The sun holds by its gravity the planets and other bodies belonging to the solar system.

Other bodies are planets and their satellites, dwarf planets and their satellites, asteroids, meteoroids, comets and space dust. But in this article we will only talk about the planets of the solar system. They make up the bulk of the mass of objects associated with the Sun by gravity (attraction). There are only eight of them: Mercury, Venus, Earth Mars, Jupiter, Saturn, Uranus and Neptune . The planets are named in order of their distance from the Sun. Until recently, Pluto, the smallest planet, was also among the planets of the solar system, but in 2006 Pluto was deprived of the status of a planet, because. In the outer part of the solar system, many objects more massive than Pluto have been discovered. After the reclassification, Pluto was added to the list of minor planets and received number 134340 in the Minor Planet Center catalog. But some scientists disagree and continue to believe that Pluto should be reclassified back into a planet.

Four planets - Mercury, Venus, Earth and Mars are called terrestrial planets. They are also called inner planets, because their orbits lie inside the Earth's orbit. The terrestrial planets are united by the fact that they are composed of silicates (minerals) and metals.

Four other planets Jupiter, Saturn, Uranus and Neptune - called gas giants, because they are mostly made up of hydrogen and helium and are much more massive than the terrestrial planets. They are also called outer planets.

Look at the image of the terrestrial planets in terms of their size in relation to each other: Earth and Venus are about the same size, and Mercury is the smallest planet among the terrestrial planets (from left to right: Mercury, Venus, Earth, Mars).

The terrestrial planets are united, as we have already said, by their composition, and also by the fact that they have a small number of satellites, that they do not have rings. The three inner planets (Venus, Earth and Mars) have an atmosphere (a shell of gas around a celestial body held by gravity); all have impact craters, rift troughs, and volcanoes.

Consider now each of the terrestrial planets.

Mercury

It is located closest to the Sun and is the smallest planet in the solar system, its mass is 3.3 10 23 kg, which is 0.055 of the mass of the Earth. The radius of Mercury is only 2439.7 ± 1.0 km. The average density of Mercury is quite high - 5.43 g / cm³, which is not much less density Earth. Considering that the Earth is larger in size, the value of the density of Mercury indicates an increased content of metals in its bowels.

The planet got its name in honor of the ancient Roman god of trade Mercury: he was swift, and the planet moves across the sky faster than other planets. Mercury has no satellites. Its only known geological features, aside from impact craters, are numerous jagged escarpments extending for hundreds of kilometers. Mercury has an extremely rarefied atmosphere, a relatively large iron core and a thin crust, the origin of which is currently a mystery. Although there is a hypothesis: the outer layers of the planet, consisting of light elements, were torn off as a result of a giant collision, which reduced the size of the planet, and also prevented the complete absorption of Mercury by the young Sun. The hypothesis is very interesting, but requires confirmation.

Mercury revolves around the Sun in 88 Earth days.

Mercury has not yet been sufficiently studied, only in 2009 its complete map was compiled based on images from the Mariner-10 and Messenger spacecraft. No natural satellites have yet been discovered near the planet, and it is not easy to notice it in the sky due to the small angular distance from the Sun.

Venus

It is the second inner planet of the solar system. It revolves around the Sun in 224.7 Earth days. The planet is close in size to the Earth, its mass is 4.8685ˑ10 24 kg, which is 0.815 of the Earth's mass. Like the Earth, it has a thick silicate shell around an iron core and an atmosphere. Venus is the third brightest object in the Earth's sky after the Sun and Moon. It is assumed that internal geological activity occurs inside the planet. The amount of water on Venus is much less than on Earth, and its atmosphere is ninety times denser. Venus has no satellites. It is the hottest planet, its surface temperature exceeds 400 °C. Most probable cause At such a high temperature, astronomers consider the greenhouse effect due to the dense atmosphere rich in carbon dioxide, which is approximately 96.5%. The atmosphere on Venus was discovered by M. V. Lomonosov in 1761.

No evidence of geological activity has been found on Venus, but since it has no magnetic field, which would prevent the depletion of its essential atmosphere, this allows us to assume that its atmosphere is regularly replenished volcanic eruptions. Venus is sometimes referred to as " sister of the earth"- they really have a lot in common: they are similar in size, gravity and composition. But there are still more differences. The surface of Venus is covered with thick clouds of highly reflective sulfuric acid, so its surface cannot be seen in visible light. But radio waves were able to penetrate its atmosphere, and with their help, its relief was studied. Disputes of scientists continued for a long time about what is under the thick clouds of Venus. And only in the 20th century, the science of planetology established that the atmosphere of Venus, which consists mainly of carbon dioxide, is explained by the fact that there is no cycle of carbon and life on Venus that could process it into biomass. Scientists believe that once, a very long time ago, there were oceans on Venus similar to those on Earth, but they completely evaporated due to the strong heating of the planet.

