Planets ss in order. Brief information about the stone planets

A little history of the solar system

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

The solar system 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.

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.

Planet 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 bombardment 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. And the Mercury days themselves are equal to 176 Earth days.

Planet 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.

Planet 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 those on Earth. 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 shades, 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.

Well, in conclusion:
Pluto, unfortunately, did not have time to get into our parade of planets in the solar system. But you should not worry about this, because all the planets remain in their places, despite changes in scientific views and concepts.

So, the answer to the question: How many planets are there in the solar system? - Eight planets.

number of planets in the solar system

solar system- this is a system of celestial bodies soldered by the forces of mutual attraction. It includes: the central star - the Sun, 8 large planets with their satellites, several thousand small planets, or asteroids, several hundred observed comets and countless meteoroids, dust, gas and small particles . It was formed through gravitational contraction gas and dust cloud approximately 4.57 billion years ago.

Sun

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Mercury is the closest planet to the Sun.

The ancient Romans considered Mercury the patron of trade, travelers and thieves, as well as the messenger of the gods. It is not surprising that a small planet, rapidly moving across the sky following the Sun, was named after him. Mercury has been known since ancient times, but the ancient astronomers did not immediately realize that they see the same star in the morning and in the evening. Mercury is closer to the Sun than the Earth: the average distance from the Sun is 0.387 AU, and the distance to the Earth varies from 82 to 217 million km. The inclination of the orbit to the ecliptic i = 7° is one of the largest in the solar system. The axis of Mercury is almost perpendicular to the plane of its orbit, and the orbit itself is very elongated (eccentricity e = 0.206). The average velocity of Mercury in orbit is 47.9 km/s. Due to the tidal influence of the Sun, Mercury fell into a resonant trap. The period of its revolution around the Sun (87.95 Earth days) measured in 1965 refers to the period of rotation around the axis (58.65 Earth days) as 3/2. Mercury completes three complete rotations around its axis in 176 days. During the same period, the planet makes two revolutions around the Sun. Thus, Mercury occupies the same position in orbit relative to the Sun, and the orientation of the planet remains the same. Mercury has no satellites. If they were, then in the process of the formation of the planet they fell on protomercury. The mass of Mercury is almost 20 times less than the mass of the Earth (0.055M or 3.3 10 23 kg), and the density is almost the same as that of the Earth (5.43 g/cm3). The radius of the planet is 0.38R (2440 km). Mercury is smaller than some of the moons of Jupiter and Saturn.

Venus

The second planet from the Sun, has an almost circular orbit. It passes closer to Earth than any other planet.

But the dense, cloudy atmosphere does not allow you to directly see its surface. Atmosphere: CO 2 (97%), N2 (approx. 3%), H 2 O (0.05%), impurities CO, SO 2, HCl, HF. Due to the greenhouse effect, the surface temperature warms up to hundreds of degrees. The atmosphere, which is a dense blanket of carbon dioxide, traps the heat that comes from the Sun. This leads to the fact that the temperature of the atmosphere is much higher than in the oven. Radar images show a very wide variety of craters, volcanoes and mountains. There are several very large volcanoes, up to 3 km high. and hundreds of kilometers wide. The outpouring of lava on Venus takes much longer than on Earth. The surface pressure is about 107 Pa. The surface rocks of Venus are similar in composition to terrestrial sedimentary rocks.
Finding Venus in the sky is easier than any other planet. Its dense clouds reflect sunlight well, making the planet bright in our sky. Every seven months for several weeks, Venus is the brightest object in the western sky in the evening. Three and a half months later, it rises three hours before the Sun, becoming the brilliant "morning star" of the eastern sky. Venus can be observed an hour after sunset or an hour before sunrise. Venus has no satellites.

