What is the solar system in which we live? The answer will be as follows: this is our central star, the Sun and all the cosmic bodies that revolve around it. These are large and small planets, as well as their satellites, comets, asteroids, gases and cosmic dust.
The name of the solar system was given by the name of its star. In a broad sense, “solar” often means any star system.
How did the solar system originate?
According to scientists, the Solar System was formed from a giant interstellar cloud of dust and gases due to gravitational collapse in a separate part of it. As a result, a protostar was formed in the center, which then turned into a star - the Sun, and a protoplanetary disk of enormous size, from which all the components of the Solar system listed above were subsequently formed. The process, scientists believe, began about 4.6 billion years ago. This hypothesis was called the nebular hypothesis. Thanks to Emmanuel Swedenborg, Immanuel Kant and Pierre-Simon Laplace, who proposed it back in the 18th century, it eventually became generally accepted, but over the course of many decades it was refined, new data was introduced into it taking into account knowledge modern sciences. Thus, it is assumed that due to the increase and intensification of collisions of particles with each other, the temperature of the object increased, and after it reached several thousand kelvins, the protostar acquired a glow. When the temperature reached millions of kelvins, a thermonuclear fusion reaction began in the center of the future Sun - the conversion of hydrogen into helium. It turned into a star.
The sun and its features
Scientists classify our star as a yellow dwarf (G2V) according to its spectral classification. This is the closest star to us, its light reaches the surface of the planet in just 8.31 seconds. From Earth, the radiation appears to have a yellow tint, although in reality it is almost white.
The main components of our luminary are helium and hydrogen. In addition, thanks to spectral analysis, it was discovered that the Sun contains iron, neon, chromium, calcium, carbon, magnesium, sulfur, silicon, and nitrogen. Thanks to the thermonuclear reaction continuously occurring in its depths, all life on Earth receives the necessary energy. Sunlight is an integral component of photosynthesis, which produces oxygen. Without the sun's rays it would not have been possible, and therefore an atmosphere suitable for the protein form of life would not have been able to form.
Mercury
This is the closest planet to our star. Together with Earth, Venus and Mars, it belongs to the so-called planets terrestrial group. Mercury received its name because of its high speed of movement, which, according to myths, distinguished the fleet-footed ancient god. The Mercury year is 88 days.
The planet is small, its radius is only 2439.7, and it is smaller in size than some of the large satellites of the giant planets, Ganymede and Titan. However, unlike them, Mercury is quite heavy (3.3 x 10 23 kg), and its density is only slightly behind that of Earth. This is due to the presence of a heavy dense core of iron on the planet.
There is no change of seasons on the planet. Its desert surface resembles the Moon. It is also covered with craters, but is even less suitable for life. Thus, on the day side of Mercury the temperature reaches +510 °C, and on the night side -210 °C. These are the sharpest changes in the entire solar system. The atmosphere of the planet is very thin and rarefied.
Venus
This planet, named after the ancient Greek goddess of love, is more similar than others in the solar system to the Earth in its physical parameters - mass, density, size, volume. For a long time they were considered twin planets, but over time it became clear that their differences are enormous. So, Venus has no satellites at all. Its atmosphere consists of almost 98% carbon dioxide, and the pressure on the planet’s surface is 92 times higher than Earth’s! Clouds above the surface of the planet, consisting of sulfuric acid vapor, never dissipate, and the temperature here reaches +434 ° C. Acid rain is falling on the planet and thunderstorms are raging. There is high volcanic activity here. Life, as we understand it, cannot exist on Venus; moreover, descending spacecraft cannot survive in such an atmosphere for long.
This planet is clearly visible in the night sky. This is the third brightest object for an earthly observer; it shines with white light and is brighter than all the stars. The distance to the Sun is 108 million km. It revolves around the Sun in 224 Earth days, and around its own axis in 243.
Earth and Mars
These are the last planets of the so-called terrestrial group, whose representatives are characterized by the presence of a solid surface. Their structure includes a core, mantle and crust (only Mercury does not have it).
