Earth is a unique planet! Of course, this is true in our solar system and beyond. Nothing observed by scientists leads to the idea that there are other planets like the Earth.
Earth is the only planet orbiting our Sun that we know has life.
Like no other planet, ours is covered in green vegetation, a vast blue ocean containing over a million islands, hundreds of thousands of streams and rivers, vast masses of land called continents, mountains, glaciers and deserts that produce a wide variety of colors and textures.
Some forms of life can be found in almost every ecological niche on the surface of the Earth. Even in very cold Antarctica, hardy microscopic creatures thrive in ponds, tiny wingless insects live in patches of mosses and lichens, and plants grow and bloom annually. From the top of the atmosphere to the bottom of the oceans, from the cold part of the poles to the warm part of the equator, life thrives. To this day, no signs of life have been found on any other planet.
The Earth is huge in size, about 13,000 km in diameter, and weighing approximately 5.981024 kg. The Earth is on average 150 million km from the Sun. If the Earth goes much faster on its 584 million km journey around the Sun, its orbit will become larger and it will move farther from the Sun. If it is too far from the narrow habitable zone, all life will cease to exist on Earth.
If this trip becomes a little slower in its orbit, the Earth will move closer to the Sun, and if it moves too close, all life will also perish. The Earth travels around the Sun in 365 days, 6 hours, 49 minutes and 9.54 seconds (sidereal year), more than a thousandth of a second!
If the average annual temperature on the Earth's surface changes by only a few degrees or so, most of the life on it will eventually become fried or frozen. This change will upset the water-glacial relationship and other important balances, with disastrous results. If the Earth spins slower than its axis, all life will die in time, either by freezing at night due to lack of heat from the Sun or by burning during the day from too much heat.
Thus, our "normal" processes on Earth are undoubtedly unique among our solar system, and, according to what we know, throughout the universe:
1. She is a habitable planet. It is the only planet in the solar system that supports life. All forms of life right from the smallest microscopic organisms to huge land and sea animals.
2. Its distance from the Sun (150 million kilometers) is reasonable to give it an average temperature of 18 to 20 degrees Celsius. It's not as hot as Mercury and Venus, and not as cold as Jupiter or Pluto.
3. It has an abundance of water (71%) that is not found on any other planet. And which is not found on any of the planets known to us in a liquid state so close to the surface.
4. Has a biosphere that provides us with food, shelter, clothing and minerals.
5. Doesn't have poisonous gases like helium or methane like Jupiter.
6. It is rich in oxygen, which makes life possible on Earth.
7. Its atmosphere acts like a blanket protecting the Earth from extreme temperatures.
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The Earth is the third planet from the Sun and the largest of the terrestrial planets. However, it is only the fifth largest planet in terms of size and mass in the solar system, but, surprisingly, the densest of all the planets in the system (5.513 kg / m3). It is also noteworthy that the Earth is the only planet in the solar system that people themselves did not name after a mythological creature - its name comes from the old English word "ertha", which means soil.
It is believed that the Earth formed somewhere around 4.5 billion years ago, and is currently the only known planet where life is possible in principle, and the conditions are such that life is literally teeming on the planet.
Throughout human history, humans have sought to understand their home planet. However, the learning curve turned out to be very, very difficult, with lots of mistakes made along the way. For example, even before the existence of the ancient Romans, the world was understood as flat, not spherical. The second clear example is the belief that the sun revolves around the earth. It wasn't until the sixteenth century, thanks to the work of Copernicus, that people learned that the earth was actually just a planet revolving around the sun.
Perhaps the most important discovery regarding our planet in the last two centuries is that the Earth is both a common and a unique place in the solar system. On the one hand, many of its characteristics are rather ordinary. Take, for example, the size of the planet, its internal and geological processes: its internal structure is almost identical to the other three terrestrial planets in the solar system. Almost the same geological processes that form the surface take place on Earth, which are characteristic of similar planets and many planetary satellites. However, with all this, the Earth has just a huge number of absolutely unique characteristics that strikingly distinguish it from almost all the planets of the terrestrial group known today.
One of the necessary conditions for the existence of life on Earth without a doubt is its atmosphere. It is composed of approximately 78% nitrogen (N2), 21% oxygen (O2) and 1% argon. It also contains very small amounts of carbon dioxide (CO2) and other gases. It is noteworthy that nitrogen and oxygen are necessary for the creation of deoxyribonucleic acid (DNA) and the production of biological energy, without which life cannot exist. In addition, the oxygen present in the ozone layer of the atmosphere protects the surface of the planet and absorbs harmful solar radiation.
It is curious that a significant amount of oxygen present in the atmosphere is created on Earth. It is formed as a by-product of photosynthesis, when plants convert carbon dioxide from the atmosphere into oxygen. Essentially, this means that without plants, the amount of carbon dioxide in the atmosphere would be much higher, and the level of oxygen would be much lower. On the one hand, if the level of carbon dioxide rises, it is likely that the Earth will suffer from the greenhouse effect as on. On the other hand, if the percentage of carbon dioxide becomes even slightly lower, then a decrease in the greenhouse effect would lead to a sharp cooling. Thus, the current level of carbon dioxide contributes to an ideal range of comfortable temperatures from -88°C to 58°C.
When observing the Earth from space, the first thing that catches your eye is the oceans of liquid water. In terms of surface area, the oceans cover approximately 70% of the Earth, which is one of the most unique features of our planet.
Like the Earth's atmosphere, the presence of liquid water is a necessary criterion for sustaining life. Scientists believe that for the first time life on Earth arose 3.8 billion years ago and it was in the ocean, and the ability to move on land appeared in living beings much later.
Planetologists explain the presence of oceans on Earth in two ways. The first of these is the Earth itself. There is an assumption that during the formation of the Earth, the atmosphere of the planet was able to capture large volumes of water vapor. Over time, the planet's geological mechanisms, primarily its volcanic activity, released this water vapor into the atmosphere, after which, in the atmosphere, this vapor condensed and fell to the planet's surface in the form of liquid water. Another version suggests that the comets that fell to the Earth's surface in the past were the source of water, the ice that prevailed in their composition and formed the existing reservoirs on Earth.
