What is Atmosphere?
The Earth consists of mainly oxygen, the air we breathe as well as some other gases. This mixture of gases is called the atmosphere. The atmosphere is a mixture of nitrogen, oxygen and other gases which surrounds the Earth. The atmosphere is thickest near the Earth’s surface and gets thinner with height. There is almost no air above 480 kilometers. Scientist have divided the atmosphere into 5 layers.
5 Layers of the Atmosphere
The troposphere is the atmosphere’s lowest layer. It ends at about 15 kilometers above the Earth’s surface. It has a high quantity of water vapour which contributes to the ‘Greenhouse Effect‘. This effect traps the heat of the sun close to the surface of the Earth and keeps our planet warm.
2. Stratosphere –
The stratosphere is located just above the troposphere and below the mesosphere and ranges between 10 to 50km above the Earth’s surface. It contains the Ozone layer, which shields us from the harmful effects of the sun’s rays.
3. Mesosphere –
The mesosphere ranges between 50 to 80 kilometers above the Earth’s surface. It is the coldest region of the atmosphere. Temperatures here fall as low as – 100 degrees Celsius.
This layer spans almost 480 kilometers and is extremely hot as the air absorbs lots of solar radiation. Temperatures can reach up to 2,400 degrees Celsius!
The exosphere is the last layer of the Earth’s atmosphere. It has no fixed end and eventually thins out till it reaches outer space.
Interesting facts about the Atmosphere
The atmosphere is vital for sustaining life on Earth. Humans and animals need it for oxygen that we breathe, while plants on the other hand need carbon dioxide for photosynthesis – generating oxygen. Also the ozone layer in the atmosphere protects us from the sun’s harmful ultraviolet rays.
Things to do –
- To see plants breathe oxygen, tie a plastic bag around it and leave it just the way it is over-night. You will find tiny-droplets of water on the plastic bag. These tiny droplets are formed when plants breathe.
- Learn more about atmospheric pressure with the help of these stories – Atmospheric Pressure – I and Atmospheric Pressure – II.