Mars has a mass equal to 10% of the mass of the Earth, which, in turn, is 5.9726 10 24 kg. Its diameter is 6780 km, almost half that of our planet. Mars is the seventh largest planet in the solar system. Unlike the Earth, 71% of whose surface is covered by oceans, Mars is entirely dry land. The water was preserved beneath the planet's surface in the form of a massive ice sheet. Its surface has a reddish tint due to the high content of iron oxide in the form of maghemite.
The atmosphere of Mars is very rarefied, and the pressure on the surface of the planet is 160 times less than what we are used to. On the surface of the planet there are impact craters, volcanoes, depressions, deserts and valleys, and at the poles there are ice caps, just like on Earth.
Martian days are slightly longer than Earth ones, and the year is 668.6 days. Unlike Earth, which has one moon, the planet has two satellites irregular shape- Phobos and Deimos. Both of them, like the Moon to the Earth, are constantly turned to Mars with the same side. Phobos is gradually approaching the surface of its planet, moving in a spiral, and will probably fall onto it over time or break into pieces. Deimos, on the contrary, is gradually moving away from Mars and may leave its orbit in the distant future.
Between the orbits of Mars and the next planet, Jupiter, there is an asteroid belt consisting of small celestial bodies.
Jupiter and Saturn
Which planet is the largest? There are four gas giants in the solar system: Jupiter, Saturn, Uranus and Neptune. Jupiter has the largest size. Its atmosphere, like that of the Sun, consists predominantly of hydrogen. The fifth planet, named after the thunder god, has an average radius of 69,911 km and a mass 318 times that of Earth. The planet's magnetic field is 12 times stronger than the Earth's. Its surface is hidden under opaque clouds. So far, scientists are finding it difficult to say with certainty what processes can occur under this dense veil. It is assumed that there is a boiling hydrogen ocean on the surface of Jupiter. Astronomers consider this planet a “failed star” due to some similarity in their parameters.
Jupiter has 39 satellites, 4 of which - Io, Europa, Ganymede and Callisto - were discovered by Galileo.
Saturn is slightly smaller than Jupiter, it is the second largest among the planets. This is the sixth, next planet, also consisting of hydrogen with admixtures of helium, a small amount of ammonia, methane, and water. Hurricanes rage here, the speed of which can reach 1800 km/h! Saturn's magnetic field is not as powerful as Jupiter's, but stronger than Earth's. Both Jupiter and Saturn are somewhat flattened at the poles due to rotation. Saturn is 95 times heavier than earth, but its density is less than that of water. This is the least dense celestial body in our system.
A year on Saturn lasts 29.4 Earth years, a day is 10 hours 42 minutes. (Jupiter has a year of 11.86 Earth years, a day of 9 hours 56 minutes). It has a system of rings consisting of solid particles of various sizes. Presumably, these may be the remains of a destroyed satellite of the planet. In total, Saturn has 62 satellites.
Uranus and Neptune - the last planets
The seventh planet of the solar system is Uranus. It is 2.9 billion km away from the Sun. Uranus is the third largest among the planets of the Solar System (average radius - 25,362 km) and the fourth largest in mass (14.6 times greater than Earth's). A year here lasts 84 Earth years, a day lasts 17.5 hours. In the atmosphere of this planet, in addition to hydrogen and helium, methane occupies a significant volume. Therefore, for an earthly observer, Uranus has a soft blue color.
Uranus is the coldest planet in the solar system. The temperature of its atmosphere is unique: -224 °C. Scientists do not know why Uranus has a lower temperature than planets that are further from the Sun.
This planet has 27 satellites. Uranus has thin, flat rings.
