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 (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.
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. smallest satellite Jupiter - Leda - 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.
By chemical composition The sun is made up of 75% hydrogen, and the other 25% of the elements has the most 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 hard 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.
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
On the this moment, Neptune is considered the last planet of 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
The boundless space that surrounds us is not just a huge airless space and emptiness. Here everything is subject to a single and strict order, everything has its own rules and obeys the laws of physics. Everything is in constant motion and is constantly interconnected with each other. This is a system in which each celestial body has its own specific place. The center of the universe is surrounded by galaxies, among which is our Milky Way. Our galaxy, in turn, is formed by stars, around which large and small planets revolve with their natural satellites. Wandering objects - comets and asteroids - complete the picture of the universal scale.
Our solar system is also located in this endless cluster of stars - a tiny astrophysical object by cosmic standards, which also includes our cosmic home - the planet Earth. For us earthlings, the size of the solar system is colossal and difficult to comprehend. In terms of the scale of the universe, these are tiny numbers - only 180 astronomical units or 2.693e + 10 km. Here, too, everything is subject to its own laws, has its own clearly defined place and sequence.
Brief description and description
The position of the Sun provides the interstellar medium and the stability of the solar system. Its location is an interstellar cloud that is part of the Orion Cygnus arm, which in turn is part of our galaxy. With scientific point of view, our Sun is located on the periphery, 25 thousand light years from the center of the Milky Way, if we consider the galaxy in the diametrical plane. In turn, the movement of the solar system around the center of our galaxy is carried out in orbit. The full rotation of the Sun around the center of the Milky Way is carried out in different ways, within 225-250 million years and is one galactic year. The orbit of the solar system has an inclination of 600 to the galactic plane. Nearby, in the neighborhood of our system, other stars and other solar systems with their large and small planets run around the center of the galaxy.
The approximate age of the solar system is 4.5 billion years. Like most objects in the universe, our star was formed as a result of the Big Bang. The origin of the solar system is explained by the action of the same laws that have operated and continue to operate today in the field of nuclear physics, thermodynamics and mechanics. First, a star was formed, around which, due to ongoing centripetal and centrifugal processes, the formation of planets began. The sun was formed from a dense collection of gases - a molecular cloud, which was the product of a colossal explosion. As a result of centripetal processes, the molecules of hydrogen, helium, oxygen, carbon, nitrogen and other elements were compressed into one continuous and dense mass.
The result of grandiose and such large-scale processes was the formation of a protostar, in the structure of which thermonuclear fusion began. This long process, which began much earlier, we observe today, looking at our Sun after 4.5 billion years from the moment of its formation. The scale of the processes occurring during the formation of a star can be represented by estimating the density, size and mass of our Sun:
- the density is 1.409 g/cm3;
- the volume of the Sun is almost the same figure - 1.40927x1027 m3;
- the mass of the star is 1.9885x1030kg.
Today, our Sun is an ordinary astrophysical object in the Universe, not the smallest star in our galaxy, but far from the largest. The sun is in its adulthood, being not only the center of the solar system, but also the main factor in the emergence and existence of life on our planet.
The final structure of the solar system falls on the same period, with a difference of plus or minus half a billion years. The mass of the entire system, where the Sun interacts with other celestial bodies of the Solar System, is 1.0014 M☉. In other words, all planets, moons and asteroids, space dust and particles of gases revolving around the Sun, in comparison with the mass of our star, are a drop in the ocean.
In the form in which we have an idea of our star and planets revolving around the Sun - this is a simplified version. For the first time, a mechanical heliocentric model of the solar system with a clockwork was presented scientific community in 1704. It should be borne in mind that the orbits of the planets of the solar system do not all lie in the same plane. They rotate around at a certain angle.
The model of the solar system was created on the basis of a simpler and more ancient mechanism - tellurium, with the help of which the position and movement of the Earth in relation to the Sun was modeled. With the help of tellurium, it was possible to explain the principle of the movement of our planet around the Sun, to calculate the duration of the earth's year.
The simplest model of the solar system is presented in school textbooks, where each of the planets and other celestial bodies occupy a certain place. In this case, it should be borne in mind that the orbits of all objects revolving around the Sun are located under different angle to the diametrical plane of the solar system. The planets of the solar system are located at different distances from the sun, rotate with different speed and rotate around their own axis in different ways.
A map - a diagram of the solar system - is a drawing where all objects are located in the same plane. In this case, such an image gives an idea only of the size of celestial bodies and the distances between them. Thanks to this interpretation, it became possible to understand the location of our planet in a number of other planets, to assess the scale of celestial bodies and to give an idea of the vast distances that separate us from our celestial neighbors.
