Earth: interesting facts about our planet

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Our Earth is also known as the "Blue Planet" because it looks like a blue ball from space. This blue color comes from the oceans, which cover more than 70 percent of the planet. Earth is the only planet in our solar system that supports natural life and has water. Our planet also comes into contact with other celestial bodies, especially the Moon and the Sun. We have collected the most interesting facts about the Earth.

Third planet from the Sun

The Earth is in third position from the Sun after Venus and Mercury. It is the fifth largest planet. Earth is one of the 4 terrestrial planets in our solar system. Earth's planets are made of rocks.

Earth is the largest of all the terrestrial planets:

• it has maximum density;
• it has maximum weight;
• it has a strong magnetic field;
• The Earth's rotation speed is greater than that of any other rocky planet.

The structure of our planet

According to its physical properties, the Earth is divided into three layers:

• the outer layer is called the cortex;
• the viscous substance under the crust is called the mantle;
• The interior of the Earth is solid and is known as the core.

The two most common elements present in the Earth are iron and oxygen.

The earth consists of three types of rocks:

• igneous rocks;
• sedimentary rocks;
• metamorphic rocks.

The Earth's land area is about 30% and it is divided into 7 continents. These are Asia, Africa, North America, Antarctica, Europe, South America and Australia.

The imaginary line that divides the Earth into the North and South Poles is called the equator.

The earth is divided into two hemispheres - northern and southern.

The Northern Hemisphere extends from the equator to the North Pole, and the Southern Hemisphere extends from the equator to the South Pole.

The Mariana Trench is the deepest place on Earth. It is located at the bottom of the Pacific Ocean.

70% of the planet consists of water. 97.5% is salt water, which is not suitable for drinking, and only 2.5% of the water is potable.

Earth's atmosphere

The atmosphere is the air that covers the surface of the Earth like a jacket. It is made up of a number of gases that allow us and other species to live on this planet. The total height of the Earth's atmosphere is about 60,000 km. At sea level, the layers of the atmosphere are denser, and its thickness decreases with increasing altitude.

The atmosphere contains three gases that are vital to our survival:

• carbon dioxide;
• ozone;
• hydrogen.

Nitrogen and oxygen are the most common gases in the atmosphere. There is 21% oxygen, and 78% nitrogen.

The atmosphere of our planet is divided into 4 layers:

• troposphere;
• stratosphere;
• mesosphere;
• thermosphere.

What structural features of our planet distinguish it from other planets in the solar system?

Our Earth is beautiful. Astronauts say that from space it looks like a precious stone. But the main feature of the Earth, its uniqueness, is that only it, of all the planets in the solar system, has life. Why is life possible on Earth?

You already know that our planet is the third closest to the Sun. Its orbit is on average 150 million km away from the Sun. The Earth accounts for a very small portion of sunlight and heat. But this amount is enough to support life. It is this, no more and no less, distance from the Sun to the Earth that allows our planet not to overheat and not freeze. Remember how hot it is on Mercury and Venus and how cold it is on Mars and more distant planets, and you will be convinced that the temperature on Earth is the most favorable for life.

At the same time, the rotation of the Earth around its axis ensures a change of light and darkness every 24 hours. This allows the earth's surface to warm up fairly evenly. If the Earth rotated more slowly, then it would probably be incredibly hot in one part of it, and terrible cold in another.

Only the Earth has huge reserves of water. But this is an amazing substance. It is part of all living organisms, performing a wide variety of work. For example, being part of the blood of humans and animals, plant sap, water ensures the movement of various substances throughout the body. The water necessary for life moves as a result of a constant cycle. Every second, millions of cubic meters of water turn into steam. Rising into the air, they form, which, together with air currents, move hundreds of kilometers, carrying with them life-giving moisture.

Our planet has an atmosphere that is different from other planets. The Earth's air envelope is very important for preserving and maintaining life. It contains oxygen, which living beings breathe, and carbon dioxide, which is necessary to nourish plants. In addition, the atmosphere contains ozone, a type of oxygen. It forms a special ozone layer that blocks radiation from space that is dangerous to organisms. In addition, the atmosphere, like a blanket, protects the Earth from severe cooling at night. It also protects the Earth from meteorites. Most of them, getting into it, burn out.