Neptune, the eighth planet from the Sun, ranks fourth in size (average radius - 24,622 km) and third in mass (17 Earth's). For a gas giant it is relatively small (only four times more than Earth). Its atmosphere is also mainly composed of hydrogen, helium and methane. Gas clouds in its upper layers move at a record speed, the highest in the solar system - 2000 km/h! Some scientists believe that under the surface of the planet, under a layer of frozen gases and water, hidden, in turn, by the atmosphere, a solid rocky core may be hiding.
These two planets are similar in composition, which is why they are sometimes classified as a separate category - ice giants.
Minor planets
Minor planets are celestial bodies that also move around the Sun in their own orbits, but differ from other planets in their small sizes. Previously, only asteroids were classified as such, but more recently, namely since 2006, they also include Pluto, which was previously included in the list of planets of the Solar System and was the last, tenth on it. This is due to changes in terminology. Thus, minor planets now include not only asteroids, but also dwarf planets - Eris, Ceres, Makemake. They were named plutoids after Pluto. The orbits of all known dwarf planets are located beyond the orbit of Neptune, in the so-called Kuiper belt, which is much wider and more massive than the asteroid belt. Although their nature, as scientists believe, is the same: it is “unused” material left after the formation of the Solar system. Some scientists have suggested that the asteroid belt is the debris of the ninth planet, Phaeton, which died as a result of a global catastrophe.
What is known about Pluto is that it is composed primarily of ice and solid rock. The main component of its ice sheet is nitrogen. Its poles are covered with eternal snow.
This is the order of the planets of the solar system, according to modern ideas.
Parade of planets. Types of parades
This is a very interesting phenomenon for those interested in astronomy. It is customary to call a parade of planets such a position in the solar system when some of them, continuously moving in their orbits, for a short time occupy a certain position for an earthly observer, as if lining up along one line.
The visible parade of planets in astronomy is the special position of the five brightest planets of the solar system for people seeing them from Earth - Mercury, Venus, Mars, as well as two giants - Jupiter and Saturn. At this time, the distance between them is relatively small and they are clearly visible in a small sector of the sky.
There are two types of parades. A large form is called when five heavenly bodies line up in one line. Small - when there are only four of them. These phenomena may be visible or invisible from different parts of the globe. At the same time, a large parade occurs quite rarely - once every few decades. The small one can be observed once every few years, and the so-called mini-parade, in which only three planets participate, almost every year.
Interesting facts about our planetary system
Venus, the only one of all the major planets in the Solar System, rotates around its axis in the direction opposite to its rotation around the Sun.
The highest mountain on the major planets of the Solar System is Olympus (21.2 km, diameter - 540 km), an extinct volcano on Mars. Not long ago, on the largest asteroid of our star system, Vesta, a peak was discovered that was somewhat superior in parameters to Olympus. Perhaps it is the highest in the solar system.
The four Galilean moons of Jupiter are the largest in the Solar System.
Except Saturn, everyone has rings gas giants, some asteroids and Saturn's moon Rhea.
Which star system is closest to us? The solar system is closest to the star system of the triple star Alpha Centauri (4.36 light years). It is assumed that planets similar to Earth may exist in it.
About planets for kids
How to explain to children what the solar system is? Her model will help here, which you can make together with the kids. To create planets, you can use plasticine or ready-made plastic (rubber) balls, as shown below. In this case, it is necessary to maintain the relationship between the sizes of the “planets” so that the model solar system really helped to form the correct ideas about space in children.
You will also need toothpicks to hold our celestial bodies, and as a background you can use a dark sheet of cardboard with small dots painted on it to imitate stars. With the help of such an interactive toy, it will be easier for children to understand what the solar system is.
The future of the solar system
The article described in detail what the Solar System is. Despite its apparent stability, our Sun, like everything in nature, evolves, but this process, by our standards, is very long. The supply of hydrogen fuel in its depths is huge, but not infinite. So, according to scientists’ hypotheses, it will end in 6.4 billion years. As it burns out, the solar core will become denser and hotter, and the outer shell of the star will become wider. The star's luminosity will also increase. It is assumed that in 3.5 billion years, because of this, the climate on Earth will be similar to Venus, and life on it in the usual sense for us will no longer be possible. There will be no water left at all; under the influence of high temperatures it will evaporate into outer space. Subsequently, according to scientists, the Earth will be absorbed by the Sun and dissolve in its depths.