3rd from Sol no planet. The speed of the Earth's circulation in an elliptical orbit around the Sun is - 29.765 km / s. The inclination of the earth's axis to the plane of the ecliptic is 66 o 33 "22"". The Earth has a natural satellite - the Moon. The Earth has a magneticmagnetic and electric fields. The Earth was formed 4.7 billion years ago from gas scattered in the protosolar system- dust substances. The composition of the Earth is dominated by: iron (34.6%), oxygen (29.5%), silicon (15.2%), magnesium (12.7%). The pressure in the center of the planet is 3.6 * 10 11 Pa, the density is about 12,500 kg / m 3, the temperature is 5000-6000 o C. Most of thethe surface is occupied by the World Ocean (361.1 million km 2; 70.8%); land is 149.1 million km 2 and forms six motherscoves and islands. It rises above the level of the world ocean by an average of 875 meters (the highest height is 8848 meters - the city of Chomolungma). Mountains occupy 30% of the land, deserts cover about 20% of the land surface, savannas and light forests - about 20%, forests - about 30%, glaciers - 10%. The average depth of the ocean is about 3800 meters, the greatest is 11022 meters (the Mariana Trench in the Pacific Ocean), the volume of water is 1370 million km 3, the average salinity is 35 g / l. The atmosphere of the Earth, the total mass of which is 5.15 * 10 15 tons, consists of air - a mixture of mainly nitrogen (78.1%) and oxygen (21%), the rest is water vapor, carbon dioxide, noble and other gases. About 3-3.5 billion years ago, as a result of the natural evolution of matter, life arose on Earth, and the development of the biosphere began.

Mars

The fourth planet from the Sun, similar to Earth, but smaller and colder. Mars has deep canyonsgiant volcanoes and vast deserts. Around the Red Planet, as Mars is also called, two small moons fly: Phobos and Deimos. Mars is the planet next to the Earth, if you count from the Sun, and the only space world, apart from the Moon, that can already be reached with modern rockets. For astronauts, this four-year journey could be the next frontier in space exploration. Near the equator of Mars, in the region called Tharsis, there are volcanoes of colossal proportions. Tarsis is the name that astronomers gave to a hill that has 400 km. wide and about 10 km. in height. There are four volcanoes on this plateau, each of which is simply a giant in comparison with any terrestrial volcano. The most grandiose volcano of Tarsis, Mount Olympus, rises above the surrounding area for 27 km. About two-thirds of the surface of Mars is a mountainous area with a large number of impact craters and surrounded by debris of hard rocks. Near the volcanoes of Tharsis snakes a vast system of canyons about a quarter of the equator long. The Mariner Valley is 600 km wide, and its depth is such that Mount Everest would sink entirely to its bottom. Sheer cliffs rise thousands of meters, from the bottom of the valley to the plateau above. In ancient times, there was a lot of water on Mars, large rivers flowed on the surface of this planet. Ice caps lie at the South and North Poles of Mars. But this ice does not consist of water, but of frozen atmospheric carbon dioxide (it freezes at a temperature of -100 o C). Scientists believe that surface water is stored in the form of ice blocks buried in the ground, especially in the polar regions. Atmospheric composition: CO 2 (95%), N 2 (2.5%), Ar (1.5 - 2%), CO (0.06%), H 2 O (up to 0.1%); pressure near the surface is 5-7 hPa. In total, about 30 interplanetary space stations were sent to Mars.

Jupiter

The fifth planet from the Sun, the largest planet in the solar system. Jupiter is not a solid planet. Unlike the four solid planets closest to the Sun, Jupiter is a gas ball. The composition of the atmosphere: H 2 (85%), CH 4 , NH 3 , He (14%). Jupiter's gas composition is very similar to that of the sun. Jupiter is a powerful source of thermal radio emission. Jupiter has 16 satellites (Adrastea, Metis, Amalthea, Thebe, Io, Lysitea, Elara, Ananke, Karma, Pasiphe, Sinope, Europa, Ganymede, Callisto, Leda, Himalia), as well as a ring 20,000 km wide, almost closely adjacent to planet. Jupiter's rotation speed is so great that the planet bulges along the equator. In addition, such a rapid rotation causes very strong winds in the upper atmosphere, where the clouds are stretched out in long colorful ribbons. There are a very large number of vortex spots in the clouds of Jupiter. The largest of them, the so-called Great Red Spot, is larger than the Earth. The Great Red Spot is a huge storm in Jupiter's atmosphere that has been observed for 300 years. Inside the planet, under enormous pressure, hydrogen from a gas turns into a liquid, and then from a liquid into a solid. At a depth of 100 km. there is a vast ocean of liquid hydrogen. Below 17000 km. hydrogen is compressed so strongly that its atoms are destroyed. And then it starts behaving like metal; in this state, it easily conducts electricity. An electric current flowing in metallic hydrogen creates a strong magnetic field around Jupiter.

