Planets of our solar system with you. Features of the terrestrial planets

Space has attracted people's attention for a long time. Astronomers began to study the planets of the solar system in the Middle Ages, looking at them through primitive telescopes. But a thorough classification, description of the features of the structure and movement of celestial bodies became possible only in the 20th century. With the advent of powerful equipment, state-of-the-art observatories and spacecraft, several previously unknown objects were discovered. Now each student can list all the planets of the solar system in order. Almost all of them have been landed by a space probe, and so far man has only been to the Moon.

What is the solar system

The universe is huge and includes many galaxies. Our solar system is part of a galaxy with over 100 billion stars. But there are very few that look 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 were formed. Over time, celestial bodies formed from them. It is believed that the Sun is now in the middle of its life path, so it will exist, as well as all celestial bodies dependent on it, for several billion more 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 dedicated to this topic. All celestial bodies are held by the Sun's strong gravitational field, which makes up over 99% of the solar system's volume. Large celestial bodies revolve around the star and around their axis in one direction and in one plane, which is called the plane of the ecliptic.

Solar system planets in order

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

Features of the terrestrial planets

What makes it possible to attribute these celestial bodies to one group? We 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);
• the presence of an atmosphere;
• the same 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 size and weight;
• they do not have a solid surface and are composed of gases, mainly helium and hydrogen (which is why they are also called gas giants);
• a 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 luminary looks three times larger than from the Earth. This also explains the strong temperature fluctuations: from -180 to +430 degrees. Mercury is moving very fast in its orbit. Maybe that's why he got such a name, because in Greek mythology, Mercury is the messenger of the gods. There is almost 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 axis of rotation. No water was found on the surface. This circumstance, as well as the anomalously high daytime temperature (as well as the low nighttime temperature) fully explain the fact that there is no life on the planet.

Venus

If we study the planets of the solar system in order, then the second one is Venus. People could observe her in the sky in ancient times, but since she was shown only in the morning and in the evening, it was believed that these were 2 different objects. By the way, our Slavic ancestors called her Flicker. It is the third brightest object in our solar system. Previously, people called it the morning and evening star, because it is best seen before sunrise and sunset. Venus and Earth are very similar in structure, composition, size and gravity. Around its axis, this planet moves very slowly, making a complete revolution in 243.02 Earth days. Of course, the conditions on Venus are very different from those on Earth. It is twice as close to the Sun, so it is very hot there. The 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 survived there for no more than an hour. A feature of the planet is also the fact that it rotates in the opposite direction, compared to most planets. Astronomers know nothing more about this celestial object yet.

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 the Earth. In the terrestrial group, it has the largest dimensions. What else is her

1. The largest gravity among the terrestrial planets.
2. Very strong magnetic field.
3. High density.
4. It is the only one among all the planets that has a hydrosphere, which contributed to the formation of life.
5. It has the largest, in comparison with its size, satellite, which stabilizes its tilt relative to the Sun and affects natural processes.

The planet Mars

It 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 drops are observed. The planet Mars is 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 furrows, 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. Their unusualness 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. 1300 Earths would fit in the volume of Jupiter, and its mass is 317 times more than the earth. Like all gas giants, its structure is hydrogen-helium, reminiscent of the composition of stars. Jupiter is the most interesting planet that has many characteristic features:

• it is the third brightest celestial body after the Moon and Venus;
• Jupiter has the strongest magnetic field of all the planets;
• it completes a full rotation around its axis in just 10 earth hours - faster than other planets;
• an interesting feature of Jupiter is a large red spot - this is how an atmospheric vortex is visible from the Earth, rotating counterclockwise;
• like all giant planets, it has rings, though not as bright as those of Saturn;
• 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 shade the surface temperature is higher than in places illuminated by the sun.

Planet Saturn

This is the second largest gas giant, also named after the ancient god. It consists of hydrogen and helium, but traces of methane, ammonia and water have been found on its surface. Scientists have found that Saturn is the most rarefied planet. Its density is less than that of water. This gas giant rotates very quickly - it completes one revolution in 10 Earth hours, as a result of which the planet is flattened from the sides. Huge speeds on Saturn and near the wind - up to 2000 kilometers per hour. It's more than the speed of sound. Saturn has another 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, exploring its surface, scientists first 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 itself. Four is the most amazing phenomenon in the solar system. Unusually, the inner rings move faster than the outer ones.