The outlook is not very bright. However, progress does not stand still, and perhaps by that time new technologies will allow humanity to explore other planets, over which other suns shine. After all, scientists do not yet know how many “solar” systems there are in the world. There are probably countless of them, and among them it is quite possible to find one suitable for human habitation. Which “solar” system will become our new home is not so important. Human civilization will be preserved, and another page will begin in its history...
The planets of the Solar System are arranged in order as follows:
1 - Mercury. The smallest real planet in the solar system
2 - Venus. The description of hell was taken from her: terrible heat, sulfur vapors and the eruptions of many volcanoes.
3 - Earth. The third planet in order from the Sun, our home.
4 - Mars. The most distant of the terrestrial planets in the Solar System.
Then there is the Main Asteroid Belt, where the dwarf planet Ceres and the minor planets Vesta, Pallas, and others are located.
Next in order are the four giant planets:
5 - Jupiter. The largest planet in the solar system.
6 - Saturn with its famous rings.
7 - Uranium. The coldest planet.
8 - Neptune. It is the farthest "real" planet in order from the Sun.
Here's what's more interesting:
9 - Pluto. A dwarf planet that is usually mentioned after Neptune. But Pluto's orbit is such that it is sometimes closer to the Sun than Neptune. For example, this was the case from 1979 to 1999.
No, Neptune and Pluto cannot collide :) - their orbits are such that they do not intersect.
The order of the planets of the solar system in the photo: 
How many planets are there in the solar system
How many planets are there in the solar system? This is not so easy to answer. For a long time it was believed that there are nine planets in the solar system:
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.
But, on August 24, 2006, Pluto ceased to be considered a planet. This was caused by the discovery of the planet Eris and other small planets of the solar system, in connection with which it was necessary to clarify which celestial bodies can be considered planets.
Several characteristics of “real” planets were identified and it turned out that Pluto does not fully satisfy them.
Therefore, Pluto was relegated to the category of dwarf planets, which includes, for example, Ceres, the former number 1 asteroid in the Main Asteroid Belt between Mars and Jupiter.
As a result, when trying to answer the question of how many planets are in the solar system, the situation became even more confused. Because in addition to the “real” ones, dwarf planets have now also appeared.
But there are also small planets, which were called large asteroids. For example Vesta, asteroid number 2 in the mentioned Main Asteroid Belt.
IN Lately the same Eris, Make-Make, Haumea and several other small ones were discovered planets of the solar system, data about which is insufficient and it is unclear whether they should be considered dwarf or small planets. Not to mention that some small asteroids are mentioned in the literature as minor planets! For example, the asteroid Icarus, whose size is only about 1 kilometer, is often referred to as a minor planet...
Which of these bodies should be taken into account when answering the question “how many planets are there in the solar system”???
In general, “we wanted the best, but it turned out as always.”
It is curious that many astronomers and even simple people They come out “in defense” of Pluto, continuing to consider it a planet, sometimes organize small demonstrations and diligently promote this idea on the Internet (mainly abroad).
Therefore, when answering the question “how many planets are there in the solar system,” the easiest way is to briefly say “eight” and not even try to discuss anything... otherwise you will immediately discover that there is simply no exact answer :)
Giant planets - the largest planets in the solar system
There are four giant planets in the solar system: Jupiter, Saturn, Uranus and Neptune. Because these planets are located outside the Main Asteroid Belt, they are called the "outer" planets of the solar system.
In terms of size, two pairs clearly stand out among these giants.
The largest giant planet is Jupiter. Saturn is quite a bit inferior to him.
And Uranus and Neptune are sharply smaller than the first two planets and they are located further from the Sun.
