Planet characteristics:

• Distance from the Sun: 149.6 million km
• Planet Diameter: 12,765 km
• Days on the planet: 23h 56min 4s*
• Year on the planet: 365 days 6h 9m 10s*
• t° on the surface: average for the planet +12°C (In Antarctica up to -85°C; in the Sahara desert up to +70°C)
• Atmosphere: 77% Nitrogen; 21% oxygen; 1% water vapor and other gases
• Satellites: Moon

* period of rotation around its own axis (in Earth days)
** orbital period around the Sun (in Earth days)

From the very beginning of the development of civilization, people were interested in the origin of the Sun, planets and stars. But most of all, the planet that is our common home, the Earth, arouses interest. Ideas about it changed along with the development of science, the very concept of stars and planets, as we understand it now, was formed only a few centuries ago, which is negligible compared to the very age of the Earth.

Presentation: planet earth

The third planet from the Sun, which has become our home, has a satellite - the Moon, and is included in the group of terrestrial planets such as Mercury, Venus and Mars. The giant planets differ significantly from them in physical properties and structure. But even such a tiny planet in comparison with them, like the Earth, has an incredible mass in terms of comprehension - 5.97x1024 kilograms. It revolves around the star in an orbit at an average distance from the Sun of 149 million kilometers, rotating around its axis, which causes the change of days and nights. And the ecliptic of the orbit itself characterizes the seasons.

Our planet plays a unique role in the solar system, because the Earth is the only planet that has life! The Earth is located in an extremely successful way. It travels in orbit at a distance of almost 150,000,000 kilometers from the Sun, which means only one thing - Earth is warm enough for water to remain in liquid form. Under the condition of hot temperatures, the water would simply evaporate, and in the cold it would turn into ice. Only on Earth is there an atmosphere in which humans and all living organisms can breathe.

History of the origin of the planet Earth

Starting from the Big Bang Theory and based on the study of radioactive elements and their isotopes, scientists have found out that the approximate age of the earth's crust is about four and a half billion years, and the age of the Sun is about five billion years. Just like the entire galaxy, the Sun was formed as a result of gravitational compression of a cloud of interstellar dust, and after the luminary, the planets included in the solar system were formed.

As for the formation of the Earth itself as a planet, its very birth and formation lasted hundreds of millions of years and took place in several phases. At the birth phase, obeying the laws of gravity, a large number of planetesimals and large cosmic bodies fell onto its ever-growing surface, which subsequently constituted almost the entire modern mass of the earth. Under the influence of such a bombardment, the planet's substance was heated and then melted. Under the influence of gravity, heavy elements such as ferrum and nickel formed the core, and lighter compounds formed the earth's mantle, the crust with continents and oceans lying on its surface, and an atmosphere that was originally very different from the present.

The internal structure of the earth

Of the planets of its group, the Earth has the largest mass and therefore has the largest internal energy - gravitational and radiogenic, under the influence of which processes in the earth's crust are still ongoing, as can be seen from volcanic and tectonic activity. Although igneous, metamorphic and sedimentary rocks have already formed, forming the outlines of landscapes, which are gradually modified under the influence of erosion.

Under the atmosphere of our planet is a solid surface called the earth's crust. It is divided into huge pieces (slabs) of solid rock, which can move and, when moving, touch and push each other. As a result of this movement, mountains and other features of the earth's surface appear.

The earth's crust is 10 to 50 kilometers thick. The crust "floats" on the liquid earth's mantle, the mass of which is 67% of the mass of the entire Earth and extends to a depth of 2890 kilometers!

The mantle is followed by the outer liquid core, which extends into the depths for another 2260 kilometers. This layer is also mobile and is capable of emitting electric currents, which create the planet's magnetic field!

At the very center of the Earth is the inner core. It is very hard and contains a lot of iron.

Atmosphere and surface of the Earth

Earth is the only one of all the planets in the solar system that has oceans - they cover more than seventy percent of its surface. Initially, water in the atmosphere in the form of steam played a big role in the formation of the planet - the greenhouse effect raised the temperature on the surface by those tens of degrees necessary for the existence of water in the liquid phase, and in combination with solar radiation gave rise to photosynthesis of living matter - organic matter.

From space, the atmosphere appears to be a blue border around the planet. This thinnest dome consists of 77% nitrogen, 20% oxygen. The rest is a mixture of various gases. The Earth's atmosphere contains much more oxygen than any other planet. Oxygen is vital for animals and plants.