Planets and other objects of the solar system
Almost the entire universe is a myriad of stars, among which there are large and small solar systems. The presence of a star of its satellite planets is a common phenomenon in space. The laws of physics are the same everywhere, and our solar system is no exception.
If you ask yourself how many planets there were in the solar system and how many there are today, it is quite difficult to answer unambiguously. Currently, the exact location of 8 major planets is known. In addition, 5 small dwarf planets revolve around the Sun. The existence of a ninth planet is currently disputed in scientific circles.
The entire solar system is divided into groups of planets, which are arranged in the following order:
Terrestrial planets:
- Mercury;
- Venus;
- Mars.
Gas planets - giants:
- Jupiter;
- Saturn;
- Uranus;
- Neptune.
All the planets presented in the list differ in structure, have different astrophysical parameters. Which planet is larger or smaller than the others? The sizes of the planets of the solar system are different. The first four objects, similar in structure to the Earth, have a solid stone surface and are endowed with an atmosphere. Mercury, Venus and Earth are the inner planets. Mars closes this group. It is followed by the gas giants: Jupiter, Saturn, Uranus and Neptune - dense, spherical gas formations.
The process of life of the planets of the solar system does not stop for a second. Those planets that we see today in the sky are the arrangement of celestial bodies that the planetary system of our star has at the current moment. The state that was at the dawn of the formation of the solar system is strikingly different from what is studied today.
The table shows the astrophysical parameters of modern planets, which also indicates the distance of the planets of the solar system to the sun.
The existing planets of the solar system are about the same age, but there are theories that there were more planets in the beginning. This is evidenced by numerous ancient myths and legends that describe the presence of other astrophysical objects and catastrophes that led to the death of the planet. This is confirmed by the structure of our star system, where, along with the planets, there are objects that are products of violent cosmic cataclysms.
A striking example of such activity is the asteroid belt located between the orbits of Mars and Jupiter. Here, objects of extraterrestrial origin are concentrated in a huge number, mainly represented by asteroids and small planets. It is these fragments irregular shape in human culture, they are considered the remains of the protoplanet Phaeton, which died billions of years ago as a result of a large-scale cataclysm.
In fact, there is an opinion in scientific circles that the asteroid belt was formed as a result of the destruction of a comet. Astronomers have discovered large asteroid Themis and on the minor planets Ceres and Vesta, which are the largest objects in the asteroid belt, the presence of water. The ice found on the surface of asteroids may indicate the cometary nature of the formation of these cosmic bodies.
Previously, Pluto, belonging to the number of large planets, is not considered a full-fledged planet today.
Pluto, which was previously ranked among the large planets of the solar system, is now translated into the size of dwarf celestial bodies revolving around the sun. Pluto, along with Haumea and Makemake, the largest dwarf planets, is in the Kuiper Belt.
These dwarf planets The solar system is located in the Kuiper belt. The region between the Kuiper belt and the Oort cloud is the most distant from the Sun, but even there space is not empty. In 2005, the most distant celestial body in our solar system, the dwarf planet Eridu, was discovered there. The process of exploring the most distant regions of our solar system continues. The Kuiper Belt and the Oort Cloud are hypothetically the boundary regions of our star system, the visible boundary. This cloud of gas is located at a distance of one light year from the Sun and is the area where comets, wandering satellites of our star, are born.
Characteristics of the planets of the solar system
The terrestrial group of planets is represented by the planets closest to the Sun - Mercury and Venus. These two cosmic bodies of the solar system, despite the similarity in physical structure with our planet, are a hostile environment for us. Mercury is the smallest planet in our star system and is closest to the Sun. The heat of our star literally incinerates the surface of the planet, practically destroying the atmosphere on it. The distance from the surface of the planet to the Sun is 57,910,000 km. In size, only 5 thousand km in diameter, Mercury is inferior to most of the large satellites that are dominated by Jupiter and Saturn.
Saturn's satellite Titan has a diameter of over 5,000 km, Jupiter's satellite Ganymede has a diameter of 5265 km. Both satellites are second only to Mars in size.
The very first planet rushes around our star at great speed, making a complete revolution around our star in 88 Earth days. It is almost impossible to notice this small and nimble planet in the starry sky due to the close presence of the solar disk. Among the terrestrial planets, it is on Mercury that the largest daily temperature drops are observed. While the surface of the planet facing the Sun heats up to 700 degrees Celsius, the reverse side of the planet is immersed in universal cold with temperatures up to -200 degrees.
The main difference between Mercury and all the planets of the solar system is its internal structure. Mercury has the largest iron-nickel inner core, which accounts for 83% of the mass of the entire planet. However, even the uncharacteristic quality did not allow Mercury to have its own natural satellites.
