As we all know, our beautiful earth is surrounded by a thick atmosphere, which is the basic condition for life on earth. We breathe fresh air freely every day, but you never thought that the air we breathe freely now is actually the result of billions of years of uninterrupted “adjustment” and “correction” of the atmosphere. Isn’t it surprising?
Among the many planets in the solar system, the earth’s atmosphere is very precious and unique. Compared with Venus’s atmosphere full of corrosive gas, and Mars’s atmosphere full of carbon dioxide and very thin, the earth is a paradise.
However, the earth’s atmosphere hidden secret, let’s take a look at it!
1、 The first mass extinction was due to oxygen
About 3 billion years ago, the earth entered another stage of development. The earth’s primitive atmosphere contained ammonia, methane, hydrogen sulfide, carbon dioxide, hydrogen, water and other components, but there was no free oxygen. Some gases in the atmosphere and some soluble substances on the surface of the crust dissolved in water, and naturally synthesized a new compound under the action of cosmic rays, ultraviolet rays of the sun, lightning and high temperature A series of small molecule organic compounds.
After that, life began to be born, and cyanobacteria quickly occupied the earth. Cyanobacteria was the earliest photosynthetic oxygen releasing organism, which played a huge role in the transformation of the earth’s surface from an anaerobic atmosphere to an aerobic environment.
At that time, the earth was basically anaerobic, so there was the first mass extinction. Since then, the earth’s atmosphere has changed from anaerobic to aerobic, creating a necessary living environment for more complex organisms.
2、 The oxygen concentration used to be twice as high as it is now
Although the oxygen in our atmosphere was initially produced by cyanobacteria, the increase in oxygen was mainly due to the production of large plants all over the world. According to research, plants began to soar in the Devonian period 405 million years ago.
In the Carboniferous period, the earth’s oxygen content reached its peak, accounting for about 40%, so the animals and plants in that period were very large.
3、 The greenhouse effect in the past is far more serious than it is today
Since the industrial revolution, carbon dioxide and other endothermic greenhouse gases discharged into the atmosphere by human beings have increased year by year, and the greenhouse effect of the atmosphere has also increased, which has caused a series of problems and attracted the attention of all countries in the world.
But you know what? In 542 million years ago, the earth’s carbon dioxide content was more than 10 times higher than today’s, so the average temperature at that time might be about 30 degrees Celsius. Later, because of the advent of the ice age, leading to global cooling, so the content of carbon dioxide also decreased.
4、 The sky is purple
Because of the Rayleigh scattering effect, the atmosphere scatters part of the light with short wavelength and suppresses the light with longer wavelength. Because the wavelength of purple is the shortest of all colors, the real color of the sky is purple. However, our naked eye is more sensitive to blue light than purple light, so we see a blue sky.
These are the secrets of the atmosphere that are not known to the public. After reading them, do you feel that you have gained knowledge! What can the atmosphere do to the earth? The natural composition of the earth’s atmosphere has many functions, including the following five aspects
1、 To maintain the cycle of water balance, all biological species on earth must rely on water.
The atmosphere is saturated with the gaseous water evaporated by the earth’s sunshine every day, and can return to the earth in the form of rain or snow and fog in the morning, which can ensure the circulation of the earth’s hydrosphere and complete the timely replenishment of water in the biosphere, which is conducive to the healthy life of the biosphere.
2、 Maintain the transition of surface oxygen
Under the action of the atmosphere, the oxygen emitted by the land and the animal circle every day can not be released into outer space. Insisting on excessive oxygen on the earth’s surface will help the biosphere support life.
3、 It acts as a shield against solar thermal radiation
The ultraviolet thermal radiation of sunlight is very fierce, and the atmosphere can act as a shield to it, which can reduce the ultraviolet radiation of sunlight to the life compliance range of the earth’s biosphere. Conducive to the benign growth of the earth’s biosphere.
4、 Ensure the fluctuation of liquid water
Under the action of the atmosphere, it can maintain the fluctuation of liquid water on the earth’s surface and ensure the stock of liquid water on land, rivers and lakes. It is conducive to the healthy life of the earth’s biosphere.
5、 It can maintain the fluctuation of surface environment
According to the detection of geographers, there are about 36 kilotons of material from space entering the atmosphere every day, which is usually the state of some rocks or asteroids entering. When giant rocks or asteroids enter, if there is no friction between the atmosphere and the earth’s surface, they will indirectly hit the earth’s surface, which will destroy the fluctuation of the living environment on the surface, so the role of the atmosphere for human beings It’s very important for us to understand the atmosphere, but some human actions are harming the atmosphere, which is absolutely impossible.
What do you think of the earth’s atmosphere? Welcome to comment area.