This unique phenomenon can be regarded as a miracle or considered an incredible coincidence. It was the ocean that gave rise to the birth of life on the planet, and, as a result, the emergence of Homo sapiens. Surprisingly, the oceans still hold many secrets. Developing, humanity continues to explore space. The entry into near-Earth orbit made it possible to comprehend in a new way many geoclimatic processes occurring on Earth, further study of the secrets of which is yet to be done by more than one generation of people.

Earth Satellite - Moon

The planet Earth has its only satellite - the Moon. The first to describe the properties and characteristics of the Moon was the Italian astronomer Galileo Galilei, he described the mountains, craters and plains on the surface of the Moon, and in 1651 the astronomer Giovanni Riccioli mapped the visible side of the lunar surface. In the 20th century, on February 3, 1966, the Luna-9 descent module landed on the Moon for the first time, and a few years later, on July 21, 1969, a human foot set foot on the Moon for the first time.

The moon is always turned to the planet Earth with only one of its sides. On this visible side of the Moon, flat "seas", chains of mountains and multiple craters of various sizes are visible. The other side, invisible from the Earth, has on the surface a large cluster of mountains and even more craters, and the light reflecting from the Moon, thanks to which at night we can see it in a pale lunar color, is weakly reflected rays from the Sun.

The planet Earth and its satellite the Moon are very different in many properties, while the ratio of stable oxygen isotopes for the planet Earth and its satellite the Moon is the same. Conducted radiometric studies have shown that the age of both celestial bodies is the same, approximately 4.5 billion years. These data give rise to the assumption that the Moon and the Earth originated from the same substance, which gives rise to several interesting hypotheses about the origin of the Moon: from the origin from the same protoplanetary cloud, the capture of the Moon by the Earth, and to the formation of the Moon from the collision of the Earth with a large object.

The Earth is in the third order in terms of distance from the Sun. It belongs to the class of terrestrial planets and is the largest in this group. As far as we know now, the unique difference of the Earth is that it has life. It was found that age of the earth is about 4.54 billion years. It was formed from cosmic dust and gas - these were the substances left after the formation of the Sun.

In the initial period of existence, our planet was in a liquid state. But over time, the reactions slowed down, the temperature dropped, and the Earth's surface began to take on a solid shape. Gradually, an atmosphere began to form. Water appeared on the surface - it entered the atmosphere in the form of ice along with asteroids and other small celestial bodies. The impact of falling comets and asteroids affected the geographic relief of the Earth, temperature and other climatic conditions on its surface.

How did the appearance of the satellite of our planet? Scientists believe that the Moon was formed as a result of a global astronomical catastrophe, when the Earth tangentially collided with a huge celestial body, not inferior in size to itself. From the fragments of this asteroid, a ring was formed around the Earth, gradually transforming into the Moon. The moon has a noticeable effect on our planet, it is the cause of the ebb and flow of the world's oceans, and even leads to a slowdown in the movement of the Earth.

After the appearance of the oceans in the atmosphere of our planet, the accumulation of oxygen began. There is still no unambiguous theory of the origin of life on earth, but it is believed that as a result of various chaotic interactions of cells with each other, more and more complexly organized cells were formed, which gave rise to the simplest multicellular creatures. Gradually, life developed, and over time, the ozone layer allowed living organisms to reach land.

The surface of the Earth is not static. The continents are in motion, and what you can see on the map now is the result of constant change. It is believed that the first supercontinent, as a result of some internal or external influences, split into parts and formed a new supercontinent Pannotia about 550 million years ago, and later Pangea, which also began to separate about 200 million years ago.

Coastal areas often have a milder climate than inland areas. For example, sea and coastal breezes can affect the climate. The surface of the Earth is warming up many times faster than the waters of the sea. In the daytime, warm air rises from the bottom to the top, while the cold air that comes from the sea takes the place of the departed warmer one. With the onset of night, the reverse process begins to occur. Due to the fact that the water in the sea cools much more slowly than the land, the breezes from the land blow on the sea.

The temperature regime is also influenced by the numerous currents of the oceans. The Atlantic Ocean is crossed diagonally by the warm current of the Gulf Stream, starting its crossing in the Gulf of Mexico and ending it already at the northwestern European coast. The sea winds that blow over the Gulf Stream towards the coast create a rather mild climate for this part of Europe, milder than on the coasts of North America located at the same latitudes. The climate is also affected by cold ocean currents. For example, the Benguela Current off the African coasts of the southwestern regions and off the western South American coasts cools the tropics, otherwise it would be much hotter there.