Next to Mercury is the closest planet to us, Venus. The distance from Earth to Venus is 38 million km, and it is very similar to our Earth. The planet has almost the same diameter and mass, slightly inferior in these parameters to our planet. However, in all other respects, our neighbor is fundamentally different from our space home. The period of revolution of Venus around the Sun is 116 Earth days, and the planet rotates extremely slowly around its own axis. The average temperature of the surface of Venus rotating around its axis for 224 Earth days is 447 degrees Celsius.
Like its predecessor, Venus is devoid of the physical conditions conducive to the existence of known life forms. The planet is surrounded by a dense atmosphere, consisting mainly of carbon dioxide and nitrogen. Both Mercury and Venus are the only planets in the solar system that do not have natural satellites.
The Earth is the last of the inner planets of the solar system, located at a distance of about 150 million km from the Sun. Our planet makes one revolution around the sun in 365 days. It rotates around its own axis in 23.94 hours. The Earth is the first of the celestial bodies located on the path from the Sun to the periphery, which has natural satellite.
Digression: The astrophysical parameters of our planet are well studied and known. Earth is the largest and densest planet of all the other inner planets in the solar system. It is here that natural physical conditions have been preserved under which the existence of water is possible. Our planet has a stable magnetic field holding the atmosphere. Earth is the most well-studied planet. The subsequent study is mainly of not only theoretical interest, but also practical.
Closes the parade of planets of the terrestrial group Mars. The subsequent study of this planet is mainly not only of theoretical interest, but also of practical interest, connected with the development of extraterrestrial worlds by man. Astrophysicists are attracted not only by the relative proximity of this planet to the Earth (on average 225 million km), but also by the absence of complex climatic conditions. The planet is surrounded by an atmosphere, although it is in an extremely rarefied state, it has its own magnetic field and temperature drops on the surface of Mars are not as critical as on Mercury and Venus.
Like the Earth, Mars has two satellites - Phobos and Deimos, the natural nature of which is recent times is being questioned. Mars is the last fourth planet with a solid surface in the solar system. Following the asteroid belt, which is a kind of inner boundary of the solar system, the realm of gas giants begins.
The largest cosmic celestial bodies in our solar system
The second group of planets that make up the system of our star has bright and large representatives. These are the largest objects in our solar system and are considered outer planets. Jupiter, Saturn, Uranus and Neptune are the most distant from our star, and their astrophysical parameters are enormous by earthly standards. These celestial bodies differ in their massiveness and composition, which is mainly of a gas nature.
The main beauties of the solar system are Jupiter and Saturn. The total mass of this pair of giants would be enough to fit in it the mass of all known celestial bodies in the solar system. So Jupiter - the largest planet in the solar system - weighs 1876.64328 1024 kg, and the mass of Saturn is 561.80376 1024 kg. These planets have the most natural satellites. Some of them, Titan, Ganymede, Callisto and Io, are the largest satellites in the solar system and are comparable in size to the terrestrial planets.
The largest planet in the solar system - Jupiter - has a diameter of 140 thousand km. In many ways, Jupiter is more like a failed star - a prime example the existence of a small solar system. This is evidenced by the size of the planet and astrophysical parameters - Jupiter is only 10 times smaller than our star. The planet rotates around its own axis quite quickly - only 10 Earth hours. The number of satellites, of which 67 pieces have been identified to date, is also striking. The behavior of Jupiter and its moons is very similar to the model of the solar system. Such a number of natural satellites for one planet puts new question how many planets in the solar system were there early stage its formation. It is assumed that Jupiter, having a powerful magnetic field, turned some of the planets into its natural satellites. Some of them - Titan, Ganymede, Callisto and Io - are the largest satellites of the solar system and are comparable in size to the terrestrial planets.
Slightly inferior in size to Jupiter is its smaller brother, the gas giant Saturn. This planet, like Jupiter, consists mainly of hydrogen and helium - gases that are the basis of our star. With its size, the diameter of the planet is 57 thousand km, Saturn also resembles a protostar that has stopped in its development. The number of satellites of Saturn is slightly inferior to the number of satellites of Jupiter - 62 versus 67. On the satellite of Saturn, Titan, as well as on Io, the satellite of Jupiter, there is an atmosphere.
In other words, the largest planets Jupiter and Saturn, with their systems of natural satellites, strongly resemble small solar systems, with their clearly defined center and system of movement of celestial bodies.