Only the Earth has soil - the top fertile layer of the earth. Soil contains substances necessary for the growth and development of plants. Green plants absorb minerals and water from the soil, carbon dioxide from the air and, with the participation of sunlight, form substances necessary for life.

All these features of our planet make it possible for a wide variety of organisms, including humans, to exist on it.

1. What features of its location and in outer space make it possible for a variety of living organisms to exist on it?
2. What significance does the atmosphere of our planet have for living things?
3. What is the ozone layer? What is its role on the planet?
4. What role does water play for living things on the planet?
5. What is the importance of soil for life on Earth?

Earth is a unique planet. Currently, of all the planets in the solar system, only life has been discovered on it. The existence of living things is facilitated by a number of features of the Earth: a certain distance from the Sun, the speed of rotation around its own axis (one revolution in 24 hours), the presence of an air shell (atmosphere) and large reserves of water, the existence of soil. Water is part of all living organisms. The air envelope of the Earth provides the breathing of living beings and nutrition of plants, protects the Earth from cooling and from meteorites. The ozone layer of the atmosphere blocks radiation from space that is dangerous to organisms. Soil contains substances necessary for the growth and development of plants.

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Brief description of planet Earth. Geographical coordinates. The uniqueness of the Earth in the family of planets of the solar system is primarily due to the fact that life exists only on our planet. The chances of finding even the simplest forms of life on neighboring planets (even on Mars) are assessed by most scientists as close to zero. Other unique features of the Earth (the presence of an atmosphere with a high oxygen content, the presence of an ocean occupying 70% of the planet’s surface, high tectonic activity, a strong magnetic field, etc.) are in one way or another connected with the presence of life: they either contributed to its emergence or are consequences of life activity .

The sphericity of the Earth (and the ancient Greeks knew that the Earth is a sphere) predetermines the allocation of concentric shells in its structure. For the first time, such an approach to the study of our planet was proposed by the Austrian geologist E. Suess, who also suggested calling these shells geospheres. The real shape of the Earth is somewhat different from the spherical one, and in strict mathematical modeling of its shape, concepts such as ellipsoid And geoid. Geoid (which means earth-like) is the most accurate model of the Earth, it is a unique geometric body, the surface of which coincides with the surface of the average level of calm water in the ocean, mentally extended under the continents so that a plumb line at any point intersects this surface at a right angle. The surfaces of the ellipsoid and geoid do not coincide; the discrepancy between them can reach ±160 m. The heights and depths of points on the real surface of the Earth are measured relative to the geoid surface. Everest has the maximum height (8848 m), and the Mariana Trench in the Pacific Ocean has the greatest depth (11022 m). The equatorial radius of the Earth is 6375.75 km, but the polar radii are not the same: the northern one is 30 meters larger than the southern one and is equal to 6355.39 km (respectively, the southern one is 6355.36 km).

The Earth's rotation axis, passing through the poles and the center of the planet, is inclined to the plane of its orbit at an angle of 66°33"22". It is this value that determines the length of day and night at different latitudes and significantly affects the thermal (climatic) characteristics of various zones of the globe. The Earth makes one revolution around its axis in 23 hours 56 minutes 4 seconds; this period of time is called a sidereal day, and a day with exactly 24 hours is called an average or solar day.

The only satellite of the Earth, the Moon, has dimensions close to the size of Mercury, its diameter is 3476 km, and the average radius of its orbit is 384.4 thousand km. The Moon's orbit is inclined to the Earth's orbit by 5 degrees. The period of rotation of the Moon around its axis absolutely coincides with the period of its revolution around the Earth, therefore only one lunar hemisphere can be seen from the Earth.

