The giant planets are Jupiter Saturn Uranus Neptune. Recurrence Uranus Neptune Saturn Mars Jupiter Earth Venus

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

Other bodies are planets and their satellites, dwarf planets and their satellites, asteroids, meteoroids, comets and cosmic dust. But in this article we will only talk about planets solar system. They make up most 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, the planets of the solar system also included Pluto, the smallest planet, but in 2006 Pluto was deprived of planet status because Many objects more massive than Pluto have been discovered in the outer solar system. Following the reclassification, Pluto was added to the list of minor planets and received catalog number 134340 from the Minor Planet Center. But some scientists disagree with this and continue to believe that Pluto should be reclassified back to 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. What the terrestrial planets have in common is that they consist of silicates (minerals) and metals.

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

Look at a picture of the terrestrial planets scaled by their sizes in relation to each other: Earth and Venus are approximately same size, and Mercury is the smallest planet among the terrestrial planets (from left to right: Mercury, Venus, Earth, Mars).

What unites the terrestrial planets, as we have already said, is their composition, as well as the fact that they have a small number of satellites and 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 in place by gravity); all have impact craters, rift basins and volcanoes.

Let us now consider 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 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 slightly less than the density of Earth. Given that the Earth is larger in size, the density value of Mercury indicates increased content in its depths there are metals.

The planet got its name in honor of the ancient Roman god of trade, Mercury: he was fleet-footed, and the planet moves across the sky faster than other planets. Mercury has no satellites. Its only known geological features, other than impact craters, are numerous jagged escarpments extending for hundreds of kilometers. Mercury has an extremely thin 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 was its complete map compiled based on images from the Mariner 10 and Messenger spacecraft. The planet’s natural satellites have not yet been discovered, and it is not easy to see in the sky due to its small angular distance from the Sun.

Venus

It is the second inner planet of the solar system. It orbits the Sun in 224.7 Earth days. The planet is close in size to Earth, its mass is 4.8685ˑ10 24 kg, which is 0.815 Earth's mass. Like 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 believed that internal geological activity occurs within 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. This is the most hot planet, its surface temperature exceeds 400 °C. Astronomers consider the most likely reason for such a high temperature to be the greenhouse effect, which occurs due to a 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 suggests that its atmosphere is regularly replenished by volcanic eruptions. Venus is sometimes called " sister of the earth“- they really have a lot in common: similar sizes, gravity and composition. But there are still more differences. The surface of Venus is covered by a thick cloud of highly reflective sulfuric acid clouds, making its surface impossible to see in visible light. But radio waves were able to penetrate its atmosphere, and with their help its relief was explored. Scientists have debated for a long time about what lies under the thick clouds of Venus. And only in the 20th century, the science of planetology established that the atmosphere of Venus, consisting mainly of carbon dioxide, is explained by the fact that on Venus there is no carbon cycle and no life that could process it into biomass. Scientists believe that once upon a time, a very long time ago, oceans similar to those on Earth existed on Venus, but they completely evaporated due to the intense heating of the planet.

The atmospheric pressure on the surface of Venus is 92 times greater than on Earth. Some astronomers believe that volcanic activity on Venus continues today, 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. She is approximately only... 500 million years old.

The temperature on Venus has been calculated to be approximately +477 °C, but scientists believe that Venus is gradually losing its internal high temperature. Observations from automatic space stations have detected thunderstorms in the planet's atmosphere.

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

Venus has been actively studied using spacecraft. The first spacecraft was the Soviet Venera 1. Then there were the Soviet Vega, the American Mariner, Pioneer Venus 1, Pioneer Venus 2, Magellan, the European Venus Express, and the Japanese Akatsuki. In 1975, the Venera 9 and Venera 10 spacecraft transmitted the first photographs of the surface of Venus to Earth, but conditions on the surface of Venus are such that none of the spacecraft 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 due to its hydrosphere (water shell). The 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 large satellite of the terrestrial planets of the Solar System.

