. Differences in stripe color are due to slight chemical and temperature differences. The positions and sizes of stripes and zones gradually change over time. The vibrant colors seen in Jupiter's clouds are likely the result of clever chemical reactions of trace elements in its atmosphere, possibly including sulfur, whose compounds create a wide variety of colors. The dark stripes and light zones of the cloud structure of Jupiter, the speed of which sometimes reaches 500 km/h, owe both their very existence and their shape to hurricane winds encircling the planet in the meridional direction. On Earth, winds are created by large differences in temperature - more than 40° Celsius between the pole and the equator. But both the pole and the equator of Jupiter have approximately the same temperature (-130 ° C), at least at the base of the clouds. Obviously, the winds of Jupiter are controlled mainly by its internal heat, and not by solar heat, as on Earth.
In general, the chemical composition of the atmosphere of the entire planet does not differ significantly from that of the sun and is similar to that of a small star.
The Great Red Spot is an oval measuring 14,000 x 35,000 km (that is, two Earth disks). Matter in the Great Red Spot moves counterclockwise, making a full revolution in 7 Earth days. The spot shifts relative to the average position, now in one direction, then in the other. Research shows that 100 years ago its size was twice as large. In 1938, the formation and development of three large white ovals was recorded near 30° south latitude. Observers also noted a series of small white ovals, which also represent vortices. Therefore, we can believe that the Red Spot is not a unique formation, but the most powerful member of the family of storms. Historical records do not reveal similar long-lasting systems in the northern mid-latitudes. There are large dark ovals near 15° north latitude, but for some reason the conditions necessary for the emergence of vortices and their subsequent transformation into stable systems like the Red Spot exist only in the Southern Hemisphere.
Sometimes collisions of such large cyclonic systems occur on Jupiter. One of these occurred in 1975, causing the red color of the Spot to fade for several years. in 2002 there was a similar collision between the Great Red Spot and the Great White Oval. The White Oval is part of a cloud belt with an orbital period shorter than the Great Red Spot. The Oval began to be slowed down by the Great Red Spot in late February 2002, and the collision continued for a month. The red color of the Great Red Spot is a mystery to scientists, and may be caused by chemicals including phosphorus. In fact, the colors and mechanisms that create the appearance of the entire Jovian atmosphere are still poorly understood and can only be explained by direct measurements of its parameters.
Compound: The upper cloud layer is about 50 km thick. In this region, the pressure in the atmosphere is comparable to that on Earth, but it increases rapidly with depth. Below the clouds there is a layer approximately 21,000 km thick, consisting of a mixture of hydrogen and helium; hydrogen gradually changes its state from gas to liquid with increasing pressure and temperature (up to 6000 ° C). Beneath the liquid hydrogen layer is a sea of liquid metallic hydrogen 40,000 km deep. Liquid metallic hydrogen, unknown on Earth, is formed at a pressure of 3 million atmospheres. Composed of protons and electrons, it is an excellent conductor of electricity. Recent experiments have shown that hydrogen does not change its phase suddenly, which means that Jupiter's interior does not have clear boundaries between layers. Scientists believe that Jupiter has a solid core one and a half times the diameter of Earth, but 10-30 times denser. Even if there is a solid surface on Jupiter, you cannot stand on it without fear of being crushed by the weight of the underlying atmosphere. According to theoretical calculations, the temperature of the planet's core is about 30,000°C, and the pressure is 30-100 million atmospheres. Such conditions are not sufficient for thermonuclear reactions, but Jupiter emits about 2 times more energy into space than it receives from the Sun. It is most likely that the planet's excess thermal radiation is the result of the planet's gravitational compression, which continues to this day. Heat moves through the atmosphere and leaks out through cloud-free areas, appropriately called "hot spots." Jupiter rotates rapidly on its own axis (2.5 times faster than the Earth), and the action of enormous centrifugal force has caused the planet to noticeably flatten. The polar radius of Jupiter is 4400 km less than the equatorial one. As on the Sun, its rotation speed at the equator has a maximum value and decreases with increasing latitude. The reason for this difference remains unclear to this day.
Jupiter is the largest planet Solar system. It is located in the fifth orbit from the Sun.
Belongs to the category gas giants and fully justifies the correctness of such a classification.
Jupiter got its name in honor of the ancient supreme god of thunder. Probably due to the fact that the planet has been known since ancient times and was sometimes found in mythology.
Weight and size.