Lines of section of the globe by planes parallel to the equatorial plane are called parallels, and lines of section by planes passing through the axis of rotation of the Earth are called meridians. Each parallel has its own latitude (north or south), and each meridian has its own longitude (west or east). The set of parallels and meridians is called a geographic grid; with its help, the geographic coordinates of any point on the surface of the Earth are determined.

The geographic latitude of an arbitrary point is the angle between the equatorial plane and the normal (plumb line) passing through this point; latitude varies from zero (at the equator) to 90 degrees. Longitude is the angle between the meridional plane of a given point and the plane of a certain meridian, conventionally accepted as the prime meridian (such a prime meridian passes through the Greenwich Astronomical Observatory * and is called Greenwich). Longitude varies from zero to 180°; the meridian, which corresponds to latitude 180°, is the date line.

For the convenience of counting time and temporal coordination of human activities, the surface of the Earth is divided (to a first approximation along the meridians) into 24 time zones. The Canadian engineer Fleming suggested using the time zone system to keep track of time in 1879; today the whole world uses this system. A change in time by 1 hour should correspond to a change in longitude by 15°, however, the boundaries of time zones strictly coincide with the meridians only in the oceans; on land, adjacent time zones are separated, as a rule, not by meridians, but by some close to them (and sometimes not very close) administrative boundaries.

The inclination of the earth's axis to the ecliptic plane, as already noted, determines the latitudinal boundaries of climatic zones (belts). The central belt of the earth's surface, the boundaries of which are the northern and southern tropics, is called tropical, the latitude of each tropic is 23 ° 26 "38". In the tropical belt, the Sun passes through the zenith twice a year at noon, and at the latitude of the tropics it is at the zenith only once: at noon on June 21 in the northern tropics and on December 22 in the southern tropics.

Geographic parallels, which correspond to a latitude of 66° 33" 22"" are called polar circles, the area between the pole and the Arctic Circle is called the polar belt. Only beyond the Arctic Circle (i.e. in a higher latitude region) such phenomena as polar day and polar night occur Between the Arctic Circle and the tropics in each hemisphere there is a temperate zone (moderate climate region).

Structure of the Earth. External and internal geospheres. The external geospheres usually include the atmosphere, hydrosphere and biosphere, although the latter of them should be considered as an intermediate shell, since it includes the hydrosphere and those areas of the atmosphere and the earth’s crust (and this is the inner shell) within which organic life exists . Sometimes the magnetosphere is considered as the external geosphere, which is also not entirely justified, since the magnetic field is present in any of the geospheres.

Atmosphere. The Earth's atmosphere is a mixture of gases; its lower layers also contain moisture and dust particles. Dry purified air near the Earth's surface contains approximately 78% nitrogen, slightly less than 21% oxygen and about 1% argon. The share of carbon dioxide is approximately 0.03%, and the share of all other gases (hydrogen, ozone, inert gases, etc.) is about 0.01%. The composition of the atmosphere remains virtually unchanged up to altitudes of about 100 km. At sea level at normal pressure (1 atm = 1.033 kg/cm 2 = 1.013 10 5 Pa), the density of dry air is 1.293 kg/m 3, but with distance from the Earth’s surface, the density of the air mass and the associated pressure quickly decrease. The atmosphere is continuously moistened due to the evaporation of water from the surface of reservoirs. The concentration of water vapor decreases with increasing altitude faster than the concentration of gases - 90% of the moisture is concentrated in the lower five-kilometer layer.

With a change in altitude, not only the density, pressure and temperature of the air change, but also other physical parameters of the atmosphere, and at high altitudes its composition also changes. Therefore, in the atmosphere it is customary to distinguish several spherical shells with different physical properties. The main ones are troposphere, stratosphere And ionosphere. The altitudinal extent (thickness) of one or another spherical shell of the Earth (this also applies to the inner shells) is often called its thickness.

The troposphere contains about 80% of the total air mass, its thickness is 8...12 km in mid-latitudes, and up to 17 km above the equator. With increasing altitude, the air temperature within the troposphere continuously decreases down to values ​​of the order of -85 ° C (the rate of temperature decrease is approximately 6 degrees per kilometer). Due to the uneven heating of the surface of the globe, tropospheric air masses are in continuous motion, carrying not only heat, but also moisture, dust and all kinds of emissions. It is these phenomena in the troposphere that primarily shape the weather and climate on Earth.