Look at the comparative sizes of the giant planets relative to the Sun: 
The giant planets protect the inner planets of the solar system from asteroids.
Without these bodies in the solar system, our Earth would be hit by asteroids and comets hundreds of times more often!
How do giant planets protect us from the falls of uninvited guests?
You can learn more about the largest planets in the solar system here:
Terrestrial planets
The terrestrial planets are the four planets of the solar system that are similar in size and composition: Mercury, Venus, Earth and Mars. 
Since one of them is the Earth, all these planets are classified as the terrestrial group. Their sizes are very similar, and Venus and Earth are generally almost the same. Their temperatures are relatively high, which is explained by their proximity to the Sun. All four planets are formed by rocks, while the giant planets are gas and ice worlds.
Mercury is the closest planet to the Sun and the smallest planet in the Solar System.
It is generally accepted that Mercury is very hot. Yes, that's right, the temperature on the sunny side can reach +427°C. But, there is almost no atmosphere on Mercury, so on the night side it can reach -170°C. And at the poles, due to the low Sun, a layer of underground permafrost is generally assumed...
Venus. For a long time it was considered the “sister” of the Earth, until Soviet research stations descended on its surface. It turned out to be real hell! Temperature +475°C, pressure of almost a hundred atmospheres and an atmosphere of toxic compounds of sulfur and chlorine. To colonize it, you will have to try very hard...
Mars. The famous red planet. It is the most distant terrestrial planet in the solar system.
Like Earth, Mars has satellites: Phobos and Deimos
It is generally a cold, rocky and dry world. Only at the equator at noon can it warm up to +20°C, the rest of the time there is severe frost, down to -153°C at the poles.
The planet does not have a magnetosphere and cosmic radiation mercilessly irradiates the surface.
The atmosphere is very rarefied and not suitable for breathing, however, its density is enough for powerful dust storms to sometimes occur on Mars.
Despite all the shortcomings. Mars is the most promising planet for colonization in the solar system. 
More information about the terrestrial planets is described in the article The largest planets of the solar system
The largest planet in the solar system
The largest planet in the solar system is Jupiter. It is the fifth planet from the Sun, its orbit lies beyond the Main Asteroid Belt. Look at the size comparison between Jupiter and Earth: 
Jupiter's diameter is 11 times larger than Earth's, and its mass is 318 times greater. Due to the large size of the planet, parts of its atmosphere rotate at different speeds, so the belts of Jupiter are clearly visible in the image. Below on the left you can see the famous Great Red Spot of Jupiter - a huge atmospheric vortex that has been observed for several centuries.
The smallest planet in the solar system
Which planet is the smallest planet in the solar system? This is not such a simple question...
Today it is generally accepted that the smallest planet in the solar system is Mercury, which we mentioned a little above. But, you already know that until August 24, 2006, Pluto was considered the smallest planet in the solar system.
More attentive readers may recall that Pluto is a dwarf planet. And there are five of them known. The smallest dwarf planet is Ceres, with a diameter of about 900 km.
But that's not all...
There are also so-called minor planets, the size of which starts at only 50 meters. Both the 1-kilometer Icarus and the 490-kilometer Pallas fall under this definition. It is clear that there are many of them, and it is difficult to choose the smallest one due to the complexity of observations and calculation of sizes. So, when answering the question “what is the name of the smallest planet in the solar system,” it all depends on what exactly is meant by the word “planet.”
or tell your friends: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 own clearly 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 did the planets of the solar system originate: approximately 5-6 billion years ago, one of the gas and dust clouds of our large Galaxy ( milky way), having the shape of a disk, began to shrink towards the center, little by little forming the present Sun. Further, according to one theory, under the influence of powerful forces of attraction, a large number of dust and gas particles revolving around the Sun began to stick together into balls - forming future planets. As another theory says, the gas and dust cloud immediately broke up into separate clusters of particles, which compressed and became denser, forming the current planets. Now 8 planets revolve around the Sun constantly.
