The solar system consists of eight planets and more than 63 of their satellites, which are being discovered more and more often, as well as several dozen comets and a large number of asteroids. All cosmic bodies move along their clear directed trajectories around the Sun, which is 1000 times heavier than all the bodies in the solar system combined.
How many planets revolve around the sun
How the planets of the solar system originated: approximately 5-6 billion years ago, one of the gas and dust clouds of our large Galaxy ( milky way), shaped like a disk, began to shrink towards the center, gradually forming the current Sun. Further, according to one of the theories, under the influence of powerful forces of attraction, a large number of dust and gas particles rotating around the Sun began to stick together into balls - forming future planets. According to another theory, the gas and dust cloud immediately broke up into separate clusters of particles, which compressed and condensed, forming the current planets. Now 8 planets revolve around the sun constantly.
Center solar system is the Sun - a star around which planets revolve in orbits. They do not emit heat and do not glow, but only reflect the light of the sun. There are currently 8 officially recognized planets in the solar system. Briefly, in order of distance from the sun, we list them all. And now some definitions.
Planet satellites. The solar system also includes the Moon and the natural satellites of other planets, which all of them have, except for Mercury and Venus. More than 60 satellites are known. Most of the satellites of the outer planets were discovered when they received photographs taken by robotic spacecraft. Jupiter's smallest moon, Leda, is only 10 km across.
The Sun is a star without which life on Earth could not exist. It gives us energy and warmth. According to the classification of stars, the Sun is a yellow dwarf. The age is about 5 billion years. It has a diameter at the equator equal to 1,392,000 km, 109 times larger than the earth. The rotation period at the equator is 25.4 days and 34 days at the poles. The mass of the Sun is 2x10 to the 27th power of tons, approximately 332950 times the mass of the Earth. The temperature inside the core is about 15 million degrees Celsius. The surface temperature is about 5500 degrees Celsius.
According to the chemical composition, the Sun consists of 75% hydrogen, and of the other 25% of the elements, most of all helium. Now, in order, let's figure out how many planets revolve around the sun, in the solar system and the characteristics of the planets.
Solar system planets in order from the sun
in pictures
Mercury is the 1st planet in the solar system
Mercury. The four inner planets (nearest to the Sun) - Mercury, Venus, Earth and Mars - have a solid surface. They are smaller than four giant planets. Mercury moves faster than other planets, burning sunbeams during the day and freezing at night.
Characteristics of the planet Mercury:
Period of revolution around the Sun: 87.97 days.
Diameter at the equator: 4878 km.
Rotation period (turn around the axis): 58 days.
Surface temperature: 350 during the day and -170 at night.
Atmosphere: very rarefied, helium.
How many satellites: 0.
The main satellites of the planet: 0.
Venus is the 2nd planet in the solar system
Venus is more similar to Earth in size and brightness. Observation of it is difficult because of the clouds enveloping it. The surface is a hot, rocky desert.
Characteristics of the planet Venus:
Period of revolution around the Sun: 224.7 days.
Diameter at the equator: 12104 km.
Rotation period (turn around the axis): 243 days.
Surface temperature: 480 degrees (average).
Atmosphere: dense, mostly carbon dioxide.
How many satellites: 0.
The main satellites of the planet: 0.
Earth is the 3rd planet in the solar system
Apparently, the Earth was formed from a gas and dust cloud, like other planets in the solar system. Particles of gas and dust, colliding, gradually "raised" the planet. The temperature on the surface reached 5000 degrees Celsius. Then the Earth cooled down and became covered with a hard stone crust. But the temperature in the bowels is still quite high - 4500 degrees. Rocks in the bowels are molten and pour out to the surface during volcanic eruptions. Only on earth there is water. That's why life exists here. It is located relatively close to the Sun to receive the necessary heat and light, but far enough away so as not to burn out.
Characteristics of the planet Earth:
Period of revolution around the Sun: 365.3 days.
Diameter at the equator: 12756 km.
The period of rotation of the planet (rotation around the axis): 23 hours 56 minutes.
Surface temperature: 22 degrees (average).
Atmosphere: mostly nitrogen and oxygen.
Number of satellites: 1.
The main satellites of the planet: the Moon.
Mars is the 4th planet in the solar system
Due to the similarity with the Earth, it was believed that life exists here. But the spacecraft that landed on the surface of Mars found no signs of life. This is the fourth planet in order.