The stratosphere extends above the troposphere to altitudes of about 50...55 km. Within this layer, the temperature increases with increasing altitude; at the upper boundary of the stratosphere, the temperature is close to zero. There is virtually no water vapor in the stratosphere. At altitudes from 20 to 40 km there is the so-called. ozonosphere, i.e. layer with a high ozone content. This layer is often called the shield of the planet, since it almost completely absorbs the hard (short-wave) ultraviolet radiation of the Sun, which is harmful to all life on Earth.

In the interval between altitudes of 55 and 80 km there is a layer in which the temperature again decreases with height. At the upper boundary of this layer, which is called mesosphere, the temperature is approximately -80°C. Behind the mesosphere, up to altitudes of about 800...1300 km, is the ionosphere (sometimes this layer is also called the thermosphere, since the temperature in this layer continuously increases with increasing altitude).

Hydrosphere. The hydrosphere consists of four types of water: the oceanosphere, i.e. salty waters of the seas and oceans (86.5% of the mass), fresh land waters (rivers and lakes), groundwater and glaciers. 97% of the waters of the oceanosphere are concentrated in the World Ocean, which is not only the main reservoir of water, but also the main heat accumulator on our planet. Thanks to the ocean, life originated on Earth, an oxygen atmosphere was formed and is preserved, the ocean maintains a low level of carbon dioxide in the atmosphere, protecting the planet from the greenhouse effect (the ocean, to a much higher degree than terrestrial vegetation, serves as the “lungs” of our planet).

In general, the world ocean, the average depth of which is about 3.6 km, is cold, only 8% of the water is warmer than 10 o C. The pressure in the water column increases with increasing depth at a rate of 0.1 at/m. The salinity of ocean waters, the average value of which is about 35 ppm (35 ‰), varies (from 6...8 ‰ in the surface waters of the Baltic to 40 ‰ on the surface of the Red Sea). At the same time, the composition and relative content of various salts are unchanged everywhere, which indicates the stability of the dynamic equilibrium between the dissolution of substances entering the ocean from land and their precipitation.

The specific heat capacity of water is approximately 4 times greater than that of air, however, due to the huge difference in density (almost 800 times), 1 cubic meter of water, cooling by 1 degree, is capable of heating more than 3000 cubic meters of air by 1 degree. In temperate and high latitudes, the waters of the World Ocean accumulate heat in the summer and release it into the atmosphere in the winter, which is why the climate in coastal areas is always milder than in the interior of the continents. In equatorial latitudes, water heats up all year round, and this heat is transferred by ocean currents to high-latitude regions, while cold waters, captured by deep countercurrents, return to the tropics. In addition to currents and countercurrents, ocean waters move and mix due to ebbs and flows, as well as waves of other nature, including wind waves, pressure waves and tsunamis.

Biosphere. The presence of a hydrosphere and an atmosphere with a high oxygen content significantly distinguishes our planet from all others in the solar system. But the main difference between the Earth is the presence of living matter on it - vegetation and animal life. The term biosphere was introduced into scientific circulation by the already mentioned E. Suess.

The biosphere covers the entire space where living matter exists - the lower part of the atmosphere, the entire hydrosphere and the upper horizons of the earth's crust. The mass of living matter, approximately 2.4·10 15 kg, is negligible in comparison even with the mass of the atmosphere (5.15·10 18 kg), however, in terms of the degree of impact on the system called Earth, this shell significantly surpasses all others.

The basis of living matter is carbon, which produces an infinite variety of chemical compounds. In addition to it, the composition of living matter includes oxygen, hydrogen and nitrogen; other chemical elements are found in small quantities, although their role in the life support of certain organisms can be extremely important. The bulk of living matter is concentrated in green plants. The process of naturally building organic matter using solar energy - photosynthesis– involves huge masses of carbon dioxide (3.6 10 14 kg) and water (1.5 10 14 kg) into the annual circulation, while 2.66 10 14 kg of free oxygen is released. From a chemical point of view, photosynthesis is a redox reaction:

CO 2 + H 2 O → CH 2 O + O 2.