Land surface
Despite the fact that most of the Earth's surface is located under its oceans, the "dry" surface has many distinctive features. When comparing the Earth with other solid bodies in the solar system, its surface is strikingly different, since it does not have craters. According to planetary scientists, this does not mean that the Earth has escaped numerous impacts of small cosmic bodies, but rather indicates that evidence of such impacts has been erased. There may be many geological processes responsible for this, but the two most important are weathering and erosion. It is believed that in many respects it was the dual impact of these factors that influenced the erasure of traces of craters from the face of the Earth.
So weathering breaks surface structures into smaller pieces, not to mention the chemical and physical means of weathering. An example of chemical weathering is acid rain. An example of physical weathering is the abrasion of river beds caused by rocks contained in running water. The second mechanism, erosion, is essentially the impact on the relief by the movement of particles of water, ice, wind or earth. Thus, under the influence of weathering and erosion, impact craters on our planet were “erased”, due to which some relief features were formed.
Scientists also identify two geological mechanisms that, in their opinion, helped shape the surface of the Earth. The first such mechanism is volcanic activity - the process of release of magma (molten rock) from the bowels of the Earth through gaps in its crust. Perhaps it was due to volcanic activity that the earth's crust was changed and islands were formed (the Hawaiian Islands are a good example). The second mechanism determines mountain building or the formation of mountains as a result of compression of tectonic plates.
Structure of the planet Earth
Like other terrestrial planets, the Earth consists of three components: core, mantle and crust. Science now believes that the core of our planet consists of two separate layers: an inner core of solid nickel and iron, and an outer core of molten nickel and iron. At the same time, the mantle is a very dense and almost completely solid silicate rock - its thickness is approximately 2850 km. The crust is also composed of silicate rocks and the difference is in its thickness. While continental ranges of crust are 30 to 40 kilometers thick, oceanic crust is much thinner, only 6 to 11 kilometers.
Another distinguishing feature of the Earth relative to other terrestrial planets is that its crust is divided into cold, rigid plates that rest on the hotter mantle below. In addition, these plates are in constant motion. Along their boundaries, as a rule, two processes are carried out at once, known as subduction and spreading. During subduction, two plates come into contact producing earthquakes and one plate runs over the other. The second process is separation, when two plates move away from each other.
Orbit and rotation of the Earth
The Earth takes approximately 365 days to make a complete orbit around the Sun. The length of our year is related to a large extent to the average orbital distance of the Earth, which is 1.50 x 10 to the power of 8 km. At this orbital distance, it takes on average about eight minutes and twenty seconds for sunlight to reach the Earth's surface.
With an orbital eccentricity of .0167, the Earth's orbit is one of the most circular in the entire solar system. This means that the difference between the Earth's perihelion and aphelion is relatively small. As a result of such a small difference, the intensity of sunlight on Earth remains almost the same all year round. However, the position of the Earth in its orbit determines this or that season.
The tilt of the Earth's axis is approximately 23.45°. At the same time, the Earth takes twenty-four hours to complete one revolution around its axis. This is the fastest rotation among the terrestrial planets, but slightly slower than all gas planets.
In the past, the Earth was considered the center of the universe. For 2000 years, ancient astronomers believed that the Earth was static, and that other celestial bodies traveled in circular orbits around it. They came to this conclusion by observing the apparent movement of the Sun and planets when viewed from the Earth. In 1543, Copernicus published his heliocentric model of the solar system, in which the sun is at the center of our solar system.
Earth is the only planet in the system not named after mythological gods or goddesses (the other seven planets in the solar system were named after Roman gods or goddesses). This refers to the five planets visible to the naked eye: Mercury, Venus, Mars, Jupiter and Saturn. The same approach with the names of the ancient Roman gods was used after the discovery of Uranus and Neptune. The very same word "Earth" comes from the old English word "ertha" meaning soil.
Earth is the densest planet in the solar system. The density of the Earth is different in each layer of the planet (the core, for example, is denser than the earth's crust). The average density of the planet is about 5.52 grams per cubic centimeter.
The gravitational interaction between the Earth and causes the tides on the Earth. It is believed that the Moon is blocked by the tidal forces of the Earth, so its period of rotation coincides with the Earth's and it always faces our planet with the same side.
Hello readers! We have a great planet, don't we? She is beautiful and loved. Today, in this article, I would like to tell you about what our planet consists of, what its shape, temperature, composition, size, and a few other interesting things...
Earth, on this planet we live, it is the fifth of the major planets in and the third from the Sun.
On Earth, in general, favorable ,
a lot of natural resources, and maybe it is the only planet where life exists.
Active geodynamic processes occurring in the bowels of the Earth are manifested in the growth of the oceanic crust and its further opening, earthquakes, eruptions, etc.
Shape and size.
For more than 2000 years, the approximate contours and dimensions of the Earth have been known. The Greek scientist quite accurately calculated the radius of the Earth back in the III century. BC e. In our time, it is already known that the polar radius of the Earth is about 12,711 km, and the equatorial radius is 12,754 km.
The surface area of the Earth is about 510.2 million km2, of which 361 million km2 is water. The volume of the Earth is approximately 1121 billion km 3. Due to the rotation of the planet, a centrifugal force arises, which is maximum at the equator and decreases towards the poles, this rotation is due to the unevenness of the Earth's radii.
If only this force acted on the Earth, then all objects on the surface would fly into space, but due to the force of gravity, this does not happen.
Gravity.
Gravity, or the force of gravity, keeps the atmosphere close to the earth's surface and the moon in orbit. With height, the force of gravity decreases. The state of weightlessness, which the astronauts feel, is explained precisely by this circumstance.
Due to the rotation of the Earth and the action of centrifugal force, gravity on its surface somewhat decreases. The acceleration of the free fall of objects, the value of which is 9.8 m/s, is due to the force of gravity.
The inhomogeneity of the Earth's surface leads to the difference in gravity in different regions. Information about the internal structure of the Earth can be obtained by measuring the acceleration of the force of weight.
Mass and density.
The mass of the Earth is approximately 5976 ∙ 10 21 tons. For comparison, the mass of the Sun is approximately 333 thousand times larger, and the mass of Jupiter is 318 times larger. But on the other hand, the mass of the Earth exceeds the mass of the Moon by 81.8 times. The density of the Earth varies from exceptionally high in the center of the planet to negligible in the upper atmosphere.
Knowing the mass and volume of the Earth, scientists calculated that its average density is approximately 5.5 times greater than the density of water. Granite is one of the most common minerals on the surface of the Earth, its density is 2.7 g/cm 3 , density in the mantle varies from 3 to 5 g/cm 3 , within the core - from 8 to 15 g/cm 3 . In the center of the Earth, it can reach 17 g/cm 3 .