Atmospheric pressure on the surface of Venus is 92 times greater than on Earth. Some astronomers believe that volcanic activity on Venus continues even now, but no clear evidence of this has been found. Not found yet... It is believed that Venus is a relatively young planet, by astronomical standards, of course. It is approximately only... 500 million years old.

The temperature on Venus has been calculated to be around +477°C, but scientists believe that Venus is gradually losing its internal heat. Observations from automatic space stations discovered in the atmosphere of the planet thunderstorms.

The planet got its name in honor of the ancient Roman goddess of love Venus.

Venus has been actively explored with the help of spacecraft. The first spacecraft was the Soviet Venera-1. Then there were the Soviet "Vega", the American "Mariner", "Pioner-Venus-1", "Pioneer-Venus-2", "Magellan", the European "Venus Express", the Japanese "Akatsuki". In 1975, the spacecraft Venera-9 and Venera-10 transmitted the first photographs of the surface of Venus to Earth, but the conditions on the surface of Venus are such that none of the spacecraft has worked on the planet for more than two hours. But research on Venus continues.

Earth

Our Earth is the largest and densest of the inner planets in the solar system. Among the terrestrial planets, the Earth is unique in connection with its hydrosphere (water shell). Earth's atmosphere differs from the atmospheres of other planets in that it contains free oxygen. The Earth has one natural satellite - the Moon, the only one large satellite terrestrial planets of the solar system.

But we have a more detailed discussion about the planet Earth in a separate article. Therefore, we will continue the story about the planets of the solar system.

Mars

This planet smaller than Earth and Venus, its mass is 0.64185 10 24 kg, which is 10.7% of the mass of the Earth. Mars is also called red planet"- due to iron oxide on its surface. Its rarefied atmosphere consists mainly of carbon dioxide (95.32%, the rest is nitrogen, argon, oxygen, carbon monoxide, water vapor, nitric oxide), and the pressure on the surface is 160 times less than that of the earth. Impact craters like those of the Moon, as well as volcanoes, valleys, deserts and polar ice caps like those of Earth, all make it possible to classify Mars as a terrestrial planet.

The planet got its name in honor of Mars - the ancient Roman god of war (which corresponds to the ancient Greek Ares). Mars has two natural, relatively small satellites - Phobos and Deimos (translated from ancient Greek - "fear" and "horror" - that was the name of the two sons of Ares, who accompanied him in battle).

Mars was studied by the USSR, the USA and the European Space Agency (ESA). The USSR / Russia, USA, ESA and Japan sent the Automatic Interplanetary Station (AMS) to Mars to study it, there were several programs to study this planet: Mars, Phobos, Mariner, Viking, Mars Global Surveyor and others.

It has been established that due to low pressure water cannot exist in a liquid state on the surface of Mars, but scientists suggest that conditions on the planet were different in the past, so they do not exclude the presence of primitive life on the planet. In 2008, water in the state of ice was discovered on Mars by NASA's Phoenix spacecraft. The surface of Mars is explored by rovers. The geological data they have collected suggests that earlier, most of the surface of Mars was covered with water. On Mars, they even discovered something like geysers - sources hot water and couple.

Mars can be seen from Earth with the naked eye.

The minimum distance from Mars to the Earth is 55.76 million km (when the Earth is exactly between the Sun and Mars), the maximum is about 401 million km (when the Sun is exactly between the Earth and Mars).

The average temperature on Mars is -50 °C. The climate, like on Earth, is seasonal.

asteroid belt

Between Mars and Jupiter is a belt of asteroids - small bodies of the solar system. Scientists suggest that these are the remnants of the formation of the solar system, which could not unite into a large body due to the gravitational perturbations of Jupiter. Asteroids vary in size from a few meters to hundreds of kilometers.

outer solar system

The outer solar system contains gas giants ( Jupiter, Saturn, Uranus and Neptune ) and their companions. The orbits of many short-period comets are also located here. Due to their greater distance from the Sun, and therefore much lower temperature, the solid objects of this region contain ices of water, ammonia, and methane. In the photo you can compare their sizes (from left to right: Jupiter, Saturn, Uranus, Neptune).

Jupiter

This is a huge planet with a mass of 318 Earth masses, which is 2.5 times more massive than all the other planets combined, and the equatorial radius is 71,492 ± 4 km. It consists mainly of hydrogen and helium. Jupiter is the most powerful (after the Sun) radio source in the solar system. The average distance between Jupiter and the Sun is 778.57 million km. The presence of life on Jupiter seems unlikely due to the low concentration of water in the atmosphere, the absence of a solid surface, etc. Although scientists do not exclude the possibility of the existence of water-hydrocarbon life on Jupiter in the form of some undefined organisms.

Jupiter has been known to people since ancient times, which is reflected in mythology different countries, and its name comes from the ancient Roman thunder god Jupiter.

There are 67 known moons of Jupiter, the largest of which were discovered by Galileo Galilei in 1610.