In the central parts of the continents, far from the softening sea influences, one can observe a harsh continental climate, which has both hot summers and cold winters.

The word "continent" has Latin roots and if we translate the word "continere" literally, we get the phrase "stick together", this word is not always applied to land, but it implies unity in structure.

The largest continent of the Earth is Eurasia. Eurasia includes Europe and Asia, these are the two parts of the world in which most of the earth's population lives.

Africa is the second largest continent of the Earth, which stretches on both sides of the equator.

South America, along with North America, are located in the western part of the Earth, and like Africa on both sides of the equator. Since these two continents are connected by the narrow Isthmus of Panama, then, in fact, this mainland should be considered one big one.

Australia is the smallest continent on Earth. It is almost 100% located in the hot zone in the southern hemisphere.

The highest continent on Earth is Antarctica. This continent is also the most severe in all biological conditions of life.

As for countries, they are classified in a variety of ways. For example, they can be classified depending on the size of the territory (the area of ​​Russia is 17 million square kilometers). Countries are also classified according to the features of the natural world and location, such as tropical European or, for example, mountainous countries. A classification takes place, taking into account the diversity and national composition of the population (Slavic, mono, Romanesque, multinational countries), taking into account the form of government and the type of political regime. Also classified according to the degree of independence. The largest countries of the world are distinguished by various criteria, most often the countries occupying the largest area are called the largest.

The largest countries in the world by area are:

1. Russian Federation - 17,075,400 sq. km.

2. Canada - 9,984,670 sq. km.

3. China - 9,596,960 sq. km.

Rarely, you can hear that China is considered the largest country on Earth. This option is also correct, because here is the largest number of people. Finally, eight countries of the world are singled out the largest in terms of their economic achievements.

These countries form the "Big Eight": Russia, Japan, Italy, Canada, Germany, France, Great Britain and the leader of the entire chain is the United States, which usually stays out of competition, because it has the highest global GDP. India is a country with the most diverse ethnic group. On the territory of India, there are more than five thousand nationalities, peoples and tribes.

At the moment, the surface of the Earth, except for Antarctica and its islands, is shared by about two hundred states.

Antarctica is the largest geographical area that does not belong to any country on the planet Earth. The international treaty states that only scientific activities can be carried out in Antarctica and the unique nature of this continent must always be preserved.

On our website you can watch from the International Space Station, as well as view it completely free of charge.

In the twentieth century, through numerous studies, mankind revealed the secret of the earth's interior, the structure of the earth in the context became known to every schoolchild. For those who do not yet know what the earth consists of, what are its main layers, their composition, what is the name of the thinnest part of the planet, we will list a number of significant facts.

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The shape and size of the planet Earth

Contrary to popular misconception our planet is not round. Its shape is called the geoid and is a slightly flattened ball. The places where the globe is compressed are called poles. The axis of the earth's rotation passes through the poles, our planet makes one revolution around it in 24 hours - an earth day.

In the middle, the planet is surrounded by an imaginary circle dividing the geoid into the Northern and Southern hemispheres.

Apart from the equator there are meridians - circles perpendicular to the equator and passing through both poles. One of them, passing through the Greenwich Observatory, is called zero - it serves as a reference point for geographic longitude and time zones.

The main characteristics of the globe include:

• diameter (km.): equatorial - 12 756, polar (near the poles) - 12 713;
• length (km.) of the equator - 40,057, meridian - 40,008.

So, our planet is a kind of ellipse - a geoid, rotating around its axis passing through two poles - North and South.

The central part of the geoid is surrounded by the equator - a circle dividing our planet into two hemispheres. In order to determine what the radius of the earth is, use half the values ​​of its diameter at the poles and the equator.

And now about that what is the earth made of what shells it is covered with and what sectional structure of the earth.

Earth shells

Basic shells of the earth distinguished according to their content. Since our planet is spherical, its shells held together by gravity are called spheres. If you look at s trinity of the earth in a section, then three areas can be seen:

In order(starting from the surface of the planet) they are located as follows:

1. The lithosphere is a solid shell of the planet, including mineral layers of the earth.
2. Hydrosphere - contains water resources - rivers, lakes, seas and oceans.
3. Atmosphere - is a shell of air that surrounds the planet.

In addition, the biosphere is also distinguished, which includes all living organisms that inhabit other shells.

Important! Many scientists refer the population of the planet to a separate vast shell called the anthroposphere.