The center of the solar system is the Sun, a star around which the planets orbit. They do not emit heat and do not glow, but only reflect the light of the Sun. There are now 8 officially recognized planets in the solar system. Let us briefly list them all in order of distance from the sun. And now a few definitions.
Satellites of the planets. The solar system also includes the Moon and the natural satellites of other planets, which they all have except Mercury and Venus. Over 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 satellite, 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. Age about 5 billion years. It has a diameter at the equator of 1,392,000 km, 109 times larger than that of 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 332,950 times the mass of the Earth. The temperature inside the core is approximately 15 million degrees Celsius. The surface temperature is about 5500 degrees Celsius.
By chemical composition The sun is made up of 75% hydrogen, and the other 25% elements are mostly 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.
Planets of the solar system in order from the sun in pictures
Mercury is the 1st planet in the solar system
Mercury. The four inner planets (closest to the Sun)—Mercury, Venus, Earth, and Mars—have a rocky surface. They are smaller than the four giant planets. Mercury moves faster than other planets, being burned by the sun's rays 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 (rotation around an 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. Observing it is difficult due to 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 (rotation around an 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 collided and gradually “grew” the planet. The temperature on the surface reached 5000 degrees Celsius. Then the Earth cooled and became covered with a hard rock crust. But the temperature in the depths is still quite high - 4500 degrees. Rocks melted in the depths and poured 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 in order to receive the necessary heat and light, but far enough so as not to burn out.
Characteristics of planet Earth:
Period of revolution around the Sun: 365.3 days.
Diameter at the equator: 12756 km.
Period of rotation of the planet (rotation around its axis): 23 hours 56 minutes.
Surface temperature: 22 degrees (average).
Atmosphere: Mainly nitrogen and oxygen.
Number of satellites: 1.
The main satellites of the planet: the Moon.
Mars is the 4th planet in the solar system
Because of its resemblance to Earth, it was believed that life existed here. But the spacecraft that descended to 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 an axis): 24 hours 37 minutes.
Surface temperature: -23 degrees (average).
The planet's atmosphere: thin, mostly carbon dioxide.
How many satellites: 2.
The main satellites in order: Phobos, Deimos.
Jupiter is the 5th planet in the solar system
Jupiter, Saturn, Uranus and Neptune are made of hydrogen and other gases. Jupiter exceeds Earth by more than 10 times 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 long does it take for planet Jupiter to become a star? We need to increase its mass by 75 times!
Characteristics of the planet Jupiter:
Period of revolution around the Sun: 11 years 314 days.
Diameter of the planet at the equator: 143884 km.
Rotation period (rotation around an 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
It is number 2, the largest of the planets in the solar system. Saturn attracts attention thanks to its ring system formed of 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:
Period of revolution around the Sun: 29 years 168 days.
Diameter of the planet at the equator: 120536 km.
Rotation period (rotation around an axis): 10 hours 14 minutes.
Surface temperature: -180 degrees (average).
Atmosphere: Mainly hydrogen and helium.
Number of satellites: 18 (+ rings).
Main satellites: Titan.
Uranus is the 7th planet in the solar system
A unique planet in the solar system. Its peculiarity is that it rotates 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 at a distance of 64,000 km and had six hours of photography time, which it successfully completed.
Characteristics of the planet Uranus:
Orbital period: 84 years 4 days.
Diameter at the equator: 51118 km.
Period of rotation of the planet (rotation around its axis): 17 hours 14 minutes.
Surface temperature: -214 degrees (average).
Atmosphere: Mainly 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 through mathematical calculations, and then it was seen through a telescope. In 1989, Voyager 2 flew by. He took stunning photographs of the blue surface of Neptune and its largest moon, Triton.
Characteristics of the planet Neptune:
Period of revolution around the Sun: 164 years 292 days.
Diameter at the equator: 50538 km.
Rotation period (rotation around an axis): 16 hours 7 minutes.
Surface temperature: -220 degrees (average).
Atmosphere: Mainly hydrogen and helium.