Conversely, the density of air near the Earth's surface is approximately 1/800 that of water, while in the upper atmosphere it is very small.
Pressure.
At sea level, the atmosphere exerts a pressure of 1 kg / cm 2 (pressure of one atmosphere), and with height it decreases. Approximately 2/3 decreases the pressure at a height of about 8 km. Inside the Earth, the pressure is growing rapidly: at the border of the core it is about 1.5 million atmospheres, and at its center - up to 3.7 million atmospheres.
Temperatures.
On Earth, temperatures vary greatly. For example, in El Azizia (Libya), a record high temperature of 58 °C was recorded (September 13, 1922), and at the Vostok station near the South Pole of Antarctica, a record low of 89.2 °C (July 21, 1983 .).
In depth, the temperature rises by 0.6 °C every 18 m, further this process slows down. The Earth's core, located in the center of the Earth, is heated to a temperature of 5000 - 6000 ° C.
The average air temperature in the near-surface sphere of the atmosphere is 15 ° C, it decreases gradually in the troposphere, and above (starting from the stratosphere) it varies within wide limits depending on the absolute height.
The cryosphere is the shell of the Earth, as a rule, the temperature within which is below 0 °C. At high latitudes, it begins at sea level, and in the tropics, at an altitude of about 4500 m. The cryosphere in the subpolar regions on the continents can extend several tens of kilometers below the earth's surface, forming a horizon.
Thus, I told you the most important facts about the Earth, as it were, from the inside. From a side that we usually never thought about. It was a brief description of the Earth. I hope this article has been the answer to your search. 🙂
» Reports for elementary grades » Earth
Earth is the third from the Sun and the fifth largest planet in the solar system. The uniqueness of our planet lies in the fact that only on it more than 3 billion years ago life originated, which still exists. Animals, plants, people are only here on planet Earth.
The earth is surrounded by a layer of air, which we call the atmosphere. Airless space, or space, begins where the atmosphere ends. If it did not exist on Earth, then life would be impossible. The air shell affects the climate of the planet: it protects it from the heat of the sun and the cold of space.
Water is another factor without which life on Earth would not be possible. Most of the world is covered with water.
- Distance from the Sun: 150,000,000 kilometers
- Day length: 24 hours (terrestrial)
- Length of a year: 365 days (Earth)
- 0 rings, 1 satellite
It is interesting…
A car traveling at an average speed of 60 miles per hour would take approximately 48 million years to reach our nearest star (after the Sun), Proxima Centauri.
Question: A report on how the planet Earth appeared. Grade 5, please.
How did the planets in our solar system form?
Nowadays, the solar system and the planets surrounding it have been studied quite well. However, scientists still do not have a clear answer to the question of its origin. So, for example, back in 1755, the German astronomer and philosopher Immanuel Kant assumed that the planets of our system were formed from the same cloud of gas and dust as the Sun itself.
How planets appear
The Soviet scientist Otto Schmidt believed that the material for the formation of planets at the initial stage was "captured" by the Sun from space.
There is also a theory that the substance for building the planetary system was separated from the Sun itself as a result of an explosion.
Which of these is true, we most likely will never know, so choose for yourself what you like best, it is even possible that the biblical tale of the birth of the solar system may turn out to be true.
Abstract on the topic
"Earth is a planet in the solar system"
Two groups of planets
Terrestrial planets. Earth-Moon system
Earth
Ancient and modern explorations of the Earth
Exploring the Earth from space
Origin of life on earth
Earth's only satellite is the Moon
Conclusion
The structure and composition of the solar system.
two groups of planets.
Our Earth is one of the 8 major planets revolving around the Sun. It is in the Sun that the main part of the matter of the solar system is concentrated. The mass of the Sun is 750 times the mass of all the planets and 330,000 times the mass of the Earth.
Under the influence of the force of its attraction, the planets and all other bodies of the solar system move around the sun.
The distances between the Sun and the planets are many times greater than their size, and it is almost impossible to draw such a diagram that would observe a single scale for the Sun, planets and the distances between them. The diameter of the Sun is 109 times larger than the Earth, and the distance between them is about the same number of times the diameter of the Sun.
In addition, the distance from the Sun to the last planet of the solar system (Neptune) is 30 times greater than the distance to the Earth. If we depict our planet as a circle with a diameter of 1 mm, then the Sun will be at a distance of about 11 m from the Earth, and its diameter will be about 11 cm. The orbit of Neptune will be shown as a circle with a radius of 330 m.
Therefore, they usually cite not a modern diagram of the solar system, but only a drawing from Copernicus's book "On the Revolution of the Celestial Circles" with other, very approximate proportions.
According to physical characteristics, large planets are divided into two groups.
One of them - the planets of the terrestrial group - is the Earth and similar Mercury, Venus and Mars. The second includes the giant planets: Jupiter, Saturn, Uranus and Neptune. Until 2006, Pluto was considered the largest planet farthest from the Sun. Now, together with other objects of similar size - long-known large asteroids (see § 4) and objects discovered on the outskirts of the solar system - it is among the dwarf planets.
The division of the planets into groups can be traced by three characteristics (mass, pressure, rotation), but most clearly by density.
Planets belonging to the same group differ insignificantly in density, while the average density of terrestrial planets is about 5 times greater than the average density of giant planets (see Fig.
Most of the mass of the terrestrial planets is in solid matter. The Earth and other planets of the terrestrial group consist of oxides and other compounds of heavy chemical elements: iron, magnesium, aluminum and other metals, as well as silicon and other non-metals.
The four most abundant elements in the solid shell of our planet (lithosphere) - iron, oxygen, silicon and magnesium - account for over 90% of its mass.
The low density of the giant planets (for Saturn it is less than the density of water) is explained by the fact that they consist mainly of hydrogen and helium, which are predominantly in gaseous and liquid states. The atmospheres of these planets also contain hydrogen compounds - methane and ammonia.
Differences between the planets of the two groups arose already at the stage of their formation (see § 5).
Of the giant planets, Jupiter is best studied, on which, even in a small school telescope, numerous dark and light stripes are visible, stretching parallel to the planet's equator. This is what cloud formations look like in its atmosphere, the temperature of which is only -140 ° C, and the pressure is about the same as at the surface of the Earth.
The reddish-brown color of the bands is apparently due to the fact that, in addition to the ammonia crystals that form the basis of the clouds, they contain various impurities.