The two gas giants are followed by cold and dark worlds, the planets Uranus and Neptune. These celestial bodies are located at a distance of 2.8 billion km and 4.49 billion km. from the Sun, respectively. Due to their great distance from our planet, Uranus and Neptune were discovered relatively recently. Unlike the other two gas giants, Uranus and Neptune have a large amount of frozen gases - hydrogen, ammonia and methane. These two planets are also called ice giants. Uranus is smaller than Jupiter and Saturn and is the third largest planet in the solar system. The planet represents the cold pole of our star system. The average temperature on the surface of Uranus is -224 degrees Celsius. Uranus differs from other celestial bodies revolving around the Sun by a strong inclination of its own axis. The planet seems to be rolling, revolving around our star.
Like Saturn, Uranus is surrounded by a hydrogen-helium atmosphere. Neptune, unlike Uranus, has a different composition. The presence of methane in the atmosphere is indicated by the blue color of the spectrum of the planet.
Both planets slowly and majestically move around our star. Uranus orbits the Sun in 84 Earth years, and Neptune circles our star twice as long - 164 Earth years.
Finally
Our solar system is a huge mechanism in which each planet, all the satellites of the solar system, asteroids and other celestial bodies move along a clearly defined route. The laws of astrophysics operate here, which have not changed for 4.5 billion years. Dwarf planets move along the outer edges of our solar system in the Kuiper belt. Comets are frequent guests of our star system. These space objects with a frequency of 20-150 years visit the inner regions of the solar system, flying in the visibility zone from our planet.
If you have any questions - leave them in the comments below the article. We or our visitors will be happy to answer them.
Planets of the solar system - a bit of history
Previously, a planet was considered to be any body that revolves around a star, glows with light reflected from it, and has a size larger than that of asteroids.
Also in Ancient Greece mentioned seven luminous bodies that move across the sky against the background of fixed stars. These cosmic bodies were: Sun, Mercury, Venus, Moon, Mars, Jupiter and Saturn. Earth was not included in this list, since the ancient Greeks considered the Earth to be the center of all things.
And only in the XVI century Nicolaus Copernicus in his scientific work titled "On the Revolution of the Celestial Spheres" came to the conclusion that not the Earth, but the Sun should be in the center of the planetary system. Therefore, the Sun and the Moon were removed from the list, and the Earth was added to it. And after the advent of telescopes, Uranus and Neptune were added, in 1781 and 1846, respectively.
Pluto was considered the last discovered planet in the solar system from 1930 until recently.
And now, almost 400 years after Galileo Galilei created the world's first telescope for observing stars, astronomers have come to the next definition of a planet.
Planet- this is a celestial body that must satisfy four conditions:
the body must revolve around a star (for example, around the Sun);
the body must have sufficient gravity to be spherical or close to it;
the body should not have other large bodies near its orbit;
the body does not have to be a star.
In turn, the polar star is a cosmic body that emits light and is a powerful source of energy. This is explained, firstly, by the thermonuclear reactions occurring in it, and secondly, by the processes of gravitational compression, as a result of which great amount energy.
Planets of the solar system today
solar system- This is a planetary system that consists of a central star - the Sun - and all natural space objects revolving around it.
So, today the solar system consists of of the eight planets: four inner, so-called terrestrial planets, and four outer planets, called gas giants.
The terrestrial planets include Earth, Mercury, Venus and Mars. All of them consist mainly of silicates and metals.
The outer planets are Jupiter, Saturn, Uranus and Neptune. The composition of gas giants consists mainly of hydrogen and helium.
The sizes of the planets in the solar system vary both within groups and between groups. So, the gas giants are much larger and more massive than the terrestrial planets.
Closest to the Sun is Mercury, then as far as the distance: Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
It would be wrong to consider the characteristics of the planets of the solar system without paying attention to its main component: the Sun itself. Therefore, we will start with it. 
The sun planet is a star that gave rise to all life in the solar system. Planets, dwarf planets and their satellites, asteroids, comets, meteorites and cosmic dust revolve around it.
The sun arose about 5 billion years ago, is a spherical, hot plasma ball and has a mass that is more than 300 thousand times the mass of the Earth. The surface temperature is over 5,000 degrees Kelvin, and the core temperature is over 13 million K.
The sun is one of the largest and most bright stars in our galaxy, which is called the Milky Way galaxy. The Sun is located at a distance of about 26 thousand light years from the center of the Galaxy and makes a complete revolution around it in about 230-250 million years! For comparison, the Earth makes a complete revolution around the Sun in 1 year.
Mercury planet
Mercury is the smallest planet in the system and is closest to the Sun. Mercury has no satellites.
The surface of the planet is covered with craters that arose about 3.5 billion years ago as a result of massive bombardments by meteorites. The diameter of the craters can range from a few meters to more than 1000 km.