Number of satellites: 8.
Main satellites: Triton.
How many planets are there 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 others already known to everyone. 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. This has been officially recognized since 2006. When arranging the planets of the solar system in order from the sun, use the ready-made picture. Do you think that maybe Pluto should not have been removed from the list of planets and that this is scientific prejudice?
How many planets are there in the solar system: video, watch for free
The solar system is a system of planets that includes its center, the Sun, as well as other objects in space. They revolve around the Sun. Until recently, “planet” was the name given to 9 objects in space that revolve around the Sun. Scientists have now established that beyond the boundaries of the solar system there are planets that orbit stars.
In 2006, the Union of Astronomers proclaimed that the planets of the solar system are spherical space objects revolving around the Sun. On the scale of the solar system, the Earth appears extremely small. In addition to the Earth, eight planets revolve around the Sun in their individual orbits. All of them are larger than the Earth in size. Rotate in the plane of the ecliptic.
Planets in the Solar System: types
Location of the terrestrial group in relation to the Sun
The first planet is Mercury, followed by Venus; Next comes our Earth and, finally, Mars.
Terrestrial planets do not have many satellites or moons. Of these four planets, only Earth and Mars have satellites.
Planets that belong to the terrestrial group are different high density, consist of metal or stone. Basically, they are small and rotate around their axis. Their rotation speed is also low.
Gas giants
These are the four space objects that are at the greatest distance from the Sun: Jupiter is at No. 5, followed by Saturn, then Uranus and Neptune.
Jupiter and Saturn are impressively sized planets made of hydrogen and helium compounds. The density of gas planets is low. They rotate at high speeds, have satellites and are surrounded by rings of asteroids.
The “ice giants,” which include Uranus and Neptune, are smaller; their atmospheres contain methane and carbon monoxide.
Gas giants have a strong gravitational field, therefore they can attract many space objects, unlike the terrestrial group.
According to scientists, asteroid rings are the remains of moons changed by the gravitational field of the planets. 
Dwarf planet
Dwarfs are space objects whose size does not reach the size of a planet, but exceeds the dimensions of an asteroid. There are a great many such objects in the Solar System. They are concentrated in the Kuiper belt region. The satellites of the gas giants are dwarf planets that have left their orbit. 
Planets of the Solar System: the process of emergence
According to the cosmic nebula hypothesis, stars are born in clouds of dust and gas, in nebulae.
Due to the force of attraction, substances come together. Under the influence of the concentrated force of gravity, the center of the nebula contracts and stars form. Dust and gases transform into rings. The rings rotate under the influence of gravity, and planetasimals are formed in the whirlpools, which increase in size and attract cosmetic objects to themselves.
Under the influence of gravity, planetesimals are compressed and acquire spherical shapes. The spheres can unite and gradually turn into protoplanets. 
There are eight planets within the solar system. They revolve around the Sun. Their location is as follows:
The closest “neighbor” of the Sun is Mercury, followed by Venus, followed by the Earth, then Mars and Jupiter, further from the Sun are Saturn, Uranus and the last one, Neptune.
The solar system - our home - consists of 8 planets and many others cosmic bodies that orbit the star. Large, medium, small in size, solid and consisting of gases, closest and farthest from the Sun, they live within the system according to a clearly established order.
Until 2006, it was believed that there were 9 planets in the solar system. However, then at the next International Astronomical Congress, the most distant object, Pluto, was crossed off the list. Scientists revised the criteria and left planets that fit the following parameters:
- orbital rotation around a star (Sun);
- gravity and spherical shape;
- the absence of other large cosmic bodies nearby, except for their own satellites.
These planets are in order from the Sun:
- Mercury. Diameter – 4.9 thousand km.
- Venus. Diameter – 12.1 thousand km.
- Earth. Diameter – 12.7 thousand km.
- Mars. Diameter – 6.8 thousand km.
- Jupiter. Diameter – 139.8 thousand km.
