Years of the solar system. Solar system planets: eight and one

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. From a 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. 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 mature age, 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 the planets, satellites and asteroids, cosmic 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 taken into account that the orbits of all objects revolving around the Sun are located at different angles to the diametrical plane of the Solar System. The planets of the solar system are located at different distances from the Sun, rotate at different speeds 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. AT 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 the ninth planet on this moment 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 formation solar system very different from what is known today.

About astrophysical parameters modern planets evidenced by the table, 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 the presence of water on the large asteroid Themis and on the minor planets Ceres and Vesta, which are the largest objects in the asteroid belt. 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 of the solar system are 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 way from the Sun to the periphery, which has a 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 that holds 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 has recently been 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 respects, Jupiter is more like a failed star - a vivid example of 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 of the solar system were at an early stage of 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. Found on the surface of Uranus average temperature-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. About the presence of methane in the atmosphere says blue color 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.

The solar system consists of eight planets and more than 63 of their satellites, which are being discovered more and more often, as well as several dozen comets and a large number of asteroids. All cosmic bodies move along their clear directed trajectories around the Sun, which is 1000 times heavier than all the bodies in the solar system combined.

How many planets revolve around the sun

How the planets of the solar system originated: approximately 5-6 billion years ago, one of the gas and dust clouds of our large Galaxy ( milky way), shaped like a disk, began to shrink towards the center, gradually forming the current Sun. Further, according to one of the theories, under the influence of powerful forces of attraction, a large number of dust and gas particles rotating around the Sun began to stick together into balls - forming future planets. According to another theory, the gas and dust cloud immediately broke up into separate clusters of particles, which compressed and condensed, forming the current planets. Now 8 planets revolve around the sun constantly.

The center of the solar system is the Sun, the star around which the planets revolve in orbits. They do not emit heat and do not glow, but only reflect the light of the Sun. There are currently 8 officially recognized planets in the solar system. Briefly, in order of distance from the sun, we list them all. And now some definitions.

Planet satellites. The solar system also includes the Moon and the natural satellites of other planets, which all of them have, except for Mercury and Venus. More than 60 satellites are known. Most of the satellites of the outer planets were discovered when they received photographs taken by robotic spacecraft. Jupiter's smallest moon, Leda, is only 10 km across.

The Sun is a star without which life on Earth could not exist. It gives us energy and warmth. According to the classification of stars, the Sun is a yellow dwarf. The age is about 5 billion years. It has a diameter at the equator equal to 1,392,000 km, 109 times larger than the earth. The rotation period at the equator is 25.4 days and 34 days at the poles. The mass of the Sun is 2x10 to the 27th power of tons, approximately 332950 times the mass of the Earth. The temperature inside the core is about 15 million degrees Celsius. The surface temperature is about 5500 degrees Celsius.

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 a solid surface. They are smaller than four giant planets. Mercury moves faster than other planets, burning sunbeams during the day and freezing at night.

Characteristics of the planet Mercury:

Period of revolution around the Sun: 87.97 days.

Diameter at the equator: 4878 km.

Rotation period (turn around the axis): 58 days.

Surface temperature: 350 during the day and -170 at night.

Atmosphere: very rarefied, helium.

How many satellites: 0.

The main satellites of the planet: 0.

Venus is the 2nd planet in the solar system

Venus is more similar to Earth in size and brightness. Observation of it is difficult because of the clouds enveloping it. The surface is a hot, rocky desert.

Characteristics of the planet Venus:

Period of revolution around the Sun: 224.7 days.

Diameter at the equator: 12104 km.

Rotation period (turn around the axis): 243 days.

Surface temperature: 480 degrees (average).

Atmosphere: dense, mostly carbon dioxide.

How many satellites: 0.

The main satellites of the planet: 0.

Earth is the 3rd planet in the solar system

Apparently, the Earth was formed from a gas and dust cloud, like other planets in the solar system. Particles of gas and dust, colliding, gradually "raised" the planet. The temperature on the surface reached 5000 degrees Celsius. Then the Earth cooled down and became covered with a hard stone crust. But the temperature in the bowels is still quite high - 4500 degrees. Rocks 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 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 outside diameter 270,000 km, but their thickness is about 30 meters.

Characteristics of the planet Saturn:

The period of revolution around the Sun: 29 years 168 days.

Diameter of the planet at the equator: 120536 km.

Rotation period (turn around the axis): 10 hours 14 minutes.

Surface temperature: -180 degrees (average).

Atmosphere: mostly hydrogen and helium.

Number of satellites: 18 (+ rings).