Characteristics of the planet Mars:
Period of revolution around the Sun: 687 days.
Diameter of the planet at the equator: 6794 km.
Rotation period (rotation around the axis): 24 hours 37 minutes.
Surface temperature: -23 degrees (average).
Atmosphere of the planet: rarefied, mostly carbon dioxide.
How many satellites: 2.
Main moons in order: Phobos, Deimos.
Jupiter is the 5th planet in the solar system
Jupiter, Saturn, Uranus and Neptune are made up of hydrogen and other gases. Jupiter is more than 10 times larger than Earth in diameter, 300 times in mass and 1300 times in volume. It is more than twice as massive as all the planets in the solar system combined. How much planet Jupiter does it take to become a star? It is necessary to increase its mass by 75 times!
Characteristics of the planet Jupiter:
The period of revolution around the Sun: 11 years 314 days.
Diameter of the planet at the equator: 143884 km.
Rotation period (turn around the axis): 9 hours 55 minutes.
Planet surface temperature: -150 degrees (average).
Number of satellites: 16 (+ rings).
The main satellites of the planets in order: Io, Europa, Ganymede, Callisto.
Saturn is the 6th planet in the solar system
This is the number 2 largest of the planets in the solar system. Saturn draws attention to itself thanks to a system of rings formed from ice, rocks and dust that orbit the planet. There are three main rings with an outer diameter of 270,000 km, but their thickness is about 30 meters.
Characteristics of the planet Saturn:
The period of revolution around the Sun: 29 years 168 days.
Diameter of the planet at the equator: 120536 km.
Rotation period (turn around the axis): 10 hours 14 minutes.
Surface temperature: -180 degrees (average).
Atmosphere: mostly hydrogen and helium.
Number of satellites: 18 (+ rings).
Main satellites: Titan.
Uranus is the 7th planet in the solar system
Unique planet in the solar system. Its peculiarity is that it revolves around the Sun not like everyone else, but "lying on its side." Uranus also has rings, although they are harder to see. In 1986, Voyager 2 flew 64,000 km and had six hours to take photos, which it successfully completed.
Characteristics of the planet Uranus:
Orbital period: 84 years 4 days.
Diameter at the equator: 51118 km.
The period of rotation of the planet (rotation around the axis): 17 hours 14 minutes.
Surface temperature: -214 degrees (average).
Atmosphere: mostly hydrogen and helium.
How many satellites: 15 (+ rings).
Main satellites: Titania, Oberon.
Neptune is the 8th planet in the solar system
At the moment, Neptune is considered the last planet in the solar system. Its discovery took place by the method of mathematical calculations, and then they saw it through a telescope. In 1989, Voyager 2 flew by. He took amazing photographs of the blue surface of Neptune and its largest moon, Triton.
Characteristics of the planet Neptune:
The period of revolution around the Sun: 164 years 292 days.
Diameter at the equator: 50538 km.
Rotation period (turn around the axis): 16 hours 7 minutes.
Surface temperature: -220 degrees (average).
Atmosphere: mostly hydrogen and helium.
Number of satellites: 8.
Main moons: Triton.
How many planets in the solar system: 8 or 9?
Previously, for many years, astronomers recognized the presence of 9 planets, that is, Pluto was also considered a planet, like the rest of everyone already known. But in the 21st century, scientists were able to prove that it is not a planet at all, which means that there are 8 planets in the solar system.
Now, if you are asked how many planets are in the solar system, answer boldly - 8 planets in our system. It has been officially recognized since 2006. When lining up the planets of the solar system in order from the sun, use the finished picture. What do you think, maybe Pluto should not have been removed from the list of planets and these are scientific prejudices?
How many planets in the solar system: video, watch for free
On March 13, 1781, English astronomer William Herschel discovered the seventh planet in the solar system - Uranus. And on March 13, 1930, American astronomer Clyde Tombaugh discovered the ninth planet in the solar system - Pluto. By the beginning of the 21st century, it was believed that the solar system included nine planets. However, in 2006, the International Astronomical Union decided to strip Pluto of this status.
