Solar system. Planets of the solar system

Earth is the third planet from the Sun and the largest of the terrestrial planets. However, it is only the fifth largest planet in terms of size and mass in the Solar System, but surprisingly, it is the densest of all the planets in the system (5.513 kg/m3). It is also noteworthy that Earth is the only planet in the solar system that people themselves have not named after a mythological creature - its name comes from the old English word "ertha", which means soil.

It is believed that the Earth was formed somewhere around 4.5 billion years ago, and is currently the only known planet where the existence of life is possible in principle, and the conditions are such that life is literally teeming on the planet.

Throughout human history, people have sought to understand their home planet. However, the learning curve turned out to be very, very difficult, with many mistakes made along the way. For example, even before the existence of the ancient Romans, the world was understood as flat, not spherical. A second clear example is the belief that the Sun revolves around the Earth. It was only in the sixteenth century, thanks to the work of Copernicus, that people learned that the Earth was actually just a planet orbiting the Sun.

Perhaps the most important discovery about our planet over the past two centuries is that the Earth is both a common and unique place in the solar system. On the one hand, many of its characteristics are rather ordinary. Take, for example, the size of the planet, its internal and geological processes: its internal structure is almost identical to the three other terrestrial planets in the solar system. On Earth, almost the same geological processes occur that form the surface, which are characteristic of similar planets and many planetary satellites. However, with all this, the Earth simply has a huge number of absolutely unique characteristics that strikingly distinguish it from almost all currently known terrestrial planets.

One of the necessary conditions for the existence of life on Earth is without a doubt its atmosphere. It consists of approximately 78% nitrogen (N2), 21% oxygen (O2) and 1% argon. It also contains very small amounts of carbon dioxide (CO2) and other gases. It is noteworthy that nitrogen and oxygen are necessary for the creation of deoxyribonucleic acid (DNA) and the production of biological energy, without which life cannot exist. In addition, oxygen present in the ozone layer of the atmosphere protects the planet's surface and absorbs harmful solar radiation.

What's interesting is that a significant amount of the oxygen present in the atmosphere is created on Earth. It is formed as a byproduct of photosynthesis, when plants convert carbon dioxide from the atmosphere into oxygen. Essentially, this means that without plants, the amount of carbon dioxide in the atmosphere would be much higher and oxygen levels much lower. On the one hand, if carbon dioxide levels rise, it is likely that the Earth will suffer from a greenhouse effect like this. On the other hand, if the percentage of carbon dioxide became even slightly lower, then the reduction in the greenhouse effect would lead to a sharp cooling. Thus, current carbon dioxide levels contribute to an ideal comfortable temperature range of -88°C to 58°C.

When observing the Earth from space, the first thing that catches your eye is oceans of liquid water. In terms of surface area, oceans cover approximately 70% of the Earth, which is one of the most unique properties of our planet.

Like the Earth's atmosphere, the presence of liquid water is a necessary criterion for supporting life. Scientists believe that life on Earth first appeared 3.8 billion years ago in the ocean, and the ability to move on land appeared in living creatures much later.

Planetologists explain the presence of oceans on Earth for two reasons. The first of these is the Earth itself. There is an assumption that during the formation of the Earth, the planet's atmosphere was able to capture large volumes of water vapor. Over time, the planet's geological mechanisms, primarily its volcanic activity, released this water vapor into the atmosphere, after which in the atmosphere, this vapor condensed and fell to the surface of the planet in the form of liquid water. Another version suggests that the source of water was comets that fell to the surface of the Earth in the past, ice which predominated in their composition and formed the reservoirs that exist on Earth.

Surface of the Earth

Despite the fact that most of the Earth's surface is located under its oceans, the "dry" surface has many distinctive features. When comparing Earth to other solid bodies in the solar system, its surface is strikingly different because it does not have craters. According to planetary scientists, this does not mean that the Earth has escaped numerous impacts from small cosmic bodies, but rather indicates that evidence of such impacts has been erased. There may be many geological processes responsible for this, but scientists identify the two most important - weathering and erosion. It is believed that in many ways it was the dual impact of these factors that influenced the erasure of traces of craters from the face of the Earth.

So weathering breaks surface structures into smaller pieces, not to mention chemical and physical methods of atmospheric exposure. An example of chemical weathering is acid rain. An example of physical weathering is the abrasion of river beds caused by rocks contained in flowing water. The second mechanism, erosion, is essentially the effect on the relief of the movement of particles of water, ice, wind or earth. Thus, under the influence of weathering and erosion, the impact craters on our planet were “erased”, due to which some relief features were formed.