If you compare the sizes of Jupiter and Earth, you can understand how much they differ. Jupiter is more than 11 times larger in radius than our planet.
Moreover, the mass of Jupiter is 318 times greater than the mass of the Earth! And this is also affected by the small density of the giant (inferior to Earth’s by almost 5 times).
Structure and composition.
The core of the planet, which is very interesting, is made of stone. Its diameter is about 20 thousand kilometers.
This is followed by a layer of metallic hydrogen, having twice the diameter of the core. The temperature of this layer ranges from 6 to 20 thousand degrees.
The next layer is made up of a substance made of hydrogen, helium, ammonia, water and others. Its thickness is also about 20 thousand kilometers. Interestingly, at the surface this layer has a gaseous form, but then gradually turns into liquid.
Well, the last, outer layer consists, for the most part, of hydrogen. There is also some helium and slightly less other elements. This layer is gaseous.
Orbit and rotation.
The speed of Jupiter's orbit is not very high. The planet completes a full revolution around the central star in almost 12 years.
But the speed of rotation around its axis, on the contrary, is high. And even more - the highest among all the planets in the system. A turnaround takes just under 10 hours.
Information about the planet Jupiter
Atmosphere.
Jupiter's atmosphere consists of approximately 89% hydrogen and 8-10% helium. The remaining crumbs come from methane, ammonium, water and more.
When observed from afar, the bands of Jupiter are clearly visible - layers of the atmosphere that differ in composition, temperature and pressure. They even have different colors - some are lighter, others are darker. Sometimes they move around the planet in different directions and almost always at different speeds, which is quite beautiful.
In the atmosphere of Jupiter, pronounced phenomena occur: lightning, storms and others. They are on a much larger scale than on our planet.
Temperature.
Despite the distance from the Sun, temperatures on the planet are very high.
In the atmosphere - from approximately -110 °C to +1000 °C. Well, as the distance to the center of the planet decreases, the temperature also increases.
But this does not happen evenly. Especially for its atmosphere, the temperature change in its different layers occurs in a rather unexpected way. It is not yet possible to explain all such changes.
— Due to its rapid rotation around its axis, Jupiter is slightly elongated in height. Thus, its equatorial radius exceeds the polar one by almost 5 thousand kilometers (71.5 thousand km and 66.8 thousand km, respectively).
— The diameter of Jupiter is as close as possible to the limit for planets of this type of structure. With a theoretical further increase in the planet, it would begin to shrink, but its diameter would remain almost unchanged. The same one she has now.
Such compression would lead to the appearance of a new Star.
— In the atmosphere of Jupiter there is a gigantic continuous hurricane - the so-called Jupiter's Red Spot(due to its color when observed). The size of this spot exceeds several diameters of the Earth! 15 by 30 thousand kilometers - this is approximately its size (and it has shrunk by 2 times over the last 100 years).
— The planet has 3 very thin and invisible rings.
“It’s raining diamonds on Jupiter.”
— Jupiter has largest number of satellites among all the planets of the solar system - 67.
One of these satellites, Europa, contains a global ocean reaching a depth of 90 kilometers. The volume of water in this ocean is larger than the volume of the Earth's oceans (although the satellite is noticeably smaller in size than the Earth). Perhaps there are living organisms in this ocean.
Jupiter is the fifth planet from the Sun in the Solar System. This is a giant planet. Jupiter's equatorial diameter is almost 11 times that of Earth. The mass of Jupiter exceeds the mass of the Earth by 318 times.
The planet Jupiter has been known to people since ancient times: like Mercury, Venus, Mars, Saturn, it can be seen in the night sky with the naked eye. When the first imperfect telescopes, telescopes, began to spread in Europe at the end of the 16th century, the Italian scientist Galileo Galilei decided to make such a device for himself. He guessed to use it for the benefit of astronomy. In 1610, Galileo saw tiny “stars” orbiting Jupiter through a telescope. These four satellites discovered by Galileo (Galilean satellites) were named Io, Europa, Ganymede, Callisto.
The ancient Romans identified many of their gods with the Greek ones. Jupiter, the supreme Roman god, is identical to the supreme god of Olympus, Zeus. The satellites of Jupiter were given the names of characters from Zeus' circle. Io is one of his many lovers. Europa is a beautiful Phoenician woman who was kidnapped by Zeus and transformed into a mighty bull. Ganymede is a handsome young cupbearer serving Zeus. Out of jealousy, Hera, the wife of Zeus, turned the nymph Callisto into a bear. Zeus placed it in the sky in the form of the constellation Ursa Major.