Saturn

The sixth planet from the Sun, has an amazing system of rings. Due to the rapid rotation around its axis, Saturn seems to be flattened at the poles. The wind speed at the equator reaches 1800 km/h. The rings of Saturn are 400,000 km wide, but they are only a few tens of meters thick. The inner parts of the rings revolve around Saturn faster than the outer ones. The rings are mostly made up of billions of small particles, each of which orbits Saturn as a separate microscopic moon. Probably, these "microsatellites" consist of water ice or rocks covered with ice. Their size ranges from a few centimeters to tens of meters. There are also larger objects in the rings - stone blocks and fragments up to hundreds of meters in diameter. The gaps between the rings arise under the influence of the gravitational forces of seventeen moons (Hyperion, Mimas, Tethys, Titan, Enceladus, etc.), which cause the rings to split. The composition of the atmosphere includes: CH 4 , H 2 , He, NH 3 .

Uranus

7th from Sun planet. It was discovered in 1781 by the English astronomer William Herschel, and named after Greek about the sky god Uranus. The orientation of Uranus in space differs from the rest of the planets of the solar system - its axis of rotation lies, as it were, "on its side" relative to the plane of revolution of this planet around the Sun. The axis of rotation is inclined at an angle of 98 o . As a result, the planet is turned to the Sun alternately with the north pole, then the south, then the equator, then the middle latitudes. Uranus has more than 27 satellites (Miranda, Ariel, Umbriel, Titania, Oberon, Cordelia, Ophelia, Bianca, Cressida, Desdemona, Juliet, Portia, Rosalind, Belinda, Pack, etc.) and a system of rings. At the center of Uranus is a core composed of stone and iron. The composition of the atmosphere includes: H 2 , He, CH 4 (14%).

Neptune

E its orbit intersects with Pluto's in some places. The equatorial diameter is the same as that of Uranus, although ra Neptune is located 1627 million km farther from Uranus (Uranus is located 2869 million km from the Sun). Based on these data, we can conclude that this planet could not be noticed in the 17th century. One of the striking achievements of science, one of the evidence of the unlimited cognizability of nature was the discovery of the planet Neptune by calculations - "on the tip of a pen." Uranus - the planet following Saturn, which for many centuries was considered the most distant planet, was discovered by V. Herschel at the end of the 18th century. Uranus is hardly visible to the naked eye. By the 40s of the XIX century. accurate observations have shown that Uranus deviates just barely from the path it should follow, given the perturbations from all the known planets. Thus the theory of motion of celestial bodies, so rigorous and precise, was put to the test. Le Verrier (in France) and Adams (in England) suggested that if perturbations from the known planets do not explain the deviation in the motion of Uranus, it means that the attraction of an as yet unknown body acts on it. They almost simultaneously calculated where behind Uranus there should be an unknown body that produces these deviations by its attraction. They calculated the orbit of the unknown planet, its mass and indicated the place in the sky where the unknown planet should have been at the given time. This planet was found in a telescope at the place indicated by them in 1846. It was called Neptune. Neptune is not visible to the naked eye. On this planet, winds blow at speeds up to 2400 km / h, directed against the rotation of the planet. These are the strongest winds in the solar system.
Atmospheric composition: H 2 , He, CH 4 . It has 6 satellites (one of them is Triton).
Neptune is the god of the seas in Roman mythology.

It's hard to believe, but once the Cosmos was completely empty. There were no planets, no satellites, no stars. Where did they come from? How was the solar system formed? These questions have troubled mankind for centuries. This article will help to give some idea of ​​what the Cosmos is and will reveal interesting facts about the planets of the solar system.

How it all began

The Universe is the entire visible and invisible Cosmos, together with all existing cosmic bodies. Several theories have been put forward:

3. Divine intervention. Our Universe is so unique, everything in it is thought out to the smallest detail, that it could not arise by itself. Only the Great Creator is capable of creating such a miracle. Absolutely not a scientific theory, but it has the right to exist.

Disputes about the causes of the true origin of outer space continue. In fact, we have an idea of ​​the solar system, which includes a burning star and eight planets with their satellites, galaxies, stars, comets, black holes and much more.