- 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. Because 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: winter reigns there for 42 Earth years, and the Sun does not appear at all, summer also lasts 42 years, and the Sun does not set at this time. In spring and autumn, the luminary 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, in 19 times greater than the path to the luminary 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 farther from the star than the Earth, and is not visible from our planet even through a telescope. Scientists discovered it, so to speak, by chance: 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, interesting features of this planet were revealed:

• 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 completes one circle in 165 years;
• Neptune is 4 times larger than the Earth and 17 times heavier, but the force of attraction is almost the same as on our planet;
• the largest of the 13 moons of this giant is Triton. It is always turned to the planet on one side and slowly approaches it. Based on these signs, scientists have suggested that it was captured by Neptune's gravity.

In the entire galaxy, the Milky Way is about a hundred billion planets. So far, scientists cannot even study 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 name of the planets of the solar system.

Planets of the solar system

According to the official position of the International Astronomical Union (IAU), an organization that assigns names to astronomical objects, there are only 8 planets.

Pluto was removed from the category of planets in 2006. because in the Kuiper belt are objects that are larger / or equal in size to Pluto. Therefore, even if it is taken as a full-fledged celestial body, then it is necessary to add Eris to this category, which has almost the same size with Pluto.

As defined by MAC, there are 8 known planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

All planets are divided into two categories depending on their physical characteristics: terrestrial and gas giants.

Schematic representation of the location of the planets

terrestrial planets

Mercury

The smallest planet in the solar system has a radius of only 2440 km. The period of revolution around the Sun, for ease of understanding, equated to the earth's year, is 88 days, while Mercury has time to complete a revolution around its own axis only one and a half times. Thus, its day lasts approximately 59 Earth days. For a long time it was believed that this planet is always turned to the Sun by the same side, since the periods of its visibility from the Earth were repeated with a frequency approximately equal to four Mercury days. This misconception was dispelled with the advent of the possibility of using radar research and conducting continuous observations using space stations. The orbit of Mercury is one of the most unstable; not only the speed of movement and its distance from the Sun change, but also the position itself. Anyone interested can observe this effect.

Mercury in color, as seen by the MESSENGER spacecraft

Mercury's proximity to the Sun has caused it to experience the largest temperature fluctuations of any of the planets in our system. The average daytime temperature is about 350 degrees Celsius, and the nighttime temperature is -170 °C. Sodium, oxygen, helium, potassium, hydrogen and argon have been identified in the atmosphere. There is a theory that it was previously a satellite of Venus, but so far this remains unproven. It has no satellites of its own.

Venus

The second planet from the Sun, the atmosphere of which is almost entirely composed of carbon dioxide. It is often called the Morning Star and the Evening Star, because it is the first of the stars to become visible after sunset, just as before dawn it continues to be visible even when all other stars have disappeared from view. The percentage of carbon dioxide in the atmosphere is 96%, there is relatively little nitrogen in it - almost 4%, and water vapor and oxygen are present in very small amounts.

Venus in the UV spectrum

Such an atmosphere creates a greenhouse effect, the temperature on the surface because of this is even higher than that of Mercury and reaches 475 ° C. Considered the slowest, the Venusian day lasts 243 Earth days, which is almost equal to a year on Venus - 225 Earth days. Many call it the sister of the Earth because of the mass and radius, the values ​​​​of which are very close to the earth's indicators. The radius of Venus is 6052 km (0.85% of the earth). There are no satellites, like Mercury.

The third planet from the Sun and the only one in our system where there is liquid water on the surface, without which life on the planet could not develop. At least life as we know it. The radius of the Earth is 6371 km and, unlike the rest of the celestial bodies in our system, more than 70% of its surface is covered with water. The rest of the space is occupied by the continents. Another feature of the Earth is the tectonic plates hidden under the planet's mantle. At the same time, they are able to move, albeit at a very low speed, which over time causes a change in the landscape. The speed of the planet moving along it is 29-30 km / s.

Our planet from space

One rotation around its axis takes almost 24 hours, and a complete orbit lasts 365 days, which is much longer in comparison with the nearest neighboring planets. The Earth day and year are also taken as a standard, but this is done only for the convenience of perceiving time intervals on other planets. The Earth has one natural satellite, the Moon.