But we will have a more detailed conversation about 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, nitrogen oxide), and the pressure on the surface is 160 times less than that on Earth. Impact craters like those on the Moon, as well as volcanoes, valleys, deserts and polar ice caps like those on Earth - all this makes 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 an Automatic Interplanetary Station (AIS) 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 in the past conditions on the planet were different, so they do not exclude the presence of primitive life on the planet. In 2008, water in the form of ice was discovered on Mars by NASA's Phoenix spacecraft. The surface of Mars is explored by rovers. The geological data they collected suggests that most of the surface of Mars was once covered with water. On Mars, they even discovered something like geysers - sources of hot water and steam.

Mars can be seen from Earth 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 there is a belt of asteroids - small bodies of the solar system. Scientists suggest that these are remnants of the formation of the Solar System, which were unable to unite into a large body due to gravitational disturbances of Jupiter. The sizes of asteroids vary: from several meters to hundreds of kilometers.

Outer Solar System

In the outer region of the Solar System there are gas giants ( Jupiter, Saturn, Uranus and Neptune ) and their companions. The orbits of many short-period comets are also located here. Because of their greater distance from the Sun, and therefore much lower temperature, the solid objects in 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 other planets combined, and its 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 unidentified 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 using ground-based and orbital telescopes; Since the 1970s, 8 interplanetary NASA probes have been sent to the planet: Pioneers, Voyagers, Galileo and others. Powerful storms, lightning, and aurorae, many times greater than those on Earth, have been observed on the planet.

Saturn

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

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

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

Saturn has 62 satellites. Of these, the largest is Titan. It is interesting because 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: Galileo Galilei noted 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 US automatic interplanetary station Pioneer 11 flew near Saturn and then finally approached it. Then the American spacecraft Voyager 1 and Voyager 2, as well as Cassini-Huygens, followed to Saturn, which, after 7 years of flight, reached the Saturn system on July 1, 2004 and entered orbit around the planet. The main objectives 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 a detailed study of the planet's largest satellite, Titan. In 2009, a joint American-European project between NASA and ESA appeared to launch the Titan Saturn System Mission to study Saturn and its satellites 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 landing module.

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 the Greek god of the sky, Uranus. It turns out that Uranus is visible in the sky with the naked eye, but those who saw it before did not realize that it was a planet, because the light from it was very dim, and the movement was very slow.

Uranus, as well as Neptune, which is similar to it, are classified as “ ice giants", since there are many modifications of ice in their depths.

The atmosphere of Uranus is mainly hydrogen and helium, but traces of methane and solid ammonia are also present. 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 rotation of this planet around the Sun. As a result, the planet turns towards the Sun alternately north pole, then the southern, then the equator, then the middle latitudes.

In 1986, the American spacecraft Voyager 2 sent back to Earth images of Uranus from close range. The images do not show images of such storms as on Jupiter, but, according to observations from Earth, seasonal changes are occurring there, and 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 greater than the mass of Uranus and is 17 Earth masses.

It is the farthest planet in the solar system. Its name is associated with the name of Neptune, the Roman god of the seas, so the astronomical symbol is Neptune's trident.

Neptune is the first planet discovered through mathematical calculations rather than 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 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 composed primarily of hydrogen and helium, with traces of hydrocarbons and possibly nitrogen, but contains a lot of ice. Neptune's core, like Uranus, consists mainly of ice and rock. The planet appears blue - this is due to traces of methane in the outer layers of the atmosphere.

Neptune's atmosphere has the strongest winds among the planets in the solar system.

Neptune has only been visited by 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 problem 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 and 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- icy 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…

There is no exact answer yet to the question of where exactly the solar system ends and interstellar space begins...

On March 13, 1781, English astronomer William Herschel discovered the seventh planet of the solar system - Uranus. And on March 13, 1930, American astronomer Clyde Tombaugh discovered the ninth planet of the solar system - Pluto. By the beginning of the 21st century, it was believed that the solar system included nine planets. However, in 2006, the International Astronomical Union decided to strip Pluto of this status.

60 are already known natural satellites Saturn, most of which were discovered using spacecraft. Most of the satellites consist of rocks and ice. The largest satellite, Titan, discovered in 1655 by Christiaan Huygens, is larger than the planet Mercury. The diameter of Titan is about 5200 km. Titan orbits Saturn every 16 days. Titan is the only moon to have a very dense atmosphere, 1.5 times larger than Earth's, consisting primarily of 90% nitrogen, with moderate methane content.

