Atmosefääris

Atmosefääris, also spelled atmosphere, refers to the layer of gases surrounding a planet or other material body of sufficient mass. Earth's atmosphere is composed primarily of nitrogen (about 78%) and oxygen (about 21%), with trace amounts of other gases such as argon, carbon dioxide, and neon. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention (the greenhouse effect), and reducing temperature extremes between day and night.

The atmosphere is divided into several layers based on temperature changes with altitude. The troposphere is the lowest layer, where weather phenomena occur and where most of the atmosphere's mass is concentrated. Above the troposphere lies the stratosphere, which contains the ozone layer that absorbs most of the Sun's UV radiation. The mesosphere and thermosphere are the next layers, followed by the exosphere, the outermost layer that gradually fades into the vacuum of space.

Atmospheric composition and structure vary significantly among different planets. For instance, Venus has a thick atmosphere composed mainly of carbon dioxide, creating a runaway greenhouse effect that results in surface temperatures hot enough to melt lead. Mars, on the other hand, has a thin atmosphere composed primarily of carbon dioxide, with trace amounts of nitrogen and argon. The gas giants, such as Jupiter and Saturn, have atmospheres composed mainly of hydrogen and helium, with trace amounts of other gases.

The study of atmospheres is crucial for understanding planetary formation, evolution, and habitability. Atmospheric science involves the investigation of various phenomena, including weather patterns, climate change, and the composition and behavior of gases in different layers of the atmosphere. By studying atmospheres, scientists can gain insights into the processes that shape planets and other celestial bodies.