Mars

The fourth planet from the Sun, known for its rarefied atmosphere. Since 1960, Mars has been actively explored by scientists from several countries, including the USSR and the USA. Not all research programs have been successful, but water found in some areas suggests that primitive life exists on Mars, or existed in the past.

The brightness of this planet allows you to see it from Earth without any instruments. Moreover, once every 15-17 years, during the Opposition, it becomes the brightest object in the sky, eclipsing even Jupiter and Venus.

The radius is almost half that of the earth and is 3390 km, but the year is much longer - 687 days. He has 2 satellites - Phobos and Deimos .

Visual model of the solar system

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• Sun

  The sun is a star, which is a hot ball of hot gases at the center of our solar system. Its influence extends far beyond the orbits of Neptune and Pluto. Without the Sun and its intense energy and heat, there would be no life on Earth. There are billions of stars, like our Sun, scattered throughout the Milky Way galaxy.

• Mercury

  Sun-scorched Mercury is only slightly larger than Earth's moon. Like the Moon, Mercury is practically devoid of an atmosphere and cannot smooth out the traces of impact from the fall of meteorites, therefore, like the Moon, it is covered with craters. The day side of Mercury is very hot on the Sun, and on the night side the temperature drops hundreds of degrees below zero. In the craters of Mercury, which are located at the poles, there is ice. Mercury makes one revolution around the Sun in 88 days.

• Venus

  Venus is a world of monstrous heat (even more than on Mercury) and volcanic activity. Similar in structure and size to Earth, Venus is covered in a thick and toxic atmosphere that creates a strong greenhouse effect. This scorched world is hot enough to melt lead. Radar images through the mighty atmosphere revealed volcanoes and deformed mountains. Venus rotates in the opposite direction from the rotation of most planets.

• Earth is an ocean planet. Our home, with its abundance of water and life, makes it unique in our solar system. Other planets, including several moons, also have ice deposits, atmospheres, seasons, and even weather, but only on Earth did all these components come together in such a way that life became possible.

• Mars

  Although details of the surface of Mars are difficult to see from Earth, telescope observations show that Mars has seasons and white spots at the poles. For decades, people have assumed that the bright and dark areas on Mars are patches of vegetation and that Mars might be a suitable place for life, and that water exists in the polar caps. When the Mariner 4 spacecraft flew by Mars in 1965, many of the scientists were shocked to see pictures of the bleak, cratered planet. Mars turned out to be a dead planet. More recent missions, however, have revealed that Mars holds many mysteries that have yet to be solved.

• Jupiter

  Jupiter is the most massive planet in our solar system, has four large moons and many small moons. Jupiter forms a kind of miniature solar system. To turn into a full-fledged star, Jupiter had to become 80 times more massive.

• Saturn

  Saturn is the most distant of the five planets that were known before the invention of the telescope. Like Jupiter, Saturn is made up mostly of hydrogen and helium. Its volume is 755 times that of the Earth. Winds in its atmosphere reach speeds of 500 meters per second. These fast winds, combined with heat rising from the planet's interior, cause the yellow and golden streaks we see in the atmosphere.

• Uranus

  The first planet found with a telescope, Uranus was discovered in 1781 by astronomer William Herschel. The seventh planet is so far from the Sun that one revolution around the Sun takes 84 years.

• Neptune

  Nearly 4.5 billion kilometers from the Sun, distant Neptune rotates. It takes 165 years to complete one revolution around the Sun. It is invisible to the naked eye due to its vast distance from Earth. Interestingly, its unusual elliptical orbit intersects with the orbit of the dwarf planet Pluto, which is why Pluto is inside Neptune's orbit for about 20 out of 248 years during which it makes one revolution around the Sun.

• Pluto

  Tiny, cold and incredibly distant, Pluto was discovered in 1930 and has long been considered the ninth planet. But after the discovery of Pluto-like worlds even further away, Pluto was reclassified as a dwarf planet in 2006.

The planets are giants

There are four gas giants located beyond the orbit of Mars: Jupiter, Saturn, Uranus, Neptune. They are in the outer solar system. They differ in their massiveness and gas composition.