The International Astronomical Union officially recognized Pluto as a planet in May 1930. At that moment, it was assumed that its mass was comparable to the mass of the Earth, but later it was found that Pluto’s mass was almost 500 times less than the Earth’s, even less than the mass of the Moon. Pluto's mass is 1.2 x 10.22 kg (0.22 Earth's mass). Pluto's average distance from the Sun is 39.44 AU. (5.9 to 10 to 12 degrees km), radius about 1.65 thousand km. The period of revolution around the Sun is 248.6 years, the period of rotation around its axis is 6.4 days. Pluto's composition is believed to include rock and ice; the planet has a thin atmosphere consisting of nitrogen, methane and carbon monoxide. Pluto has three moons: Charon, Hydra and Nix.

At the end of XX and beginning of XXI centuries, many objects have been discovered in the outer solar system. It has become obvious that Pluto is only one of the largest Kuiper Belt objects known to date. Moreover, at least one of the belt objects - Eris - is a larger body than Pluto and is 27% heavier. In this regard, the idea arose to no longer consider Pluto as a planet. On August 24, 2006, at the XXVI General Assembly of the International Astronomical Union (IAU), it was decided to henceforth call Pluto not a “planet”, but a “dwarf planet”.

At the conference, a new definition of a planet was developed, according to which planets are considered bodies that revolve around a star (and are not themselves a star), have a hydrostatically equilibrium shape and have “cleared” the area in the area of their orbit from other, smaller objects. Dwarf planets will be considered objects that orbit a star, have a hydrostatically equilibrium shape, but have not “cleared” the nearby space and are not satellites. Planets and dwarf planets are two different classes of objects in the Solar System. All other objects orbiting the Sun that are not satellites will be called small bodies of the Solar System.

Thus, since 2006, there have been eight planets in the solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. The International Astronomical Union officially recognizes five dwarf planets: Ceres, Pluto, Haumea, Makemake, and Eris.

On June 11, 2008, the IAU announced the introduction of the concept of "plutoid". It was decided to call celestial bodies revolving around the Sun in an orbit whose radius is greater than the radius of Neptune’s orbit, whose mass is sufficient for gravitational forces to give them an almost spherical shape, and which do not clear the space around their orbit (that is, many small objects orbit around them). ).

Since it is still difficult to determine the shape and thus the relationship to the class of dwarf planets for such distant objects as plutoids, scientists recommended temporarily classifying all objects whose absolute asteroid magnitude (brilliance from a distance of one astronomical unit) is brighter than +1 as plutoids. If it later turns out that an object classified as a plutoid is not a dwarf planet, it will be deprived of this status, although the assigned name will be retained. The dwarf planets Pluto and Eris were classified as plutoids. In July 2008, Makemake was included in this category. On September 17, 2008, Haumea was added to the list.

The material was prepared based on information from open sources

There are already 60 known natural satellites of Saturn, most of which were discovered using spacecraft. Most of the satellites consist of rocks and ice. The largest satellite, Titan, discovered in 1655 by Christiaan Huygens, is larger than the planet Mercury. The diameter of Titan is about 5200 km. Titan orbits Saturn every 16 days. Titan is the only moon to have a very dense atmosphere, 1.5 times larger than Earth's, consisting primarily of 90% nitrogen, with moderate methane content.

At the end of the 20th and beginning of the 21st centuries, many objects were discovered in the outer solar system. It has become obvious that Pluto is only one of the largest Kuiper Belt objects known to date. Moreover, at least one of the belt objects - Eris - is a larger body than Pluto and is 27% heavier. In this regard, the idea arose to no longer consider Pluto as a planet. On August 24, 2006, at the XXVI General Assembly of the International Astronomical Union (IAU), it was decided to henceforth call Pluto not a “planet”, but a “dwarf planet”.

The material was prepared based on information from open sources

Space has long attracted people's attention. Astronomers began studying the planets of the Solar System back in the Middle Ages, examining them through primitive telescopes. But a thorough classification and description of the structural features and movements of celestial bodies became possible only in the 20th century. With the advent of powerful equipment, state-of-the-art observatories and spaceships Several previously unknown objects were discovered. Now every schoolchild can list all the planets of the solar system in order. I fell for almost all of them space probe, and man has only visited the Moon so far.