For almost three centuries, only the Galilean satellites remained known to science as satellites of Jupiter. In 1892, the fifth satellite of Jupiter, Amalthea, was discovered. Amalthea is a divine goat who fed Zeus with her milk when his mother was forced to shelter her newborn son from the unbridled wrath of his father, the god Kronos. The Horn of Amalthea became a fairytale cornucopia. After Amalthea, discoveries of Jupiter's moons began to pour in like a cornucopia. Currently, 63 satellites of Jupiter are known.
Jupiter and its moons are not only studied by scientists from Earth using modern scientific methods, but have also been examined from closer distances using spacecraft. The American interplanetary automatic station Pioneer 10 first came to a relatively close distance to Jupiter in 1973, Pioneer 11 a year later. In 1979, the American spacecraft Voyager 1 and Voyager 2 approached Jupiter. In 2000, the Cassini automatic interplanetary station passed by Jupiter, transmitting photographs and unique information about the planet and its satellites to Earth. From 1995 to 2003, the Galileo spacecraft operated within the Jupiter system, whose mission was to conduct a detailed study of Jupiter and its moons. Spacecraft not only helped to collect a large amount of information about Jupiter and its many satellites, but also discovered a ring around Jupiter consisting of small solid particles.
The entire swarm of Jupiter's satellites can be divided into two groups. One of them is internal (located closer to Jupiter), which includes four Galilean satellites and Amalthea. All of them, except for the relatively small Amalthea, are large cosmic bodies. The diameter of the smallest of the Galilean moons, Europa, is approximately 0.9 times the diameter of our Moon. The diameter of the largest, Ganymede, is 1.5 times the diameter of the Moon. All these satellites move in their almost circular orbits in the plane of Jupiter's equator in the direction of the planet's rotation. Like our Moon, the Galilean satellites of Jupiter are always turned to their planet with the same side: the time of revolution of each satellite around its axis and around the planet is the same. Most scientists believe that these five moons of Jupiter formed along with their planet.
A huge number of outer satellites of Jupiter are small cosmic bodies. The outer satellites in their motion do not adhere to the plane of the Jupiterian equator. Most of Jupiter's outer satellites orbit in the direction opposite to the planet's rotation. Most likely, they are all “strangers” in the world of Jupiter. Perhaps they are fragments of large cosmic bodies that collided in the vicinity of Jupiter, or of one progenitor that fell apart in a strong gravitational field.
To date, scientists have collected a large amount of information about the planet Jupiter and its satellites; spacecraft have transmitted to earth a huge number of photographs taken from relatively close distances. But a real sensation, which broke the previously existing ideas of scientists about the satellites of planets, was the fact that volcanic eruptions occur on Jupiter’s satellite Io. Small cosmic bodies cool down in outer space during their existence; their depths should not maintain the enormous temperature necessary to maintain volcanic activity.
Io is not just a body that still retains some traces of subsoil activity, but the most active volcanic body in the Solar System known at the present time. Volcanic eruptions on Io can be considered almost continuous. And in their strength they are many times greater than the eruptions of terrestrial volcanoes.
Characteristics of Jupiter
What gives “life” to a small cosmic body that should have long ago turned into a dead block. Scientists believe that the planet's body is constantly heating up due to friction in the rocks that form the satellite, under the influence of the enormous gravitational force of Jupiter and the gravitational forces of Europa and Ganymede. For each revolution, Io changes its orbit twice, moving radially 10 km towards and away from Jupiter. Periodically compressing and unclenching, Io's body heats up in the same way as a bent wire heats up.
Interest children in the well-known facts and as-yet-unrevealed secrets of Jupiter and members of its large family. The Internet provides an opportunity to satisfy interest in this topic.
4.14. Jupiter
4.14.1. Physical characteristics
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Jupiter (gas giant) is the fifth planet of the solar system.
Equatorial radius: 71492 ± 4 km, polar radius: 66854 ± 10 km.
Mass: 1.8986 × 10 27 kg or 317.8 Earth masses.
Average density: 1.326 g/cm³.
Jupiter's spherical albedo is 0.54.
The internal heat flux per unit area of the “surface” of Jupiter is approximately equal to the flux received from the Sun. In this respect, Jupiter is closer to the stars than to the terrestrial planets. However, the source of Jupiter's internal energy is obviously not nuclear reactions. The energy reserve accumulated during the gravitational compression of the planet is emitted.
