Life is possible on the Earth because of the following reasons:
1. Presence of essential elements:
The earth has essential elements like carbon, hydrogen, nitrogen and oxygen. These elements combine to form proteins- the building blocks of life.
2. Presence of oxygen:
Life cannot survive without oxygen. The Earth has a large amount of oxygen in the air.
3. Presence of water:
Water is also essential for life. The Earth has vast reserves of water. Water regulates body temperature and also helps in processes like digestion, excretion, etc.
4. Presence of atmosphere:
The atmosphere has a protective layer of ozone gas which saves the Earth from harmful effects of ultraviolet radiation from the sun.
5. Temperature of Earth:
The Earth’s distance from the sun gives it the right temperature for the development of life-forms. If there were even a ten percent increase or decrease in the distance from the sun, the Earth would have been a cold or hot desert.
6. Right amount of mass and gravitational force:
The Earth has the right amount of mass. This mass produces strong gravitational force. This force holds the atmosphere intact.