What is the Solar System

The Universe is huge and includes many galaxies. Our Solar System is part of a galaxy containing more than 100 billion stars. But there are very few that are like the Sun. Basically, they are all red dwarfs, which are smaller in size and do not shine as brightly. Scientists have suggested that the solar system was formed after the emergence of the Sun. Its huge field of attraction captured a gas-dust cloud, from which, as a result of gradual cooling, particles of solid matter formed. Over time, celestial bodies were formed from them. It is believed that the Sun is now in the middle of its life path, therefore, it, as well as all the celestial bodies dependent on it, will exist for several more billions of years. Near space has been studied by astronomers for a long time, and any person knows what planets of the solar system exist. Photos of them taken from space satellites can be found on the pages of various information resources devoted to this topic. All celestial bodies are held by the strong gravitational field of the Sun, which makes up more than 99% of the volume of the Solar System. Large celestial bodies rotate around the star and around its axis in one direction and in one plane, which is called the ecliptic plane.

Planets of the Solar System in order

In modern astronomy, it is customary to consider celestial bodies starting from the Sun. In the 20th century, a classification was created that includes 9 planets of the solar system. But recent space exploration and new discoveries have prompted scientists to revise many provisions in astronomy. And in 2006, at an international congress, due to its small size (a dwarf with a diameter not exceeding three thousand km), Pluto was excluded from the number of classical planets, and there were eight of them left. Now the structure of our solar system has taken on a symmetrical, slender appearance. It includes the four terrestrial planets: Mercury, Venus, Earth and Mars, then comes the asteroid belt, followed by the four giant planets: Jupiter, Saturn, Uranus and Neptune. On the outskirts of the solar system there is also what scientists call the Kuiper belt. This is where Pluto is located. These places are still little studied due to their remoteness from the Sun.

Features of the terrestrial planets

What allows us to classify these celestial bodies as one group? Let us list the main characteristics of the inner planets:

relatively small size;
hard surface, high density and similar composition (oxygen, silicon, aluminum, iron, magnesium and other heavy elements);
presence of atmosphere;
identical structure: a core of iron with nickel impurities, a mantle consisting of silicates, and a crust of silicate rocks (except for Mercury - it has no crust);
a small number of satellites - only 3 for four planets;
rather weak magnetic field.

Features of the giant planets

As for the outer planets, or gas giants, they have the following similar characteristics:

large sizes and weights;
they do not have a solid surface and consist of gases, mainly helium and hydrogen (therefore they are also called gas giants);
liquid core consisting of metallic hydrogen;
high rotation speed;
a strong magnetic field, which explains the unusual nature of many processes occurring on them;
there are 98 satellites in this group, most of which belong to Jupiter;
The most characteristic feature of gas giants is the presence of rings. All four planets have them, although they are not always noticeable.

The first planet is Mercury

It is located closest to the Sun. Therefore, from its surface the star appears three times larger than from the Earth. This also explains the strong temperature changes: from -180 to +430 degrees. Mercury moves very quickly in its orbit. Maybe that's why it got such a name, because in Greek mythology Mercury is the messenger of the gods. There is practically no atmosphere here and the sky is always black, but the Sun shines very brightly. However, there are places at the poles where its rays never hit. This phenomenon can be explained by the tilt of the rotation axis. No water was found on the surface. This circumstance, as well as the abnormally high daytime temperature (as well as the low nighttime temperature) fully explain the fact of the absence of life on the planet.

Venus

If you study the planets of the solar system in order, then Venus comes second. People could observe it in the sky back in ancient times, but since it was shown only in the morning and evening, it was believed that these were 2 different objects. By the way, our Slavic ancestors called it Mertsana. It is the third brightest object in our solar system. People used to call it the morning and evening star, because it is best visible before sunrise and sunset. Venus and Earth are very similar in structure, composition, size and gravity. This planet moves very slowly around its axis, making a full revolution in 243.02 Earth days. Of course, conditions on Venus are very different from those on Earth. It is twice as close to the Sun, so it is very hot there. High temperature is also explained by the fact that thick clouds of sulfuric acid and an atmosphere of carbon dioxide create a greenhouse effect on the planet. In addition, the pressure at the surface is 95 times greater than on Earth. Therefore, the first ship that visited Venus in the 70s of the 20th century stayed there for no more than an hour. Another peculiarity of the planet is that it rotates in the opposite direction compared to most planets. Astronomers still know nothing more about this celestial object.