Based on the method of nutrition and relationship to the external environment, living organisms are divided into autotrophic and heterotrophic. The latter feed on other organisms and their remains, while the food for autotrophic organisms is mineral (inorganic) substances. Most organisms are aerobic, that is, they are able to exist only in an environment containing air (oxygen). A smaller part (mostly microorganisms) are anaerobic, living in an oxygen-free environment.

When living organisms die, a process opposite to photosynthesis occurs; organic substances decompose through oxidation. The processes of formation and decomposition of organic matter are in dynamic equilibrium, due to which the total amount of biomass has remained virtually unchanged since the origin of life on Earth.

The influence of the biosphere on the processes of geological evolution of the Earth was analyzed in detail by the outstanding Russian scientist Academician V.I. Vernadsky. For more than three billion years, living matter absorbed and transformed the energy of the Sun. A significant part of this energy is conserved in mineral deposits of organic origin, the other part is used in the processes of formation of various rocks, the accumulation of salts in the world's oceans, the accumulation of oxygen contained in the atmosphere, as well as dissolved in ocean water and included in rocks. Vernadsky was the first to point out the leading role of the biosphere in the formation of the chemical composition of the atmosphere, hydrosphere and lithosphere, due to the unusually high geochemical activity of living matter.

Life on Earth exists in a huge variety of forms, but all these forms do not exist autonomously, but are connected by complex relationships into a single continuously developing giant complex.

Internal geospheres are shells in the solid body of the Earth. Three large areas (main internal shells) can be distinguished in it: central - core, intermediate – mantle and external - earth's crust. So far, it has been possible to delve into the depths of the Earth for the purpose of direct study only to a depth of just over 12 km; such an ultra-deep well was drilled in our country (on the Kola Peninsula). But 12 km is less than 0.2% of the earth's radius. Therefore, with the help of deep and ultra-deep drilling, it is possible to obtain data on the structure, composition and parameters of the earth’s interior only within the upper crustal horizons.

Geophysicists obtain information about deep areas, including surfaces separating various internal shells, by analyzing and summarizing the results of numerous seismic (from the Greek “ seismic" - vibration, earthquake) research. The essence of these studies (in a simplified form) is that by measuring the time of passage of a seismic wave between two points on the surface (or inside) of the globe, its speed can be determined, and by the magnitude of the wave speed, the parameters of the medium in which it propagated .

The earth's crust is the upper rock shell, the thickness of which in various areas ranges from 6 - 7 km (under deep ocean basins) to 70 - 80 km under the Himalayas and Andes. We can say that the lower surface of the earth's crust is a kind of “mirror reflection” of the outer surface of the solid body of the Earth. This surface - the interface between the crust and the mantle - is called the Mohorovic interface.

The chemical composition of the earth's crust is dominated by silicon and aluminum, hence the conventional name for this shell - "sial". The structure of the earth's crust is characterized by great complexity, the manifestation of which is clearly expressed vertical and horizontal heterogeneities. In the vertical direction within the earth's crust, three layers are traditionally distinguished - sedimentary, granite and basalt. The rocks that form these layers are different in composition and origin.

The mantle is located between the core and the earth's crust, the surface separating the mantle and the core is called the Wichert-Gutenberg section. This is the intermediate and largest shell of the Earth; it extends to depths of about 2900 km. The mass of the mantle makes up about 2/3 of the total mass of the planet. At the boundary of the earth's crust and mantle, the temperature can exceed 1000 o C and the pressure 2000 MPa. Under these conditions, the substance of the mantle can transition from a crystalline state to an amorphous (vitreous) state. It is much more difficult to judge the chemical composition of the mantle substance; nevertheless, this shell is called " sima"This means that the predominant elements in the mantle (at least in the upper mantle) are silicon and magnesium.