4.14.2. Elements of orbit and features of motion
The average distance of Jupiter from the Sun is 778.55 million km (5.204 AU). The orbital eccentricity is e = 0.04877. The period of revolution around the Sun is 11.859 years (4331.572 days); average orbital speed – 13.07 km/s. The inclination of the orbit to the ecliptic plane is 1.305°. Rotation axis tilt: 3.13°. Since the equatorial plane of the planet is close to the plane of its orbit, there are no seasons on Jupiter.
Jupiter rotates faster than any other planet in the solar system, and the angular speed of rotation decreases from the equator to the poles. The rotation period is 9.925 hours. Due to its rapid rotation, Jupiter's polar compression is quite noticeable: the polar radius is 6.5% less than the equatorial radius.
Jupiter has the largest atmosphere among the planets in the solar system, which extends to a depth of more than 5000 km. Since Jupiter does not have a solid surface, the inner boundary of the atmosphere corresponds to a depth at which the pressure is 10 bar (i.e., approximately 10 atm).
Jupiter's atmosphere is mainly composed of molecular hydrogen H2 (about 90%) and helium He (about 10%). The atmosphere also contains simple molecular compounds: water, methane, hydrogen sulfide, ammonia, and phosphine, etc. Traces of the simplest hydrocarbons - ethane, benzene and other compounds have also been found.
The atmosphere has a pronounced striped structure, consisting of light zones and dark belts, which are the result of the manifestation of convective flows that carry internal heat to the surface.
In the area of light zones there is increased pressure corresponding to upward flows. The clouds forming the zones are located at a higher level, and their light color is apparently explained by the increased concentration of ammonia NH 3 and ammonium hydrosulfide NH 4 HS.
The dark belt clouds below presumably contain compounds of phosphorus and sulfur, as well as some simple hydrocarbons. These compounds, which are colorless under normal conditions, acquire a dark color as a result of exposure to UV radiation from the Sun. Clouds in dark zones have a higher temperature than in light zones and represent areas of downdrafts. Zones and belts have different speeds of movement in the direction of Jupiter's rotation.
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Jupiter in the IR range |
At the boundaries of belts and zones where strong turbulence is observed, vortex structures arise, the most striking example of which is the Great Red Spot (GRS), a giant cyclone in the atmosphere of Jupiter that has existed for more than 350 years. The gas in the BKP rotates counterclockwise with a rotation period of about 6 Earth days. The wind speed inside the spot exceeds 500 km/h. The bright orange color of the spot is apparently due to the presence of sulfur and phosphorus in the atmosphere.
Jupiter is the most massive planet
The length of the BCP is about 30 thousand km in length, width - 13 thousand km (significantly larger than the Earth). The size of the spot is constantly changing, and there is a tendency towards its reduction, since 100 years ago the BKP was approximately 2 times larger. The spot moves parallel to the planet's equator.
4.14.4. Internal structure
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Internal structure of Jupiter |
It is currently believed that Jupiter has a solid core at its center, followed by a layer of liquid metallic hydrogen mixed with a small amount of helium, and an outer layer of mostly molecular hydrogen. Despite the general, generally formed concept, it nevertheless contains many uncertain and unclear details.
To describe the core, the model of the rocky core of the planet is most often used, but neither the properties of the substance at the extreme pressures and temperatures reached in the core (at least 3000–4500 GPa and 36000 K) nor its detailed composition are known. The presence of a solid core weighing from 12 to 45 Earth masses (or 3–15% of Jupiter's mass) follows from measurements of Jupiter's gravitational field. In addition, the solid (ice or rock) embryo of the proto-Jupiter for the subsequent accretion of light hydrogen and helium is a necessary element in modern models of the origin of planetary systems (see section 4.6).
The core is surrounded by a layer of metallic hydrogen with an admixture of helium and neon condensed into droplets. This shell extends to approximately 78% of the planet's radius. To achieve the state of liquid metallic hydrogen, a pressure of at least 200 GPa and a temperature of about 10,000 K are required (estimated).
Above the layer of metallic hydrogen lies a shell consisting of gas-liquid (in a supercritical state) hydrogen with an admixture of helium. The upper part of this shell smoothly passes into the outer layer - the atmosphere of Jupiter.
Within the framework of this simple three-layer model, there is no clear boundary between the main layers, however, the regions of phase transitions are also small in thickness. Consequently, we can assume that almost all processes are localized, which allows us to consider each layer separately.
