The Earth's atmosphere is a layered shell of gases, held in place by gravity, with a significant portion of its mass concentrated near the surface. Dominated by nitrogas at about 78% and oxygen at around 21%, the remaining percentage is made up of argon, CO2, water vapor, and trace gases. As you move up, the temperature generally declines in the lowermost troposphere, before rising in the stratosphere due to the presence of the ozone layer, and again increasing in the thermosphere. The atmosphere's mass is mostly confined to the upper 5.6 km, with a staggering 99.99997% below the 100 km mark, where the Kármán line serves as a boundary into space.
Earth's atmosphere is essential to life, yet the invisible gases that form our "security blanket" can be hard to grasp. A new five-part series looks at our atmosphere, human impacts on it and ways NASA is studying the changing air we breathe.
science.nasa.govEarth - Atmosphere, Climate, Ozone: Earth is surrounded by a relatively thin atmosphere (commonly called air) consisting of a mixture of gases, primarily molecular nitrogen (78 percent) and molecular oxygen (21 percent). Also present are much smaller amounts of gases such as argon (nearly 1 percent), water vapour (averaging 1 percent but highly variable in time and location), carbon dioxide (0.0395 percent [395 parts per million] and presently rising), methane (0.00018 percent [1.8 parts per...
www.britannica.comAll around and reaching up to thousands of kilometers above the surface of the Earth extends an invisible layer that makes life on this planet possible. The atmosphere that living things enjoy resulted from Earth's position as the third planet from the sun, combined with billions of years of gas accumulation. The atmosphere comprises the air that organisms breathe, all the weather that happens in every corner of the globe, and the protective layer that keeps the sun’s rays from damaging life.
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