The earth's shells - the lithosphere, hydrosphere and atmosphere - are distinguished according to the principle of combining a homogeneous component. In the lithosphere - these are solid rocks, soil, the internal contents of the planet, in the hydrosphere - all of it, in the atmosphere - all the air and other gases.

Atmosphere

The atmosphere is a gaseous envelope its composition includes: , nitrogen, carbon dioxide, gas, dust.

1. Troposphere - the upper layer of the earth, containing most of the earth's air and extending from the surface to a height of 8-10 (at the poles) to 16-18 km (at the equator). Clouds and various air masses form in the troposphere.
2. The stratosphere is a layer in which the air content is much lower than in the troposphere. His average thickness is 39-40 km. This layer begins at the upper boundary of the troposphere and ends at an altitude of about 50 km.
3. The mesosphere is a layer of the atmosphere that extends from 50-60 to 80-90 km above the earth's surface. Characterized by a steady decrease in temperature.
4. Thermosphere - located 200-300 km from the surface of the planet, differs from the mesosphere by an increase in temperature as altitude increases.
5. Exosphere - starts from the upper boundary, lying below the thermosphere, and gradually passes into open space, it is characterized by low air content, high solar radiation.

Attention! In the stratosphere at an altitude of about 20-25 km there is a thin layer of ozone that protects all life on the planet from harmful ultraviolet rays. Without it, all living things would have perished very soon.

The atmosphere is the earth's shell, without which life on the planet would be impossible.

It contains the air necessary for the breathing of living organisms, determines suitable weather conditions, protects the planet from the negative impact of solar radiation.

The atmosphere consists of air, in turn, air is approximately 70% nitrogen, 21% oxygen, 0.4% carbon dioxide and other rare gases.

In addition, there is an important ozone layer in the atmosphere, at about 50 km altitude.

Hydrosphere

The hydrosphere is all the liquids on the planet.

This shell by location water resources and their degree of salinity includes:

• the world ocean is a huge space occupied by salt water and includes four and 63 seas;
• the surface waters of the continents are freshwater, as well as occasionally brackish water bodies. They are subdivided according to the degree of fluidity into reservoirs with a course - rivers on and reservoirs with stagnant water - lakes, ponds, swamps;
• groundwater - fresh water below the earth's surface. Depth their occurrence varies from 1-2 to 100-200 and more meters.

Important! A huge amount of fresh water is currently in the form of ice - today in the permafrost zones in the form of glaciers, huge icebergs, permanent non-melting snow, there are about 34 million km3 of fresh water reserves.

The hydrosphere is primarily, a source of fresh drinking water, one of the main climate-forming factors. Water resources are used as means of communication and objects of tourism and recreation (leisure).

Lithosphere

The lithosphere is solid ( mineral) layers of the earth. The thickness of this shell ranges from 100 (under the seas) to 200 km (under the continents). The lithosphere includes the earth's crust and the upper part of the mantle.

What is located below the lithosphere is directly the internal structure of our planet.

The slabs of the lithosphere mainly consist of basalt, sand and clay, stone, and also the soil layer.

The scheme of the structure of the earth together with the lithosphere is represented by the following layers:

• Earth's crust - upper, consisting of sedimentary, basalt, metamorphic rocks and fertile soil. Depending on the location, there are continental and oceanic crust;
• mantle - located under the earth's crust. It weighs about 67% of the total mass of the planet. The thickness of this layer is about 3000 km. The upper layer of the mantle is viscous, lies at a depth of 50-80 km (under the oceans) and 200-300 km (under the continents). The lower layers are harder and denser. The composition of the mantle includes heavy iron and nickel materials. The processes occurring in the mantle determine many phenomena on the planet's surface (seismic processes, volcanic eruptions, formation of deposits);
• The central part of the earth is the core, consisting of an inner solid and an outer liquid part. The thickness of the outer part is about 2200 km, the inner one is 1300 km. Distance from surface d about the core of the earth is about 3000-6000 km. The temperature in the center of the planet is about 5000 Cº. According to many scientists, the core land by composition is a heavy iron-nickel melt with an admixture of other elements similar in properties to iron.

Important! Among a narrow circle of scientists, in addition to the classical model with a semi-molten heavy core, there is also a theory that an inner luminary is located in the center of the planet, surrounded on all sides by an impressive layer of water. This theory, in addition to a small circle of adherents in the scientific community, has found wide circulation in science fiction literature. An example is the novel by V.A. Obruchev "Plutonia", which tells about the expedition of Russian scientists to the cavity inside the planet with its own small luminary and the world of animals and plants extinct on the surface.

