Stages of the Earth’s Formation

The earth in its earliest stage existed in a molten form but gradually cooled off to give its hard outer surface but the core of the earth still exist in the molten form. Initially there was no water on the surface and the atmosphere did not contain any water. Now 71% of the earth’s surface is covered with water, one will ask where that water came from if the earth once existed in a molten form. One scientific explanation is that the water were deposits of icy comets collisions into the earth. Another explanation is that the water was a product of volcanic eruptions.

It is scientifically believed that the presence of the oceans (water) and the carbon dioxide rich atmosphere gave birth to simple structured species like algae.

The bio activities of these species started releasing oxygen into the atmosphere about 2.5 billion years ago, there was enough oxygen in the atmosphere for complex life to start. Currently our atmosphere is made up of 77 % nitrogen, 21 % oxygen, with significant amount of carbon dioxide, argon and water. Carbon dioxide supports plant life and also controls the temperature of the atmosphere and prevents cold temperature that might freeze the oceans.