The origin of the earth took place approximately 4600 million years ago. Initially, the earth was rocky, hot and barren. Its atmosphere was sparse, which was made of hydrogen and helium gases. It was very different from today’s Earth’s atmosphere. With many events and actions, this rocky, deserted and warn! earth has turned into a beautiful planet. About 380 million years ago, life originated on this planet. The structure of the earth is spherical, whose outer part has less density and the inner part has more density.