Jupiter has a powerful magnetic field. The field strength at the level of the visible cloud surface is 14 oersteds at the north pole and 10.7 oersteds at the south pole. The dipole axis is inclined to the rotation axis by 10°, and the polarity is opposite to the polarity of the earth's magnetic field. The existence of a magnetic field is explained by the presence of metallic hydrogen in the depths of Jupiter, which, being a good conductor, rotating at high speed, creates magnetic fields.
Jupiter is surrounded by a powerful magnetosphere, which on the day side extends to a distance of 50–100 radii of the planet, and on the night side it extends beyond the orbit of Saturn. If Jupiter's magnetosphere could be seen from the surface of the Earth, its angular dimensions would exceed the dimensions of the Moon.
Compared to the Earth's magnetosphere, the Jupiter magnetosphere is not only larger in size and power, but also has a slightly different shape, and also, along with the dipole, has pronounced quadrupole and octupole components. The shape of Jupiter's magnetosphere is determined by two additional factors that are absent in the case of the Earth - the rapid rotation of Jupiter and the presence of a nearby and powerful source of magnetospheric plasma - Jupiter's satellite Io.
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Jupiter in the radio range |
Thanks to volcanic activity, Io, located at a distance of only about 4.9R J from the upper layer of the planet, supplies up to 1 ton of neutral gas rich in sulfur, sulfur dioxide, oxygen, and sodium into Jupiter’s magnetosphere every second. This gas is partially ionized and forms a plasma torus near Io's orbit.
As a result of the combined action of rapid rotation and intramagnetospheric plasma formation, an additional source of magnetic field is created - the Jupiter magnetodisk. The plasma concentrates in the core of the magnetosphere in the low-latitude region, forming a magnetodisk - a thin current layer, the value of the azimuthal current in which decreases in proportion to the distance from the planet. The total current in the magnetodisk reaches a value of about 100 million amperes.
Electrons moving in Jupiter's radiation belts are a source of powerful incoherent synchrotron radiation from the magnetosphere in the radio range.
4.14.6. General characteristics of the satellites and rings of Jupiter
It is currently known that Jupiter has 63 natural satellites and a ring system. All satellites are divided into two categories: regular and irregular.
Eight regular satellites orbit Jupiter in the direction of its rotation in almost circular orbits. Regular satellites, in turn, are divided into internal (satellites of the Amalthea group) and main (or Galilean).
Shepherd companions. The four inner satellites of Jupiter - Metis (dimensions 60 × 40 × 34 km), Adrastea (20 × 16 × 14 km), Amalthea (250 × 146 × 128 km) and Theba (116 × 98 × 84 km) - have an irregular shape and play the role of the so-called shepherd moons that keep the rings of Jupiter from disintegrating.
Rings of Jupiter. Jupiter has faint rings that are located at an altitude of 55,000 km from the atmosphere. There are two main rings and one very thin inner ring, with a characteristic orange color. The main part of the rings has a radius of 123–129 thousand km. The thickness of the rings is about 30 km. The rings are almost always edge-on towards the earthly observer, which is why they went unnoticed for a long time. The rings themselves consist mainly of dust and small stone particles that poorly reflect the sun's rays, and therefore they are difficult to distinguish.
Galilean satellites. The four Galilean moons of Jupiter (Io, Europa, Ganymede and Callisto) are among the largest moons in the Solar System. The total mass of the Galilean moons is 99.999% of all objects orbiting Jupiter (for more information on the Galilean moons, see section 4.14.7 below).
Irregular satellites. It is customary to call irregular satellites those satellites whose orbits have large eccentricities; or satellites that move in orbit in the opposite direction; or satellites whose orbits are characterized by large inclinations to the equatorial plane. The irregular satellites are, apparently, asteroids captured from among the “Trojans” or “Greeks”.
Irregular satellites that orbit Jupiter in the direction of its rotation:
Themisto (does not form a family);
Himalia group (Leda, Himalia, Lysitia, Elara, S/2000 J 11);
Carpo (does not form a family).
Irregular satellites that orbit Jupiter in the opposite direction:
S/2003 J 12 (does not form a family);
Karme group (13 satellites);
Ananke group (16 satellites);
Pasiphe group (17 satellites);
S/2003 J 2 (does not form a family).
4.14.7. Galilean moons: Io, Europa, Ganymede and Callisto
The Galilean moons of Jupiter (Io, Europa, Ganymede and Callisto) were discovered by Galileo Galilei (after whom they were named) on January 8, 1610.