The images taken by spacecraft show traces of intense and sometimes persistent atmospheric processes. So, for over 350 years, an atmospheric vortex, called the Great Red Spot, has been observed on Jupiter. In the earth's atmosphere, cyclones and anticyclones exist on average for about a week. Atmospheric currents and clouds have been recorded by spacecraft on other giant planets, although they are less developed than on Jupiter.
Structure. It is assumed that as it approaches the center of the giant planets, due to an increase in pressure, hydrogen should pass from a gaseous to a gaseous state, in which its gaseous and liquid phases coexist.
At the center of Jupiter, the pressure is millions of times higher than the atmospheric pressure that exists on Earth, and hydrogen acquires the properties characteristic of metals.
In the depths of Jupiter, metallic hydrogen, together with silicates and metals, forms a core, which is approximately 1.5 times larger in size and 10–15 times larger in mass than the Earth.
Weight. Any of the giant planets exceeds in mass all the terrestrial planets combined. The largest planet in the solar system - Jupiter is larger than the largest planet of the terrestrial group - the Earth by 11 times in diameter and more than 300 times in mass.
Rotation.
The differences between the planets of the two groups are also manifested in the fact that the giant planets rotate faster around the axis, and in the number of satellites: there are only 3 satellites for 4 terrestrial planets, more than 120 for 4 giant planets.
All these satellites consist of the same substances as the terrestrial planets - silicates, oxides and sulfides of metals, etc., as well as water (or water-ammonia) ice. In addition to numerous craters of meteorite origin, tectonic faults and cracks in their crust or ice cover have been found on the surface of many satellites. The discovery of about a dozen active volcanoes on the closest satellite to Jupiter, Io, turned out to be the most surprising.
This is the first reliable observation of terrestrial-type volcanic activity outside our planet.
In addition to satellites, giant planets also have rings, which are clusters of small bodies.
They are so small that they cannot be seen individually. Due to their circulation around the planet, the rings appear to be continuous, although both the surface of the planet and the stars shine through the rings of Saturn, for example. The rings are located in close proximity to the planet, where large satellites cannot exist.
Terrestrial planets. Earth-Moon system
Due to the presence of a satellite, the Moon, the Earth is often called a double planet. This emphasizes both the commonality of their origin and the rare ratio of the masses of the planet and its satellite: the Moon is only 81 times smaller than the Earth.
Sufficiently detailed information will be given about the nature of the Earth in subsequent chapters of the textbook.
Therefore, here we will talk about the rest of the planets of the terrestrial group, comparing them with ours, and about the Moon, which, although it is only a satellite of the Earth, by its nature belongs to planetary-type bodies.
Despite the common origin, the nature of the moon is significantly different from the earth, which is determined by its mass and size. Due to the fact that the force of gravity on the surface of the Moon is 6 times less than on the surface of the Earth, it is much easier for gas molecules to leave the Moon.
Therefore, our natural satellite is devoid of a noticeable atmosphere and hydrosphere.
The absence of an atmosphere and slow rotation around its axis (a day on the Moon is equal to an Earth month) lead to the fact that during the day the surface of the Moon heats up to 120 ° C, and cools down to -170 ° C at night.
Due to the absence of an atmosphere, the lunar surface is subject to constant “bombardment” by meteorites and smaller micrometeorites that fall on it at cosmic speeds (tens of kilometers per second). As a result, the entire Moon is covered with a layer of finely divided substance - regolith. As the American astronauts who have been on the Moon describe, and as the photographs of the traces of lunar rovers show, in terms of their physical and mechanical properties (particle sizes, strength, etc.)
n.) regolith is similar to wet sand.
When large bodies fall on the surface of the Moon, craters up to 200 km in diameter are formed. Craters meter and even centimeter in diameter are clearly visible in the panoramas of the lunar surface obtained from spacecraft.
Under laboratory conditions, samples of rocks delivered by our automatic stations "Luna" and American astronauts who visited the Moon on the Apollo spacecraft were studied in detail.
This made it possible to obtain more complete information than in the analysis of the rocks of Mars and Venus, which was carried out directly on the surface of these planets. Lunar rocks are similar in composition to terrestrial rocks such as basalts, norites, and anorthosites. The set of minerals in lunar rocks is poorer than in terrestrial, but richer than in meteorites. Our satellite does not have and never had a hydrosphere or an atmosphere of the same composition as on Earth.
Therefore, there are no minerals that can be formed in the aquatic environment and in the presence of free oxygen. Lunar rocks are depleted in volatile elements compared to terrestrial ones, but they are distinguished by a high content of iron and aluminum oxides, and in some cases titanium, potassium, rare earth elements and phosphorus. No signs of life, even in the form of microorganisms or organic compounds, have been found on the Moon.
The light areas of the Moon - the "continents" and the darker ones - the "seas" differ not only in appearance, but also in relief, geological history and the chemical composition of the substance covering them.
On the younger surface of the "seas", covered with solidified lava, there are fewer craters than on the older surface of the "continents". In various parts of the Moon, such relief forms as cracks are noticeable, along which the crust is shifted vertically and horizontally. In this case, only fault-type mountains are formed, and there are no folded mountains, so typical for our planet, on the Moon.
The absence of erosion and weathering processes on the Moon allows us to consider it a kind of geological reserve, where all the landforms that have arisen during this time have been preserved for millions and billions of years.
Thus, the study of the Moon makes it possible to understand the geological processes that took place on Earth in the distant past, of which no traces remain on our planet.
3. Earth.
Earth is the third planet from the Sun in the solar system. It orbits the star at an average distance of 149.6 million km.
km over a period of 365.24 days.
The Earth has a satellite, the Moon, which revolves around the Sun at an average distance of 384,400 km. The inclination of the earth's axis to the plane of the ecliptic is 66033'22".
The period of rotation of the planet around its axis is 23 hours 56 minutes 4.1 seconds. Rotation around its axis causes the change of day and night, and the tilt of the axis and circulation around the Sun - the change of seasons. The shape of the Earth is a geoid, approximately a triaxial ellipsoid, a spheroid. The average radius of the Earth is 6371.032 km, equatorial - 6378.16 km, polar - 6356.777 km.
The surface area of the globe is 510 million km², the volume is 1.083 * 1012 km², the average density is 5518 kg / m³. The mass of the Earth is 5976 * 1021 kg.