Jupiter is explored with ground and orbital telescopes; Since the 1970s, 8 NASA interplanetary vehicles have been sent to the planet: Pioneers, Voyagers, Galileo and others. On the planet, powerful storms, lightning, auroras, many times superior to those on earth, have been noticed.

Saturn

A planet known for its ring system. In fact, these romantic rings are just flat concentric formations of ice and dust that lie in the equatorial plane of Saturn. Saturn has a structure of the atmosphere and magnetosphere somewhat similar to Jupiter, but much smaller: 60% of Jupiter's mass (5.6846 10 26 kg). Equatorial radius - 60 268 ± 4 km.

The name of the planet was in honor of the Roman god of agriculture, Saturn, so its symbol is a sickle.

The main component of Saturn is hydrogen with helium impurities and traces of water, methane, ammonia and heavy elements.

Saturn has 62 moons. Of these, the largest is Titan. It is interesting in that it is larger than the planet Mercury and has the only dense atmosphere among the satellites of the solar system.

Observations of Saturn have been going on for a long time: even Galileo Galilei noticed in 1610 that Saturn has “two companions” (satellites). And Huygens in 1659, using a more powerful telescope, saw the rings of Saturn and discovered its largest satellite, Titan. Then, gradually, astronomers discovered other satellites of the planet.

The modern study of Saturn began in 1979, when the Pioneer 11 automatic interplanetary station of the United States flew near Saturn, and then finally approached it. Then the American AMS Voyager 1 and Voyager 2 followed to Saturn, as well as Cassini-Huygens, which, after 7 years of flight on July 1, 2004, reached the Saturn system and entered orbit around the planet. The main tasks were to study the structure and dynamics of the rings and satellites, as well as to study the dynamics of the atmosphere and magnetosphere of Saturn and detailed study the planet's largest moon, Titan. In 2009, a joint American-European project between NASA and ESA appeared to launch the AMS Titan Saturn System Mission to study Saturn and its moons Titan and Enceladus. During it, the station will fly to the Saturn system for 7-8 years, and then become a satellite of Titan for two years. It will also launch a probe balloon into Titan's atmosphere and a lander.

The lightest of the outer planets is 14 Earth masses (8.6832 10 25 kg). Uranus was discovered in 1781 by the English astronomer William Herschel using a telescope and named after Greek god the sky of Uranus. It turns out that Uranus is distinguishable in the sky with the naked eye, but those who saw it before did not guess that it was a planet, because. the light from it was very dim, and the movement was very slow.

Uranus, as well as Neptune similar to it, are classified into the category " ice giants”, as there are many modifications of ice in their bowels.

The atmosphere of Uranus is mostly hydrogen and helium, but there are also traces of methane, solid ammonia. Its atmosphere is the coldest (−224 °C).

Uranus also has a ring system, a magnetosphere and 27 moons. The axis of rotation of Uranus lies, as it were, “on its side” relative to the plane of revolution of this planet around the Sun. As a result, the planet is turned towards the Sun alternately then north pole, then the south, then the equator, then the middle latitudes.

In 1986 the American spacecraft Voyager 2 returned images of Uranus to Earth close range. The images do not show images of such storms as on Jupiter, but according to observations from Earth, seasonal changes are taking place there, weather activity has been noticed.

Neptune

Neptune is smaller than Uranus (equatorial radius 24 764 ± 15 km), but its mass is 1.0243 10 26 kg more than the mass of Uranus and is 17 Earth masses.

It is the most distant planet in the solar system. Its name is associated with the name of Neptune - the Roman god of the seas, so the trident of Neptune is an astronomical symbol.

Neptune is the first planet discovered by mathematical calculations, not observations (Neptune is not visible to the naked eye), and this happened in 1846. This was done by a French mathematician who studied celestial mechanics, who worked most of his life at the Paris Observatory - Urbain Jean Joseph Le Verrier.

Although Galileo Galilei observed Neptune in 1612 and 1613, he mistook the planet for a fixed star in conjunction with Jupiter in the night sky. Therefore, the discovery of Neptune is not attributed to Galileo.

Soon, its satellite Triton was also discovered, but the remaining 12 satellites of the planet were discovered in the 20th century.

Neptune, like Saturn and Pluto, has a ring system.

Neptune's atmosphere, like that of Jupiter and Saturn, is mostly hydrogen and helium, with traces of hydrocarbons and possibly nitrogen, but contains a lot of ice. The core of Neptune, like that of Uranus, consists mainly of ice and rocks. The planet seems of blue color- this is due to traces of methane in the outer layers of the atmosphere.

In the atmosphere of Neptune, the strongest winds among the planets of the solar system rage.

Neptune was visited by only one spacecraft, Voyager 2, which flew close to the planet on August 25, 1989.

This planet, like all the others, holds many mysteries. For example, for unknown reasons, the planet's thermosphere has an abnormally high temperature. But it is too far from the Sun for it to heat up the thermosphere with ultraviolet radiation. Here's a challenge for you, future astronomers. And the Universe sets a lot of such tasks, enough for everyone ...