The core is the central and densest shell of the Earth, its radius is 3470 km. At the Wichert-Gutenberg boundary, the transverse waves disappear, which allows us to conclude that the outer part of the core is in a liquid state. Within the inner part of the core (its radius is approximately 1250 km), the speed of longitudinal waves increases again, and the substance is believed to turn into a solid state again. The chemical composition of the outer and inner cores is approximately the same, iron and nickel predominate, hence the conventional name of this shell - “nife”.

Physical fields of the Earth. A description of the structure of our planet will be incomplete if we do not consider its physical fields, primarily gravitational and magnetic fields. The concept of “field” is used in cases where each point in a certain region of space can be associated with the value of a certain physical quantity. In this sense, we can talk about a temperature field (thermal field), a velocity field, a force field, etc. In accordance with the nature of the physical quantity, fields are divided into vector and scalar.

Earth's gravitational field. The law of universal gravitation established by I. Newton is expressed by the formula

F t = GMm/r 2,

where F t is the force of gravity, M and m are the masses of interacting bodies, r is the distance between the centers of gravity of these bodies, G = 6.673·10 -11 m 3 s -2 kg -1 is the gravitational constant.

Describing the gravitational interaction of any small body with mass m with a large celestial body (for example, the Earth), it is convenient to write the law of gravity in the form:

where l = GM is the gravitational constant of the celestial body in question. In the case of the Earth, this constant has a value of about 4·10 14 m 3 s -2.

If a small body (gravitating point) is in close proximity above the surface of a celestial body, the force of attraction is determined as

where g = l/r 2 is the acceleration of a freely falling body. In the case of the Earth, as is known, g = 9.8 m/s 2.

Note that if it is necessary to determine the gravitational force with great accuracy, it is necessary to take into account the dependence of the value of g on the coordinates of the point at which this force is determined. Assuming a uniform distribution of mass throughout the volume of the Earth, the force of gravity at any given point can be calculated. Deviations in practice of actual (measured) values ​​of acceleration g from calculated ones (so-called gravitational anomalies) are primarily due to the uneven distribution of masses. A thorough study of the Earth's gravitational field makes it possible not only to identify major tectonic disturbances, but also to search for mineral deposits.

Earth's magnetic field. The fact that the Earth has magnetic properties has been known since ancient times. Suffice it to say that the history of direct magnetic measurements on the globe goes back more than 400 years (the results of experimental studies of the “large magnet - the Earth” were published by the English naturalist W. Gilbert in 1600). Our planet is indeed a large magnet; the shape of the Earth's current magnetic field is close to that which would be created by a magnetic dipole placed in the core.

Any earthly rock at the moment of its formation under the influence of a geomagnetic field acquires magnetization, which remains until this rock is heated to temperatures exceeding the Curie temperature. By studying the natural remanent magnetization of rocks whose age is known, one can learn about the spatial distribution and temporal changes of the geomagnetic field in the past. We can say that information about the evolution of the geomagnetic field is literally “recorded” in the bowels of the earth. The role of a magnetic carrier is best performed by igneous rocks that erupted from volcanoes at high temperatures (above the Curie temperature for the ferromagnetic materials contained in these rocks). One of the most important results of such paleomagnetic research is the discovery of the so-called. inversions geomagnetic field (sometimes the term " reversion"), i.e. changing the direction of the Earth's magnetic moment to the opposite.

The magnetic poles of our planet do not coincide with the geographical ones and can change their position over time. Over the past 100 years, as observations show, the north magnetic pole has been moving eastward (from northern Canada through the Arctic Ocean to Siberia), its movement has already amounted to about 1000 km. It is not yet entirely clear whether this is the beginning of another inversion, or part of a normal oscillation, after which the pole will return to its usual place.

Thermal field of the Earth. Planet Earth is in thermodynamic equilibrium with its environment; it simultaneously absorbs and emits approximately equal amounts of heat. The main source of external energy for the Earth is the Sun. The average solar energy flux density above the Earth's atmosphere is approximately 0.14 W/cm2. Almost half of the incident energy (about 45%) is reflected into space, the rest of the energy is accumulated by the atmosphere, water, soil and green plants. Converted into heat, the energy of solar radiation sets in motion masses of atmospheric air and huge masses of water in the world's oceans.

