Atmosphere is a set of gases that surround the Earth, it has no smell, color and taste. This part of the biosphere is indispensable, as it offers living conditions on the planet, in addition to regulating the temperature of the Earth, provide conditions for the occurrence of the combustion process, facilitate the propagation of sound and spread the light.
According to estimates, the appearance of the atmosphere took place approximately 4 billion years ago. Its formation took place when the planet Earth, after having undergone enormous heating, began to cool down, so from its interior was being expelled water vapor, and a considerable amount of gases, among others elements. They headed towards outer space, but a part was fixed around the planet, an event provided by the gravitational force.
The primitive atmosphere held in its composition gases with poisonous substances, the unfeasible reality for life underwent changes positive from the emergence of oceans and (marine) plants that, through the process of photosynthesis, changed the condition adverse. The current configuration of the atmosphere was consolidated about 65 million years ago.
The Earth's atmosphere today is made up of different gases, of which we can highlight: nitrogen, with 78%; oxygen, 21%; and other gases (such as carbon dioxide, neon, ozone, helium and water vapor) 1%. The percentages presented are essential for the proliferation of life on the planet.
The atmosphere is composed of several layers, which differ according to physical and chemical aspects. The layers of the Earth's atmosphere are: troposphere, stratosphere, mesosphere, thermosphere and exosphere.
By Eduardo de Freitas
Graduated in Geography
Source: Brazil School - https://brasilescola.uol.com.br/geografia/a-origem-atmosfera.htm