The Galilean satellites rotate synchronously and always face the same side towards Jupiter (i.e., they are in a 1:1 spin-orbit resonance) due to the influence of the powerful tidal forces of the giant planet. In addition, Io, Europa and Ganymede are in orbital resonance - their orbital periods are in the ratio 1:2:4. The stability of the orbital resonances of the Galilean satellites has been observed since the discovery, i.e., for 400 Earth years and more than 20 thousand “satellite” (Ganymede) years (the orbital period of Ganymede is 7.155 Earth days).
Io(average diameter - 3640 km, mass - 8.93 × 10 22 kg or 0.015 Earth mass, average density - 3.528 g / cm 3) is closer than other Galilean satellites to Jupiter (on average at a distance of 4.9R J from its surface) than , apparently, is due to its volcanic activity - the highest in the solar system. More than 10 volcanoes can erupt on Io's surface at the same time. As a result, Io's topography completely changes over the course of several hundred years. The largest eruptions of Ionian volcanoes eject matter at a speed of 1 km/s to a height of up to 300 km. Like terrestrial volcanoes, the volcanoes on Io emit sulfur and sulfur dioxide. Impact craters are practically absent on Io, as they are destroyed by constant eruptions and lava flows. In addition to volcanoes, Io has non-volcanic mountains, lakes of molten sulfur, and viscous lava flows hundreds of kilometers long. Unlike the other Galilean moons, Io has no water or ice.
Europe(diameter - 3122 km, mass - 4.80 × 10 22 kg or 0.008 Earth mass, average density - 3.01 g / cm 3) is located on average at a distance of 8.4R J from the surface of Jupiter. Europe is completely covered by a layer of water, presumably about 100 km thick (partly in the form of an icy surface crust 10–30 km thick; partly, it is believed, in the form of a subsurface liquid ocean). Further down lies the rocks, and in the center there is supposedly a small metal core. The depth of the ocean is up to 90 km, and its volume exceeds the volume of the Earth's oceans. The heat required to maintain it in a liquid state is presumably generated due to tidal interactions (in particular, tides raise the surface of the satellite to a height of up to 30 meters). The surface of Europa is very flat, with only a few hill-like formations being several hundred meters high. The high albedo (0.67) of the satellite indicates that the surface ice is quite clean. The number of craters is small; there are only three craters with a diameter greater than 5 km.
Jupiter's strong magnetic field causes electric currents in Europa's salty ocean, which form its unusual magnetic field.
The magnetic poles are located near the equator of the satellite and are constantly shifting. Changes in field strength and orientation correlate with Europa's passage through Jupiter's magnetic field. It is believed that life may exist in Europa's ocean.
There are mainly two types of regions on the surface of Ganymede: very old, heavily cratered dark regions and younger (but also ancient) light regions marked by extended rows of ridges and notches. The origin of the light regions is obviously associated with tectonic processes. Numerous impact craters are present on both types of Ganymede's surface, which indicates their antiquity - up to 3–3.5 billion years (similar to the lunar surface).
Callisto(diameter - 4821 km, mass - 1.08 × 10 23 kg or 0.018 Earth mass, average density - 1.83 g / cm 3) is on average located at a distance of 25.3R J from the surface of Jupiter. Callisto is one of the most cratered bodies in the Solar System. Consequently, the surface of the satellite is very old (about 4 billion years), and its geological activity is extremely low. Callisto has the lowest density of all the Galilean moons (a trend is observed: the further the satellite is from Jupiter, the lower its density) and consists of probably 60% ice and water and 40% rock and iron. It is assumed that Callisto is covered with an ice crust 200 km thick, under which there is a layer of water about 10 km thick. The deeper layers appear to consist of compressed rocks and ice, with a gradual increase in rock and iron towards the center.