- Saturn. Diameter – 116.5 thousand km.
- Uranus. Diameter – 50.7 thousand km.
- Neptune. Diameter – 49.2 thousand km.
Attention! Scientists were prompted to revise the parameters by the discovery of another planet-like body - Eris, which turned out to be heavier than Pluto. Both objects were classified as dwarf planets.
Terrestrial planets: Mercury and Venus
The planets in the Solar System are divided into two groups: terrestrial (inner) and gas (outer). They are separated from each other by an asteroid belt. According to one hypothesis, it is a planet that could not form under the strong influence of Jupiter. The terrestrial group includes planets with a solid surface.
There are 8 planets
Mercury– the first object of the system from the sun. Its orbit is the smallest, and it revolves around the star faster than the others. A year here is equal to 88 Earth days. But Mercury rotates very slowly around its axis. The local day here is longer than the local year and amounts to 4224 Earth hours.
Attention! The movement of the sun in the black sky of Mercury is very different from that on Earth. Due to the peculiarities of rotation and orbit at different points, it may look as if the star is freezing, “backing away,” rising and setting several times a day.
Mercury is the smallest planet in the solar system. It is even smaller than some of the satellites of the gas group of planets. Its surface is covered with many craters with a diameter ranging from several meters to hundreds of kilometers. There is almost no atmosphere on Mercury, so the surface can be very hot during the day (+440°C) and cold at night (-180°C). But already at a depth of 1 m the temperature is stable and is approximately +75°C at any time.
Venus- the second planet from the Sun. Its powerful atmosphere of carbon dioxide (more than 96%) for a long time hid the surface from human eyes. Venus is very hot (+460°C), but unlike Mercury, the main reason for this is the greenhouse effect due to the density of the atmosphere. The pressure on the surface of Venus is 92 times greater than that on Earth. Under the clouds of sulfuric acid lie hurricanes and thunderstorms that never subside here.
Terrestrial planets: Earth and Mars
Earth- the largest of the inner group and the only planet in the system suitable for life. The Earth's atmosphere contains nitrogen, oxygen, carbon dioxide, argon, and water vapor. Surface protected ozone layer And magnetic field just enough for life to be born on it in the form in which it exists now. Earth's satellite is the Moon.
Mars closes the four terrestrial planets. The planet has a very thin atmosphere, a surface with craters, a topography with valleys, deserts, extinct volcanoes and polar glaciers. Including the huge Olympus volcano, which is the largest peak on the planets of the solar system - 21.2 km. It has been proven that the surface of the planet was once . But today there is only ice and dust devils.
The location of the planets in the solar system
Gas group planets
Jupiter- the largest planet in the solar system. It is more than 300 times heavier than the Earth, although it consists of gases: hydrogen and helium. Jupiter has quite powerful radiation to influence nearby objects. It has the most satellites - 67. Some of them are quite large bodies, different in structure.
Jupiter itself is covered in liquid. On its surface there are noticeable many stripes of light and dark colors moving parallel to the equator. These are clouds. Winds of up to 600 km/h rage beneath them. For several centuries, astronomers have been observing a red spot on the surface of Jupiter larger than the Earth, which is a giant storm.
Attention! Jupiter rotates around its axis faster than all the planets in the solar system. A day here is less than 10 hours.
Saturn popularly known as the ringed planet. They consist of ice and dust particles. The planet's atmosphere is dense, almost entirely consisting of hydrogen (more than 96%) and helium. Saturn has more than 60 open moons. The surface density is the smallest among the planets of the system, less than the density of water.
Uranus and Neptune They are classified as ice giants because they have a lot of ice on their surface. And the atmosphere consists of hydrogen and helium. Neptune is very stormy, Uranus is much calmer. As the most distant planet in the system, Neptune has the longest year - almost 165 Earth years. Behind Neptune is the little-studied Kuiper Belt, a cluster of small bodies of various structures and sizes. It is considered the outskirts of the solar system.
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