Scientists also identify two geological mechanisms that, in their opinion, helped shape the Earth's surface. The first such mechanism is volcanic activity - the process of release of magma (molten rock) from the Earth's interior through breaks in its crust. Perhaps it was due to volcanic activity that the earth's crust was changed and islands were formed (the Hawaiian Islands are a good example). The second mechanism determines mountain building, or the formation of mountains as a result of compression of tectonic plates.

Structure of planet earth

Like other terrestrial planets, the Earth consists of three components: the core, mantle and crust. Science now believes that the core of our planet consists of two separate layers: an inner core of solid nickel and iron and an outer core of molten nickel and iron. At the same time, the mantle is a very dense and almost completely solid silicate rock - its thickness is approximately 2850 km. The bark also consists of silicate rocks and varies in thickness. While continental crust ranges from 30 to 40 kilometers in thickness, oceanic crust is much thinner, only 6 to 11 kilometers.

Another distinctive feature of Earth relative to other terrestrial planets is that its crust is divided into cold, rigid plates that rest on a hotter mantle below. In addition, these plates are in constant motion. Along their boundaries, as a rule, two processes occur simultaneously, known as subduction and spreading. During subduction, two plates come into contact producing earthquakes and one plate rides on the other. The second process is separation, where two plates move away from each other.

Earth's orbit and rotation

It takes the Earth approximately 365 days to complete its orbit around the Sun. The length of our year is related largely to the average orbital distance of the Earth, which is 1.50 x 10 to the power of 8 km. At this orbital distance, it takes on average about eight minutes and twenty seconds for sunlight to reach the Earth's surface.

At an orbital eccentricity of .0167, the Earth's orbit is one of the most circular in the entire solar system. This means that the difference between Earth's perihelion and aphelion is relatively small. As a result of this small difference, the intensity of sunlight on Earth remains essentially the same year-round. However, the position of the Earth in its orbit determines one season or another.

The Earth's axial tilt is approximately 23.45°. In this case, the Earth takes twenty-four hours to complete one rotation around its axis. This is the fastest rotation among the terrestrial planets, but slightly slower than all the gas planets.

In the past, the Earth was considered the center of the Universe. For 2000 years, ancient astronomers believed that the Earth was static and that other celestial bodies traveled in circular orbits around it. They came to this conclusion by observing the obvious movement of the Sun and planets when observed from Earth. In 1543, Copernicus published his heliocentric model of the solar system, which places the Sun at the center of our solar system.

Earth is the only planet in the system that was not named after mythological gods or goddesses (the other seven planets in the solar system were named after Roman gods or goddesses). This refers to the five planets visible to the naked eye: Mercury, Venus, Mars, Jupiter and Saturn. The same approach with the names of the ancient Roman gods was used after the discovery of Uranus and Neptune. The word “Earth” itself comes from the old English word “ertha” meaning soil.

Earth is the densest planet in the solar system. The density of the Earth differs in each layer of the planet (the core, for example, is denser than the crust). The average density of the planet is about 5.52 grams per cubic centimeter.

The gravitational interaction between the Earth causes tides on Earth. It is believed that the Moon is blocked by the Earth's tidal forces, so its rotation period coincides with the Earth's and it always faces our planet with the same side.

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.

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.

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 is 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 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”.

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 revolve 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

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 the planets of the 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 are composed 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 the picture of the terrestrial planets scaled by their sizes 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).

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. Considering that the Earth is larger in size, the density value of Mercury indicates an increased content of metals in its depths.

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 notice 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 hottest 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.

There is no evidence of geological activity on Venus, but since it has no magnetic field to prevent the depletion of its substantial atmosphere, it is assumed 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 is smaller than Earth and Venus, its mass is 0.64185·10 24 kg, which is 10.7% of the Earth's mass. 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 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 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 the mythology of 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 faces the Sun alternately with the north pole, the south pole, the equator, and the middle latitudes.

In 1986, the American spacecraft Voyager 2 transmitted close-range images of Uranus to Earth. 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, therefore 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 and 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...

solar system– these are 8 planets and more than 63 of their satellites, which are being discovered more and more often, several dozen comets and a large number of asteroids. All cosmic bodies move along their own clearly directed trajectories around the Sun, which is 1000 times heavier than all the bodies in the solar system combined. The center of the solar system is the Sun, a star around which the planets orbit. They do not emit heat and do not glow, but only reflect the light of the Sun. There are now 8 officially recognized planets in the solar system. Let us briefly list them all in order of distance from the sun. And now a few definitions.