Planets of the solar system, not to scale

Jupiter

The fifth planet from the Sun and the largest planet in our system. Its radius is 69912 km, it is 19 times larger than the Earth and only 10 times smaller than the Sun. A year on Jupiter is not the longest in the solar system, lasting 4333 Earth days (incomplete 12 years). His own day has a duration of about 10 Earth hours. The exact composition of the planet's surface has not yet been determined, but it is known that krypton, argon and xenon are present on Jupiter in much larger quantities than on the Sun.

There is an opinion that one of the four gas giants is actually a failed star. This theory is also supported by the largest number of satellites, of which Jupiter has many - as many as 67. To imagine their behavior in the orbit of the planet, a fairly accurate and clear model of the solar system is needed. The largest of them are Callisto, Ganymede, Io and Europa. At the same time, Ganymede is the largest satellite of the planets in the entire solar system, its radius is 2634 km, which is 8% larger than the size of Mercury, the smallest planet in our system. Io has the distinction of being one of only three moons with an atmosphere.

Saturn

The second largest planet and the sixth largest in the solar system. In comparison with other planets, the composition of chemical elements is most similar to the Sun. The surface radius is 57,350 km, the year is 10,759 days (almost 30 Earth years). A day here lasts a little longer than on Jupiter - 10.5 Earth hours. In terms of the number of satellites, it is not far behind its neighbor - 62 versus 67. The largest satellite of Saturn is Titan, just like Io, which is distinguished by the presence of an atmosphere. Slightly smaller than it, but no less famous for this - Enceladus, Rhea, Dione, Tethys, Iapetus and Mimas. It is these satellites that are the objects for the most frequent observation, and therefore we can say that they are the most studied in comparison with the rest.

For a long time, the rings on Saturn were considered a unique phenomenon, inherent only to him. Only recently it was found that all gas giants have rings, but the rest are not so clearly visible. Their origin has not yet been established, although there are several hypotheses about how they appeared. In addition, it was recently discovered that Rhea, one of the satellites of the sixth planet, also has some kind of rings.

This is a system of planets, in the center of which is a bright star, the source of energy, heat and light - the Sun.
According to one theory, the Sun was formed along with the solar system about 4.5 billion years ago as a result of the explosion of one or more supernovae. Initially, the solar system was a cloud of gas and dust particles, which, in motion and under the influence of their mass, formed a disk in which a new star, the Sun, and our entire solar system arose.

At the center of the solar system is the Sun, around which nine large planets revolve in orbits. Since the Sun is displaced from the center of the planetary orbits, then during the cycle of revolution around the Sun, the planets either approach or move away in their orbits.

There are two groups of planets:

Terrestrial planets: And . These planets are small in size with a rocky surface, they are closer than others to the Sun.

Giant planets: And . These are large planets, consisting mainly of gas, and they are characterized by the presence of rings consisting of ice dust and many rocky pieces.

And here does not fall into any group, because, despite its location in the solar system, it is located too far from the Sun and has a very small diameter, only 2320 km, which is half the diameter of Mercury.

Planets of the solar system

Let's start a fascinating acquaintance with the planets of the solar system in order of their location from the Sun, and also consider their main satellites and some other space objects (comets, asteroids, meteorites) in the gigantic expanses of our planetary system.

Rings and moons of Jupiter: Europa, Io, Ganymede, Callisto and others...
The planet Jupiter is surrounded by a whole family of 16 satellites, and each of them has its own, unlike other features ...

Rings and moons of Saturn: Titan, Enceladus and more...
Not only the planet Saturn has characteristic rings, but also on other giant planets. Around Saturn, the rings are especially clearly visible, because they consist of billions of small particles that revolve around the planet, in addition to several rings, Saturn has 18 satellites, one of which is Titan, its diameter is 5000 km, which makes it the largest satellite of the solar system ...

Rings and moons of Uranus: Titania, Oberon and others...
The planet Uranus has 17 satellites and, like other giant planets, thin rings encircling the planet, which practically do not have the ability to reflect light, therefore they were discovered not so long ago in 1977 quite by accident ...