Internal sources also make a certain contribution to the creation of the Earth's thermal field. There are quite a lot of these sources, but only three should be considered the main ones: the decay of radioactive elements, density (gravitational) differentiation of matter and tidal friction.

The Earth's scalar thermal field has a rather complex structure. In the upper layer of the earth's crust (up to 30 - 40 m) the effect of heating the surface by the sun's rays is felt, which is why this layer is called solar thermal zone. The temperature in this zone changes periodically throughout the day and throughout the year. The longer the period of surface temperature fluctuations, the deeper these fluctuations penetrate into the earth's interior, but in any case, the amplitude of temperature fluctuations decreases exponentially with increasing depth.

The temperature regime of the lower zone of the earth's crust, called geothermal zone, is determined by internal heat. In this zone, with increasing depth, the temperature increases, the rate of its change is different in different parts of the surface of the globe, which is associated both with the different thermal conductivity of rocks and with the unevenness of the heat flow going from the earth's interior.

Between the heliothermal and geothermal zones there is a belt of constant temperatures, within which the average annual temperature corresponding to a particular region is approximately constant. The depth of this belt depends on the thermophysical properties of the rocks and on the latitude of the area (increases with increasing latitude). If the average annual temperature of a certain area is negative, then atmospheric precipitation seeping into the depths turns into ice, under these conditions the so-called ice is formed. permafrost. In permafrost zones, the total area of ​​which is about a quarter of the entire solid surface of our planet, the top layer of soil thaws in the summer to a depth of from a few centimeters to 3 - 4 meters.

The development of the domestic and global economy is still based on the growth of energy consumption. In the twentieth century, the world's population increased by 2.2 times, and energy consumption by 8.5 times. In the context of the impending energy crisis, solar energy, as well as thermal energy from the earth’s interior, can and should compete with traditional energy sources (oil, gas, coal, nuclear fuel).

Our planet Earth is inimitable and unique, despite the fact that planets have been discovered around a number of other stars. Like other planets in the solar system, Earth formed from interstellar dust and gases. Its geological age is 4.5-5 billion years. Since the beginning of the geological stage, the Earth's surface has been divided into continental protrusions And oceanic trenches. A special granite-metamorphic layer was formed in the earth's crust. When gases were released from the mantle, the primary atmosphere and hydrosphere were formed.

Natural conditions on Earth turned out to be so favorable that a billion years later since the formation of the planet on it life appeared. The emergence of life is determined not only by the characteristics of the Earth as a planet, but also by its optimal distance from the Sun ( about 150 million km). For planets closer to the Sun, the flow of solar heat and light is too great and heats their surfaces above the boiling point of water. Planets that are more distant than Earth receive too little solar heat and are too cool. For planets whose mass is significantly less than that of Earth, the gravitational force is so small that it does not provide the ability to maintain a sufficiently powerful and dense atmosphere.

During the existence of the planet, its nature has changed significantly. Tectonic activity periodically intensified, the sizes and outlines of land and oceans changed, cosmic bodies fell onto the surface of the planet, and ice sheets repeatedly appeared and disappeared. However, these changes, although they influenced the development of organic life, did not significantly disturb it.

The uniqueness of the Earth is associated with the presence of a geographical shell that arose as a result of the interaction of the lithosphere, hydrosphere, atmosphere and living organisms.

No other celestial body similar to Earth has yet been discovered in the observable part of outer space.

The Earth, like other planets in the solar system, has spherical shape. The ancient Greeks were the first to talk about sphericity ( Pythagoras ). Aristotle , observing lunar eclipses, noted that the shadow cast by the Earth on the Moon always has a round shape, which prompted the scientist to think about the sphericity of the Earth. Over time, this idea was substantiated not only by observations, but also by accurate calculations.