Planet 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 other large bodies near its orbit;
4. the body should not be a star

Star is a cosmic body that emits light and is a powerful source of energy. This is explained, firstly, by the thermonuclear reactions occurring in it, and secondly, by the processes of gravitational compression, as a result of which a huge amount of energy is released.

Satellites of the planets. The solar system also includes the Moon and the natural satellites of other planets, which they all have except Mercury and Venus. Over 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 satellite, 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. Age about 5 billion years. It has a diameter at the equator of 1,392,000 km, 109 times larger than that of 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 332,950 times the mass of the Earth. The temperature inside the core is approximately 15 million degrees Celsius. The surface temperature is about 5500 degrees Celsius. In terms of its chemical composition, the Sun consists of 75% hydrogen, and of the other 25% elements the majority is 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.
The four inner planets (closest to the Sun) - Mercury, Venus, Earth and Mars - have a solid surface. They are smaller than the 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 (rotation around an 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 similar to Earth in size and brightness. Observing it is difficult due to 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 (rotation around an 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 collided and gradually “grew” the planet. The temperature on the surface reached 5000 degrees Celsius. Then the Earth cooled and became covered with a hard rock crust. But the temperature in the depths is still quite high - 4500 degrees. Rocks in the depths 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 in order to receive the necessary heat and light, but far enough so as not to burn out. Period of revolution around the Sun: 365.3 days.
Diameter at the equator: 12756 km.
Period of rotation of the planet (rotation around its axis): 23 hours 56 minutes.
Surface temperature: 22 degrees (average).
Atmosphere: Mainly nitrogen and oxygen.
Number of satellites: 1.
The main satellites of the planet: the Moon.

Because of its resemblance to Earth, it was believed that life existed 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 an axis): 24 hours 37 minutes.
Surface temperature: –23 degrees (average).
The planet's atmosphere: thin, mostly carbon dioxide.
How many satellites: 2.
The main satellites in order: Phobos, Deimos.

Jupiter, Saturn, Uranus and Neptune are made of hydrogen and other gases. Jupiter exceeds Earth by more than 10 times 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 long does it take for planet Jupiter to become a star? We need to increase its mass by 75 times! Period of revolution around the Sun: 11 years 314 days.
Diameter of the planet at the equator: 143884 km.
Rotation period (rotation around an axis): 9 hours 55 minutes.
Planet surface temperature: –150 degrees (average).
Number of satellites: 16 (+ rings).
The main satellites of the planets in order: Io, Europa, Ganymede, Callisto.

It is number 2, the largest of the planets in the solar system. Saturn attracts attention thanks to its ring system formed of 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. Period of revolution around the Sun: 29 years 168 days.
Diameter of the planet at the equator: 120536 km.
Rotation period (rotation around an axis): 10 hours 14 minutes.
Surface temperature: –180 degrees (average).
Atmosphere: Mainly hydrogen and helium.
Number of satellites: 18 (+ rings).
Main satellites: Titan.

A unique planet in the solar system. Its peculiarity is that it rotates 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 at a distance of 64,000 km, he had six hours to take photographs, which he successfully implemented. Orbital period: 84 years 4 days.
Diameter at the equator: 51118 km.
Period of rotation of the planet (rotation around its axis): 17 hours 14 minutes.
Surface temperature: -214 degrees (average).
Atmosphere: Mainly hydrogen and helium.
How many satellites: 15 (+ rings).
Main satellites: Titania, Oberon.

At the moment, Neptune is considered the last planet in the solar system. Its discovery took place through mathematical calculations, and then it was seen through a telescope. In 1989, Voyager 2 flew past. He took stunning photographs of the blue surface of Neptune and its largest moon, Triton. Period of revolution around the Sun: 164 years 292 days.
Diameter at the equator: 50538 km.
Rotation period (rotation around an axis): 16 hours 7 minutes.
Surface temperature: –220 degrees (average).
Atmosphere: Mainly hydrogen and helium.
Number of satellites: 8.
Main satellites: Triton.

On August 24, 2006, Pluto lost its 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 takes on 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 disk-shaped gas and dust clouds of our large Galaxy (Milky Way) began to shrink toward the center, gradually forming the present Sun. Further, according to one theory, under the influence of powerful forces of attraction, a large number of dust and gas particles revolving around the Sun began to stick together into balls - forming future planets. As another theory says, the gas and dust cloud immediately broke up into separate clusters of particles, which compressed and became denser, forming the current planets. Now 8 planets revolve around the Sun constantly.