Rings and moons of Neptune: Triton, Nereid and others...
Initially, before the exploration of Neptune by the Voyager 2 spacecraft, it was known about two satellites of the planet - Triton and Nerida. An interesting fact is that the Triton satellite has a reverse direction of orbital motion, and strange volcanoes were also discovered on the satellite that spewed nitrogen gas like geysers, spreading a dark mass (from liquid to vapor) for many kilometers into the atmosphere. During its mission, Voyager 2 discovered six more satellites of the planet Neptune...

Our planet Earth is the third planet from the Sun in the solar system. She enters earthly group of planets(four planets of the solar system: Mercury, Venus, Earth, Mars). They are also called inner planets. The Earth is the largest planet among the terrestrial group of planets in terms of diameter, mass and density.

Earth is called the Blue Planet. It is indeed blue, as in a picture taken from space, but the main thing is that it is the only currently known planet in the solar system inhabited by living organisms.

The mass of the Earth is 5.9736 10 24 kg, its surface area is 510,072,000 km², and the average radius is 6,371.0 km.

Scientists have determined the age of the Earth - about 4.54 billion years. So, in general, she is already an old woman ... And her origin is from the solar nebula. She wandered the sky alone for a short time: she soon acquired a satellite for herself - the Moon, this is her only natural satellite.

Scientists say that life appeared on Earth about 3.5 billion years ago. But we will talk about this in more detail in the section of our website "Planet Earth", where we will consider various hypotheses about the origin of life on Earth.

With the advent of life, the Earth's atmosphere changed significantly, began to form ozone layer, which, together with the Earth's magnetic field, weakens harmful solar radiation and preserves the conditions of life on the planet.

What is the "ozone layer"? This is a part of the stratosphere at an altitude of 12 to 50 km, in which, under the influence of ultraviolet radiation from the Sun, molecular oxygen (O 2) dissociates into atoms, which then combine with other O 2 molecules, forming ozone(O 3).

The outer shell of the earth (geosphere) is called the earth's crust. So, the Earth's crust is divided into several segments, or tectonic plates(relative to integral blocks), which are in constant motion relative to each other, which explains the occurrence of earthquakes, volcanoes and mountain formation processes.

Approximately 70.8% of the surface of the planet Earth is World Ocean- the water shell of the Earth, surrounding the continents and islands and characterized by a common salt composition. The rest of the surface is occupied by continents (continents) and islands.

Liquid water, known to us by the formula H 2 O, does not exist on the surfaces of other planets in the solar system. But it is necessary for life in any form. In a solid state, water is called ice, snow or hoarfrost, and in a gaseous state - water vapor - in this state it is found on other celestial bodies, but in liquid form - only on Earth. About 71% of the Earth's surface is covered with water (oceans, seas, lakes, rivers, ice).

Earth's interior is quite active and consists of a thick, highly viscous layer called the mantle. Mantle- this is the part of the Earth (geosphere), located directly under the crust and above the core. The mantle contains most of the Earth's matter. The mantle is also found on other planets. The mantle covers the liquid outer core (which is the source of the Earth's magnetic field) and the inner solid core, presumably iron.

The Earth in space interacts (attracts) with other objects, including the Sun and the Moon. The Earth revolves around the Sun in 365.26 days. The Earth's axis of rotation is tilted 23.4° relative to its orbital plane, which causes seasonal changes on the planet's surface with a period of one tropical year (365.24 solar days). Tropical year- this is the length of time during which the Sun completes one cycle of the seasons. Day are approximately 24 hours

The composition of the Earth's atmosphere includes 78.08% nitrogen (N 2), 20.95% oxygen (O 2), 0.93% argon, 0.038% carbon dioxide, about 1% water vapor (depending on climate).

Relating to the terrestrial planets, the Earth has a solid surface. The largest of the four terrestrial planets in the solar system in both size and mass, the Earth has the highest density, the strongest surface gravity (gravity), and the strongest magnetic field of the four planets, generated by intraterrestrial sources.

earth shape

The shape of the Earth is an oblate ellipsoid.

The highest point on the solid surface of the Earth is a mountain Everest, or, translated from Tibetan, Chomolungma which is located in the Himalayas. Its height is 8848 m above sea level. And the lowest point Mariana Trench, which is located in the west of the Pacific Ocean, next to the Mariana Islands. Its depth is 11,022 m below sea level. Let's talk a little about her.

