Earth
Earth is the third planet from the Sun in the Solar System, the only planet on which life is known, the home of humanity. Earth belongs to the terrestrial planets and is the largest of these planets in the solar system.
Scientists believe that our entire solar system, and stars, and planets, and their satellites were formed from clouds of cosmic gas and dust almost at the same time - about 4.5 billion years ago.
If you look at our planet from space, it looks like a giant ball. The earth is like a big ball that is slightly compressed from above and below.
Most of our planet is covered with water. Dry land occupies only ¼ of the surface of the globe. The rest of the area is occupied by oceans, seas and other bodies of water. Therefore, if you look at our planet from space, most of its surface will be blue.
The Earth is surrounded by an atmosphere - a dense layer of air more than 500 km thick. The atmosphere protects our planet from meteorites, most of which burn up in the upper layers of this protective shell without ever reaching the earth's surface. In addition, the atmosphere contains oxygen - the gas that all living things breathe.
The structure of the atmosphere: the troposphere (rain, snow, hail are born here - everything we call precipitation), the ozone layer (a thin layer of ozone gas that protects our Earth from ultraviolet solar radiation), the stratosphere (it is always sunny in the stratosphere. In this layer, jet aircraft flights), ionosphere (the air here is very rarefied, radio waves "travel" through the ionosphere around the Earth).
A very thick layer of atmospheric air passes the sun's rays, which illuminate and warm the Earth, and, like a transparent fur coat, keeps the heat received by the Earth inside. Thus, it is the atmosphere that protects the planet from hypothermia and overheating.
The earth is like a giant multi-layered cake, the layers of which are formed by different rocks. The upper layer is called the earth's crust, the middle layer is called the mantle, and the inner layer is called the core.
Earth’s crust
Earth's crust is the layer on which you and I live. The earth's crust does not end where the sea begins, but continues underwater. At the bottom of the oceans, it is 6-10 km thick, and on the continents - 35-70 km.
The mantle is a layer of rocks 3,000 km thick that underlies the Earth's crust. The temperature inside the mantle is high - about 2000 C. This is enough for some rocks to melt, collecting underground in huge lakes of heated substance mixed with gases - magma.
Earth's core was discovered by scientists in 1936. It is divided into external and internal. Like a huge internal battery, the core helps the Sun warm our planet.
The outer core is liquid and consists mainly of very hot - 4000-5000 C - molten metals.
In the very center of the planet is the inner solid core. Scientists assume that its temperature reaches 6000 C.
It is not easy to learn anything about the structure of the Earth's interior, because the depth of the deepest well is a little more than 12 km, and the distance from the Earth's crust to the center of the core is about 6370 km. Seismology, the science of earthquakes, comes to the aid of scientists. During earthquakes, seismic waves occur that spread from the center of the earthquake in different directions. By the nature of these waves and the speed of their propagation, scientists learn about the properties of substances in the depths of the Earth.
The surface of our planet
The surface layer of the Earth is called the Earth's crust. Under it is the mantle, which makes up 80% of the planet's volume. In the center of the Earth there is a core: outer liquid and inner solid. The temperature inside the Earth reaches 5000 C.
Oceans of our planet
Oceans occupy more than 71% of the Earth's surface. There are four oceans on Earth: Pacific (178.7 million sq. km), Atlantic (91.6 million sq. km), Indian (76.2 million sq. km), Arctic Ocean (14.8 million sq. km .km).
Forests produce only 20% of the oxygen on the planet, 80% is produced by phytoplankton drifting in the ocean.
The equator divides the globe into the Northern and Southern hemispheres. Its length is over 40,000 km. The equator crosses 13 countries. At the equator, the duration of day and night is the same throughout the year. There is no twilight here.
There are 170 rivers on earth with a total length of more than 1000 km. The longest rivers are the Amazon (6992 km) and the Nile (6853 km).
There are 117 million lakes on the planet Earth, which is 4% of the Earth's surface.
The highest point on Earth is Mount Jomolungma (8848 m above sea level). Man first visited its peak in 1953.
The lowest point in the ocean is the Challenger Trench in the Mariana Trench in the Pacific Ocean (10,994 m below sea level).
Continents of our planet
There are 6 continents on Earth: Eurasia (54.7 million sq. km), North America (24.7 million sq. km), South America (17.8 million sq. km), Africa (30.3 million . sq. km), Australia (7.7 million sq. km), Antarctica (14 million sq. km).
Asia is the largest part of the world. All climatic zones are represented here - from the zone of arctic deserts to humid tropical forests.
America is a part of the world that unites two continents: North America and South America. It is located in the western hemisphere of the Earth.
Africa is the hottest part of the world. Here is the largest desert in the world - the Sahara (9 million square kilometers).
Africa is the second largest continent after Eurasia. The total area of the continent is more than 30.27 million square kilometers. Africa is the only continent located in all four hemispheres of the Earth: Northern, Southern, Eastern and Western.
Antarctica is the only uninhabited part of the world. The entire area of Antarctica is covered by a thick layer of ice. This is the highest continent, the average height is about 2 thousand meters above sea level.