Atmosphere

The atmosphere is the layer of gases that surrounds the earth. It is held in place by the planet’s gravity and forms a protective envelope around it. The atmosphere is essential for life because it provides the air that humans, animals, and plants need. It also helps control Earth’s temperature and protects living things from the sun’s harmful radiation and space debris.

The atmosphere is made up of several gases. The main ones are nitrogen (about 78%), oxygen (about 21%), and small amounts of other gases such as argon, carbon dioxide, and water vapor. oxygen is used by animals and humans for breathing, while plants use carbon dioxide for photosynthesis. Water vapor in the atmosphere helps form clouds and rain.

Scientists divide the atmosphere into layers based on temperature changes. The lowest layer is the troposphere, where we live and where most weather happens. Above it is the stratosphere, which contains the ozone layer that absorbs most of the Sun’s ultraviolet radiation. Next are the mesosphere, where meteors burn up, and the thermosphere, which can get very hot and contains the auroras or northern and southern lights. The outermost layer is the exosphere, where the atmosphere gradually fades into space.

The atmosphere plays an important role in keeping Earth’s temperature suitable for life. It traps heat from the Sun through a process called the greenhouse effect, keeping the planet warm enough for water to stay liquid. Without the atmosphere, Earth would be much colder during the night and much hotter during the day.

The air in the atmosphere moves constantly, creating winds that distribute heat and moisture around the planet. This movement helps shape weather patterns such as rain, snow, storms, and calm days. Air pressure and temperature differences cause the movement of air between regions, forming global wind systems that affect climate and ocean currents.

The atmosphere is also shared by all living things. Pollutants from human activity, like smoke and gases from factories or vehicles, can harm the atmosphere and affect air quality. Scientists study the atmosphere to understand climate change, predict weather, and protect the balance of gases that make Earth suitable for life.