The British were the first to explore the Mariana Trench. They rebuilt a military three-masted Challenger corvette with sailing equipment into an oceanographic vessel for hydrological, geological, chemical, biological and meteorological work. This was done back in 1872. But the first data on the depth of the Mariana Trench, or, as it is sometimes called, the Mariana Trench, were obtained only in 1951: they measured the depression and determined its depth at 10,863 m. (Challenger Deep). Imagine that the highest mountain of our planet, Everest, can easily fit in the depths of the Mariana Trench, and there will still be more than a kilometer of water above it to the surface ... Of course, we are not talking about the area, but only about the depth.

Then the Mariana Trench was explored by Soviet scientists on the Vityaz research vessel, and in 1957 they declared the maximum depth of the trench equal to 11,022 meters, but the most striking thing is that they refuted the opinion prevailing at that time about the impossibility of life at a depth of more than 6000-7000 meters - life in the Mariana Trench exists!

And on January 23, 1960, the first and only dive of a man to the bottom of the Mariana Trench took place. The only people to have been "at the bottom of the Earth" were US Navy Lieutenant Don Walsh and explorer Jacques Picard. They dived on the Trieste bathyscaphe. At the bottom, the researchers were only 12 minutes, but that was enough for them to make a sensational discovery about the presence of life at such a depth - they saw flat fish there, similar to flounder, up to 30 cm in size.

But the researchers of the trench were repeatedly frightened by unknown phenomena in the depths, so the mystery of the Mariana Trench has not yet been fully disclosed.

The chemical composition of the Earth

The earth consists mainly of iron (32.1%), oxygen (30.1%), silicon (15.1%), magnesium (13.9%), sulfur (2.9%), nickel (1.8 %), calcium (1.5%) and aluminum (1.4%); the remaining elements account for 1.2%. It is assumed that the internal space consists of iron (88.8%), a small amount of nickel (5.8%), sulfur (4.5%).

Geochemist Frank Clark calculated that the earth's crust is just over 47% oxygen. The most common rock-constituting minerals of the earth's crust are almost entirely composed of oxides.

Like all planets of the terrestrial group, it has a layered structure. You can see the composition on the diagram. Let's take a closer look at each part.

Earth's crust is the upper part of solid ground. There are two types of crust: continental and oceanic. The thickness of the crust ranges from 6 km under the ocean to 30-50 km on the continents. Three geological layers are distinguished near the continental crust: sedimentary cover, granite and basalt. Under the earth's crust is mantle- the shell of the Earth, composed mainly of rocks consisting of silicates of magnesium, iron, calcium, etc. The mantle makes up 67% of the entire mass of the Earth and about 83% of the total volume of the Earth. It extends from depths of 5-70 kilometers below the boundary with the earth's crust to the boundary with the core at a depth of 2900 km. Above the border of 660 kilometers is upper mantle, and lower - lower. These two parts of the mantle have different composition and physical properties. Although information about the composition of the lower mantle is limited.

Core- the central, deep part of the Earth, the geosphere, located under the mantle and consisting of an iron-nickel alloy with an admixture of other elements. But these figures are speculative. Depth - 2900 km. The core of the Earth is divided into a solid inner core with a radius of about 1300 km and a liquid outer core with a radius of about 2200 km, between which a transition zone is sometimes distinguished. The temperature in the center of the Earth's core reaches 5000°C. The mass of the core is 1.932 10 24 kg.

Earth's hydrosphere

This is the totality of all the water resources of the Earth: oceans, a network of rivers, groundwater, as well as clouds and water vapor in the atmosphere. Part of the water is in a solid state (cryosphere): glaciers, snow cover, permafrost.

Earth's atmosphere

This is the name of the gaseous envelope around the Earth. The atmosphere is divided into troposphere(8-18 km), tropopause(transitional layer from the troposphere to the stratosphere, in which the decrease in temperature with height stops), stratosphere(at an altitude of 11-50 km), stratopause(about 0 °C), mesosphere(from 50 to 90 km), mesopause(about -90 °C), Karman line(height above sea level, which is conventionally accepted as the boundary between the Earth's atmosphere and space, about 100 km above sea level), boundary of the earth's atmosphere(about 118 km), thermosphere(upper limit about 800 km), thermopause(area of ​​the atmosphere adjacent to the top of the thermosphere), exosphere(scattering sphere, above 700 km). The gas in the exosphere is highly rarefied, and hence its particles leak into interplanetary space.