The weather on Neptune is characterized by strong storms, winds reaching almost supersonic speeds (about 600 m/s).

Other bodies of the solar system

This comets- small bodies of the solar system, usually only a few kilometers in size, consisting mainly of volatile substances (ices), centaurs- ice comet-like objects, trans-Neptunian objects located in space beyond Neptune, Kuiper belt- fragments similar to the asteroid belt, but consisting mainly of ice, scattered disk…

To the question of where exactly the solar system ends and interstellar space begins, there is no exact answer yet ...

solar system- these are 8 planets and more than 63 of their satellites, which are being discovered more often, several dozen comets and a large number of asteroids. All cosmic bodies move along their clear directed trajectories around the Sun, which is 1000 times heavier than all the bodies in the solar system combined. Center solar system is the Sun - a star around which planets revolve in orbits. They do not emit heat and do not glow, but only reflect the light of the sun. There are currently 8 officially recognized planets in the solar system. Briefly, in order of distance from the sun, we list them all. And now some definitions.

Planet- this is a celestial body that must satisfy four conditions:
1. the body must revolve around a star (for example, around the Sun);
2. the body must have sufficient gravity to have a spherical or close to it shape;
3. the body should not have others near its orbit large bodies;
4. the body should not be a star

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 great amount energy.

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

is a star, without which life on Earth could not exist. It gives us energy and warmth. According to the classification of stars, the Sun is a yellow dwarf. The age is about 5 billion years. It has a diameter at the equator equal to 1,392,000 km, 109 times larger than the earth. The rotation period at the equator is 25.4 days and 34 days at the poles. The mass of the Sun is 2x10 to the 27th power of tons, approximately 332950 times the mass of the Earth. The temperature inside the core is about 15 million degrees Celsius. The surface temperature is about 5500 degrees Celsius. By chemical composition The sun is made up of 75% hydrogen, and the other 25% of the elements has the most helium. Now let's figure out in order how many planets revolve around the sun, in the solar system and the characteristics of the planets.
Four inner planets(nearest to the Sun) - Mercury, Venus, Earth and Mars - have a solid surface. They are smaller than four giant planets. Mercury moves faster than other planets, being burned by the sun's rays during the day and freezing at night. Period of revolution around the Sun: 87.97 days.
Diameter at the equator: 4878 km.
Rotation period (turn around the axis): 58 days.
Surface temperature: 350 during the day and -170 at night.
Atmosphere: very rarefied, helium.
How many satellites: 0.
The main satellites of the planet: 0.

More like the Earth in size and brightness. Observation of it is difficult because of the clouds enveloping it. The surface is a hot rocky desert. Period of revolution around the Sun: 224.7 days.
Diameter at the equator: 12104 km.
Rotation period (turn around the axis): 243 days.
Surface temperature: 480 degrees (average).
Atmosphere: dense, mostly carbon dioxide.
How many satellites: 0.
The main satellites of the planet: 0.


Apparently, the Earth was formed from a gas and dust cloud, like other planets. Particles of gas and dust, colliding, gradually "raised" the planet. The temperature on the surface reached 5000 degrees Celsius. Then the Earth cooled down and became covered with a hard stone crust. But the temperature in the depths is still quite high - 4500 degrees. Rocks in the bowels are molten and pour out to the surface during volcanic eruptions. Only on earth there is water. That's why life exists here. It is located relatively close to the Sun to receive the necessary heat and light, but far enough away so as not to burn out. Period of revolution around the Sun: 365.3 days.
Diameter at the equator: 12756 km.
The period of rotation of the planet (rotation around the axis): 23 hours 56 minutes.
Surface temperature: 22 degrees (average).
Atmosphere: mostly nitrogen and oxygen.
Number of satellites: 1.
The main satellites of the planet: the Moon.

Due to the similarity with the Earth, it was believed that life exists here. But the spacecraft that landed on the surface of Mars found no signs of life. This is the fourth planet in order. Period of revolution around the Sun: 687 days.
Diameter of the planet at the equator: 6794 km.
Rotation period (rotation around the axis): 24 hours 37 minutes.
Surface temperature: -23 degrees (average).
Atmosphere of the planet: rarefied, mostly carbon dioxide.
How many satellites: 2.
Main moons in order: Phobos, Deimos.


Jupiter, Saturn, Uranus and Neptune are made up of hydrogen and other gases. Jupiter is more than 10 times larger than Earth in diameter, 300 times in mass and 1300 times in volume. It is more than twice as massive as all the planets in the solar system combined. How much planet Jupiter does it take to become a star? It is necessary to increase its mass by 75 times! The period of revolution around the Sun: 11 years 314 days.
Diameter of the planet at the equator: 143884 km.
Rotation period (turn around the axis): 9 hours 55 minutes.
Surface temperature of the planet: -150 degrees (average).
Number of satellites: 16 (+ rings).
The main satellites of the planets in order: Io, Europa, Ganymede, Callisto.