The atmosphere of Mercury is highly rarefied, consists mainly of helium and is blown by the solar wind. Since the planet is located very close to the Sun and does not have an atmosphere that would keep warm at night, the temperature on the surface ranges from -180 to +440 degrees Celsius.
By earthly standards, Mercury makes a complete revolution around the Sun in 88 days. On the other hand, a Mercury day is equal to 176 Earth days.
Venus planet
Venus is the second closest planet to the Sun in the solar system. Venus is only slightly smaller than Earth, which is why it is sometimes referred to as "Earth's sister". Has no satellites.
The atmosphere consists of carbon dioxide mixed with nitrogen and oxygen. The air pressure on the planet is more than 90 atmospheres, which is 35 times more than the earth.
Carbon dioxide and, as a result, the greenhouse effect, a dense atmosphere, as well as proximity to the Sun, allow Venus to carry the title of "hottest planet". The temperature on its surface can reach 460°C.
Venus is one of the brightest objects in the Earth's sky after the Sun and Moon.
Planet Earth 
Earth is the only known planet in the universe today that has life on it. The earth has largest sizes, mass and density among the so-called inner planets of the solar system.
The age of the Earth is about 4.5 billion years, and life appeared on the planet about 3.5 billion years ago. The Moon is a natural satellite, the largest of the satellites of the terrestrial planets.
The atmosphere of the Earth is fundamentally different from the atmospheres of other planets due to the presence of life. Most of atmosphere consists of nitrogen, it also includes oxygen, argon, carbon dioxide and water vapor. The ozone layer and the Earth's magnetic field, in turn, weaken the life-threatening effects of solar and cosmic radiation.
Due to the carbon dioxide contained in the atmosphere, the greenhouse effect also takes place on Earth. It does not appear as strongly as on Venus, but without it, the air temperature would be approximately 40 ° C lower. Without the atmosphere, temperature fluctuations would be very significant: according to scientists, from -100 ° C at night to + 160 ° C during the day.
About 71% of the Earth's surface is occupied by the oceans, the remaining 29% are continents and islands.
mars planet
Mars is the seventh largest planet in the solar system. "Red Planet", as it is also called due to the presence a large number iron oxide in the soil. Mars has two moons: Deimos and Phobos.
The atmosphere of Mars is highly rarefied, and the distance to the Sun is almost one and a half times greater than that of the Earth. Therefore, the average annual temperature on the planet is -60 ° C, and temperature drops in some places reach 40 degrees during the day.
Distinctive features of the surface of Mars are impact craters and volcanoes, valleys and deserts, ice polar caps like those on Earth. On Mars is the most high mountain in the solar system: dormant volcano Olympus, whose height is 27 km! As well as the largest canyon: the Marinera Valley, the depth of which reaches 11 km, and the length is 4500 km 
Jupiter planet
Jupiter is the largest planet in the solar system. It is 318 times heavier than the Earth, and almost 2.5 times more massive than all the planets in our system combined. In its composition, Jupiter resembles the Sun - it consists mainly of helium and hydrogen - and radiates a huge amount of heat, equal to 4 * 1017 watts. However, in order to become a star like the Sun, Jupiter must be another 70-80 times heavier.
Jupiter has as many as 63 satellites, of which it makes sense to list only the largest ones - Callisto, Ganymede, Io and Europa. Ganymede is the largest moon in the solar system, larger than even Mercury.
Due to certain processes in the inner atmosphere of Jupiter, many vortex structures appear in its outer atmosphere, for example, stripes of clouds of brown-red hues, as well as the Great Red Spot, a giant storm known since the 17th century.
saturn planet
Saturn is the second largest planet in the solar system. The hallmark of Saturn is, of course, its ring system, which consists mainly of ice particles. different size(from tenths of a millimeter to several meters), as well as rocks and dust.
Saturn has 62 moons, the largest of which are Titan and Enceladus.
In its composition, Saturn resembles Jupiter, but in density it is inferior even to ordinary water.
The outer atmosphere of the planet looks calm and homogeneous, which is explained by a very dense layer of fog. However, the wind speed in some places can reach 1800 km/h.
Uranus planet
Uranus is the first planet to be discovered with a telescope, and also the only planet in the solar system that wraps around the sun, "lying on its side."
Uranus has 27 moons named after Shakespearean heroes. The largest of them are Oberon, Titania and Umbriel.
The composition of the planet differs from the gas giants in the presence of a large number of high-temperature modifications of ice. Therefore, along with Neptune, scientists have identified Uranus in the category of "ice giants". And if Venus has the title of "hottest planet" in the solar system, then Uranus is the coldest planet with minimum temperature around -224°C.