Main satellites: Titan.

Uranus is the 7th planet in the solar system

Unique planet in the solar system. Its peculiarity is that it revolves around the Sun not like everyone else, but "lying on its side." Uranus also has rings, although they are harder to see. In 1986, Voyager 2 flew 64,000 km and had six hours to take photos, which it successfully completed.

Characteristics of the planet Uranus:

Orbital period: 84 years 4 days.

Diameter at the equator: 51118 km.

The period of rotation of the planet (rotation around the axis): 17 hours 14 minutes.

Surface temperature: -214 degrees (average).

Atmosphere: mostly hydrogen and helium.

How many satellites: 15 (+ rings).

Main satellites: Titania, Oberon.

Neptune is the 8th planet in the solar system

At the moment, Neptune is considered the last planet in the solar system. Its discovery took place by the method of mathematical calculations, and then they saw it through a telescope. In 1989, Voyager 2 flew by. He took amazing photographs of the blue surface of Neptune and its largest moon, Triton.

Characteristics of the planet Neptune:

The period of revolution around the Sun: 164 years 292 days.

Diameter at the equator: 50538 km.

Rotation period (turn around the axis): 16 hours 7 minutes.

Surface temperature: -220 degrees (average).

Atmosphere: mostly hydrogen and helium.

Number of satellites: 8.

Main moons: Triton.

How many planets in the solar system: 8 or 9?

Previously, for many years, astronomers recognized the presence of 9 planets, that is, Pluto was also considered a planet, like the rest of everyone already known. But in the 21st century, scientists were able to prove that it is not a planet at all, which means that there are 8 planets in the solar system.

Now, if you are asked how many planets are in the solar system, answer boldly - 8 planets in our system. It has been officially recognized since 2006. When lining up the planets of the solar system in order from the sun, use the finished picture. What do you think, maybe Pluto should not have been removed from the list of planets and these are scientific prejudices?

How many planets in the solar system: video, watch for free

> Planets

Explore everything planets of the solar system in order and learn the names, new scientific facts and interesting features surrounding worlds with photos and videos.

There are 8 planets in the solar system: Mercury, Venus, Mars, Earth, Jupiter, Saturn, Uranus and Neptune. The first 4 belong to the inner solar system and are considered terrestrial planets. Jupiter and Saturn are large planets of the solar system and representatives of gas giants (huge and filled with hydrogen and helium), while Uranus and Neptune are ice giants (large and represented by heavier elements).

Previously, Pluto was considered the ninth planet, but since 2006 it has moved into the category of dwarf planets. This dwarf planet was first discovered by Clyde Tomb. Now it is one of the largest objects in the Kuiper belt - a cluster of icy bodies on the outer edge of our system. Pluto lost its planetary status after the IAU (International Astronomical Union) revised the concept itself.

According to the decision of the IAU, a planet of the solar system is a body that performs an orbital passage around the Sun, endowed with sufficient mass to form in the form of a sphere and clear the area around it from foreign objects. Pluto could not meet the last requirement, and therefore became a dwarf planet. Other similar objects include Ceres, Makemake, Haumea, and Eridu.

With a small atmosphere, harsh surface features and 5 satellites, Pluto is considered the most complex dwarf planet and one of amazing planets in our solar system.

But scientists do not lose hope of finding the mysterious Ninth Planet - after they announced a hypothetical object in 2016 that affects bodies from the Kuiper belt by gravity. In terms of parameters, it is 10 times the mass of the Earth and 5,000 times more massive than Pluto. Below is a list of the planets of the solar system with photos, names, descriptions, detailed characteristics and interesting facts for children and adults.

Variety of planets

Astrophysicist Sergei Popov on gas and ice giants, binary star systems and single planets:

Hot planetary coronas

Astronomer Valery Shematovich on the study of gas shells of planets, hot particles in the atmosphere and discoveries on Titan:

Terrestrial planets of the solar system

The first 4 planets from the Sun are called terrestrial planets because their surface is rocky. Pluto also has a solid surface layer (frozen), but it belongs to the dwarf type planets.

Gas giant planets of the solar system

4 gas giants live in the outer solar system, as they are quite huge and gaseous. But Uranus and Neptune are different because they more ice. Therefore, they are also called ice giants. However, all gas giants have one thing in common: they are all made up of hydrogen and helium.

The IAU put forward the definition of a planet:

• The object must revolve around the sun;
• Have enough mass to take the shape of a ball;
• Clear your orbital path from foreign objects;

Pluto could not meet the last requirement, as it shares an orbital path with huge amount bodies from the Kuiper belt. But not everyone agreed with the definition. However, dwarf planets such as Eris, Haumea and Makemake appeared on the scene.

