Environment: Shielded by ozone
Dear friends, our earth is the most beautiful and life-sustaining planet in our Solar System. A blanket of invisible air covers it. Clean air is important for all living things. It helps to nourish plants and ensures the safe existence of animals. All gasses and particles in nature, particularly air, work like a team so that we can enjoy life on earth.
Earth’s atmosphere is composed of a variety of gases and other small particles. The most common gases in the air are nitrogen, oxygen and argon. In the air, oxygen is present in three different forms — oxygen atoms (O), as oxygen molecules (O2) and as ozone (O3).
Earth and the sun
We all know that earth receives light from the sun. Without the sun, earth would be dark and cold. The sun warms our seas and makes our seasons. Plants and trees also need sunlight for growth.
The sun emits two types of rays, infrared rays and ultraviolet rays. Infrared rays are visible to us and important to maintain life on earth, on the other hand, ultraviolet (UV) rays are both harmful and helpful for us. We cannot see these UV rays and they are of different types, just like visible light. The most common types are called UVA and UVB.
The UVB rays are harmful for all of us. The atmosphere offers resistance against this constant bombardment of harmful UV radiation before they reach earth’s surface, with the help of the ozone layer. Most UVB is absorbed by the ozone layer, so 99 percent of the ultraviolet radiation that reaches earth’s surface is UVA.