Amazing discoveries or interesting facts about the planets of the solar system

Outer spaces beckon with their mystery. Each celestial body keeps its own mystery. Thanks to astronomical discoveries, valuable information about heavenly wanderers appears.

Closest to the sun is Mercury. There is an opinion that it was once a satellite of Venus. But as a result of a cosmic catastrophe, the cosmic body separated from Venus and acquired its own orbit. A year on Mercury is 88 days, and a day is 59 days.

Mercury is the only planet in the solar system where you can observe the movement of the Sun in the opposite direction. This phenomenon has a completely logical explanation. The speed of rotation of the planet around its axis is much slower than the movement in its orbit. Due to such a difference in speed regimes, the effect of changing the movement of the Sun arises.

On Mercury you can observe a fantastic phenomenon: two sunsets and sunrises. And if you move to the meridians 0˚ and 180̊, then you can witness three sunsets and sunrises per day.

Venus goes next to Mercury. Lights up in the sky during sunset on Earth, but you can observe it for only a couple of hours. Because of this feature, she was nicknamed "Evening Star". Interestingly, the orbit of Venus lies inside the orbit of our planet. But it moves in the opposite direction, counterclockwise. A year on the planet lasts 225 days, and 1 day is 243 Earth days. Venus, like the Moon, has a phase change, transforming either into a thin sickle or into a wide circle. There is an assumption that some types of terrestrial bacteria can live in the atmosphere of Venus.

Earth- truly a pearl of the solar system. Only on it there is a huge variety of life forms. People feel so comfortable on this planet and do not even realize that it is rushing along its orbit at a speed of 108,000 km per hour.

The fourth planet from the Sun is Mars. He is accompanied by two companions. A day on this planet is equivalent in duration to the earth - 24 hours. But 1 year lasts 668 days. Just like on Earth, the seasons change here. Seasons cause changes in the appearance of the planet.

Jupiter- the largest space giant. It has many satellites (more than 60 pieces) and 5 rings. It is 318 times the mass of Earth. But, despite its impressive size, it moves quite quickly. It turns around its own axis in just 10 hours, but it overcomes the distance around the Sun in 12 years.

The weather on Jupiter is bad - constant storms and hurricanes, accompanied by lightning. A striking representative of such weather conditions is the Great Red Spot - a whirlwind moving at a speed of 435 km / h.

hallmark Saturn, certainly are his rings. These flat formations are made up of dust and ice. The thickness of the circles ranges from 10 - 15 m to 1 km, the width from 3,000 km to 300,000 km. The rings of the planet are not a single whole, but represent formations in the form of thin spokes. Also, the planet is surrounded by more than 62 satellites.

Saturn has an incredibly high rate of rotation, so much so that it is compressed at the poles. A day on the planet lasts 10 hours, a year - 30 years.

Uranus, like Venus, it moves around the star counterclockwise. The uniqueness of the planet lies in the fact that it "lies on its side", its axis is tilted at an angle of 98˚. There is a theory that the planet took this position after a collision with another space object.

Like Saturn, Uranus has a complex ring system consisting of a combination of an inner and outer group of rings. In total, Uranus has 13 of them. It is believed that the rings are the remains of the former satellite of Uranus, which collided with the planet.

Uranus does not have a solid surface, a third of the radius, approximately 8,000 km, is a gaseous shell.

Neptune is the last planet in the solar system. It is surrounded by 6 dark rings. The most beautiful shade of the sea wave to the planet is given by methane, which is present in the atmosphere. Neptune makes one revolution in its orbit in 164 years. But around its axis it moves quite quickly, and the day passes for
16 hours. In some places, the orbit of Neptune intersects with the orbit of Pluto.

Neptune has a large number of moons. Basically, they all rotate in front of the orbit of Neptune and are called internal. There are only two outer satellites accompanying the planet.

You can see it on Neptune. However, outbreaks are too weak and occur throughout the planet, and not exclusively at the poles, as on Earth.

Once upon a time, there were 9 planets in space. This number also included Pluto. But due to its small size, the astronomical community has identified it as a series of dwarf planets (asteroids).

These are interesting facts and amazing stories about the planets of the solar system that are revealed in the process of exploring the black depths of the Cosmos.