Ceres also lives between Mars and Jupiter. She was noticed in 1801 and considered a planet. Some still consider it the 10th planet of the solar system.

Dwarf planets of the solar system

Formation of planetary systems

Astronomer Dmitry Wiebe about stone planets and giant planets, the diversity of planetary systems and hot Jupiters:

Solar system planets in order

Below are the characteristics of the 8 major planets of the solar system in order from the sun:

The first planet from the Sun is Mercury

Mercury is the first planet from the Sun. It rotates in an elliptical orbit with a distance of 46-70 million km from the Sun. It spends 88 days on one orbital span, and 59 days on an axial span. Due to the slow rotation, a day spans 176 days. The axial tilt is extremely small.

With a diameter of 4887 km, the first planet from the Sun reaches 5% of the earth's mass. Surface gravity - 1/3 of the earth. The planet is practically devoid of an atmospheric layer, so it is hot during the day and freezes at night. The temperature mark fluctuates between +430°C and -180°C.

There is a crater surface and an iron core. But the magnetic field is inferior to the earth. Initially, radars indicated the presence of water ice at the poles. The Messenger confirmed the assumptions and found deposits at the bottom of the craters, which are all the time immersed in shadow.

The first planet from the Sun is located close to the star, so it can be seen before dawn and just after sunset.

• Name: the messenger of the gods in the Roman pantheon.
• Diameter: 4878 km.
• Orbit: 88 days.
• Day length: 58.6 days.

Second planet from the Sun - Venus

Venus is the second planet from the Sun. Travels in an almost circular orbit at a distance of 108 million km. It comes closest to the Earth and can reduce the distance to 40 million km.

It spends 225 days on an orbital path, and an axial rotation (clockwise) lasts 243 days. A day covers 117 Earth days. The axial tilt is 3 degrees.

In diameter (12100 km), the second planet from the Sun almost converges with the earth and reaches 80% of the earth's mass. The gravity indicator is 90% of the earth. The planet has a dense atmospheric layer, where the pressure is 90 times higher than the earth's. The atmosphere is filled with carbon dioxide with thick sulfur clouds, which creates a powerful the greenhouse effect. It is because of this that the surface warms up by 460 ° C (the hottest planet in the system).

The surface of the second planet from the Sun is hidden from direct observation, but scientists managed to create a map using radar. Sheltered by large volcanic plains with two huge continents, mountains and valleys. There are also impact craters. A weak magnetic field is observed.

• Detection: The ancients saw without the use of tools.
• Name: Roman goddess responsible for love and beauty.
• Diameter: 12104 km.
• Orbit: 225 days.
• Day length: 241 days.

Third planet from the Sun - Earth

Earth is the third planet from the Sun. It is the largest and densest of the inner planets. The orbital path is 150 million km away from the Sun. It has a single companion and developed life.

The orbital flyby takes 365.25 days, and the axial rotation takes 23 hours, 56 minutes and 4 seconds. The length of the day is 24 hours. The axial tilt is 23.4 degrees, and the diameter index is 12742 km.

The third planet from the Sun formed 4.54 billion years ago and most its existence near is the moon. It is believed that the satellite appeared after a huge object crashed into the Earth and pulled material into orbit. It was the Moon that stabilized the earth's axial tilt and acts as a source of tide formation.

The satellite in diameter covers 3747 km (27% of the Earth's) and is located at a distance of 362000-405000 km. Experiencing planetary gravitational influence, due to which it slowed down the axial rotation and got into the gravitational block (therefore, one side is turned towards the Earth).

The planet is protected from stellar radiation by a powerful magnetic field formed by an active core (molten iron).

• Diameter: 12760 km.
• Orbit: 365.24 days.
• Day length: 23 hours and 56 minutes.

The fourth planet from the Sun is Mars

Mars is the fourth planet from the Sun. The red planet moves along an eccentric orbital path - 230 million km. It spends 686 days on one flight around the Sun, and an axial rotation - 24 hours and 37 minutes. It is tilted at 25.1 degrees and a day lasts 24 hours and 39 minutes. The slope resembles the Earth, so it has seasons.

The diameter of the fourth planet from the Sun (6792 km) is half that of the earth, and the mass reaches 1/10 of the earth. The gravity indicator is 37%.

Mars is unprotected as magnetic field, so the original atmosphere was destroyed by the solar wind. The devices recorded the outflow of atoms into space. As a result, the pressure reaches 1% of the earth's, and a thin atmospheric layer is represented by 95% carbon dioxide.