At the end 17th century Newton suggested the polar compression of the Earth due to its axial rotation. Measurements of the lengths of meridian segments near the poles and the equator, carried out in the middle 18th century proved the “oblateness” of the planet at the poles. It was determined that The equatorial radius of the Earth is 21 km longer than its polar radius. Thus, of the geometric bodies, the figure of the Earth most closely resembles ellipsoid of revolution , not a ball.

Circumnavigation around the world, an increase in the distance of the visible horizon with altitude, etc. are often cited as evidence of the sphericity of the Earth. Strictly speaking, this is only evidence of the convexity of the Earth, and not its sphericity.

Scientific evidence of sphericity is photographs of the Earth from space, geodetic measurements on the Earth's surface and lunar eclipses.

As a result of changes carried out in various ways, the main parameters of the Earth were determined:

average radius – 6371 km;

equatorial radius – 6378 km;

polar radius – 6357 km;

circumference of the equator – 40,076 km;

surface area – 510 million km 2;

weight - 5976 ∙ 10 21 kg.

Earth- the third planet from the Sun (after Mercury and Venus) and the fifth largest among the other planets of the Solar System (Mercury is about 3 times smaller than the Earth, and Jupiter is 11 times larger). The Earth's orbit has the shape of an ellipse. The maximum distance between the Earth and the Sun is 152 million km, minimum – 147 million km.

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The Earth is a unique planet, and why exactly is what will be discussed in the article.

The Earth is a beautiful planet, blue from the water that covers it and green from its varied vegetation. It was here that the conditions for the origin of life appeared, and it began to sparkle with all its diversity and splendor.

Earth is a unique planet of the solar system, universe

Since his appearance on Earth, Homo sapiens has wondered whether we are alone in the Universe? Is there life on other stars and planets? At the moment, there is no reliable data on whether another such Earth exists somewhere in space.

Only on it, with its rivers and meadows, gorges and mountain ranges, ocean basins and high mountain plains, tropical forests and vast deserts, many different life forms exist and are constantly developing, which adapt to the environment and, if necessary, even mutate.

The uniqueness of planet Earth

The Earth itself and its inhabitants affirm the primacy of life and its superiority over non-existence:

• annual plant growth cycles
• microscopic representatives of flora and fauna at the greatest depths of the seas and oceans
• under multi-ton ice at the planet's poles
• in the high layers of the atmosphere - where else can you find such splendor and diversity of life forms and species?!

All this was made possible thanks to the balanced orbit in which the Earth revolves around the Sun - the heart of our solar system. The approximate distance to it from our home planet (which weighs 6.6 sextillion tons) is about 150 million km. Having a diameter of approximately 13 thousand km, Mother Earth annually cruises around the star, which extends over 584 million km and lasts 365 days + 6 hours + 49 minutes + 9.54 seconds.

If something in this scheme is violated (the speed of rotation around the Sun increases or decreases, the trajectory of movement changes, the magnetic poles shift), then life - this priceless gift of nature - on the planet may die (after all, the luminary can either burn all living things if we let us get too close to it, or, conversely, freeze it due to lack of heat when moving too far from it).

This suggests that the work of the solar system and the place of the Earth in its structure are truly unique and work with the precision of a Swiss watch mechanism. If we consider the most significant aspects of all amazing earthly processes briefly, we get the following picture:

• Earth is the only inhabited planet in the solar system (in any case, to this day scientific data contradicting this has not been found).
• There is a wide variety of flora and fauna on the planet in a full size grid (from microscopic representatives to giant ones).
• The temperature regime maintained on Earth is optimal for the full development of all life forms present on it, in contrast to neighboring planets.
• Earthlings have more than 70% of water on the surface of the planet, and it is this that is the real basis of life;
• The Earth has a biosphere that gives minerals and food elements to all living things, and gives humanity a roof over their heads and clothes to boot;
• Our atmosphere is enriched with oxygen and is not saturated with gases that are poisonous to living organisms, and it is also a protective cover from extreme temperatures that could threaten the existence of life on the planet.

Video: Unique planet Earth