Neptune planet
Neptune is the most distant planet from the center of the solar system. The history of its discovery is interesting: before observing the planet through a telescope, scientists calculated its position in the sky using mathematical calculations. This happened after the discovery of inexplicable changes in the movement of Uranus in its own orbit.
To date, 13 satellites of Neptune are known to science. The largest of them - Triton - is the only satellite that moves in the opposite direction to the rotation of the planet. The fastest winds in the solar system also blow against the rotation of the planet: their speed reaches 2200 km/h.
The composition of Neptune is very similar to Uranus, therefore it is the second "ice giant". However, like Jupiter and Saturn, Neptune has internal source heat and radiates 2.5 times more energy than it receives from the sun.
Blue color the planet is given traces of methane in outer layers atmosphere.
Conclusion
Pluto, unfortunately, did not have time to get into our parade of planets in the solar system. But it is absolutely not worth worrying about this, because all the planets remain in their places, despite changes in scientific views and concepts.
So, we answered the question of how many planets are there in the solar system. There are only 8 .
Our home in space is the solar system - star system, consisting of eight planets and part of the Milky Way galaxy. In the center is a star called the Sun. The solar system is four and a half billion years old. We live on the third planet from the sun. Do you know about other planets in the solar system? Now we will tell you a little about them.
Mercury is the smallest planet in the solar system. Its radius is 2440 km. The period of revolution around the Sun is 88 Earth days. During this time, Mercury has time to complete a revolution around its own axis only one and a half times. A day on Mercury lasts approximately 59 Earth days. The orbit of Mercury is one of the most unstable: not only the speed of movement and its distance from the Sun change there, but also the position itself. There are no satellites.
Neptune is the eighth planet in the solar system. It is close enough to Uranus. The radius of the planet is 24547 km. A year on Neptune is equal to 60190 days, that is, somewhere around 164 Earth years. Has 14 satellites. Has an atmosphere in which the most strong wind— up to 260 m/s.
By the way, Neptune was discovered not with the help of observations, but through mathematical calculations.
Uranus is the seventh planet in the solar system. Radius - 25267 km. The coldest planet is a surface temperature of -224 degrees. A year on Uranus is equal to 30,685 Earth days, that is, approximately 84 years. Day - 17 hours. Has 27 satellites.
Saturn is the sixth planet in the solar system. The radius of the planet is 57350 km. It is the second largest after Jupiter. A year on Saturn is equal to 10759 days, which is almost 30 Earth years. A day on Saturn is almost equal to a day on Jupiter - 10.5 Earth hours. Most similar to the Sun in the composition of chemical elements.
Has 62 satellites.
The main feature of Saturn is its rings. Their origin has not yet been established.
Jupiter is the fifth planet from the sun. It is the largest planet in the solar system. The radius of Jupiter is 69912 km. This is already 19 times more earth. A year there lasts as much as 4333 Earth days, that is, almost incomplete 12 years. A day has a duration of about 10 Earth hours.
Jupiter has 67 moons. The largest of them are Callisto, Ganymede, Io and Europa. At the same time, Ganymede is 8% larger than Mercury, the smallest planet in our system, and has an atmosphere.
Mars is the fourth planet in the solar system. Its radius is 3390 km, which is almost half the size of the Earth. A year on Mars is 687 Earth days. It has 2 satellites - Phobos and Deimos.
The atmosphere of the planet is rarefied. The water found on some parts of the surface suggests that some kind of primitive life on Mars was once before or even exists now.
Venus is the second planet in the solar system. It is similar in mass and radius to the Earth. There are no satellites.
The atmosphere of Venus is almost entirely composed of carbon dioxide. The percentage of carbon dioxide in the atmosphere is 96%, nitrogen is approximately 4%. Water vapor and oxygen are also present, but in very small quantities. Due to the fact that such an atmosphere creates a greenhouse effect, the temperature on the surface of the planet reaches 475 ° C. A day on Venus is 243 earthly days. A year on Venus is 255 days.
Pluto is a dwarf planet at the edges of the solar system, which is the dominant object in a distant system of 6 small cosmic bodies. The radius of the planet is 1195 km. The period of revolution of Pluto around the Sun is approximately 248 Earth years. A day on Pluto is 152 hours. The mass of the planet is approximately 0.0025 of the mass of the Earth.
It is noteworthy that Pluto was excluded from the category of planets in 2006 due to the fact that in the Kuiper belt there are objects that are larger or equal in size to Pluto, which is why, even if it is taken as a full-fledged planet, then in this case it is necessary add Eris to this category - it has almost the same size as Pluto.
Not so long ago, anyone educated person to the question of how many planets are in the solar system, he would answer without hesitation - nine. And he would be right. If you do not particularly follow the events in the world of astronomy and are not a regular viewer of the Discovery Channel, then today you will answer the same question to the question posed. However, this time you will be wrong.
