Sol – Our Sun

Life on earth was possible due to the presence of water, oxygen, an atmosphere and the ideal ambient temperature. Sun has been the biggest supporter of life on Earth.

The Sun is a hot ball of hydrogen gas emitting heat from 150 million kilometres. The distance is just appropriate for the Earth to be in the habitable zone also known as “Goldilocks Zone or Circumsteller Habitable Zone“. This zone is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressure. This zone varies in distance with respect to the star. The star type dictates the boundaries of the CHZ and any object found orbiting the star in this region is an ideal location to search for life.

The CHZ ensures the ambient temperature is optimum for various life forms to grow and evolve in the natural environment. If the star was closer than it is right now, the temperatures on the planet will not have let plants and water to survive. Plants would die of excessive heat while the water would evaporate. The gravity would also be stronger than it is resulting in the atmosphere to be much higher from the surface and hence the density of air and atmospheric pressure at sea level to be reduced. If Sun, on the other hand, was further away than it is now, the temperatures on the planet would drop sharply causing everything to be frozen, the water would not stay in liquid form and hence the life would not be possible.

According to the most acceptable theory on “Formation of Water on Earth”, the water was the result of tragic and violent past of the solar system. It is believed that comets came crashing on Earth and carried a large chunk of water and other chemicals like nitrogen and hydro-carbon which were the building blocks of life. If Sun was not there at the centre in the beginning, it gravitational pull would not have pulled all the troubled comets towards the inner solar system and hence these compounds would not have reached earth.

The heat of Sun also ensures the water is evaporated and condensed at regular interval causing the water to flow inland like the glaciers in the Himalayas, Alps etc. The rains on the land ensures ground water storage which provide water to the population living inlands away from big water sources.

The light of Sun causes the plants to make their own food using chlorophyll with water and minerals available in the soil. This makes the plants survive. They give out Oxygen and consume CO2 which is essential for us humans and other species to survive.If plants were not filtering the atmosphere, we would have exhausted all the oxygen and would have not survived this long. The plants are also used as food for the herbivorous animals and vegetarians human being. This is their direct source of energy. While carnivorous animals do not eat plants but they are dependent on most of the herbivorous species and hence indirectly receive their food or energy from the plants and by extension from Sun.

Of course there were more such factors and we can not rule out the role of Moon and the active core of Earth but the most important role has been played by Sun in our existence and the existence of our planet..