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.

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 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 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 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 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 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 bombardment 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 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 planet

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 those on Earth. On Mars is the highest mountain in the solar system: the extinct 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 shades, 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 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 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 a minimum temperature of about -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 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 .

What is the solar system in which we live? The answer will be as follows: this is our central star, the Sun and all the cosmic bodies that revolve around it. These are large and small planets, as well as their satellites, comets, asteroids, gases and cosmic dust.

The name of the solar system was given by the name of its star. In a broad sense, "solar" is often understood as any star system.

How did the solar system originate?

According to scientists, the solar system was formed from a giant interstellar cloud of dust and gases due to gravitational collapse in a separate part of it. As a result, a protostar formed in the center, then turned into a star - the Sun, and a huge protoplanetary disk, from which all the components of the solar system listed above were subsequently formed. The process is believed to have begun about 4.6 billion years ago. This hypothesis has been called the nebular one. Thanks to Emmanuel Swedenborg, Immanuel Kant and Pierre-Simon Laplace, who proposed it back in the 18th century, it eventually became generally accepted, but over the course of many decades it was refined, new data were introduced into it, taking into account the knowledge of modern sciences. Thus, it is assumed that due to the increase and intensification of collisions of particles with each other, the temperature of the object increased, and after it reached a value of several thousand kelvins, the protostar acquired a glow. When the temperature indicator reached millions of kelvins, a thermonuclear fusion reaction began in the center of the future Sun - the conversion of hydrogen into helium. It turned into a star.

The sun and its features

Our luminary scientists refer to the type of yellow dwarfs (G2V) according to the spectral classification. This is the closest star to us, its light reaches the surface of the planet in just 8.31 seconds. From Earth, the radiation appears to have a yellow tint, although in reality it is almost white.

The main components of our luminary are helium and hydrogen. In addition, thanks to spectral analysis, it was found that iron, neon, chromium, calcium, carbon, magnesium, sulfur, silicon, and nitrogen are present on the Sun. Thanks to the thermonuclear reaction continuously going on in its depths, all life on Earth receives the necessary energy. Sunlight is an integral part of photosynthesis, which produces oxygen. Without sunlight, it would be impossible, therefore, an atmosphere suitable for a protein-based life form could not form.

Mercury

This is the closest planet to our star. Together with the Earth, Venus and Mars, it belongs to the planets of the so-called terrestrial group. Mercury got its name because of the high speed of movement, which, according to myths, distinguished the fleet-footed ancient god. The Mercury year is 88 days.

The planet is small, its radius is only 2439.7, and it is smaller in size than some of the large satellites of the giant planets, Ganymede and Titan. However, unlike them, Mercury is quite heavy (3.3 10 23 kg), and its density is only slightly behind the earth's. This is due to the presence of a heavy dense core of iron in the planet.

There is no change of seasons on the planet. Its desert surface resembles that of the Moon. It is also covered with craters, but even less habitable. So, on the day side of Mercury the temperature reaches +510 °C, and on the night side -210 °C. These are the sharpest drops in the entire solar system. The planet's atmosphere is very thin and rarefied.

Venus

This planet, named after the ancient Greek goddess of love, is more similar to the Earth than others in the solar system in terms of its physical parameters - mass, density, size, volume. For a long time they were considered twin planets, but over time it turned out that their differences are huge. So, Venus has no satellites at all. Its atmosphere consists of almost 98% carbon dioxide, and the pressure on the planet's surface exceeds the earth's by 92 times! Clouds above the surface of the planet, consisting of sulfuric acid vapor, never dissipate, and the temperature here reaches +434 °C. Acid rains are falling on the planet, thunderstorms are raging. There is high volcanic activity here. Life, in our understanding, cannot exist on Venus; moreover, descent spacecraft cannot withstand such an atmosphere for a long time.

This planet is clearly visible in the night sky. This is the third brightest object for an earthly observer, it shines with white light and surpasses all stars in brightness. The distance to the Sun is 108 million km. It completes a revolution around the Sun in 224 Earth days, and around its own axis - in 243.

Earth and Mars

These are the last planets of the so-called terrestrial group, the representatives of which are characterized by the presence of a solid surface. In their structure, the core, mantle and crust are distinguished (only Mercury does not have it).