And here's the thing. In 2006, namely, on August 26, 2.5 thousand participants in the congress of the International Astronomical Union made a sensational decision and actually crossed out Pluto from the list of planets in the solar system, since 76 years after the discovery it ceased to meet the requirements set by scientists for the planets.
Let's first understand what a planet is, and also how many planets in the solar system astronomers have left us, and consider each of them separately.
A bit of history
Previously, a planet was considered to be any body that revolves around a star, glows with light reflected from it, and has a size larger than that of asteroids.
Even in ancient Greece, seven luminous bodies were mentioned that move across the sky against the background of fixed stars. These cosmic bodies were: Sun, Mercury, Venus, Moon, Mars, Jupiter and Saturn. Earth was not included in this list, since the ancient Greeks considered the Earth to be the center of all things. And only in the 16th century, Nicolaus Copernicus, in his scientific work entitled “On the Revolution of the Celestial Spheres,” came to the conclusion that not the Earth, but the Sun should be in the center of the planetary system. Therefore, the Sun and the Moon were removed from the list, and the Earth was added to it. And after the advent of telescopes, Uranus and Neptune were added, in 1781 and 1846, respectively.
Pluto was considered the last discovered planet in the solar system from 1930 until recently.
And now, almost 400 years after Galileo Galilei created the world's first telescope for observing stars, astronomers have come to the next definition of a planet.
Planet- this is a celestial body that must satisfy four conditions:
the body must revolve around a star (for example, around the Sun);
the body must have sufficient gravity to be spherical or close to it;
the body should not have other large bodies near its orbit;
The body does not have to be a star.
In its turn star- This is a cosmic body that emits light and is a powerful source of energy. This is explained, firstly, by the thermonuclear reactions occurring in it, and secondly, by the processes of gravitational compression, as a result of which a huge amount of energy is released.
Planets of the solar system today
solar system- This is a planetary system that consists of a central star - the Sun - and all natural space objects revolving around it.
So, today the solar system consists of of the eight planets: four inner, so-called terrestrial planets, and four outer planets, called gas giants.
The terrestrial planets include Earth, Mercury, Venus and Mars. All of them consist mainly of silicates and metals.
The outer planets are Jupiter, Saturn, Uranus and Neptune. The composition of gas giants consists mainly of hydrogen and helium.
The sizes of the planets in the solar system vary both within groups and between groups. So, the gas giants are much larger and more massive than the terrestrial planets.
Closest to the Sun is Mercury, then as far as the distance: Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
It would be wrong to consider the characteristics of the planets of the solar system without paying attention to its main component: the Sun itself. Therefore, we will start with it.
The sun 
The sun is the star that gave rise to all life in the solar system. Planets, dwarf planets and their satellites, asteroids, comets, meteorites and cosmic dust revolve around it.
The sun arose about 5 billion years ago, is a spherical, hot plasma ball and has a mass that is more than 300 thousand times the mass of the Earth. The surface temperature is over 5,000 degrees Kelvin, and the core temperature is over 13 million K.
The Sun is one of the largest and brightest stars in our galaxy, which is called the Milky Way galaxy. The Sun is located at a distance of about 26 thousand light years from the center of the Galaxy and makes a complete revolution around it in about 230-250 million years! For comparison, the Earth makes a complete revolution around the Sun in 1 year.
Mercury
Mercury is the smallest planet in the system and is closest to the Sun. Mercury has no satellites.
The surface of the planet is covered with craters that arose about 3.5 billion years ago as a result of massive bombardments by meteorites. The diameter of the craters can range from a few meters to more than 1000 km.
The atmosphere of Mercury is highly rarefied, consists mainly of helium and is blown by the solar wind. Since the planet is located very close to the Sun and does not have an atmosphere that would keep warm at night, the temperature on the surface ranges from -180 to +440 degrees Celsius.
By earthly standards, Mercury makes a complete revolution around the Sun in 88 days. On the other hand, a Mercury day is equal to 176 Earth days.
Venus
Venus is the second closest planet to the Sun in the solar system. Venus is only slightly smaller than Earth, which is why it is sometimes referred to as "Earth's sister". Has no satellites.
The atmosphere consists of carbon dioxide mixed with nitrogen and oxygen. The air pressure on the planet is more than 90 atmospheres, which is 35 times more than the earth.
Carbon dioxide and, as a result, the greenhouse effect, a dense atmosphere, as well as proximity to the Sun, allow Venus to carry the title of "hottest planet". The temperature on its surface can reach 460°C.
Venus is one of the brightest objects in the Earth's sky after the Sun and Moon.