Such a common earth structure map, including the earth's crust, mantle and core, every year more and more improved and refined.

Many parameters of the model with the improvement of research methods and the advent of new equipment will be updated more than once.

For example, in order to know exactly how many kilometers to outer part of the nucleus, it will take more years of scientific research.

At the moment, the deepest mine in the earth's crust, dug by man, is about 8 kilometers, so the study of the mantle, and even more so the core of the planet, is possible only in a theoretical context.

Layered structure of the Earth

We study what layers the Earth consists of inside

Conclusion

Having considered sectional structure of the earth we have seen how interesting and complex our planet is. The study of its structure in the future will help mankind to understand the mysteries of natural phenomena, will more accurately predict devastating natural disasters, and discover new, as yet undeveloped mineral deposits.

Planet Earth, the third planet in terms of distance from the Sun, it is the largest in terms of mass among other Earth-like planets in the solar system. The uniqueness of the Earth lies in the fact that it is the only planet known today on which life exists. Science says that the planet Earth was formed 4.5 billion years ago, and soon after its formation, with its gravitational field, it attracted the only satellite for today - the Moon.

It is believed that life on earth arose about 3.5 billion years ago, i.e. 1 billion years after the formation of the earth. The possibility of the formation of life on Earth is due to the fact that after its formation and up to the present day, the planet's biosphere has changed its various abiotic factors, as well as the atmosphere itself, this has led to the emergence and formation of the Earth's ozone ball, as well as the emergence and continuous growth of anaerobic organisms, which, in cooperation with harmful radiation was blocked by a magnetic field. All these factors, and especially the blocking of external cosmic radiation, made it possible for life to develop at a continuous pace, allowing it to evolve.

The crust of the globe is divided into several tectonic plates. Tectonic plates tend to change their location and constantly move (migrate), but their movement is measured in millions of years.

About 70% of the entire earth's surface is sea water, the rest of the space (about 30%) is continents and islands. Liquid water is essential for the existence of all life forms on Earth, but today water in this state can only be found on Earth and on no other planet. Water also exists on other planets of the solar system, but in a solid state, this, as well as a number of other factors, does not allow life to develop on these planets.

Planet Earth, like other cosmic bodies in the solar system and throughout the universe, interacts with other cosmic objects - the Sun and the Moon. The Earth revolves around the Sun, and it makes a complete revolution around the Sun in 365.26 Earth days. This period of time is called the sidereal year.

A sidereal year is equal to 365.26 solar days on earth.

The Earth is constantly rotating, and its axis of rotation is tilted by 24.3 degrees relative to its orbital plane.

The only and constant satellite of the Earth is the Moon. Scientists believe that the Moon was attached to the Earth and began its rotation around it about 4.53 billion years ago. The moon has its own specific functions and has a considerable influence on life on Earth.

In addition, early cosmic bombardment by comets played a certain role in the formation of the Earth, namely in the formation of the oceans on the planet. Such bombardments in the early stages of formation played a very significant role, and those asteroids that fell to Earth after the formation of the oceans had a strong impact on the formation of the environment on the planet.

Many scientists attribute the role of "destroyers of life", since, in their opinion, it is asteroids that are responsible for the extinction of several species of living beings before the appearance of mankind.

In shape, our planet is very similar to an ellipsoid, and not to a round one, as it was depicted a little earlier. To be precise, the planet Earth has a spherical shape, which is thickened at the equator. The diameter of the planet is almost 12,750 km.

The chemical composition that the planet possesses consists mainly of iron (32.1%), aluminum (1.5%), nickel (1.8%), calcium (1.5%), magnesium (13.9%), sulfur (2.9%), silicon (about 15%), as well as from oxygen (30.1%). All other elements on earth account for about 1-1.2%.

The internal structure of the Earth is usually distinguished into:

atmosphere;

Biosphere;

the hydrosphere;

Lithosphere;

Pyrosphere;

Centrosphere

Which are also divided into several components.

The atmosphere of the Earth is the outer gaseous shell of the planet, the lower boundary of which runs through the hydrosphere and lithosphere, and the upper line of the atmosphere is at an altitude of 1000 kilometers from the surface. In the atmosphere, it is also customary to distinguish between the troposphere, which is considered the moving layer, the stratosphere, which is located above the troposphere, and the last (upper) layer - the ionosphere.

