The Sun is the main source of energy for earth. It gives us heat and light and helps us to remove darkness and bring light all around the world. The Sun rises in the east and sets in the west. In olden days people use to worship Sun as God because it was the only visible powerful thing. In the early morning, birds welcome the Sun with a lovely and chirping song and this gives an indication to the mankind about the arrival of the new day. In the early morning, the sunrays helps us by providing Vitamin D which is essential for our skin. Some people are seen basking in the sunshine to get useful Vitamin D and get tanned as well.
The Sun helps the plants in preparing their food through its light by a process called as photosynthesis. Thus, Sun is also essential for plant because if there were no Sun, plants would not have been able to prepare their food and survive. Human beings get their food from plants and so in the absence of the sunlight human also would have died. In this modern world conventional sources of energy like coal, petrol, diesel and gas are being used extensively and so their stock are getting reduced. Scientists are worried that with this speed, these conventional sources of energy will be fully exhausted and so they are trying to harness the Sun by using its energy for solar batteries, solar heaters, and for running cars as well.
Sunlight also helps to stop the growth of bacteria, insects and thus prevent the spread of diseases like malaria, typhoid, etc. If there were no sun there would have been severe cold all around and no human beings, birds, and animals and plant could have survived. The Sun is the centre of solar system and all the nine planets revolve around its fixed orbit. During a solar eclipse, the Sun, Earth and Moon come in a straight line such that moon lies in between the Earth and the Sun. We should not see the Sun with our naked eyes because the rays emerging out are harmful for our eyes. The ozone layer above the atmosphere prevents the harmful ultraviolet rays from entering into the earth's atmosphere and thus protect the mankind from the harmful rays of the Sun.