There are already 60 known natural satellites of Saturn, most of which have been discovered using spacecraft. Most satellites are made up of rocks and ice. The largest satellite, Titan, discovered in 1655 by Christian Huygens, is larger than the planet Mercury. The diameter of Titan is about 5200 km. Titan orbits Saturn every 16 days. Titan is the only satellite to have a very dense atmosphere, 1.5 times the size of Earth's, and consisting mostly of 90% nitrogen, with a moderate amount of methane.
The International Astronomical Union officially recognized Pluto as a planet in May 1930. At that moment, it was assumed that its mass was comparable to the mass of the Earth, but later it was found that the mass of Pluto is almost 500 times less than the Earth's, even less than the mass of the Moon. The mass of Pluto is 1.2 times 1022 kg (0.22 Earth masses). The average distance of Pluto from the Sun is 39.44 AU. (5.9 by 10 to the 12th degree km), the radius is about 1.65 thousand km. The period of revolution around the Sun is 248.6 years, the period of rotation around its axis is 6.4 days. The composition of Pluto supposedly includes rock and ice; the planet has a thin atmosphere composed of nitrogen, methane and carbon monoxide. Pluto has three moons: Charon, Hydra and Nyx.
In the late 20th and early 21st centuries, many objects were discovered in the outer solar system. It has become clear that Pluto is only one of the largest Kuiper belt objects known to date. Moreover, at least one of the objects of the belt - Eris - is a larger body than Pluto and 27% heavier than it. In this regard, the idea arose to no longer consider Pluto as a planet. On August 24, 2006, at the XXVI General Assembly of the International Astronomical Union (IAU), it was decided to henceforth call Pluto not a "planet", but a "dwarf planet".
At the conference, a new definition of the planet was developed, according to which planets are considered to be bodies revolving around a star (and not being a star themselves), having a hydrostatic equilibrium shape and "clearing" the area in the region of their orbit from other, smaller, objects. Dwarf planets will be considered objects that revolve around a star, have a hydrostatically equilibrium shape, but have not "cleared" the nearby space and are not satellites. Planets and dwarf planets are two different classes of solar system objects. All other objects revolving around the Sun and not being satellites will be called small bodies of the solar system.
Thus, since 2006, there have been eight planets in the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. Five dwarf planets are officially recognized by the International Astronomical Union: Ceres, Pluto, Haumea, Makemake, and Eris.
On June 11, 2008, the IAU announced the introduction of the concept of "plutoid". It was decided to call plutoids celestial bodies that revolve around the Sun in an orbit whose radius is greater than the radius of Neptune's orbit, whose mass is sufficient for gravitational forces to give them an almost spherical shape, and which do not clear the space around their orbit (that is, many small objects revolve around them ).
Since it is still difficult to determine the shape and thus the relation to the class of dwarf planets for such distant objects as plutoids, scientists recommended temporarily assigning to plutoids all objects whose absolute asteroid magnitude (brilliance from a distance of one astronomical unit) is brighter than +1. If it later turns out that the object assigned to the plutoids is not a dwarf planet, it will be deprived of this status, although the assigned name will be left. The dwarf planets Pluto and Eris were classified as plutoids. In July 2008, Makemake was included in this category. On September 17, 2008, Haumea was added to the list.
The material was prepared on the basis of information from open sources
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Satellites of the planets of the solar system: the exact number for the planets of the inner and outer systems, the largest and smallest satellite, description, photo, research.
For many centuries, people could observe the only available satellite - the Moon. But in 1610, Galileo makes a breakthrough and finds 4 satellites of Jupiter, proving that other celestial bodies have moons. But how many of them are there in our system?
How many satellites are in the solar system
It is difficult to answer how many satellites the planets of the solar system have, because there are confirmed candidates. Now they can be counted up to 173, but if you take into account the dwarf planets, then 182. You can study in more detail each satellite for the solar planets in order in the tablet.
| Group Amalthea |
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| Galilean satellites |
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| Group Themisto |
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| Group Himalaya |
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| Group Ananke |
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| Group Karma |
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| Pasife Group | · · · · · · · · · · · · · |
| Group Karpo |
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The solar system is also home to 200 very tiny objects located in the Kuiper belt, and representatives of TNOs (trans-Neptunian objects). Approximately 150 orbit Saturn (62 with officially confirmed orbits). If we combine everything, we get the result of 545 moons.
internal system
The inner system is the zone with the first four planets from the Sun. But here we only consider our planet Earth and Mars, because Venus and Mercury rotate alone.