This is the number 2 largest of the planets in the solar system. Saturn draws attention to itself thanks to a system of rings formed from ice, rocks and dust that orbit the planet. There are three main rings with an outer diameter of 270,000 km, but their thickness is about 30 meters. The period of revolution around the Sun: 29 years 168 days.
Diameter of the planet at the equator: 120536 km.
Rotation period (turn around the axis): 10 hours 14 minutes.
Surface temperature: -180 degrees (average).
Atmosphere: mostly hydrogen and helium.
Number of satellites: 18 (+ rings).
Main satellites: Titan.


unique planet solar system. Its peculiarity is that it revolves around the Sun not like everyone else, but "lying on its side." Uranus also has rings, although they are harder to see. In 1986, Voyager 2 flew 64,000 km and had six hours of photography, which it successfully completed. Orbital period: 84 years 4 days.
Diameter at the equator: 51118 km.
The period of rotation of the planet (rotation around the axis): 17 hours 14 minutes.
Surface temperature: -214 degrees (average).
Atmosphere: mostly hydrogen and helium.
How many satellites: 15 (+ rings).
Main satellites: Titania, Oberon.

On this moment, Neptune is considered the last planet of the solar system. Its discovery took place by the method of mathematical calculations, and then they saw it through a telescope. In 1989, Voyager 2 flew by. He took amazing photographs of the blue surface of Neptune and its largest moon, Triton. The period of revolution around the Sun: 164 years 292 days.
Diameter at the equator: 50538 km.
Rotation period (turn around the axis): 16 hours 7 minutes.
Surface temperature: -220 degrees (average).
Atmosphere: mostly hydrogen and helium.
Number of satellites: 8.
Main moons: Triton.


On August 24, 2006, Pluto lost planetary status. The International Astronomical Union has decided which celestial body should be considered a planet. Pluto does not meet the requirements of the new formulation and loses its "planetary status", at the same time, Pluto passes into a new quality and becomes the prototype of a separate class of dwarf planets.

How did the planets appear? Approximately 5–6 billion years ago, one of the gas and dust clouds of our large Galaxy ( 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.

Previously, a planet was called any cosmic body that revolves around a star, emits light that reflects this star, and has dimensions more asteroid. Also in Ancient Greece they talked about 7 planets as luminous bodies that move across the sky against the background of stars. These are Mercury, Sun, Venus, Mars, Moon, Jupiter, Saturn. Note that the Sun, which is a star, and the Moon, a satellite of our Earth, are indicated here. The earth is not included in this list because the Greeks considered it to be the center of everything.

In the 15th century, Copernicus figured out that the center of the system was the sun, not the earth. He laid out his statements in the work "On the Revolution of the Celestial Spheres". The moon and the sun were removed from the list, and the planet Earth was included. When telescopes were invented, three more planets were discovered. Uranus in 1781, Neptune in 1846, Pluto in 1930, which, by the way, more planet does not count.

At the moment, researchers are giving a new meaning to the word "planet", namely: it is a celestial body that satisfies 4 conditions:

  • The body must revolve around the star.
  • Have a spherical or approximate shape, that is, the body must have sufficient gravity.
  • It doesn't have to be a star.
  • The celestial body should not have other large bodies in the vicinity of the orbit.

A star is a body that emits light and has a powerful source of energy.

Planets in the solar system

The solar system includes the planets and other objects that revolve around the sun. 4.5 billion years ago, clumps of stellar matter clouds began to form in the Galaxy. The gases heated up and radiated heat. As a result of the increase in temperature and density, nuclear reactions began, hydrogen turned into helium. So there was a powerful source of energy - the Sun. This process took tens of millions of years. Planets with satellites were created. The entire formation of the solar system ended about 4 billion years ago.

To date, the solar system includes 8 planets, which are divided into two groups. The first is the terrestrial group, the second is the gas giants. The terrestrial planets - Venus, Mercury, Mars and Earth - are composed of silicates and metals. The gas giants - Saturn, Jupiter, Neptune and Uranus - are made up of hydrogen and helium. At the planets different sizes both in comparison between the two groups and among themselves. Accordingly, the giants are much larger and more massive than the terrestrial planets.

Mercury is closest to the Sun, next is Neptune. Before characterizing the planets of the solar system, you need to talk about its main object - the Sun. This is a star, thanks to which all living and non-living things in the system began to exist. The Sun is a spherical, plasma, hot ball. A large number of space objects revolve around it - satellites, planets, meteorites, asteroids and cosmic dust. This star appeared about 5 billion years ago. Its mass is 300 thousand times greater than the mass of our planet. The temperature of the core is 13 million degrees Kelvin, and on the surface - 5 thousand degrees Kelvin (4727 degrees Celsius). In the Milky Way galaxy, the Sun is one of the largest and bright stars. The distance from the Sun to the center of the Galaxy is 26,000 light years. The sun makes a complete revolution around the galactic center in 230-250 million years.