Mars has a mass equal to 10% of the mass of the Earth, which, in turn, is 5.9726 10 24 kg. Its diameter is 6780 km, almost half that of our planet. Mars is the seventh largest planet in the solar system. Unlike Earth, which has 71% of its surface covered by oceans, Mars is completely dry land. Water has been preserved under the surface of the planet in the form of a massive ice sheet. Its surface has a reddish hue due to the high content of iron oxide in the form of maghemite.

The atmosphere of Mars is very rarefied, and the pressure on the surface of the planet is 160 times less than we are used to. On the surface of the planet there are impact craters, volcanoes, depressions, deserts and valleys, and at the poles there are ice caps, just like on Earth.

The Martian day is slightly longer than the Earth day, and the year is 668.6 days. Unlike the Earth, which has one moon, the planet has two irregular satellites - Phobos and Deimos. Both of them, like the Moon to the Earth, are constantly turned to Mars by the same side. Phobos is gradually approaching the surface of its planet, moving in a spiral, and is likely to eventually fall on it or fall apart. Deimos, on the other hand, is gradually moving away from Mars and may leave its orbit in the distant future.

Between the orbits of Mars and the next planet, Jupiter, there is an asteroid belt consisting of small celestial bodies.

Jupiter and Saturn

What planet is the largest? There are four gas giants in the solar system: Jupiter, Saturn, Uranus and Neptune. Jupiter is the largest of them. Its atmosphere, like that of the Sun, is predominantly hydrogen. The fifth planet, named after the god of thunder, has an average radius of 69,911 km and a mass exceeding that of the earth by 318 times. The planet's magnetic field is 12 times stronger than Earth's. Its surface is hidden under opaque clouds. So far, scientists find it difficult to say exactly what processes can occur under this dense veil. It is assumed that on the surface of Jupiter there is a boiling hydrogen ocean. Astronomers consider this planet a "failed star" due to some similarity in their parameters.

Jupiter has 39 satellites, 4 of which - Io, Europa, Ganymede and Callisto - were discovered by Galileo.

Saturn is somewhat smaller than Jupiter, it is the second largest among the planets. This is the sixth, next planet, also consisting of hydrogen with helium impurities, a small amount of ammonia, methane, water. Hurricanes rage here, the speed of which can reach 1800 km / h! Saturn's magnetic field is not as strong as Jupiter's, but stronger than Earth's. Both Jupiter and Saturn are somewhat flattened at the poles due to rotation. Saturn is 95 times heavier than earth, but its density is less than that of water. It is the least dense celestial body in our system.

A year on Saturn lasts 29.4 Earth days, a day is 10 hours 42 minutes. (Jupiter has a year - 11.86 Earth, a day - 9 hours 56 minutes). It has a system of rings consisting of solid particles of various sizes. Presumably, these may be the remains of the collapsed satellite of the planet. In total, Saturn has 62 satellites.

Uranus and Neptune are the last planets

The seventh planet of the solar system is Uranus. It is 2.9 billion km away from the Sun. Uranus is the third largest among the planets of the solar system (average radius - 25,362 km) and the fourth largest (exceeds the earth by 14.6 times). A year here lasts 84 Earth hours, a day - 17.5 hours. In the atmosphere of this planet, in addition to hydrogen and helium, a significant volume is occupied by methane. Therefore, for an earthly observer, Uranus has a pale blue color.

Uranus is the coldest planet in the solar system. The temperature of its atmosphere is unique: -224 °C. Why Uranus has a lower temperature than planets farther from the Sun is unknown to scientists.

This planet has 27 moons. Uranus has thin, flat rings.

Neptune, the eighth planet from the Sun, ranks fourth in size (average radius - 24,622 km) and third in mass (17 Earth). For a gas giant, it is relatively small (only four times the size of the Earth). Its atmosphere is also mainly composed of hydrogen, helium and methane. Gas clouds in its upper layers move at a record speed, the highest in the solar system - 2000 km / h! Some scientists believe that under the surface of the planet, under the thickness of frozen gases and water, hidden, in turn, by the atmosphere, a solid stone core can hide.

These two planets are close in composition, and therefore they are sometimes classified as a separate category - ice giants.