Third planet from the Sun

The only place in the Solar System, and indeed in the entire Universe known to astronomers, where life exists is Earth. IN earth group it has the largest dimensions. What else are her

The highest gravity among the terrestrial planets.
Very strong magnetic field.
High density.
It is the only one among all the planets that has a hydrosphere, which contributed to the formation of life.
It has the largest satellite compared to its size, which stabilizes its tilt relative to the Sun and influences natural processes.

Planet Mars

This is one of the smallest planets in our Galaxy. If we consider the planets of the solar system in order, then Mars is the fourth from the Sun. Its atmosphere is very rarefied, and the pressure on the surface is almost 200 times less than on Earth. For the same reason, very strong temperature changes are observed. The planet Mars has been little studied, although it has long attracted the attention of people. According to scientists, this is the only celestial body on which life could exist. After all, in the past there was water on the surface of the planet. This conclusion can be drawn from the fact that there are large ice caps at the poles, and the surface is covered with many grooves, which could be dried up river beds. In addition, there are some minerals on Mars that can only be formed in the presence of water. Another feature of the fourth planet is the presence of two satellites. What makes them unusual is that Phobos gradually slows down its rotation and approaches the planet, while Deimos, on the contrary, moves away.

What is Jupiter famous for?

The fifth planet is the largest. The volume of Jupiter would fit 1300 Earths, and its mass is 317 times that of Earth. Like all gas giants, its structure is hydrogen-helium, reminiscent of the composition of stars. Jupiter is the most interesting planet, which has many characteristic features:

it is the third brightest celestial body after the Moon and Venus;
Jupiter has the strongest magnetic field of any planet;
it completes a full rotation around its axis in just 10 Earth hours - faster than other planets;
An interesting feature of Jupiter is the large red spot - this is how an atmospheric vortex rotating counterclockwise is visible from Earth;
like all giant planets, it has rings, although not as bright as Saturn’s;
this planet has the largest number of satellites. He has 63 of them. The most famous are Europa, on which water was found, Ganymede - the largest satellite of the planet Jupiter, as well as Io and Calisto;
Another feature of the planet is that in the shadow the surface temperature is higher than in places illuminated by the Sun.

Planet Saturn

It is the second largest gas giant, also named after ancient god. It is composed of hydrogen and helium, but traces of methane, ammonia and water have been found on its surface. Scientists have found that Saturn is the rarest planet. Its density is less than that of water. This gas giant rotates very quickly - it makes one revolution in 10 Earth hours, as a result of which the planet is flattened from the sides. Huge speeds on Saturn and the wind - up to 2000 kilometers per hour. This is faster than the speed of sound. Saturn has another one distinctive feature- it holds 60 satellites in its field of attraction. The largest of them, Titan, is the second largest in the entire solar system. The uniqueness of this object lies in the fact that by examining its surface, scientists for the first time discovered a celestial body with conditions similar to those that existed on Earth about 4 billion years ago. But the most important feature of Saturn is the presence of bright rings. They encircle the planet around the equator and reflect more light than herself. Four is the most amazing phenomenon in the solar system. What's unusual is that the inner rings move faster than the outer rings.

- Uranus

So, we continue to consider the planets of the solar system in order. The seventh planet from the Sun is Uranus. It is the coldest of all - the temperature drops to -224 °C. In addition, scientists did not find metallic hydrogen in its composition, but found modified ice. Therefore, Uranus is classified as a separate category of ice giants. An amazing feature of this celestial body is that it rotates while lying on its side. The change of seasons on the planet is also unusual: for as many as 42 Earth years, winter reigns there, and the Sun does not appear at all; summer also lasts 42 years, and the Sun does not set during this time. In spring and autumn, the star appears every 9 hours. Like all giant planets, Uranus has rings and many satellites. As many as 13 rings revolve around it, but they are not as bright as those of Saturn, and the planet holds only 27 satellites. If we compare Uranus with the Earth, then it is 4 times larger than it, 14 times heavier and is located at a distance from the Sun of 19 times the path to the star from our planet.

