Air is a mixture of gases, mainly nitrogen (78%) and oxygen O 2 (21%). The bulk of the air (80%) is in the lower atmosphere - the troposphere. The troposphere is located at an altitude of up to 15 km from the Earth's surface. Above are the upper layers of the atmosphere, in which the air is so thin that they are unsuitable for life and are called "airless space."
Door to space
Above the troposphere, up to about 60 km in height above the surface of the Earth, a vast airless space extends. This is the stratosphere. This layer is called "pre-cosmos", or "door to space." Its main feature is a gradual increase in temperature vertically. From minus 60 ° C at an altitude of 15-20 km from the Earth's surface to plus 2 ° C, respectively, at the highest point of the stratosphere, approximately at an altitude of 55-60 km.
The stratosphere is a stable layer of the atmosphere in which air convection is absent.
Water vapor in this layer is practically absent. But at an altitude of about 25 km, so-called “pearly” clouds are sometimes observed. Their study and clarification of the nature of origin is carried out by scientists around the world.
Ozone layer - protective barrier
An important discovery was the discovery in the stratosphere of the ozone layer, consisting of special oxygen molecules O 3 . This layer has a thickness of only 2-3 mm, but performs a very important function of protecting the planet and all life on it from the harmful effects of ultraviolet solar radiation. Studying the properties of the ozone shield, scientists have found that freon gas, which was actively used in industry at one time, can destroy it. Currently, the use of freon is prohibited worldwide, since the destruction of the ozone layer will inevitably lead to the death of all life on Earth.
Space open spaces
Outside the atmosphere of the earth begins an endless airless space. This is space. Scientists believe that the whole cosmos consists of many galaxies. Each galaxy has its own structure. Humanity lives in a galaxy called the Solar System, which consists of a star - the Sun - and planets orbiting around it.
Scientists distinguish such concepts as "near" and "deep" space.
Near space objects are within the solar system. These are planets and their satellites, the moon, meteorites, asteroids, comets. Deep space objects are located outside the solar system. These are stars, galaxies, nebulae, black holes. Distances to them are calculated in light years.
Airless space. Learning difficulties
The main difficulty in studying the stratosphere is that at this altitude the air is extremely rarefied. Man cannot survive here without a special spacesuit. In addition to lack of oxygen for breathing, very low atmospheric pressure leads to the fact that blood boils in the human body. Naturally, this is incompatible with life. Therefore, the study of the stratosphere began relatively recently - in the 30s of the 20th century, when the so-called stratostat was invented. For the first time, the Swiss O. Picard and P. Kipfer climbed a stratosphere balloon to a height of 16 km. After 3 years, in 1934, the Soviet crew rose into the stratosphere layer. Unfortunately, this scientific expedition ended tragically - the entire crew died.
If the stratosphere is difficult to study, space exploration is generally incredibly complex, tremendously expensive, and often impossible at this stage of the development of science.
To study the objects of "near" space, spacecraft and interplanetary stations are used. So far, man has given way to machines in direct space exploration, since this place is extremely dangerous.
The study of objects of "deep" space is still possible only theoretically.
Anthropological use of airless space
Vacuum is a space absolutely free from any kind of matter, including air, that is, it is also an airless space. In heavy and light industry, in medicine, in construction, vacuum devices are widely used. In everyday life, this is a well-known vacuum cleaner. Obtaining absolute emptiness is incredibly difficult, and scientists are on the way to this goal. A truly deep vacuum exists only in space.
The stratosphere is an ideal place for military pilots. Shells do not fly so high, and bombers or reconnaissance flying vehicles here are practically invulnerable to air defense. Unmanned balloons, which help meteorologists to accurately predict the weather, are launched on the "second floor" of the atmosphere.
An airless space called space is used to launch satellites that provide communication on the planet, help in the search for minerals, give predictions of impending storms, cyclones and storms, and help prevent drought and floods.
The study of outer space radically changed some of the ideas of scientists about matter.
In addition, the study of space is driven by endless human curiosity, the desire to “look into the window”, to know the mysterious.