Further reading:
T. Owen, S. Atreya, H. Nieman. “Sudden guess”: the first results of sounding the atmosphere of Titan by the Huygens spacecraft
Basic data
| Object | radius orbits, million km. Planet Jupiter brief description |
orbital circulation period |
radius, thousand km | weight, kg | circulation period around its axis, days |
free fall acceleration, g | surface temperature, K |
| Sun | — | — | 695 | 2*10^30 | 24,6 | ||
| Mercury | 58 | 88 days | 2,4 | 3,3*10^23 | 58,6 | 0,38 | 440 |
| Venus | 108 | 225 days | 6,1 | 4,9*10^24 | 243 (arr.) | 0,91 | 730 |
| Earth | 150 | 365 days | 6,4 | 6*10^24 | 1 | 1 | 287 |
| Mars | 228 | 687 days | 3,4 | 6,4*10^23 | 1,03 | 0,38 | 218 |
| Jupiter | 778 | 12 years old | 71 | 1,9*10^27 | 0,41 | 2,4 | 120 |
| Saturn | 1429 | 29 years old | 60 | 5,7*10^26 | 0,45 | 0,92 | 88 |
| Uranus | 2871 | 84 years old | 26 | 8,7*10^25 | 0.72 (rev) | 0,89 | 59 |
| Neptune | 4504 | 165 years | 25 | 1,0*10^26 | 0,67 | 1,1 | 48 |
The largest satellites of the planets
| Object | radius orbits, thousand km. |
orbital circulation period, days |
radius, km | weight, kg | revolves around |
| Gannymede | 1070 | 7,2 | 2634 | 1,5*10^23 | Jupiter |
| Titanium | 1222 | 16 | 2575 | 1,4*10^23 | Saturn |
| Callisto | 1883 | 16,7 | 2403 | 1,1*10^23 | Jupiter |
| Io | 422 | 1,8 | 1821 | 8,9*10^22 | Jupiter |
| Moon | 384 | 27,3 | 1738 | 7,4*10^22 | Earth |
| Europe | 671 | 3,6 | 1565 | 4,8*10^22 | Jupiter |
| Triton | 355 | 5.9 (arr.) | 1353 | 2,2*10^22 | Neptune |
obr - rotates in the direction opposite to the orbital movement
Jupiter is the largest planet in the solar system, its diameter is 11 times the diameter of the Earth, and its mass is 318 times the mass of the Earth. Jupiter's orbit around the Sun takes 12 years, while the average distance to the Sun is 800 million km. The cloud belts in the atmosphere and the Great Red Spot make Jupiter a very picturesque planet.
Jupiter is not a rocky planet. Unlike the four rocky planets closest to the Sun, Jupiter is a huge ball of gas. There are three more gas giants that are even further away from the Sun: Saturn, Uranus and Neptune. In their chemical composition, these gas planets are very similar to the Sun and are very different from the rocky inner planets of the Solar System. Jupiter's atmosphere, for example, is 85 percent hydrogen and about 14 percent helium. Although we can't see any solid, rocky surface through Jupiter's clouds, deep inside the planet the hydrogen is under such pressure that it takes on some of the characteristics of a metal.
Jupiter rotates on its axis extremely quickly - it makes one revolution every 10 hours. The rotation speed is so high that the planet bulges along the equator. This rapid rotation is also the cause of very strong winds in the upper atmosphere, where clouds stretch out into long, colorful ribbons. Different parts of the atmosphere rotate at slightly different speeds, and it is this difference that gives rise to cloud bands. Clouds over Jupiter are patchy and stormy, so the appearance of cloud bands can change in just a few days. In addition, the clouds of Jupiter contain a very large number of vortices and large spots. The largest of them is the so-called Great Red Spot, which is larger than the Earth. It can be seen even through a small telescope. The Great Red Spot is a huge storm in Jupiter's atmosphere that has been observed for 300 years. There are at least 16 moons in orbit around Jupiter. One of
them, is the largest satellite in our solar system; it is larger than the planet Mercury.
Travels to Jupiter
Five spacecraft have already been sent to Jupiter. The fifth of these, Galileo, was launched on a six-year journey in October 1989. The Pioneer 10 and Pioneer 11 spacecraft made measurements for the first time. They were followed by the two Voyager spacecraft in 1979, which provided close-up photographs that are simply breathtaking. After 1991, the Hubble Space Telescope began photographing Jupiter, and these images are not inferior in quality to those taken by Voyagers. In addition, the Hubble Space Telescope will take photographs for several years, while Voyagers had only a short period of time at their disposal while they flew past Jupiter.
Clouds of poisonous gas
The dark, reddish stripes on Jupiter are called belts, and the lighter stripes are called zones. Photos taken by spacecraft and the Hubble Space Telescope reveal noticeable changes in waistlines and butts in just a few weeks. This is due to the fact that the characteristic features of Jupiter visible to us are actually the colored and white clouds of the upper atmosphere. Near the Great Red Spot, clouds form beautiful patterns with vortices and waves. Clouds spinning in vortices are blown away along the stripes by strong winds, the speed of which exceeds 500 km/h.