Biosphere of the Earth

This is a set of parts of the earth's shells (litho-, hydro- and atmosphere), which is inhabited by living organisms, is under their influence and is occupied by the products of their vital activity.

Earth's magnetic field

The Earth's magnetic field, or geomagnetic field, is a magnetic field generated by intraterrestrial sources.

Earth rotation

It takes the Earth 23 hours 56 minutes and 4.091 seconds to complete one revolution around its axis. The rotation of the Earth is unstable: the speed of its rotation changes, the geographic poles move, the axis of rotation fluctuates. In general, the movement is slowing down. It is calculated that the duration of one revolution of the Earth has increased over the past 2000 years by an average of 0.0023 seconds per century.

Around the Sun, the Earth moves in an elliptical orbit at a distance of about 150 million km with an average speed of 29.765 km/sec.

Geographic information about the Earth

Square

• Surface: 510.073 million km²
• Land: 148.94 million km²
• Water: 361.132 million km²
• 70.8% of the planet's surface is covered with water and 29.2% is land.

coastline length 286,800 km

First…

The Earth was first photographed from space in 1959 by the Explorer 6. The first person to see the Earth from space was Yuri Gagarin in 1961. The crew of Apollo 8 in 1968 was the first to observe Earth rising from lunar orbit. In 1972, the crew of Apollo 17 took the famous picture of the Earth - "The Blue Marble" - "Blue Marble Ball".

Our planet is a huge ellipsoid consisting of rocks, metals and covered with water and soil. The Earth is one of the nine planets that revolve around the Sun; ranks fifth in terms of the size of the planets. The sun, together with the planets revolving around it, forms. Our galaxy, the Milky Way, has a diameter of about 100,000 light-years (that's how long it takes for light to travel to the last point of a given space).

The planets of the solar system describe ellipses around the sun, while also rotating around their own axes. The four planets closest to the Sun (, Venus, Earth, Mars) are called internal, the rest (, Uranus, Pluto) are external. Recently, scientists have found many planets in the solar system that are equal to or slightly smaller than Pluto in size, so in astronomy today there are only eight planets that make up the solar system, but we will stick to the standard theory.

The Earth moves in its orbit around the Sun at a speed of 107,200 km/h (29.8 km/s). In addition, it rotates around its axis of an imaginary rod passing through the northernmost and southernmost points of the Earth. The earth's axis is inclined to the plane of the ecliptic at an angle of 66.5°. Scientists calculated that if the Earth stopped, it would instantly burn out from the energy of its own speed. The ends of the axis are called the North and South Poles.

The Earth describes its path around the Sun in one year (365.25 days). Every fourth year contains 366 days (an extra day accumulates over 4 years), it is called a leap year. Due to the fact that the earth's axis has a tilt, the northern hemisphere is most tilted towards the Sun in June, and the southern - in December. In the hemisphere that is currently most inclined towards the Sun, it is summer. This means that in the other hemisphere it is winter and it is now the least illuminated by the sun's rays.

The imaginary lines running north and south of the equator, called the Tropic of Cancer and the Tropic of Capricorn, show where the sun's rays fall vertically on the surface of the Earth at noon. In the northern hemisphere this happens in June (the Tropic of Cancer) and in the southern hemisphere in December (the Tropic of Capricorn).

The solar system consists of nine planets orbiting the Sun, their satellites, many minor planets, comets and interplanetary dust.

Earth Movement

The Earth performs 11 different movements, but of these, the daily movement around the axis and the annual revolution around the Sun have important geographical significance.

In this case, the following definitions are introduced: aphelion is the most distant point in the orbit from the Sun (152 million km). Earth passes over it on July 5th. Perihelion is the closest point in orbit from the Sun (147 million km). The earth passes over it on January 3rd. The total length of the orbit is 940 million km.

The movement of the Earth around its axis goes from west to east, a complete revolution takes 23 hours 56 minutes 4 seconds. This time is taken as a day. The daily movement has 4 consequences:

• Compression at the poles and spherical;
• Change of day and night, seasons;
• The Coriolis force (named after the French scientist G. Coriolis) - the deviation of horizontally moving bodies in the Northern Hemisphere to the left, in the Southern Hemisphere - to the right, this affects the direction of movement, etc.;
• tidal phenomena.