The troposphere is about 10 km, and its mass is about 34 of the entire mass of the atmosphere (i.e. approximately 75%). A layer of the stratosphere extends to a height of about 80 km above the troposphere. Above all layers is the ionosphere. This layer got its name because it is constantly ionized by cosmic rays.

The hydrosphere occupies about 71% of the entire surface of the planet. The salinity of this layer is 35 hl, and the temperature ranges from 3 to 32°C.

The most unique layer on our planet, the biosphere, merges with the lithosphere, hydrosphere and atmosphere. The biosphere itself is subdivided into several spheres - the sphere of plants, which have a population of about 500,000 different species, as well as the animal sphere, which has a total number of species of over 1 million.

The lithosphere is the stone shell of the planet. Its thickness varies from 40 to 100 kilometers; it makes up the bottom of the oceans, continents and islands.

Immediately below the lithosphere is the pyrosphere and is considered to be the fiery shell of the globe. The temperature of the pyrosphere rises by about one degree every 33 meters of depth. There is a hypothesis that due to the pyrosphere, the rocks located in the depths of the Earth are in a molten state.

The Earth's centrosphere, according to many scientists, is located approximately at a depth of 1800 kilometers and consists mainly of nickel and iron. The temperature of the centrosphere reaches several thousand degrees, and the pressure is about 3 million atmospheres.

It is so nice to know that the planet Earth turned out to be the most suitable for various forms of life. There are ideal temperature conditions, enough air, oxygen and safe light. It's hard to believe that this never happened. Or almost nothing but a molten cosmic mass of indeterminate shape, floating in zero gravity. But first things first.

Explosion on a global scale

Early theories of the origin of the universe

Scientists have put forward various hypotheses to explain the birth of the Earth. In the 18th century, the French claimed that the cause was a cosmic catastrophe resulting from the collision of the Sun with a comet. The British claimed that an asteroid flying past the star cut off part of it, from which a number of celestial bodies subsequently appeared.

German minds have moved on. The prototype of the formation of the planets of the solar system, they considered a cold dust cloud of incredible size. Later it was decided that the dust was red-hot. One thing is clear: the formation of the Earth is inextricably linked with the formation of all the planets and stars that make up the solar system.

Related materials:

How fast does the earth move around its axis and the sun?

Today, astronomers and physicists are unanimous in their opinion that the universe was formed after Big Bang. Billions of years ago, a giant fireball exploded into pieces in outer space. This caused a gigantic ejection of matter, the particles of which possessed colossal energy. It was the power of the latter that prevented the elements from creating atoms, forcing them to repel each other. This was facilitated by the high temperature (about a billion degrees). But after a million years, space has cooled down to about 4000º. From that moment, the attraction and formation of atoms of light gaseous substances (hydrogen and helium) began.

Over time, they clustered into clusters called nebulae. These were the prototypes of future celestial bodies. Gradually, the particles inside rotated faster and faster, building up temperature and energy, causing the nebula to contract. Having reached the critical point, at a certain moment a thermonuclear reaction was launched, contributing to the formation of the nucleus. Thus the bright sun was born.

The emergence of the Earth - from gas to solid

The young luminary possessed powerful gravitational forces. Their influence caused the formation of other planets at different distances from accumulations of cosmic dust and gases, including the Earth. If we compare the composition of different celestial bodies in the solar system, it will become noticeable that they are not the same.

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Earth collisions with meteorites

Mercury is primarily made up of a metal that is most resistant to solar radiation. Venus, Earth have a rocky surface. And Saturn and Jupiter remain gas giants because of the greatest remoteness. By the way, they protect other planets from meteorites, pushing them away from their orbits.

Formation of the Earth

The formation of the Earth began according to the same principle that underlay the appearance of the Sun itself. This happened about 4.6 billion years ago. Heavy metals (iron, nickel) as a result of gravity and compression penetrated into the center of the young planet, forming the core. The high temperature created all the conditions for a series of nuclear reactions. There was a separation of the mantle and the core.

The release of heat melted and ejected light silicon to the surface. He became the prototype of the first bark. As the planet cooled, volatile gases broke out from the depths. This was accompanied by volcanic eruptions. Molten lava later formed rocks.

Gas mixtures were kept at a distance around the Earth by gravity. They made up the atmosphere, at first without oxygen. Encounters with icy comets and meteorites led to the emergence of oceans from vapor condensate and melted ice. The continents were separated, reunited, floating in a hot mantle. This has been repeated many times for almost 4 billion years.