Minor planets

Small planets are called celestial bodies, which also move around the Sun in their own orbits, but differ from other planets in insignificant sizes. Previously, only asteroids were included in them, but more recently, namely, since 2006, Pluto, which was previously included in the list of planets in the solar system and was the last, tenth, belongs to them. This is due to changes in terminology. Thus, the minor planets now include not only asteroids, but also dwarf planets - Eris, Ceres, Makemake. They were named plutoids after Pluto. The orbits of all known dwarf planets are beyond the orbit of Neptune, in the so-called Kuiper belt, which is much wider and more massive than the asteroid belt. Although their nature, as scientists believe, is the same: it is the "unused" material left after the formation of the solar system. Some scientists have suggested that the asteroid belt is the debris of the ninth planet, Phaeton, which died as a result of a global catastrophe.

Pluto is known to be composed primarily of ice and solid rock. The main component of its ice sheet is nitrogen. Its poles are covered with eternal snows.

This is the order of the planets of the solar system, according to modern ideas.

Parade of planets. Types of parades

This is a very interesting phenomenon for those who are interested in astronomy. It is customary to call a parade of planets such a position in the solar system when some of them, continuously moving along their orbits, for a short time occupy a certain position for an earthly observer, as if lining up along one line.

The visible parade of planets in astronomy is a special position of the five brightest planets of the solar system for people who see them from Earth - Mercury, Venus, Mars, as well as two giants - Jupiter and Saturn. At this time, the distance between them is relatively small and they are clearly visible in a small sector of the sky.

There are two types of parades. A big one is its appearance when five celestial bodies line up in one line. Small - when there are only four of them. These phenomena can be visible or invisible from different parts of the globe. At the same time, a large parade is quite rare - once every few decades. The small one can be observed once every few years, and the so-called mini-parade, in which only three planets participate, is almost every year.

Interesting facts about our planetary system

Venus, the only one of all the major planets in the solar system, rotates around its axis in the opposite direction to its rotation around the Sun.

The highest mountain on the major planets of the solar system is Olympus (21.2 km, diameter - 540 km), an extinct volcano on Mars. Not so long ago, on the largest asteroid in our star system, Vesta, a peak was discovered that somewhat exceeds Olympus in terms of parameters. Perhaps it is the highest in the solar system.

Jupiter's four Galilean moons are the largest in the solar system.

In addition to Saturn, all gas giants, some asteroids and Saturn's moon Rhea have rings.

What system of stars is closest to us? The solar system is closest to the star system of the triple star Alpha Centauri (4.36 light years). It is assumed that planets similar to Earth can exist in it.

To kids about planets

How to explain to children what the solar system is? Her model, which can be made with the kids, will help here. To create planets, you can use plasticine or ready-made plastic (rubber) balls, as shown below. At the same time, it is necessary to observe the ratio between the sizes of the “planets”, so that the model of the solar system really helps to form the correct ideas about space in children.

You will also need toothpicks that will hold our celestial bodies, and as a background, you can use a dark sheet of cardboard with small dots imitating stars painted on with paint. With the help of such an interactive toy, it will be easier for children to understand what the solar system is.

The future of the solar system

The article described in detail what the solar system is. Despite its seeming stability, our Sun, like everything in nature, is evolving, but this process, by our standards, is very long. The supply of hydrogen fuel in its bowels is huge, but not infinite. So, according to the hypotheses of scientists, it will end in 6.4 billion years. As it burns out, the solar core will become denser and hotter, and the outer shell of the star will become wider and wider. The luminosity of the star will also increase. It is assumed that in 3.5 billion years, because of this, the climate on Earth will be similar to Venusian, and life on it in the usual sense for us will no longer be possible. There will be no water left at all; under the influence of high temperatures, it will evaporate into outer space. Subsequently, according to scientists, the Earth will be absorbed by the Sun and dissolved in its depths.

The outlook is not very bright. However, progress does not stand still, and, perhaps, by that time, new technologies will allow mankind to master other planets, over which other suns shine. After all, how many "solar" systems in the world, scientists do not yet know. There are probably countless of them, and among them it is quite possible to find one suitable for human habitation. Which "solar" system will become our new home is not so important. Human civilization will be preserved, and another page will begin in its history...