Neptune: the invisible planet

After Pluto was excluded from the number of planets, Neptune became the last from the Sun in the system. It is located 30 times further from the star than the Earth, and is not visible from our planet even with a telescope. Scientists discovered it, so to speak, by accident: observing the peculiarities of the movement of the planets closest to it and their satellites, they concluded that there must be another large celestial body beyond the orbit of Uranus. After discovery and research it became clear interesting features of this planet:

due to the presence of a large amount of methane in the atmosphere, the color of the planet from space appears blue-green;
Neptune's orbit is almost perfectly circular;
the planet rotates very slowly - it makes one circle every 165 years;
Neptune 4 times more than Earth and 17 times heavier, but the force of gravity is almost the same as on our planet;
the largest of the 13 satellites of this giant is Triton. It is always turned to the planet with one side and slowly approaches it. Based on these signs, scientists suggested that it was captured by the gravity of Neptune.

Throughout the galaxy Milky Way- about one hundred billion planets. So far, scientists cannot study even some of them. But the number of planets in the solar system is known to almost all people on Earth. True, in the 21st century, interest in astronomy has faded a little, but even children know the names of the planets of the solar system.

PLANETS

In ancient times, people knew only five planets: Mercury, Venus, Mars, Jupiter and Saturn, the only ones that can be seen with the naked eye.
Uranus, Neptune and Pluto were discovered using telescopes in 1781, 1846 and 1930. For a long time, astronomers studied the planets by observing them from Earth. They determined that all the planets, except Pluto, move in circular orbits in the same plane and in the same direction, calculated the sizes of the planets and the distances from them to the Sun, formed their idea of the structure of the planets, and even assumed that Venus and Mars could be similar Earth, and there may be life on them.

The launch of automatic space stations to the planets made it possible to significantly expand, and in many ways revise, ideas about the planets: it became possible to see photographs of the surface, explore the soil and atmosphere of the planets.

Mercury.

Mercury is a small planet, slightly larger than the Moon. Its surface is also dotted with craters from collisions with meteorites. No geological processes have erased these dents from his face. Mercury is cold inside. It moves around the Sun faster than other planets, but around its axis very slowly. Having circled the Sun twice, Mercury only has time to turn around its axis three times. Because of this, the temperature on the sunny side of the planet exceeds 300 degrees, and on the unlit side there is darkness and severe cold. Mercury has virtually no atmosphere.

Venus.

Exploring Venus is not easy. It is shrouded in a thick layer of clouds, and under this serene exterior lies a real hell, the pressure is a hundred times higher than on Earth, the temperature on the surface is about 500 degrees, which is caused by the “greenhouse effect”. Soviet automatic station Venera 9 was the first to transmit images of a lava-filled and rock-covered surface to Earth. In the conditions of Venus, the apparatus lowered to the surface of the planet quickly breaks down, so American scientists decided to obtain data on the planet’s topography in a different way.

The Magellan robotic probe, having flown around Venus many times, probed the planet with radar, resulting in a comprehensive picture of the surface. In some places, the relief of Venus is similar to that of Earth, but mostly the landscapes are strange: high mountainous round areas surrounded by mountain ranges 250 - 300 km in diameter, the entire area of which is occupied by volcanoes; other volcanic formations resemble cakes with steep edges and a flat top. The surface of the planet is cut by channels laid by lava. Traces of active volcanic activity are visible everywhere. Meteor craters on the surface of Venus are distributed evenly, which means that its surface took shape at the same time. Scientists cannot explain how this could happen; Venus seemed to boil and be flooded with lava. Now volcanic activity is not detected on the planet.

The atmosphere of Venus is not at all similar to that of Earth; it mainly consists of carbon dioxide. Thickness gas shell Venus, compared to Earth, is monstrously large. The cloud layer reaches 20 km. The presence of concentrated aqueous solution sulfuric acid. Sunlight does not reach the surface of Venus, twilight reigns there, sulfur rain falls, the landscape is constantly illuminated by flashes of lightning. High in the planet's atmosphere, constant winds rage, driving clouds at tremendous speed; the upper layer of the Venusian atmosphere makes a full revolution around the planet within four earthly days. Solid Venus, on the contrary, rotates around its axis very slowly and in a different direction than all the other planets. Venus has no satellites.

Mars.