The fourth planet from the Sun is extremely frosty, where temperatures drop to -87°C in winter and rise to -5°C in summer. It is a dusty place with gigantic storms capable of covering the entire surface.

• Detection: The ancients saw without the use of tools.
• Title: Roman god of war.
• Diameter: 6787 km.
• Orbit: 687 days.
• Day length: 24 hours and 37 minutes.

Fifth planet from the Sun - Jupiter

Jupiter is the fifth planet from the Sun. In addition, in front of you is the largest planet in the system, which is 2.5 times more massive than all the planets and covers 1/1000 of the solar mass.

It is 780 million km away from the Sun and spends 12 years on an orbital path. It is filled with hydrogen (75%) and helium (24%) and may have a rocky core immersed in liquid metallic hydrogen with a diameter of 110,000 km. The total planetary diameter is 142,984 km.

AT top layer atmosphere are 50-kilometer clouds, represented by ammonia crystals. They are in lanes moving on different speeds and latitudes. The Great Red Spot, a large-scale storm, seems noteworthy.

The fifth planet from the Sun spends 10 hours on an axial rotation. This is a rapid speed, which means that the equatorial diameter is 9000 km more than the polar one.

• Detection: The ancients saw without the use of tools.
• Name: the main god in the Roman pantheon.
• Diameter: 139822 km.
• Orbit: 11.9 years.
• Day length: 9.8 hours.

The sixth planet from the Sun is Saturn

Saturn is the sixth planet from the Sun. Saturn is in the 2nd position in terms of scale in the system, exceeding the earth's radius by 9 times (57,000 km) and 95 times more massive.

It is 1400 million km away from the Sun and spends 29 years on an orbital flight. Filled with hydrogen (96%) and helium (3%). May have a rocky core in liquid metallic hydrogen with a diameter of 56,000 km. The upper layers are represented by liquid water, hydrogen, ammonium hydrosulfide and helium.

The core is heated up to 11700°C and produces more heat than the planet receives from the Sun. The higher we climb, the lower the degree drops. At the top, the temperature is kept at -180°C and 0°C at a depth of 350 km.

The cloud layers of the sixth planet from the Sun resemble the picture of Jupiter, but they are fainter and wider. There is also a large White spot- brief periodic storm. It spends 10 hours and 39 minutes on an axial turn, but it is difficult to give an exact figure, since there are no fixed surface features.

• Detection: The ancients saw without the use of tools.
• Name: god of economy in the Roman pantheon.
• Diameter: 120500 km.
• Orbit: 29.5 days.
• Day length: 10.5 hours.

The seventh planet from the Sun is Uranus

Uranus is the seventh planet from the Sun. Uranus is a representative of the ice giants and is the 3rd largest in the system. In diameter (50,000 km) it is 4 times larger than the earth and 14 times more massive.

It is distant by 2900 million km and spends 84 years on the orbital path. Surprisingly, according to the axial tilt (97 degrees), the planet literally rotates on its side.

It is believed that there is a small rocky core around which a mantle of water, ammonia and methane is concentrated. This is followed by a hydrogen, helium and methane atmosphere. The seventh planet from the Sun is also distinguished by the fact that it does not radiate more internal heat, so the temperature mark drops to -224 ° C (the frostiest planet).

• Discovery: Noticed by William Herschel in 1781.
• Name: personification of the sky.
• Diameter: 51120 km.
• Orbit: 84 years old.
• Day length: 18 hours.

Neptune is the eighth planet from the Sun. Neptune has been the official last planet in the solar system since 2006. The diameter is 49,000 km, and in terms of massiveness it is 17 times larger than the earth.

It is distant by 4500 million km and spends 165 years on an orbital flight. Due to the remoteness, only 1% comes to the planet solar lighting(compared to Earth). The axial tilt is 28 degrees, and the rotation is completed in 16 hours.

The meteorology of the eighth planet from the Sun is more pronounced than that of Uranus, so powerful storm actions can be seen at the poles in the form of dark spots. The wind accelerates to 600 m/s, and the temperature mark drops to -220°C. The core is heated up to 5200°C.

• Discovery: 1846.
• Title: Roman god of water.
• Diameter: 49530 km.
• Orbit: 165 years.
• Day length: 19 hours.

This is a small world, inferior in size to the terrestrial satellite. The orbit intersects with Neptune and in 1979-1999. it could be considered the 8th planet in terms of distance from the Sun. Pluto will remain beyond the orbit of Neptune for more than two hundred years. The orbital path is tilted to the system plane by 17.1 degrees. Frosty World visited New Horizons in 2015.