Earth 
Earth is the only known planet in the universe today that has life on it. The Earth has the largest size, mass and density among the so-called inner planets of the solar system.
The age of the Earth is about 4.5 billion years, and life appeared on the planet about 3.5 billion years ago. The Moon is a natural satellite, the largest of the satellites of the terrestrial planets.
The atmosphere of the Earth is fundamentally different from the atmospheres of other planets due to the presence of life. Most of the atmosphere is nitrogen, but it also contains oxygen, argon, carbon dioxide and water vapor. The ozone layer and the Earth's magnetic field, in turn, weaken the life-threatening effects of solar and cosmic radiation.
Due to the carbon dioxide contained in the atmosphere, the greenhouse effect also takes place on Earth. It does not appear as strongly as on Venus, but without it, the air temperature would be approximately 40 ° C lower. Without the atmosphere, temperature fluctuations would be very significant: according to scientists, from -100 ° C at night to + 160 ° C during the day.
About 71% of the Earth's surface is occupied by the oceans, the remaining 29% are continents and islands.
Mars
Mars is the seventh largest planet in the solar system. The "Red Planet", as it is also called due to the presence of a large amount of iron oxide in the soil. Mars has two moons: Deimos and Phobos.
The atmosphere of Mars is highly rarefied, and the distance to the Sun is almost one and a half times greater than that of the Earth. Therefore, the average annual temperature on the planet is -60 ° C, and temperature drops in some places reach 40 degrees during the day.
Distinctive features of the surface of Mars are impact craters and volcanoes, valleys and deserts, ice polar caps like Earth's. The highest mountain in the solar system is located on Mars: the extinct volcano Olympus, whose height is 27 km! As well as the largest canyon: the Valley of the Mariner, the depth of which reaches 11 km, and the length is 4500 km.
Jupiter
Jupiter is the largest planet in the solar system. It is 318 times heavier than the Earth, and almost 2.5 times more massive than all the planets in our system combined. In its composition, Jupiter resembles the Sun - it consists mainly of helium and hydrogen - and radiates a huge amount of heat, equal to 4 * 1017 watts. However, in order to become a star like the Sun, Jupiter must be another 70-80 times heavier.
Jupiter has as many as 63 satellites, of which it makes sense to list only the largest ones - Callisto, Ganymede, Io and Europa. Ganymede is the largest moon in the solar system, larger than even Mercury.
Due to certain processes in the inner atmosphere of Jupiter, many vortex structures appear in its outer atmosphere, for example, stripes of clouds of brown-red hues, as well as the Great Red Spot, a giant storm known since the 17th century.
Saturn
Saturn is the second largest planet in the solar system. The hallmark of Saturn is, of course, its ring system, which consists mainly of ice particles of various sizes (from tenths of a millimeter to several meters), as well as rocks and dust.
Saturn has 62 moons, the largest of which are Titan and Enceladus.
In its composition, Saturn resembles Jupiter, but in density it is inferior even to ordinary water.
The outer atmosphere of the planet looks calm and homogeneous, which is explained by a very dense layer of fog. However, the wind speed in some places can reach 1800 km/h.
Uranus
Uranus is the first planet to be discovered with a telescope, and also the only planet in the solar system that wraps around the sun, "lying on its side."
Uranus has 27 moons named after Shakespearean heroes. The largest of them are Oberon, Titania and Umbriel.
The composition of the planet differs from the gas giants in the presence of a large number of high-temperature modifications of ice. Therefore, along with Neptune, scientists have identified Uranus in the category of "ice giants". And if Venus has the title of "hottest planet" in the solar system, then Uranus is the coldest planet with a minimum temperature of about -224 ° C.
Neptune
Neptune is the most distant planet from the center of the solar system. The history of its discovery is interesting: before observing the planet through a telescope, scientists calculated its position in the sky using mathematical calculations. This happened after the discovery of inexplicable changes in the movement of Uranus in its own orbit.
To date, 13 satellites of Neptune are known to science. The largest of them - Triton - is the only satellite that moves in the opposite direction to the rotation of the planet. The fastest winds in the solar system also blow against the rotation of the planet: their speed reaches 2200 km/h.
The composition of Neptune is very similar to Uranus, therefore it is the second "ice giant". However, like Jupiter and Saturn, Neptune has an internal source of heat and radiates 2.5 times more energy than it receives from the Sun.
The planet's blue color comes from traces of methane in the outer atmosphere.
Conclusion
Pluto, unfortunately, did not have time to get into our parade of planets in the solar system. But it is absolutely not worth worrying about this, because all the planets remain in their places, despite changes in scientific views and concepts.
So, we answered the question of how many planets are there in the solar system. There are only 8 .