The Earth's Moon extends in a radius of 1737 km, and in terms of mass - 7.3477 x 10 22 kg. Density index - 3.3464 g / cm 3. It is believed that it was formed after the collision of the Earth with a large celestial body.
The Martian lunar family consists of Phobos and Deimos. Both are in a tidal block and resemble asteroids. It is believed that the planet pulled them from the asteroid belt. Phobos is located closer (9377 km) and extends for 27 km.
Deimos spans only 12.6 km and is 23,460 km distant, which means it takes 30.35 hours to orbit. In total, 3 satellites live in the internal system.
External system
Beyond the asteroid belt, the outer solar system begins and the lunar quantity increases sharply. And it all starts with the gas giant and the largest planet - Jupiter. He has the largest number - 79, which can grow to 200 if applicants are confirmed.
The four largest were named after the discoverer Galileo Galilei - Galilean: Io (the most volcanic), Europa (with an underground ocean), Ganymede (the largest in the system) and Callisto (underground ocean and ancient surface).
There is also the Almateya group with four satellites less than 200 km in diameter. Irregular satellites are very tiny and distant over long distances. They are also divided into families according to composition and orbital path.
Saturn may have 150 moons, but 62 are considered official (53 have names). 34 of them have a diameter of less than 10, and 14 - from 10 to 50 km. But there are also large-scale specimens stretching for 5000 km. All of them got their names in honor of the titans.
The interiors are composed of water ice and have a rocky core, icy mantle, and crust. The outer ones go beyond the E-ring. Titan is considered the largest with a diameter of 5150 km and a mass of 1350 x 10 20 kg. It contains 96% of the mass of the entire planetary orbit.
There are 27 moons revolving around Uranus. Among the largest are Miranda, Ariel (the brightest), Umbriel (the darkest), Oberon and Titania.
All of these moons are believed to have originated in the accretion disk of the planet. Each has an equal volume of rock and ice. Only Miranda is almost completely icy.
Neptune has 14 moons named after sea nymphs. The right ones are close to the planet, while the wrong ones formed from the remnants of early collisions and move far in retrograde orbits.
The largest is Triton with a diameter of 2700 km. It is distant at 354,759 km from the planet and has enough mass to achieve hydrostatic balance.
Dwarf planets and other objects
A detailed study of the system showed that the moons revolve not only around the planets. There are also dwarf, TNO and other bodies. Mostly seen near Pluto, Eris, Haumea and Makemake.
Pluto has 5 moons, among which Charon is the largest and closest.
There are also Nikta and Hydra found in 2005, Kerberus in 2011 and Styx in 2012. Among them all, only Nikta and Hydra have an elongated shape and could not become spherical. Some believe that Pluto and Charon should be taken as a binary system. They are located in the tidal block, and the satellite may have cryogeysers.
Hiiaka and Nakama, found in 2005, revolve around Haumea. The first extends for 310 km and may be part of a dwarf planet. The second makes an orbital passage in 18 days.
Eris has Dysnomnia, seen in 2005.
In 2016, S/2015 (136472) was discovered near Makemake, stretching for 175 km, and its distance is 21,000 km.
The largest and smallest satellites of the solar system
The king of all moons in the system is Ganymede with a diameter of 5262.4 km. And the smallest are S / 2003 J9 and S / 2003 J12, whose size is only 1 km.
Now you know how many satellites are in the solar system. Do not forget that we are talking only about those satellites that we managed to detect.
solar system- these are 8 planets and more than 63 of their satellites, which are being discovered more and more often, several dozen comets and a large number of asteroids. All cosmic bodies move along their clear directed trajectories around the Sun, which is 1000 times heavier than all the bodies in the solar system combined. The center of the solar system is the Sun - a star around which planets revolve in orbits. They do not emit heat and do not glow, but only reflect the light of the sun. There are currently 8 officially recognized planets in the solar system. Briefly, in order of distance from the sun, we list them all. And now some definitions.