• Discovery: 1930 - Clyde Tombaugh.
• Title: Roman god of the underworld.
• Diameter: 2301 km.
• Orbit: 248 years.
• Day length: 6.4 days.

The ninth planet is a hypothetical object living in external system. Its gravity should explain the behavior of trans-Neptunian objects.

The solar system is a system of planets, which includes its center - the Sun, as well as other objects of the Cosmos. They revolve around the sun. More recently, 9 objects of the Cosmos that revolve around the Sun were called “planet”. Now scientists have established that beyond the boundaries of the solar system there are planets that revolve around stars.

In 2006, the Union of Astronomers declared 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 to be 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. They 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.
The terrestrial planets do not have many satellites or moons. Of these four planets, only Earth and Mars have moons.

The planets that belong to the terrestrial group are different high density, are made of metal or stone. Basically, they are small and rotate around their own axis. Their rotation speed is also low.

gas giants

These are four space objects that are on greatest distance from the Sun: at number 5 is Jupiter, followed by Saturn, then Uranus and Neptune.

Jupiter and Saturn are impressive planets, made up of compounds of hydrogen and helium. The density of gas planets is low. revolve with high speed, have satellites and are surrounded by asteroid rings.
“Ice giants”, which include Uranus and Neptune, are smaller, their atmospheres contain methane, carbon monoxide.

Gas giants have a strong gravitational field, so they can attract many space objects, unlike the terrestrial group.

According to scientists, asteroid rings are the remains of moons altered by the gravitational field of the planets.

dwarf planet

Dwarfs are space objects, the size of which does not reach the planet, but exceeds the dimensions of the asteroid. There are 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

Hypothetically space nebulae, stars are born in clouds of dust and gas, in nebulae.
Due to the force of attraction, substances are combined. Under the influence of the concentrated force of gravity, the center of the nebula is compressed and stars are formed. Dust and gases are transformed into rings. The rings rotate under the influence of gravity, and planetasimals form in whirlpools, which increase and attract cosmetic objects to themselves.

Under the influence of the force of gravity, the planetazimals are compressed and acquire a spherical shape. Spheres can combine and gradually turn into protoplanets.



There are eight planets within the solar system. They revolve around the sun. Their location is:
The nearest “neighbor” of the Sun is Mercury, followed by Venus, then the Earth, then Mars and Jupiter, further from the Sun are Saturn, Uranus and the last one, Neptune.

From the course of school astronomy, which is included in the curriculum of geography lessons, we all know about the existence of the solar system and its 8 planets. They "circle" around the Sun, but not everyone knows that there are celestial bodies with retrograde rotation. Which planet revolves around reverse direction? In fact, there are several. These are Venus, Uranus and a recently discovered planet located on the far side of Neptune.

retrograde rotation

The movement of each planet is subject to one order, and the solar wind, meteorites and asteroids, colliding with it, make it rotate around its axis. However, gravity plays the main role in the movement of celestial bodies. Each of them has its own inclination of the axis and orbit, the change of which affects its rotation. Planets move counterclockwise with orbital inclinations ranging from -90° to 90°, while celestial bodies with an angle of 90° to 180° are retrograde rotation bodies.

Axis Tilt

As for the tilt of the axis, for retrogrades this value is 90 ° -270 °. For example, Venus has an axial tilt of 177.36°, which prevents it from moving counterclockwise, and the recently discovered space object Nika has an inclination of 110°. It should be noted that the influence of mass celestial body on its rotation is not fully understood.

Fixed Mercury

Along with retrograde, there is a planet in the solar system that practically does not rotate - this is Mercury, which has no satellites. The reverse rotation of the planets is not such a rare phenomenon, but most often it occurs outside the solar system. There is no universally accepted model of retrograde rotation today, which enables young astronomers to make amazing discoveries.

Causes of retrograde rotation

There are several reasons why planets change their course of motion:

• collision with larger space objects
• change in orbital inclination
• tilt change
• changes in the gravitational field (intervention of asteroids, meteorites, space debris etc.)

Also, the reason for the retrograde rotation may be the orbit of another cosmic body. There is an opinion that the reason for the reverse motion of Venus could be the solar tides, which slowed down its rotation.

planet formation

Almost every planet during its formation was subjected to many asteroid impacts, as a result of which its shape and radius of the orbit changed. An important role is also played by the fact of the close formation of a group of planets and a large accumulation of space debris, as a result of which the distance between them is minimal, which, in turn, leads to a violation of the gravitational field.