In the 20th century, the planet Mars was chosen by science fiction writers; in their novels, the Martian civilization was incomparably higher than the earthly one. The mysterious, inaccessible Mars began to reveal its secrets when Soviet and American automatic spacecraft began to be sent to study it.

The Mariner 9 station, orbiting Mars, took photographs of all parts of the planet, which made it possible to create detailed map surface relief. Researchers have discovered traces of active geological processes on the planet: huge volcanoes, the largest of them, Olympus Mons, 25 km high, and a huge fault in the Martian crust, called Valles Marineris, which crosses an eighth of the planet.

Gigantic structures grew in the same place for billions of years, unlike the Earth with its drifting continents, the surface of Mars did not move. The geological structures of the Earth, compared to those on Mars, are dwarfs. Are volcanoes active on Mars now? Scientists believe that geological activity on the planet is obviously a thing of the past.

Martian landscapes are dominated by reddish rocky deserts. Light transparent clouds float above them in the pink sky. The sky turns blue at sunset. The atmosphere of Mars is very thin. Every few years there are dust storms that cover almost the entire surface of the planet. A day on Mars lasts 24 hours 37 minutes, the inclination of the axis of rotation of Mars to the orbital plane is almost the same as that of the Earth, so the change of seasons on Mars is quite consistent with the change of seasons on Earth. The planet is poorly heated by the Sun, so its surface temperature even on a summer day does not exceed 0 degrees, and in winter, frozen carbon dioxide settles on the rocks due to the severe cold, and the Polar Caps are mainly made of it. No traces of life have yet been found.

From Earth, Mars is visible as a reddish star, which is probably why it bears the name of the god of war, Mars. His two companions were named Phobos and Deimos, which translated from ancient Greek means “fear” and “horror.” Satellites of Mars - space "rocks" irregular shape. Phobos measures 18km x 22km, and Deimos measures 10km x 16km.

The planets are giants.

In 1977, American scientists and engineers launched an automatic interplanetary station towards Jupiter as part of the Voyager program. Once every 175 years, Jupiter, Saturn, Neptune and Pluto are positioned in such a way relative to the Earth that a launched spacecraft can examine all these planets in one flight. Scientists have calculated that, under certain conditions, a spacecraft, approaching a planet, falls into a gravitational slingshot, and the planet itself sends the apparatus further to another planet. The calculations turned out to be correct. Earthlings were able to see these distant planets and their satellites through the “eyes” of space robots, and unique information was transmitted to Earth.

Jupiter.

Jupiter is the most big planet in the solar system. It does not have a solid surface and consists mainly of hydrogen and helium. Due to the high speed of rotation around its axis, it is noticeably compressed at the poles. Jupiter has a huge magnetic field; if it became visible, it would look the size of the solar disk from Earth.

In the photographs, scientists were able to see only clouds in the planet’s atmosphere, which create stripes parallel to the equator. But they moved with great speed, bizarrely changing their shape. Numerous vortices, auroras and lightning flashes were recorded in the cloud cover of Jupiter. On the planet, wind speeds reach one hundred kilometers per hour. The most amazing formation in the atmosphere of Jupiter is a large red spot 3 times the size of the Earth. Astronomers have observed it since the 17th century. It is possible that this is the tip of a gigantic tornado. Jupiter releases more energy than it receives from the Sun. Scientists believe that in the center of the planet, gases are compressed to the state of a metallic liquid. This hot core is power plant, generating winds and a monstrous magnetic field.

But the main surprises for scientists were presented not by Jupiter itself, but by its satellites.

Satellites of Jupiter.

There are 16 known satellites of Jupiter. The largest of them, Io, Europa, Callisto and Ganymede, were discovered by Galileo; they are visible even with strong binoculars. It was believed that the satellites of all planets are similar to the Moon - they are cold and lifeless. But Jupiter's moons surprised researchers.

Io- the size of the Moon, but it is the first celestial body other than Earth on which active volcanoes have been discovered. Io is completely covered in volcanoes. Its surface is washed by multi-colored lava flows, volcanoes emit sulfur. But what is the reason for the active volcanic activity of such a small cosmic body? Revolving around the huge Jupiter, Io either approaches it or moves away.