Astrophysics - comparatively young science. But it was she who began to study interesting facts about the planets of the solar system, everything about their structure and composition. Having separated from astronomy, she studies physical composition of celestial bodies.

The sky has always been the object of close attention and interest of mankind. The stars have been observed since the time of the mythical Atlantis. The structure of celestial bodies, the trajectories of their movement, the change of seasons on Earth - all this was attributed to the influence of stars. Many theories were confirmed, others were rejected. Over time it was discovered that the Earth not the only planet in our galaxy.

List of celestial bodies

Moving on to describing the interesting features of each, you need to list all the small and large planets of the solar system. A table indicating the position from the sun will be placed just below. Here we will limit ourselves to an alphabetical listing:

• Venus;
• Earth;
• Mars;
• Mercury;
• Neptune;
• Saturn;
• Jupiter;
• Uranus.

Attention! It is noteworthy that the top three included bodies on which, according to science fiction writers, people will eventually settle. Scientists doubt this option, but everything is subject to science fiction.

Curious facts

Everyone has seen the film “Carnival Night,” so there is no need to retell the plot. But even in terms of New Year's celebrations, which are discussed in the film, there should be a report on the topic: “Is there life on Mars?”

What happened to the lecturer and the report itself is well known to the audience. There is often information about Mars in the news.

Astronomical information also includes the fact that it rotates along the fourth trajectory, if we count from the Sun, belongs to the terrestrial group etc.

Mars

It is interesting that all the names of the nearest planets are named after ancient Roman gods. Mars is the god of war according to ancient mythology. There is a little confusion as many consider him to be a fertility god. Both are right. The Romans considered him the god of fertility, who could both destroy and save the harvest. Then, already in ancient Greek mythology, he received the name Ares (Mars) - the god of war.

Attention! Red Planet - Mars acquired its unofficial name due to the high iron content on its surface, which gives it a reddish tint. God received his formidable name in Greek mythology for the same reason. The reddish tint resembled the color of blood.

Few people know that the first month of spring is named after the god of fertility. It sounds the same in almost any language. Mars - March, Mars – March.

Mars is considered one of the most interesting planets in the solar system for children:

1. The highest point on Earth three times lower than the highest point on Mars. Mount Everest is over 8 km high. Mount Olympus (Mars) - 27 km.
2. Due to weaker gravity on Mars you can jump three times higher.
3. Like Earth, Mars has 4 seasons. Each lasts 6 months, and the entire a year is 687 Earth days(2 earth years -365x2=730).
4. It has its own Bermuda Triangle. Of every three satellites launched towards it, only one returns. Two disappear.
5. Moons of Mars (two of them) revolve around it at approximately the same speed towards each other. Because orbital radii are different, they never collide.

Venus

An inexperienced user will immediately answer that the hottest planet in the solar system is the first from the sun - Mercury. However our Earth's twin Venus will easily give him a head start. Mercury has no atmosphere, and although it 44 days heated by the Sun, it spends the same number of days cooling down (A year on Mercury is 88 days). Venus due to the presence of an atmosphere with a high content of carbon dioxide maintains high temperature constantly.

Attention! Located between Mercury and Earth, Venus is almost constantly under a “greenhouse” cap. The temperature stays around 462 degrees. For comparison, lead melts at a temperature of 327 degrees.

Facts about Venus:

1. She has no companions, but itself is so bright that it can cast a shadow.
2. A day on it lasts more than a year - 243 earth days(year - 225).
3. 3. All planets in the Solar System rotate counterclockwise . Only Venus rotates the other way.
4. The wind speed on it can reach 360 km/h.

Mercury

Mercury - first planet from the Sun. Let's look at some interesting information about him:

1. Despite the dangerous proximity with his hot neighbor, he there are glaciers.
2. Mercury boasts geysers. Because there is no oxygen on it, they consist of pure hydrogen.
3. American research satellites detected presence of a small magnetic field.
4. Mercury is eccentric. Its trajectory has an ellipse, the maximum diameter of which is almost twice the minimum.
5. Mercury is covered in wrinkles and, since it has a minimum atmospheric thickness. As a result of this the inner core cools down, shrinking. Therefore, his mantle was covered with wrinkles, the height of which could reach hundreds of meters.