Much of Jupiter's atmosphere would be harmful to humans. In addition to the predominant gases - hydrogen and helium - it also contains methane, poisonous ammonia, water vapor and acetylene. You would find such a place smelly. This gas composition is similar to that of the sun.
White clouds contain crystals of frozen ammonia and water ice. Brown, red and blue clouds may owe their color to chemicals like our dyes or sulfur. Thunderstorm lightning can be seen through the outer layers of the atmosphere.
The active cloud layer is quite thin, less than one hundredth the radius of the planet. Below the clouds the temperature gradually increases. And although on the surface of the cloud layer it is -160 ° C, descending through the atmosphere only 60 km, we would find the same temperature as on the surface of the Earth. And a little deeper, the temperature already reaches the boiling point of water.
Unusual substance
In the depths of Jupiter, matter begins to carry itself in a very unusual way. Although it cannot be ruled out that there is a small iron core in the center of the planet, the largest part of the deep region consists of hydrogen. Inside the planet, under enormous pressure, hydrogen turns from a gas into a liquid. At deeper and deeper levels, pressure continues to try due to the colossal weight of the overlying layers of the atmosphere.
At a depth of about 100 km there is a vast ocean of liquid hydrogen. Below 17,000 km, hydrogen becomes so compressed that its atoms are destroyed. And then it begins to behave like metal; in this state it easily conducts electricity. Electric current flowing through metallic hydrogen creates a strong magnetic field around Jupiter.
Metallic hydrogen in the depths of Jupiter is an example of an unusual type of matter that astronomers can study that is almost impossible to reproduce in the laboratory.
Almost a star
Jupiter releases more energy than it receives from the Sun. Measurements made by spacecraft have shown that Jupiter emits about 60 percent more thermal energy than it receives from solar radiation.
It is believed that additional heat comes from three sources: from heat reserves remaining from the formation of Jupiter; silt of energy released in the process of slow compression, contraction of the planet; and, finally, from the energy of radioactive decay.
Planet Jupiter
This heat, however, does not arise from the cessation of hydrogen into helium, as happens in stars. In fact, even the smallest stars harnessing the energy of such termination are about 80 times more massive than Jupiter. This means that other “solar systems” may have planets larger than Jupiter, although smaller than the star.
Radio station Jupiter
Jupiter is a natural radio station. No meaning can be extracted from Jupiter's radio signals, since they consist entirely of noise. These radio signals are created by electrons rushing through Jupiter's very strong magnetic field. Powerful storms and lightning strikes are superimposed on the chaotic radio roar. Jupiter has a strong magnetic field that extends 50 planet diameters in all directions. No other planet in the solar system has such strong magnetism or produces such powerful radio emission.
Moons of Jupiter
The family of 16 moons of Jupiter is like a miniature solar system, where Jupiter plays the role of the Sun, and its magnifying glasses play the role of the planets. The largest moon is Ganymede, its diameter is 5262 km. It is covered with a thick crust of ice lying on top of a rocky core. There are numerous traces of meteorite bombardment, as well as evidence of a collision with a giant asteroid 4 billion years ago.
Callisto is almost as large as Ganymede, and its entire surface is densely dotted with craters. Europe has the lightest surface. One-fifth of Europe consists of water, which forms an ice shell 100 km thick on it. This icy coating reflects light as strongly as the clouds of Venus.
Of all the loops, the most picturesque is Io, which rotates closest to Jupiter. Io's cyst is completely unusual - it is a mixture of black, red and yellow. This amazing coloring is explained by the fact that a large amount of sulfur was erupted from the depths of Io. Voyager's cameras showed several active volcanoes on Io; they emit fountains of sulfur 200 km high above the surface. Sulfur lava flies out at a speed of 1000 m and a second. Some of this lava material escapes from Io's zero gravity and forms a ring encircling Jupiter.
The surface of Io was grinding. We can promise this because it almost has the appearance of meteorite craters. Io's orbit is less than 400,000 km from Jupiter. Therefore, Io is subject to enormous tidal forces. The constant alternation of stretching and compressing tides inside Io generates intense internal friction. Thanks to this, the inner regions remain hot and molten, despite Io's great distance from the Sun.
In addition to four large moons, Jupiter also has small “lups”. Four of them fly lower above Jupiter's surface than Io, and scientists believe they are simply large pieces of other moons that have ceased to exist.