Under the influence of either increasing or decreasing gravitational force Io alternately contracts and expands. Friction forces heated its inner layers to enormous temperatures. Io's volcanic activity is incredible, its surface changing before our eyes. Io moves in Jupiter's powerful magnetic field, so it accumulates a huge electrical charge, which is discharged onto Jupiter in the form continuous flow lightning, causing storms on the planet.

Europe has a relatively smooth surface, virtually without relief. It is covered with a layer of ice, and it is likely that the ocean is hidden underneath it. Instead of molten rocks, water oozes from cracks here. This is a completely new type of geological activity.

Ganymede- the largest satellite in the solar system. Its size is almost the same as that of Mercury.

Callisto dark and cold, its surface, pockmarked with meteorite craters, has not changed for billions of years.

Saturn.

Saturn, like Jupiter, does not have a solid surface - it is a gas giant planet. It also consists of hydrogen and helium, but it is cooler, since it produces less heat itself and receives less of it from the Sun. But on Saturn the winds are faster than on Jupiter. Stripes, vortices and other formations are observed in the atmosphere of Saturn, but they are short-lived and irregular.

Naturally, scientists' attention was directed to the rings that surround the planet's equator. They were discovered by astronomers back in the 17th century, and since then scientists have been trying to understand what they are. Photos of rings transmitted to the ground automatically space station, surprised the researchers. They were able to identify several hundred rings nested inside one another, some intertwined with each other, dark stripes were found on the rings that appeared and disappeared, they were called knitting needles. Scientists were able to see the rings of Saturn from a fairly close distance, but they had more questions than answers.

In addition to the rings, 15 satellites move around Saturn. The largest of them is Titan, slightly smaller than Mercury. Titan's dense atmosphere is much thicker than Earth's and consists almost entirely of nitrogen; it did not allow us to see the surface of the satellite, but scientists suggest that internal structure Titan's structure is similar to that of the Earth. The temperature at its surface is below minus 200 degrees.

Uranus.

Uranus differs from all other planets in that its axis of rotation lies almost in the plane of its orbit, all planets look like a toy top, and Uranus rotates as if “lying on its side.” Voyager was able to “see” little in the atmosphere of Uranus; the planet turned out to be very monotonous in appearance. There are 5 satellites orbiting Uranus.

Neptune.

It took Voyager 12 years to get to Neptune. How surprised the scientists were when, on the outskirts of the solar system, they saw a planet very similar to Earth. It was a deep blue color, with white clouds moving in different directions in the atmosphere. The winds on Neptune blow much stronger than on other planets.

There is so little energy on Neptune that the wind, once it picks up, cannot stop. Scientists have discovered a system of rings around Neptune, but they are incomplete and represent arcs; there is no explanation for this yet. Neptune and Uranus are also giant planets, but not gas, but ice.

Neptune has 3 satellites. One of them is that Triton rotates in the direction opposite to the direction of rotation of Neptune itself. Perhaps it did not form in Neptune's gravitational zone, but was pulled toward the planet when it came close to it and fell into its gravitational zone. Triton is the coldest body in the solar system, its surface temperature is slightly above absolute zero (minus 273 degrees). But nitrogen geysers were discovered on Triton, which indicates its geological activity.

Pluto

Now Pluto is officially no longer a planet. It should now be considered a "dwarf planet", one of three in the Solar System. Pluto's fate was determined in 2006 by a vote of members of the International Astronomical Society in Prague.

To avoid confusion and not clutter maps of the Solar System, the International Astronomical Union has prescribed that fairly large celestial bodies that are not among the eight previously defined planets be classified as dwarf planets. In particular, Pluto, Charon (a former satellite of Pluto), the asteroid Ceres, orbiting between the orbits of Mars and Jupiter, as well as the so-called Kuiper belt objects Xena (object UB313) and Sedna (object 90377) received a new status.

Discussing:

Gogol "Taras Bulba" (6th grade): Describing the steppe, Gogol is an excellent master of verbal painting,...
Competitions and Olympiads in English for schoolchildren!: Today, learning English is especially relevant and should...
“Denisovan man” “inherited” most of all in the genome of Asians: The fact that a species of ancient people discovered in 2010 in Denisova Cave in...
Why Dante? Dante. Dante's Hell. Topography: Ugolino (In the last circle of hell before us...) UGOLINO (Legend from Dante) In...