The earth has magnetic and electric fields. The gravitational field of the Earth determines its spherical shape and the existence of the atmosphere.
According to modern cosmogonic concepts, the Earth was formed about 4.7 billion years ago from the gaseous matter scattered in the protosolar system. As a result of the differentiation of matter, the Earth, under the influence of its gravitational field, under the conditions of heating of the earth's interior, arose and developed different in chemical composition, state of aggregation and physical properties of the shell - the geosphere: core (in the center), mantle, earth's crust, hydrosphere, atmosphere, magnetosphere.
The composition of the Earth is dominated by iron (34.6%), oxygen (29.5%), silicon (15.2%), magnesium (12.7%). The earth's crust, mantle and inner part of the core are solid (the outer part of the core is considered liquid).
From the surface of the Earth to the center, pressure, density and temperature increase.
The pressure in the center of the planet is 3.6 * 1011 Pa, the density is about 12.5 * 103 kg / m³, the temperature ranges from 50000ºС to 60000ºС.
The main types of the earth's crust are continental and oceanic; in the transition zone from the mainland to the ocean, a crust of intermediate structure is developed.
Most of the Earth is occupied by the World Ocean (361.1 million km²; 70.8%), the land is 149.1 million km² (29.2%), and forms six continents and islands. It rises above the world ocean level by an average of 875 m (the highest height is 8848 m - Mount Chomolungma), mountains occupy more than 1/3 of the land surface.
Report: Earth as a planet of the solar system
Deserts cover about 20% of the land surface, forests - about 30%, glaciers - over 10%. The average depth of the world ocean is about 3800 m (the greatest depth is 11020 m - the Mariana Trench (trough) in the Pacific Ocean). The volume of water on the planet is 1370 million km³, the average salinity is 35 g/l. The atmosphere of the Earth, the total mass of which is 5.15 * 1015 tons, consists of air - a mixture of mainly nitrogen (78.08%) and oxygen (20.95%), the rest is water vapor, carbon dioxide, as well as inert and other gases.
The maximum land surface temperature is 570º-580º C (in the tropical deserts of Africa and North America), the minimum is about -900º C (in the central regions of Antarctica). The formation of the Earth and the initial stage of its development belong to pregeological history.
The absolute age of the most ancient rocks is over 3.5 billion years. The geological history of the Earth is divided into two unequal stages: the Precambrian, which occupies approximately 5/6 of the entire geological chronology (about 3 billion years) and the Phanerozoic, covering the last 570 million years.
About 3-3.5 billion years ago, as a result of the natural evolution of matter, life arose on Earth, and the development of the biosphere began.
The totality of all living organisms inhabiting it, the so-called living matter of the Earth, had a significant impact on the development of the atmosphere, hydrosphere and sedimentary shell.
A new factor that has a powerful influence on the biosphere is the production activity of man, who appeared on Earth less than 3 million years ago. The high growth rate of the Earth's population (275 million people in 1000, 1.6 billion people in 1900 and approximately 6.3 billion people in 1995) and the increasing influence of human society on the natural environment have put forward the problems of the rational use of all natural resources and nature protection.
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Earth in the solar system
Our planet Earth is the third planet from the Sun in the solar system.
She enters earthlygroup 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 1024 kg, its surface area is 510,072,000 km², and its 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 ozonelayer, 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 (O2) dissociates into atoms, which then combine with other O2 molecules, forming ozone(O3).
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 H2O, 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). Tropicalyear 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 (N2), 20.95% oxygen (O2), 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.
Earth is a unique planet!
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 in the depths of the Mariana Trench, the highest mountain of our planet, Everest, can easily fit, and above it there will still be more than a kilometer of water 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.
The internal structure of the Earth
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 total 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.
Nucleus- 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 1024 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".
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.
For the existence of all life forms on Earth, liquid water is essential, 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.
A report on how the planet Earth appeared Grade 5 please.
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:
- the atmosphere;
- the biosphere;
- 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 3/4 of the entire mass of the atmosphere (ie, 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 g/l, 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.
in natural history
on the topic: "The uniqueness of the planet Earth"
Completed: student 5 "d" class
Galiev Edgar
Edited by: Vasinkina Yu.V.
Zainsk 2012
geography
Fifth grade
the first solar system
A few decades ago, human flight was fantastic in space. And today, not only the beginning of a spacecraft with a crew has become a reality, but the first space tourists have appeared, and we are preparing scientific expeditions to other planets.
Who knows, maybe this textbook is reading the next participant in the flight to Mars. But even if this is not the case, the information they contain is needed by everyone. This will help you feel like a part of not only a small settlement, a city and a large country, but also an infinite universe with many galaxies, one of which belongs to our solar system.
Our star home is the solar system.
Planet Earth is part of the solar system, the center of which is the Star of the Sun. It is a huge red gas ball, consisting of hydrogen.
Thermonuclear reactions take place in the Sun, resulting in a huge amount of heat and light. The temperature in the room reaches 15 million degrees Celsius! Our planet is in an eternally cold and dark space, and the Sun provides the energy it needs.
Without sunlight and light, there would be no life on Earth.
Our planet is a bit small compared to the sun, with poppies along a big orange, for example. The sun is huge, like all the "inhabitants" of the solar system together. Its diameter is 109 times the diameter of the Earth.
The gravitational force of the Sun acts on all the bodies of the Sun system and makes them turn to their orbits.
orbit(from the Latin "orbit" - between them) - the path along which any natural or artificial celestial body moves.
The composition of the solar system includes eight planets. They are divided into terrestrial planets (Merkur, Venus, Earth, Mars) and giant planets (Jupiter, Saturn, Uranus, Neptune).
Earth group planets. All four planetary groups of planets are located near the Sun.
They are small, composed of dense rocks and slowly rotate around their axis. They have only a few satellites or not: for example, the Earth has one (Moon), Mars has two, Mercury and Venus are nothing. These planets do not have fingers.
1. Scheme of the structure of the solar system. 2. Sun. The photo was taken using special light filters. 3. mercury. 4. Venus.
Mercury is the first planet in the solar system.
In order to be closer to other planets to the Sun, he turns to the earliest possible time. A year in Merkur is one revolution of the planet around the Sun, these are 88 Earth days.
The sun radiates so strongly from this small planet that the daily surface temperature reaches 430°C.
But at night it drops to -170 ° C. Under such circumstances, the existence of living organisms is excluded. Mercury has such deep craters that sunlight never reaches the bottom. It's always very cold there.