Mercury

It is closest to the sun and is smallest planet solar system. The planet has no satellites. On the surface of Mercury there are many craters that were formed by many meteorites that fell on the planet more than 3 billion years ago. Their diameter is varied - from a couple of meters to 1000 kilometers. The planet's atmosphere is mostly helium and blown by the Sun's wind. The temperature can reach +440 degrees Celsius. The planet makes a revolution around the Sun in 88 Earth days. A day on the planet equals 176 Earth hours.

Venus

Venus is the second planet from the Sun. Its dimensions are close to the dimensions of the Earth. The planet has no satellites. The atmosphere is carbon dioxide mixed with nitrogen and oxygen. Air pressure is 90 atmospheres, which is 35 times greater than on Earth. Venus is called the hottest planet because the dense atmosphere, carbon dioxide, the proximity of the Sun and the greenhouse effect create very high temperatures on the planet's surface. It can reach 460 degrees Celsius. Venus can be seen from the Earth's surface. It is the brightest space object after the Moon and the Sun.

Earth

The only planet adapted for life. Maybe it exists on other planets, but so far no one can say with certainty. In its group, it is the largest in terms of mass, density and size. Its age is over 4 billion years. Life here originated more than 3 billion years ago. The Earth's satellite is the Moon. The atmosphere on the planet is fundamentally different from others. Most of it is made up of nitrogen. It also includes carbon dioxide, oxygen, water vapor and argon. The ozone layer and the magnetic field reduce the level of solar and cosmic radiation. Due to the content of carbon dioxide in the Earth's atmosphere, a greenhouse effect is formed on the planet. Without it, the temperature on the Earth's surface would be 40 degrees less. Islands and continents occupy 29% of the planet's surface, and the rest is the oceans.

Mars

It is also called the "red planet" due to the presence of a large amount of iron oxide in the soil. Mars is the seventh largest planet in the solar system. Two satellites fly near the planet - Deimos and Phobos. Due to too rarefied atmosphere and far distance from the Sun mean annual temperature planet is minus 60 degrees. At some points during the day, temperature drops can reach 40 degrees. The presence of volcanoes and craters, deserts and valleys, ice polar caps distinguishes Mars from other planets of the solar system. Also here is the most high mountain- an extinct volcano Olympus, reaching a height of 27 kilometers. The Mariner Valley is the largest canyon among the planets. Its length is 4500 km and the depth is 11 m.

Jupiter

This is the most major planet in the solar system. Jupiter is 318 times heavier than Earth and 2.5 times more massive than other planets. The main constituents of the planet are helium and hydrogen. Jupiter radiates a lot of heat - 4 * 1017 W. To become a star like the Sun, it must reach a mass 70 times greater than the current one. The planet has the largest number of satellites - 63. Europa, Callisto, Ganymede and Io are the largest of them. Ganymede is also the largest moon in the entire solar system and is even larger than Mercury. There are many eddies in Jupiter's atmosphere that have a brown-red color band of clouds, or a giant storm, known as the Great Red Spot since the 17th century.

Saturn

Like Jupiter, it is a large planet that follows Jupiter in size. The ring system, which consists of ice particles of various sizes, rocks and dust, distinguishes this planet from others. It has one fewer satellites than Jupiter. The largest are Enceladus and Titan. In composition, Saturn resembles Jupiter, but in density it is inferior to the simplest water. The atmosphere looks quite uniform and calm, which can be explained by a dense layer of fog. Saturn has a huge wind speed, it can reach 1800 km per hour.

Uranus

This planet was the first to be discovered using a telescope. Uranus is the only planet in the solar system that lies on its side and revolves around the sun. Uranus has 27 satellites, which are named after the heroes of Shakespeare's plays. The largest among them are Titania, Oberon and Umbriel. Uranus contains a large number of high-temperature modifications of ice. He is also the most cold planet. The temperature here is minus 224 degrees Celsius.

Neptune

It is the most distant planet from the Sun, although until 2006 this title belonged to Pluto. This planet was discovered without the help of a telescope, but by mathematical calculations. The existence of Neptune was suggested to scientists by Uranus, on which strange changes were discovered while moving in its own orbit. The planet has 13 satellites. The largest among them is Triton. Its peculiarity is that it moves opposite to the planet. The most blown in the same direction strong winds Solar system, the speed of which reaches 2200 km per hour. The compositions of Neptune and Uranus are similar, but it is also similar in composition to Jupiter and Saturn. The planet has an internal heat source, from which it receives 2.5 times more energy than from the Sun. The outer layers of the atmosphere contain methane, which gives the planet a blue tint.

That's how mysterious the world of space is. Many satellites and planets have their own characteristics. Scientists are making changes to this world, for example, excluding Pluto from the list of planets.

Explore the planets on the portal site - it's very interesting.