The Earth's orbit has several important points corresponding to the days of the equinoxes and solstices. June 22 - the day of the summer solstice, when in the Northern Hemisphere - the longest, and in the Southern
- the shortest day of the year. On the Arctic Circle and inside it on this day - the polar day, on the South Arctic Circle and inside it - the polar night. December 22 is the winter solstice, the shortest day of the year in the northern hemisphere and the longest day in the southern hemisphere. Within the Arctic Circle - the polar night. South Arctic Circle - polar day. March 21 and September 23 are the days of the spring and autumn equinoxes, since the rays of the Sun fall vertically on the equator, on the whole Earth (except for the poles) the day is equal to the night.

Tropics - parallels with latitudes of 23.5 °, in which the Sun is at its zenith only once a year. Between the Northern and Southern tropics, the Sun is at its zenith twice a year, and outside them, the Sun is never at its zenith.

The Arctic Circles (Northern and Southern) are parallels in the Northern and Southern hemispheres with latitudes of 66.5 °, on which the polar day and night last exactly a day.

The polar day and night reach their maximum duration (six months) at the poles.

Time Zones. In order to regulate the differences in time resulting from the rotation of the Earth around its axis, the globe is conventionally divided into 24. Without them, no one could answer the question: "What time is it in other parts of the world?". The boundaries of these belts approximately coincide with the lines of longitude. In each time zone, people set their clocks to their own local time, depending on the point on Earth. The gap between the belts is 15°. In 1884, Greenwich Mean Time was introduced, which is calculated from the meridian passing through the Greenwich Observatory and having a longitude of 0 °.

The 180° East and West longitude lines coincide. This common line is called the International Date Line. Time at points on the Earth located west of this line is 12 hours ahead of time at points east of this line (symmetrical with respect to the date line). The time in these neighboring zones coincides, but traveling east you find yourself in yesterday, traveling west you find yourself in tomorrow.

Earth parameters

• Equatorial radius - 6378 km
• Polar radius - 6357 km
• Compression of the earth ellipsoid - 1: 298
• Average radius - 6371 km
• Equator circumference - 40,076 km
• Meridian length - 40,008 km
• Surface - 510 million km2
• Volume - 1.083 trillion. km3
• Weight - 5.98 10 ^ 24 kg
• Free fall acceleration - 9.81 m/s^2 (Paris) Distance from the Earth to the Moon - 384,000 km Distance from the Earth to the Sun - 150 million km.

Solar system

Planet	The duration of one revolution around the sun	Period of revolution around its axis (days)	Average orbital speed (km/s)	Orbit deviation, deg (from the plane of the Earth's surface)	Gravity (Earth value = 1)
Mercury	88 days	58,65	48	7	0,38
Venus	224.7 days	243	34,9	3,4	0.9
Earth	365.25 days	0,9973	29,8	0	1
Mars	687 days	1,02-60	24	1,8	0.38
Jupiter	11.86 years old	0,410	12.9	1,3	2,53
Saturn	29.46 years old	0,427	9,7	2,5	1,07
Uranus	84.01 years	0,45	6,8	0,8	0,92
Neptune	164.8 years	0,67	5,3	1,8	1,19
Pluto	247.7 years	6,3867	4,7	17,2	0.05

Planet	Diameter, in km	Distance from the Sun, in million km	Number of moons	Equator diameter (km)	Mass (Earth = 1)	Density (water = 1)	Volume (Earth = 1)
Mercury	4878	58	0	4880	0,055	5,43	0,06
Venus	12103	108	0	12104	0,814	5,24	0,86
Earth	12756	150	1	12756	1	5,52	1
Mars	6794	228	2	6794	0,107	3,93	0,15
Jupiter	143800	778	16	142984	317,8	1,33	1323
Saturn	120 OOO	1429	17	120536	95,16	0,71	752
Uranus	52400	2875	15	51118	14,55	1,31	64
Neptune	49400	4504	8	49532	17,23	1,77	54
Pluto	1100	5913	1	2320	0,0026	1,1	0,01