Planet- this is a celestial body that must satisfy four conditions:
1. the body must revolve around a star (for example, around the Sun);
2. the body must have sufficient gravity to have a spherical or close to it shape;
3. the body should not have other large bodies near its orbit;
4. the body should not be a star
Planet satellites. The solar system also includes the Moon and the natural satellites of other planets, which all of them have, except for Mercury and Venus. More than 60 satellites are known. Most of the satellites of the outer planets were discovered when they received photographs taken by robotic spacecraft. Jupiter's smallest moon, Leda, is only 10 km across.
is a star, without which life on Earth could not exist. It gives us energy and warmth. According to the classification of stars, the Sun is a yellow dwarf. The age is about 5 billion years. It has a diameter at the equator equal to 1,392,000 km, 109 times larger than the earth. The rotation period at the equator is 25.4 days and 34 days at the poles. The mass of the Sun is 2x10 to the 27th power of tons, approximately 332950 times the mass of the Earth. The temperature inside the core is about 15 million degrees Celsius. The surface temperature is about 5500 degrees Celsius. According to the chemical composition, the Sun consists of 75% hydrogen, and of the other 25% of the elements, most of all helium. Now let's figure out in order how many planets revolve around the sun, in the solar system and the characteristics of the planets.
The four inner planets (nearest to the Sun) - Mercury, Venus, Earth and Mars - have a solid surface. They are smaller than four giant planets. Mercury moves faster than other planets, being burned by the sun's rays during the day and freezing at night.
Period of revolution around the Sun: 87.97 days. Diameter at the equator: 4878 km.
Rotation period (turn around the axis): 58 days.
Surface temperature: 350 during the day and -170 at night.
Atmosphere: very rarefied, helium.
How many satellites: 0.
The main satellites of the planet: 0.
More like the Earth in size and brightness. Observation of it is difficult because of the clouds enveloping it. The surface is a hot rocky desert. 
Period of revolution around the Sun: 224.7 days.
Diameter at the equator: 12104 km.
Rotation period (turn around the axis): 243 days.
Surface temperature: 480 degrees (average).
Atmosphere: dense, mostly carbon dioxide.
How many satellites: 0.
The main satellites of the planet: 0.
Apparently, the Earth was formed from a gas and dust cloud, like other planets. Particles of gas and dust, colliding, gradually "raised" the planet. The temperature on the surface reached 5000 degrees Celsius. Then the Earth cooled down and became covered with a hard stone crust. But the temperature in the depths is still quite high - 4500 degrees. Rocks in the bowels are molten and pour out to the surface during volcanic eruptions. Only on earth there is water. That's why life exists here. It is located relatively close to the Sun to receive the necessary heat and light, but far enough away so as not to burn out.
Period of revolution around the Sun: 365.3 days. Diameter at the equator: 12756 km.
The period of rotation of the planet (rotation around the axis): 23 hours 56 minutes.
Surface temperature: 22 degrees (average).
Atmosphere: mostly nitrogen and oxygen.
Number of satellites: 1.
The main satellites of the planet: the Moon.
Due to the similarity with the Earth, it was believed that life exists here. But the spacecraft that landed on the surface of Mars found no signs of life. This is the fourth planet in order. 
Period of revolution around the Sun: 687 days.
Diameter of the planet at the equator: 6794 km.
Rotation period (rotation around the axis): 24 hours 37 minutes.
Surface temperature: -23 degrees (average).
Atmosphere of the planet: rarefied, mostly carbon dioxide.
How many satellites: 2.
Main moons in order: Phobos, Deimos.
Jupiter, Saturn, Uranus and Neptune are made up of hydrogen and other gases. Jupiter is more than 10 times larger than Earth in diameter, 300 times in mass and 1300 times in volume. It is more than twice as massive as all the planets in the solar system combined. How much planet Jupiter does it take to become a star? It is necessary to increase its mass by 75 times!
The period of revolution around the Sun: 11 years 314 days. Diameter of the planet at the equator: 143884 km.
Rotation period (turn around the axis): 9 hours 55 minutes.
Surface temperature of the planet: -150 degrees (average).
Number of satellites: 16 (+ rings).
The main satellites of the planets in order: Io, Europa, Ganymede, Callisto.
This is the number 2 largest of the planets in the solar system. Saturn draws attention to itself thanks to a system of rings formed from ice, rocks and dust that orbit the planet. There are three main rings with an outer diameter of 270,000 km, but their thickness is about 30 meters. 
The period of revolution around the Sun: 29 years 168 days.
Diameter of the planet at the equator: 120536 km.
Rotation period (turn around the axis): 10 hours 14 minutes.
Surface temperature: -180 degrees (average).
Atmosphere: mostly hydrogen and helium.
Number of satellites: 18 (+ rings).
