Earthatmosphere

The Earth's atmosphere is the layer of gases surrounding our planet that is held in place by gravity. It is crucial for life on Earth, providing breathable air and regulating temperature. The atmosphere is primarily composed of nitrogen (about 78%) and oxygen (about 21%), with smaller amounts of argon, carbon dioxide, and trace gases.

The atmosphere is divided into several layers, each with distinct characteristics. The troposphere is the lowest layer, extending from the Earth's surface up to about 7-20 kilometers. This is where weather occurs and where most life exists. Above the troposphere is the stratosphere, which contains the ozone layer. The ozone layer absorbs most of the Sun's harmful ultraviolet radiation, protecting life on Earth.

Further up are the mesosphere, where meteors burn up, and the thermosphere, which is very hot but has very low density. The exosphere is the outermost layer, where the atmosphere gradually fades into outer space.

The atmosphere plays a vital role in the Earth's climate system. Greenhouse gases like carbon dioxide trap heat, preventing the planet from becoming too cold. However, increased concentrations of these gases due to human activities are leading to global warming and climate change. The atmosphere also protects us from harmful solar radiation and impacts from space.