Saturn

Saturn, despite the minimal amount of light and heat, not covered by glaciers, since its main components are gases: helium and hydrogen. It is one of the ringed planets in the Solar System. Galileo, who first saw the planet, suggested that the rings were a trace of the movement of two satellites, but they rotate very quickly.

Interesting information:

1. Shape of Saturn - oblate ball. This is due to the rapid rotation of the celestial body around its axis. Its diameter at the widest part is 120 thousand km, at the narrowest - 108 thousand km.
2. It ranks second in the solar system in terms of the number of its satellites - 62 pieces. At the same time, there are giants larger than Mercury, and there are very small ones with a diameter of up to 5 km.
3. The main decoration of the gas giant are its rings.
4. Saturn is 760 times larger than Earth.
5. Its density is second only to water.

Researchers have proposed an interesting interpretation of the last two facts when teaching children:

• If you create a bag the size of Saturn, then it would fit exactly 760 balls, the diameter of which is equal to the globe.
• If a giant bathtub comparable to its size was filled with water, then Saturn would float on the surface.

Pluto

Pluto is of particular interest.

Until the end of the twentieth century, it was considered the most the farthest planet from the Sun, but due to the discovery of the second asteroid belt beyond Neptune, in which fragments were found weighing and diameter exceeding Pluto, since the beginning of the 21st century it has been transferred to the status of dwarf planets.

An official name to designate bodies of this size has yet to be invented. At the same time, this “shard” has five of its satellites. One of them, Charon, is almost equal in its parameters to Pluto itself.

There is no planet in our system with a blue sky, except for Earth and... Pluto. In addition, it is noted that there is a lot of ice on Pluto. Unlike Mercury's ice sheets, this ice is frozen water, since the planet is quite far from the main body.

Jupiter

But the most interesting planet is Jupiter:

1. He has rings. Five of them are fragments of meteorites approaching him. Unlike Saturn's rings, they do not contain ice.
2. The moons of Jupiter were named after the mistresses of the ancient Greek god after whom he was named.
3. It is the most dangerous for radio and magnetic devices. Its magnetic field can damage the instruments of a ship that tries to approach it.
4. The speed of Jupiter is also interesting. Days on it are only 10 hours, and year is the time during which it occurs orbit around a star, 12 years.
5. The mass of Jupiter is several times greater than the weight of all other planets orbiting the Sun.

Earth

Interesting facts.

1. The South Pole - Antarctica, contains almost 90% of all the ice on the globe. Almost 70% of the world's fresh water is located there.
2. Longest mountain range is underwater. Its length is more than 600,000 km.
3. The longest range on land is the Himalayas (over 2500 km),
4. The Dead Sea is the second deepest point in the world. Its bottom located at 400 meters below ocean level.
5. Scientists suggest that our celestial body used to have two moons. After a collision with him, the second one crumbled and became an asteroid belt.
6. Many years ago, the globe was not green-blue, as in today's photographs from space, but purple, due to the large number of bacteria.

These are not all the interesting facts about planet Earth. Scientists can tell hundreds of interesting, sometimes funny, pieces of information.

Gravity

The simplest interpretation of this term is attraction.

People walk on a horizontal surface because it attracts. A thrown stone still falls sooner or later - gravity effect. If you are unsure on a bike, you fall - gravity again.

The solar system and gravity are interconnected. Celestial bodies have their own orbits around the star.

Without gravity, there would be no orbits. This entire swarm flying around our star would scatter in different directions.

Attraction is also reflected in the fact that all planets are round in shape. Gravity depends on distance: several pieces of any substance are mutually attracted, resulting in a ball.

Table of length of day and years

It is clear from the table that the further the object is from the main luminary, the shorter the day and the longer the years. Which planet has the shortest year? On Mercury it is only 3 earth months. Scientists have not yet been able to confirm or refute this figure, because not a single earthly telescope can constantly observe it. The proximity of the main luminary will definitely damage the optics. The data was obtained through space research vehicles.

The length of the day also depends on body diameter and the speed of its rotation. The white planets of the Solar System (terrestrial type), the names of which are presented in the first four cells of the table, have a rocky structure and a rather slow speed.

10 interesting facts about the solar system

Our solar system: Planet Uranus

Conclusion

The giant planets located beyond the asteroid belt are mostly gaseous, due to which they rotate faster. Moreover, all four have poles and an equator rotate at different speeds. On the other hand, since they are at a greater distance from the star, their complete orbital flight takes quite a long time.

All space objects are interesting in their own way, and each of them contains some kind of mystery. Their study is a long and very interesting process, which every year reveals to us new secrets of the Universe.