The rotation of the planets

All planets, in addition to their orbit, also rotate around their axis. The period for which they make a complete revolution is defined as the epoch. Most of the planets in the solar system rotate in the same direction on their axis as they do around the sun, but Uranus and Venus rotate in the opposite direction. Scientists are watching big difference in the length of a day on the planets - Venus takes 243 Earth days to complete one rotation around its axis, while the planets of the gas giant group need only a couple of hours. The rotation period of exoplanets is not known, but their close location to the stars means that eternal day reigns on one side, and eternal night reigns on the other.

Why are all planets so different? Thanks to high temperature closer to the star, ice and gas evaporated very quickly. The giant planets could not form, but there was an accumulation of metal particles. Thus, Mercury was formed, which contains the largest amount of metals. The farther we are from the center, the lower temperature. Celestial bodies appeared, where a significant percentage was made up of rocks. The four planets that are closer to the center of the solar system are called the inner planets. With the discovery of new systems, more and more questions arise. New research will help answer them.

Scientists claim that our system is unique. All planets are built in a strict order. The largest is closer to the Sun, respectively, the smallest is farther. Our system has a more complex structure, because the planets are not lined up by their mass. The sun makes up more than 99 percent of all objects in the system.

Theories about how it came about , a great many. The first of these was the famous theory put forward by the German philosopher Immanuel Kant in 1755. He believed that the occurrence solar system originated from some primary matter, before that it was freely dispersed in space.

One of the subsequent cosmogonic theories is the theory of "catastrophes". According to it, our planet Earth was formed after some kind of outside interference, for example, the meeting of the Sun with some other star, this meeting could cause the eruption of some part of the solar substance. As a result of incandescence, gaseous matter quickly cooled down and condensed, while forming many small solid particles, their accumulations were a kind of embryonic planets.

Planets of the solar system

The central body in our system is the Sun. Refers to the stars, belongs to the yellow dwarf class. The Sun is the most massive object in our planetary system. The closest star to Earth, as well as the main body in our planetary system. In our system, the planets are more or less ordinary. No, for example, almost non-reflective. Images of planets are often used in interior signs.

The very first planet from the Sun in our solar system is Mercury - it is also the smallest terrestrial planet in size (in addition to Earth and Mercury, it includes Mars and Venus).

Next, second in a row, is Venus. Next comes the Earth, the home of all mankind. Our planet has a satellite - the Moon, which is almost 80 times lighter than the Earth. The Moon is the only satellite of the Earth orbiting the Earth. After the Sun, it is the brightest object in the sky. The fourth planet is Mars - this desert planet has two satellites. Followed by large group planets are the so-called giant planets.


The sun and other planets played a big role in different. There were many religions that worshiped the Sun. And astrology, which studies the effect of the planets on a person, still influences many people. Astrology used to be considered a science, but nowadays many consider it.

The largest and most massive of all giants is Jupiter, it is our solar system in miniature. Jupiter has more than 40 satellites, the largest of them are Ganymede, Io, Europa, Callisto. These satellites have another name - Galilean, in honor of the man who discovered them - Galileo Galilei.

Next comes the giant planet Uranus - it is unusual in that it has a “lying on its side” position - which is why Uranus has a rather sharp change of seasons. Has 21 satellites and distinguishing feature in the form of rotation in the opposite direction.

The last giant planet is Neptune (Neptune's largest satellite is Triton). All giant planets have distinguishing feature in the form of many satellites, as well as a system of rings.

But the most distant and last planet in the solar system is Pluto, it is also the smallest planet in our system. Pluto has one satellite - Charon, it is slightly smaller than the planet itself.

The cosmos is incomprehensible, its scale and magnitude are hard to imagine. The sky hides so many mysteries that, having answered one question, scientists are faced with twenty new ones. Even answering how many planets are in the solar system is quite difficult. Why? It's not easy to explain, but we'll try. Read on: it will be interesting.

How many planets are in the solar system according to the latest data

Until 2006 in all school textbooks and astronomical encyclopedias wrote in black and white: there are exactly nine planets in the solar system.

But the American mathematician Michael Brown was one of those who made even people far from science talk about space. The scientist initiated a revision of the concept of "planet". According to the new criteria, Pluto has dropped out of the planetary list.

The poor fellow was enrolled in a new class - "dwarf planetoids." Why did it happen? According to the fourth parameter, a planet is considered to be a cosmic body whose gravity dominates the orbit. Pluto is only 0.07 of the mass concentrated in its orbit. For comparison: the Earth is 1.7 million times heavier than anything that gets in its way.

The same class included Haumea, Makemake, Eris and Ceres, which was previously considered an asteroid. All of them are part of the Kuiper belt - a special cluster of space objects, similar to the asteroid belt, but 20 times wider and heavier.

Anything beyond the orbit of Neptune is called a trans-Neptunian object. In the early 2000s, scientists discovered Sedna, a planetoid with an unusually remote and elongated orbit around the Sun. In 2014, another object with similar parameters was discovered.

