The Earth's Atmosphere
The layer of gas surrounding the Earth is called the atmosphere. This layer of gases plays a crucial role in sustaining life on our planet by providing oxygen for breathing, regulating temperature, and protecting us from harmful radiation from the sun.

Composition of the Atmosphere
The Earth's atmosphere is primarily composed of nitrogen (about 78%) and oxygen (about 21%), with trace amounts of other gases such as carbon dioxide, argon, and water vapor. These gases are essential for various biological and physical processes on Earth.

Layers of the Atmosphere
The atmosphere is divided into different layers based on temperature and composition. The troposphere is the layer closest to the Earth's surface where weather phenomena occur. Above the troposphere lies the stratosphere, followed by the mesosphere, thermosphere, and exosphere.

Functions of the Atmosphere
- The atmosphere acts as a protective shield by absorbing harmful ultraviolet radiation from the sun.
- It helps regulate the Earth's temperature by trapping heat through the greenhouse effect.
- The atmosphere also plays a crucial role in the water cycle by facilitating the movement of water vapor through evaporation, condensation, and precipitation.

Importance of the Atmosphere
The atmosphere is essential for sustaining life on Earth. Without it, the planet would be inhospitable, with extreme temperatures and high levels of radiation. By understanding the composition and functions of the atmosphere, we can better appreciate the delicate balance that supports life on our planet.

Atmosphere