The range is much smaller than our Earth: 20 planets like Merkur can be found in the world.
Venus- the other - from the solar planet.
It is the size of our Earth. The planet is surrounded by a strong layer of carbon dioxide. This thick shell of gas passes through the sun's rays and retains heat like a film in a greenhouse without releasing it into space. Therefore, the average temperature in the surface layer of the atmosphere of Venus is about 470 ° C.
The atmosphere is compressed on the surface of Venus with a great force, almost 100 times greater than the earth's atmosphere.
country- the third planet from the Sun, the only one in the solar system on which the conditions are favorable for the existence of life: the presence of an atmosphere containing oxygen; the temperature necessary for the development of living organisms; Protective ozone layer in the atmosphere; liquid water, carbon.
The fourth group of the planet Earth is Mars. Its mass is 9.3 times less than the mass of the Earth. He has two companions.
The surface of Mars has a rusty hue because it contains a lot of iron oxide. The Martian landscape is like pale orange dunes in the desert, with stallions.
Severe storms often rage over the planet. They kick up so much brown dust that the sky turns red. In airless weather, it is pink.
Like us, we change the season on Mars, there is a change of day and night. The Martian year is twice as long as Earth.
The red planet, scientists say, has an atmosphere, but not as dense as Earth or Venus.
big planet. A large planet (Jupiter, Saturn, Uranus, Neptune) is located far from the Sun as a planet of the Earth group. The farthest of them is Neptune: while he revolutionizes the Sun, he will be 165 years on Earth. These planets are also called gas giants because they are almost entirely gas and are large.
For example, the radius of Neptune is around the radius of the Earth, Saturn is nine, and Jupiter is eleven. The atmosphere of the giant planets consists mainly of hydrogen and helium.
The gas giants rotate much faster than the Earth's planets on their axis. (Watch the use of the terms "rotation" and "circling.") If the Earth completes a full rotation on its axis in almost 24 hours, then Jupiter takes 10 hours, Uranus 18, and Neptune 16.
Another feature of the planets of this group is the presence of many satellites.
For example, Jupiter has 60 scientists. The attraction of this wheel is so strong that it attracts all space debris like a big vacuum cleaner: particles of stones, ice and dust that form rings.
They revolve around the planet and every gas giant. Looking through a telescope, we can clearly see Saturn's bright, glossy ring.
1. The first photographs of the surface of Mars were taken from the American automatic station Viking in 1976. 2. Jupiter. 3. Saturn. 4. Uranus. 5. Neptune.
Small bodies of the solar system.
In addition to the planets and their satellites, there are many smaller planets in the solar system - asteroids (from the Greek "asters" - stars), which means "star" in Russian.
Planet Earth
Most of them rotate the Sun and form a belt of asteroids located between the orbits of Mars and Jupiter. As astronomers suggest, these are fragments of a destroyed planet or building material for an unformed celestial body. Asteroids do not have a well-defined shape, they are stone mud, sometimes with metal.
In the solar system there are also meteorite bodies - fragments of rocks of different sizes.
Take in the Earth's atmosphere, heat up strongly as a result of friction against air and burn, making a bright gesture in the sky - these are meteors (in Greek - blue in the air). The destruction of a meteoroid that has not burned up in the atmosphere and has not reached the Earth's surface is called a meteorite.
The weight of a meteorite ranges from a few grams to several tons. One of the largest - the Tunguska meteorites at the beginning of the last century fell on the territory of our country in the center of Siberia.
The solar system also includes comets (from the Greek.
"Comet" is durable). They circulate around the Sun in very elongated orbits. The more comets the Sun, the greater the speed of its movement. It has a core composed of frozen gases or cosmic dust. As it approaches the Sun, the core of the nucleus evaporates and begins to glow, and then the "head" and "tail" become visible in "space dive".
The most famous comet is Galloya - every 76 years it approaches the Earth. In ancient times, his approach caused terrible horror in people. Today, scientists around the world are interested in this incredible astronomical phenomenon.
1. Asteroid Ida. 2. Meteor in the sky.
3. The Luzhenga meteorite, located 30 km southwest of Veliky Ustyug. 4. Halley's Comet flew over the Earth in 1985. It will next be seen in 2061.
With the help of radio telescopes, special cameras equipped with light filters, astronomers receive new information about the Sun, the planets of the solar system, asteroids and other space bodies.
Questions and tasks
- How many planets revolve around the sun? Name them. Which planet in the solar system is the hottest? Which scientists call them the "Red Planet"?
- Do you know what the term "fallen star" means? Have you ever seen a shooting star? What is their scientific name?
- Write the text as many words as possible with the following concepts: a) planet, b) cosmic bodies, c) solar system. Explain what combines the words you find.
- Read the text again, find and write the names of the nearest and most distant planets from the Sun. What groups of planets in the solar system belong to? Consider and explain, depending on what signs the planets of the solar system are divided into groups.
- How do you think the bodies of the solar system revolve around the sun?
- In the text, find the main differences between the planets of the Earth and the giant planets. Draw a table in a notebook and fill it in.
Features of the Earth's planets from the giant planets
Draw a notebook and prepare a story.
For the curious
- Jupiter is the first largest gas giant among the planets of the solar system. Its entire surface is a huge ocean of liquid hydrogen. It is 2.5 times larger than all other planets in the solar system, its radius is 11 times the radius of the Earth.
It has over 60 satellites and more fingers. In Jupiter's vast atmosphere, hurricanes are angry; their speed exceeds 100 m/s.
On the surface of Jupiter, telescopes have captured a huge red part of the size of our Earth, which is an atmospheric vortex.
- The sun is the closest star to us. The size is so large that it could have over a million planets like Earth. Light from the Sun to the Earth comes in 8 minutes. The second star closest to Earth is Proxima Centauri.
- Venus rotates on its axis, not from west to east, like most planets in the solar system, but in the opposite direction. On Venus, a day is one revolution of the planet around its axis, about 243 Earth days. It is the brightest object in the sky of the Sun and Moon. Venus is usually seen in the evening after sunset or in the morning before sunrise against the backdrop of dawn.
the first
Comparative characteristics of the planets of the solar system. 2. The nearest satellites of Jupiter. 3. Chemical composition of Jupiter's atmosphere (diagram).
- Uranus is the only one of all the planets in the solar system that rotates around its axis, "lies on its side."
