The Earth’s 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 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 layers.
THE LAYERS OF THE ATMOSPHERE
The ionosphere is the upper-most part of the atmosphere ranging between 85km to 600km. It is divided into four sub-layers. The ionosphere contains electrically charged atoms and molecules.
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.
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.
The troposphere is the atmosphere’s lowest layer. It ends at about 15 kilometers above the Earth’s surface. The atmosphere is thickest here. The troposphere is made up mostly of nitrogen and oxygen. It contains other gases as well, but in smaller quantities.
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 our easy-to-do experiments on www.mocomi.com
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