Main satellites: Titan.
Unique planet in the solar system. Its peculiarity is that it revolves around the Sun not like everyone else, but "lying on its side." Uranus also has rings, although they are harder to see. In 1986, Voyager 2 flew 64,000 km and had six hours of photography, which it successfully completed.
Orbital period: 84 years 4 days. Diameter at the equator: 51118 km.
The period of rotation of the planet (rotation around the axis): 17 hours 14 minutes.
Surface temperature: -214 degrees (average).
Atmosphere: mostly hydrogen and helium.
How many satellites: 15 (+ rings).
Main satellites: Titania, Oberon.
At the moment, Neptune is considered the last planet in the solar system. Its discovery took place by the method of mathematical calculations, and then they saw it through a telescope. In 1989, Voyager 2 flew by. He took amazing photographs of the blue surface of Neptune and its largest moon, Triton. 
The period of revolution around the Sun: 164 years 292 days.
Diameter at the equator: 50538 km.
Rotation period (turn around the axis): 16 hours 7 minutes.
Surface temperature: -220 degrees (average).
Atmosphere: mostly hydrogen and helium.
Number of satellites: 8.
Main moons: Triton.
On August 24, 2006, Pluto lost planetary status. The International Astronomical Union has decided which celestial body should be considered a planet. Pluto does not meet the requirements of the new formulation and loses its "planetary status", at the same time, Pluto passes into a new quality and becomes the prototype of a separate class of dwarf planets.
How did the planets appear? Approximately 5-6 billion years ago, one of the gas and dust clouds of our large Galaxy (the Milky Way), which has the shape of a disk, began to shrink towards the center, gradually forming the current Sun. Further, according to one of the theories, under the influence of powerful forces of attraction, a large number of dust and gas particles rotating around the Sun began to stick together into balls - forming future planets. According to another theory, the gas and dust cloud immediately broke up into separate clusters of particles, which compressed and condensed, forming the current planets. Now 8 planets revolve around the sun constantly.
The central star of our system, in different orbits around which all the planets pass, is called the Sun. Its age is about 5 billion years. This is a yellow dwarf, so the size of the star is small. It doesn't run out very quickly. The solar system has reached approximately the middle of its life cycle. After 5 billion years, the balance of gravitational forces will be disturbed, the star will increase in size, gradually heat up. converts all of the sun's hydrogen into helium. By this time, the size of the star will be three times larger. Ultimately, the star will cool down, decrease. Today the Sun is made up almost entirely of hydrogen (90%) and some helium (10%).
Today, the satellites of the Sun are 8 planets, around which other celestial bodies, several dozen comets, as well as a huge number of asteroids revolve. All these objects move in their orbit. If you add up the mass of all the satellites of the Sun, it turns out that they are 1000 times lighter than their star. The main celestial bodies of the system deserve detailed consideration.
General concept of the solar system
To consider the satellites of the Sun, you need to familiarize yourself with the definitions: what is a star, planet, satellite, etc. A star is a body that radiates light and energy into space. This is possible due to the thermonuclear reactions occurring in it and the processes of compression under the influence of gravity. There is only one star in our system - the Sun. 8 planets revolve around it.
A planet today is a celestial body that revolves around a star and has a spherical (or close to it) shape. Such objects do not emit light (they are not stars). They can reflect it. Also, the planet does not have other large celestial bodies near its orbit.
A satellite is also called an object that revolves around other, larger stars or planets. It is kept in orbit by the force of gravity of this large celestial body. To understand how many satellites the Sun has, it should be noted that this list, in addition to planets, includes asteroids, comets, meteorites. It is almost impossible to count them.
planets
Until recently, it was believed that our system has 9 planets. After much discussion, Pluto was removed from this list. But it is also part of our system.
The 8 major planets are held in their orbits by the Sun. A satellite (planet) can also have celestial bodies revolving around it. There are quite large objects. All planets are divided into 2 groups. The first includes the inner satellites of the Sun, and the second - the outer ones.
The planets of the terrestrial (first) group are as follows:
- Mercury (closest to the star).
- Venus (the hottest planet).
- Earth.
- Mars (the most accessible object for research).
They consist of metals, silicates, their surface is hard. The outer group are the gas giants. These include:
- Jupiter.
- Saturn.
- Uranus.
- Neptune.