Scientists believe that he "fell on his side" as a result of a collision with a large cosmic body millions of years ago. Like Venus, Uranus rotates on its axis in the opposite direction from the clock.
- The duration of one year on the planet Neptune is 164.8 Earth days, Mercury - 88 Earth days.
- Merkur is the planet closest to the Sun. Due to the smaller tilt of the axis to the plane of its orbit, there are no noticeable seasonal changes on this planet.
Mercury has no followers.
Merkur is a small planet. Its mass is a twentieth of the mass of the Earth, and its diameter is almost 2.5 times smaller than the Earth.
For observations from Earth, the Merkur is a difficult subject, since it is only visible against the background of an evening or morning dawn that is slightly above the horizon, and in addition, the observer sees only half of his disk at that time.
Earth is the third planet from the Sun and the fifth largest. Among all celestial objects of the terrestrial group, it is the largest in mass, diameter and density. It has other designations - the Blue Planet, the World or Terra. At the moment, it is the only planet known to man with the presence of life.
According to scientific research, it turns out that the Earth as a planet was formed approximately 4.54 billion years ago from the solar nebula, after which it acquired a single satellite - the Moon. Life appeared on the planet about 3.9 billion years ago. Since then, the biosphere has greatly changed the structure of the atmosphere and abiotic factors. As a result, the number of aerobic living organisms and the formation of the ozone layer were determined. The magnetic field together with the layer reduce the negative impact of solar radiation on life. The radiation due to the earth's crust has decreased quite a lot since its formation due to the gradual decay of radionuclides. The crust of the planet is divided into several segments (tectonic plates) that move several centimeters per year.
The oceans occupy about 70.8% of the Earth's surface, and the rest belongs to the continents and islands. Continents have rivers, lakes, groundwater and ice. Together with the World Ocean, they form the planet's hydrosphere. Liquid water sustains life above and below ground. The Earth's poles are covered by ice caps, which include the Antarctic ice sheet and Arctic sea ice.
The inner regions of the Earth are quite active and consist of a very viscous, thick layer - the mantle. It covers the outer liquid core, which is composed of nickel and iron. The physical characteristics of the planet have kept life alive for 3.5 billion years. Approximate calculations of scientists indicate the duration of the same conditions for another 2 billion years.
The earth is attracted by gravitational forces along with other space objects. The planet revolves around the sun. A full turn is 365.26 days. The axis of rotation is tilted at 23.44°, which causes seasonal changes at intervals of 1 tropical year. The approximate time of a day on Earth is 24 hours. In turn, the Moon revolves around the Earth. This has been going on since its inception. Thanks to the satellite, the ocean ebbs and flows on the planet. In addition, it stabilizes the tilt of the Earth, which gradually slows down its rotation. According to some theories, it turns out that asteroids (fireballs) fell on the planet at one time and thus directly affected existing organisms.
The earth is home to millions of different life forms, including humans. The entire territory is divided into 195 states interacting with each other through diplomacy, brute force and trade. Man has formed many theories about the universe. The most popular are the Gaia hypothesis, the geocentric system of the world and the flat Earth.
History of our planet
The most modern theory concerning the question of the origin of the Earth is called the solar nebula hypothesis. From it it turns out that the solar system appeared from a large cloud of gas and dust. The composition included helium and hydrogen, which were formed as a result of the Big Bang. Also, heavy elements appeared in this way. About 4.5 billion years ago, the cloud began to compress due to a shock wave, which in turn went after a supernova explosion. After the cloud contracted, angular momentum, inertia and gravity flattened it into a protoplanetary disk. After that, the debris in the disk, being under the influence of gravity, began to collide and merge, thereby forming the first planetoids.
This process was called accretion, and dust, gas, debris and planetoids began to form larger objects - planets. Approximately the entire process took about 10-20 billion years.
The only satellite of the Earth - the Moon - formed a little later, although its origin has not yet been explained. Many hypotheses have been put forward, one of which says that the Moon appeared due to accretion from the substance of the Earth remaining after the collision with an object similar in size to Mars. The outer layer of the Earth was evaporated and melted. Part of the mantle was thrown into the orbit of the planet, which is why the Moon is severely deprived of metals and has a composition known to us. Own gravity influenced the adoption of a spherical shape and the formation of the moon.
The proto-Earth increased due to accretion and was very hot to melt minerals and metals. Siderophile elements, geochemically similar to iron, began to sink towards the center of the Earth, which affected the separation of the inner layers into the mantle and the metallic core. The magnetic field of the planet began to form. Volcanic activity and the release of gases led to the appearance of the atmosphere. The condensation of water vapor enhanced by ice led to the formation of oceans. At that time, the Earth's atmosphere consisted of light elements - helium and hydrogen, but in comparison with the current state, it had a large amount of carbon dioxide. The magnetic field appeared about 3.5 billion years ago. Due to this, the solar wind could not devastate the atmosphere.
Changes in the surface of the planet have been going on for hundreds of millions of years. New continents appeared and collapsed. Sometimes, as they moved, they created a supercontinent. About 750 million years ago, the earliest supercontinent, Rodinia, began to break apart. A little later, its parts formed a new one - Pannotia, after which, having broken up again after 540 million years, Pangea appeared. It broke up 180 million years later.
The emergence of life on earth
There are many hypotheses and theories about this. The most popular of them says that about 3.5 billion years ago there was a single universal ancestor of all current organisms.
Thanks to the development of photosynthesis, living organisms were able to use solar energy. The atmosphere began to fill with oxygen, and in its upper layers there was an ozone layer. The symbiosis of large cells with small ones began to develop eukaryotes. About 2.1 billion years ago, representatives of multicellular organisms appeared.
In 1960, scientists put forward the Snowball Earth hypothesis, according to which it turned out that in the period from 750 to 580 million years ago, our planet was completely covered with ice. This hypothesis easily explains the Cambrian explosion - the emergence of a large number of different life forms. So far, this hypothesis has been confirmed.
The first algae formed 1200 million years ago. The first representatives of higher plants - 450 million years ago. Invertebrates appeared in the Ediacaran period, and vertebrates in the Cambrian explosion.