The researchers wondered: why are the orbits of these cosmic bodies so elongated? It was assumed that they are affected by a hidden massive object. Michael Brown and his Russian colleague Konstantin Batygin mathematically calculated the trajectory of the planets known to us, taking into account the available data.

The results stunned scientists: the theoretical orbits did not match the real ones. This confirmed the assumption of the presence of a massive planet "X". We also managed to find out its approximate trajectory of movement: the orbit is elongated, and the nearest point to us is 200 times the distance from the Earth to the Sun.

Scientists believe that the potential ninth planet is an ice giant, whose mass more earth 10–16 times.

Mankind is already watching the proposed region of space, where an unknown planet will appear. The probability of an error in the calculations is 0.007%. This means virtually guaranteed detection between 2018 and 2020.

For observation, the Japanese Subaru telescope is used. Perhaps the observatory in Chile with the LSST telescope will come to its aid, the construction of which is planned to be completed in three years, in 2020.

Solar system: location of the planets

The planets of the solar system are divided into two groups:

  • The first includes relatively small space bodies that have a rocky surface, 1–2 satellites, and a relatively small mass.
  • The second one is giant planets from dense gas and ice. They absorbed 99% of the matter in solar orbit. They are characterized by a large number of satellites and rings that can be observed from Earth only near Saturn.

Let's take a closer look at the planets in the order of their location from the Sun:

  1. Mercury is the closest planet to the Sun. Presumably at an early stage in history, a strong collision with some object tore off most of the surface. Therefore, Mercury has a relatively large iron core and a thin crust. The Earth year on Mercury lasts only 88 days.

  1. Venus is a planet named after ancient greek goddess love and fertility. Its size is almost comparable to the Earth. She, like Mercury, has no satellites. Venus is the only one in the solar system that rotates counterclockwise. The temperature on the surface reaches 400 degrees Celsius. Perhaps this is due to the greenhouse effect, which creates a super-dense atmosphere.

  1. The earth is our only home so far. The uniqueness of the planet, if you do not take into account the presence of life, lies in the hydro and atmosphere. The amount of water and free oxygen exceeds that of any other known planet.

  1. Mars is our red neighbor. The color of the planet is due to the high content of oxidized iron in the soil. Here is Olympus. No kidding, this is the name of the volcano, and its dimensions correspond to the name - 21 km high and 540 km wide! Mars is accompanied by two moons that are believed to be asteroids captured by the planet's gravity.

Between the terrestrial planets and the gas giants is the asteroid belt. This cluster is relatively small from 1 m to 100 km in diameter. celestial bodies. Previously, it was believed that there was a planet in this orbit that collapsed as a result of a catastrophe. However, the theory was not confirmed. It is now believed that the ring of asteroids is nothing more than an accumulation of matter left after the formation of the solar system. Roughly speaking - unnecessary rubbish.

  1. Jupiter is the largest planet in the solar system. It is 2.5 times heavier than the other planets. Because of high pressure storms of hydrogen and helium rage here. The largest eddy reaches 40-50 thousand km in length and 13 thousand km in width. If a person were at the epicenter, if he survived in the atmosphere, the wind would tear him to pieces, because his speed reaches 500 km / h!

  1. Saturn is considered by many to be the most beautiful planet. Known for its rings, which are made up primarily of water ice and dust. Their width on a cosmic scale is incredibly small - 10–1000 meters. The planet has 62 moons - 5 less than Jupiter. It is believed that about 4.5 billion years ago there were more of them, but Saturn swallowed them up, which is why the rings formed.

  1. Uranus. Due to the nature of the rotation, this ice giant is called a "rolling ball". The axis of the planet relative to the orbit around the Sun is tilted by 98 degrees. After the impeachment, Pluto became the coldest planet (‒224 degrees Celsius). This is due to the relatively low temperature of the core - approximately 5 thousand degrees.

  1. Neptune is a blue planet, which is explained big amount methane in an atmosphere that also contains nitrogen, ammonia, and water ice. Remember we talked about the winds on Jupiter? Forget it, because here its speed is more than 2000 km / h!

A little about the outsider

Most likely, Pluto was not very offended that he was expelled from the planetary family. By by and large what difference does it make what people think on a distant Earth. But, one way or another, it is necessary to say a few words about the recently ninth planet from the Sun.

Pluto is the coldest place in the system. The temperature here is close to absolute zero and drops to -240 degrees Celsius. It is six times lighter and three times smaller than the moon. The largest moon of the planet Charon is one third of the size of Pluto. The remaining four satellites revolve around them. Therefore, it is possible that they will be reclassified as a binary planetary system. By the way, the bad news - the New Year on Pluto will have to wait 500 years!

What do we end up with? According to the latest data, there are eight planets in the solar system, but, according to mathematical calculations, there should be a ninth. If you think that calculations are nothing, here's a fact for you: Neptune was discovered by mathematicians in 1846, and they could only see it up close in 1989, when the Voyager 2 spacecraft flew by. With all the scale of our house, we are just grains of sand in the space of space.