Their composition is characterized by a high content of hydrogen and helium. These are systems.
planetary satellites
Considering the question of how many satellites the Sun has, we should mention the celestial bodies revolving around the planets. IN Ancient Greece Venus, Mercury, Sun, Mars, Moon, Jupiter, Saturn were considered planets. Only in the 16th century the Earth was included in this list. The sun has taken in the understanding of people its central importance in our system. The moon turned out to be a satellite of the Earth.
With the advent of more advanced technologies, it was found that almost all planets have their own satellites. Only Venus and Mercury do not have them. Today, about 60 satellites of the planets are known, which are characterized by different sizes. The least known of them is Leda. This one is only 10 km in diameter.
Most of these objects, located in the orbit of gas giants, were discovered using automatic space technology. She provided scientists with photographs of such celestial objects.
Mercury and Venus
Our star has two rather small objects closest to itself. The Sun's satellite Mercury is the smallest planet in the system. Venus is slightly larger than him. But both of these planets do not have their satellites.
Mercury has a highly rarefied helium atmosphere. He circles his star in 88 earth days. But the duration of a revolution around its axis for this planet is 58 days (by our standards). The temperature on the sunny side reaches +400 degrees. At night, cooling down to -200 degrees is recorded here.
At Venus, the atmosphere consists of hydrogen with impurities of nitrogen and oxygen. There is a greenhouse effect here. Therefore, the surface heats up to a record +480 degrees. This is more than on Mercury. This planet is best seen from Earth, as its orbit is closest to us.
Earth
Our planet is the largest among all representatives of the terrestrial group. It is unique in many ways. Earth has the largest celestial body in its orbit among the first 4 planets from a star. The satellite of the Sun, which is our planet, differs significantly from all in its atmosphere. Thanks to this, life became possible on it.
About 71% of the surface is occupied by water. The remaining 29% is land. The basis of the atmosphere is nitrogen. It also includes oxygen, carbon dioxide, argon and water vapor.
The Earth's satellite, the Moon, has no atmosphere. There is no wind, sounds, weather on it. It is a rocky, bare surface covered with craters. On Earth, traces of meteorite impacts are smoothed out under the influence of vital activity various kinds due to wind and weather. There is nothing on the moon. Therefore, all traces of her past are reflected very clearly.
Mars
It is the closing planet of the terrestrial group. It is called the "Red Planet" due to the high content of iron oxide in the soil. It is quite similar to the Earth satellite. It revolves around the Sun for 678 Earth days. Scientists believed that life could once exist here. However, studies have not confirmed this. Mars' moons are Phobos and Deimos. They are smaller than the moon.
It's colder here than on our planet. At the equator, the temperature reaches 0 degrees. At the poles, it drops to -150 degrees. This world is already available for astronaut flights. Spaceship can reach the planet in 4 years.
In ancient times, rivers flowed on the surface of the planet. There was water here. Now there are ice caps at the poles. Only they are not made of water, but of carbon dioxide atmosphere. Scientists suggest that water may be frozen in large chunks below the surface of the planet.
gas giants
Beyond Mars are the largest objects that accompany the Sun. The planets (satellites of the planets of this group) were studied using various techniques. The largest object in our system is Jupiter. It is 2.5 times more massive than all the planets orbiting the Sun combined. It consists of helium, hydrogen (which is similar to our star). The planet radiates heat. However, to be considered a star, Jupiter needs to become 80 times heavier. It has 63 satellites.
Saturn is slightly smaller than Jupiter. He is known for his rings. These are ice particles of various diameters. The density of the planet is less than that of water. It has 62 satellites.
Uranus and Neptune are even further away than the previous two planets. They were discovered with a telescope. They contain a large number of high-temperature modifications of ice. These are Ice Giants. Uranus has 23 moons and Neptune has 13.
Pluto
The sun's moons are also complemented by a small object called Pluto. From 1930 to 2006, he held the title of the planet. However, after lengthy discussions, scientists came to the conclusion that this is not a planet. Pluto falls into a different category. From the point of view of the current planetary classification, this is a prototype. The surface of the object is covered with frozen ice from methane and nitrogen. Pluto has 1 satellite.
Having studied the main satellites of the Sun, it should be said that this is a whole system consisting of a large number of different objects. Their characteristics and indicators are different. What unites all these objects is a force that makes them constantly rotate around their central star.