There have been 5 mass extinctions since the Cambrian Explosion. At the end of the Permian period, approximately 90% of living beings died. This was the most massive destruction, after which the archosaurs appeared. Dinosaurs appeared at the end of the Triassic period and dominated the planet throughout the Jurassic and Cretaceous periods. About 65 million years ago, the Cretaceous-Paleogene extinction occurred. The reason, most likely, was the fall of a huge meteorite. As a result, almost all large dinosaurs and reptiles died, and small animals managed to escape. Their prominent representatives were insects and the first birds. Over the next million years, most of the different animals appeared, and a couple of million years ago, the first ape-like animals with the ability to walk upright. These beings began to use tools and communication as an exchange of information. No other form of life has been able to develop as quickly as man. In a very short time, people curbed agriculture and formed civilizations, and recently began to directly influence the state of the planet and the number of other species.
The last ice age began 40 million years ago. Its bright middle fell on the Pleistocene (3 million years ago).
Earth structure
Our planet belongs to the terrestrial group and has a solid surface. It has the greatest density, mass, gravity, magnetic field and dimensions. Earth is the only known planet with active movement of tectonic plates.
The bowels of the Earth are divided into layers according to physical and chemical properties, but unlike other planets, it has a pronounced outer and inner core. The outer layer is represented by a hard shell, consisting mainly of silicate. It is separated from the mantle by a boundary with an increased velocity of seismic longitudinal waves. The upper viscous part of the mantle and the hard crust form the lithosphere. Below it is the asthenosphere.
The main changes in the crystal structure occur at a depth of 660 km. It separates the lower mantle from the upper. Under the mantle itself is a liquid layer of molten iron with impurities of sulfur, nickel and silicon. This is the core of the Earth. The above seismic measurements have shown that the core consists of two parts - liquid outer and solid inner.
The form
The earth has the shape of an oblate ellipsoid. The average diameter of the planet is 12742 km, the circumference is 40000 km. The equatorial bulge was formed due to the rotations of the planet, due to which the equatorial diameter is 43 km larger than the polar one. The highest point is Mount Everest, and the deepest is the Mariana Trench.
Chemical composition
The approximate mass of the Earth is 5.9736 1024 kg. The approximate number of atoms is 1.3-1.4 1050. Composition: iron - 32.1%; oxygen - 30.1%; silicon - 15.1%; magnesium - 13.9%; sulfur - 2.9%; nickel - 1.8%; calcium - 1.5%; aluminum - 1.4%. All other elements make up 1.2%.
Internal structure
Like other planets, the Earth has an internal layered structure. This is mainly a metal core and hard silicate shells. The internal heat of the planet is possible due to a combination of residual heat and radioactive isotope decays.
The solid shell of the Earth - the lithosphere - consists of the upper part of the mantle and the earth's crust. It features movable folded belts and stable platforms. Lithospheric plates move along the plastic asthenosphere, which behaves like a viscous superheated fluid, where the level of seismic wave velocity decreases.
The earth's crust represents the upper solid part of the earth. It is separated from the mantle by the Mohorovich boundary. There are two types of crust - oceanic and continental. The first is composed of rocks of basic composition and sedimentary cover, the second - of granite, sedimentary and basalt. The entire earth's crust is divided into lithospheric plates of different sizes, which move relative to each other.
The thickness of the earth's continental crust is 35-45 km, in the mountains it can reach 70 km. With increasing depth, the amount of iron and magnesium oxides increases in the composition, and silica decreases. The upper part of the continental crust is represented by a discontinuous layer of volcanic and sedimentary rocks. The layers are often crumpled into folds. There is no sedimentary shell on the shields. Below is a boundary layer of granites and gneisses. Behind it is a basaltic layer composed of gabbro, basalts and metamorphic rocks. They are separated by a conditional boundary - the Konrad surface. Under the oceans, the thickness of the crust reaches 5-10 km. It is also divided into several layers - upper and lower. The first consists of bottom sediments a kilometer in size, the second consists of basalt, serpentinite, and sediment layers.
The Earth's mantle is a silicate shell located between the core and the earth's crust. It makes up 67% of the total mass of the planet and approximately 83% of its volume. It occupies a wide range of depths and has phase transitions, which affects the density of the structure of minerals. The mantle is also divided into lower and upper parts. The second, in turn, consists of a substrate, layers of Gutenberg and Golitsyn.
The results of current research indicate that the composition of the earth's mantle is similar to chondrites - stone meteorites. Basically, oxygen, silicon, iron, magnesium and other chemical elements are present here. Together with silicon dioxide, they form silicates.
The deepest and central part of the Earth is the Core (geosphere). The proposed composition is iron-nickel alloys and siderophile elements. It lies at a depth of 2900 km. The approximate radius is 3485 km. The temperature in the center can reach 6000°C with pressure up to 360 GPa. Approximate weight - 1.9354 1024 kg.
The geographic envelope represents the near-surface parts of the planet. The earth has a special variety of relief. Approximately 70.8% is covered with water. The underwater surface is mountainous and consists of mid-ocean ridges, submarine volcanoes, oceanic plateaus, trenches, submarine canyons and abyssal plains. 29.2% belongs to the surface parts of the Earth, which consist of deserts, mountains, plateaus, plains, etc.
Tectonic processes and erosion constantly affect the change in the surface of the planet. The relief is formed under the influence of precipitation, temperature fluctuations, weathering and chemical influences. Glaciers, coral reefs, meteorite impacts and coastal erosion also have a particular impact.
The hydrosphere is all the water resources of the Earth. The unique feature of our planet is the presence of liquid water. The main part is in the seas and oceans. The total mass of the World Ocean is 1.35 1018 tons. All water is divided into salt and fresh, of which only 2.5% is drinking. Most of the fresh water is enclosed in glaciers - 68.7%.
Atmosphere
The atmosphere is the gaseous envelope surrounding the planet, which consists of oxygen and nitrogen. In small quantities are carbon dioxide and water vapor. Under the influence of the biosphere, the atmosphere has changed a lot since its formation. Thanks to the advent of oxygenic photosynthesis, aerobic organisms began their development. The atmosphere protects the Earth from cosmic rays and determines the weather on the surface. It also regulates the circulation of air masses, the water cycle and heat transfer. The atmosphere is divided into stratosphere, mesosphere, thermosphere, ionosphere and exosphere.
Chemical composition: nitrogen - 78.08%; oxygen - 20.95%; argon - 0.93%; carbon dioxide - 0.03%.
Biosphere
The biosphere is a collection of parts of the shells of the planet inhabited by living organisms. She is susceptible to their influence and busy with the results of their vital activity. It consists of parts of the lithosphere, atmosphere and hydrosphere. It is home to several million species of animals, microorganisms, fungi and plants.
