ORIGIN OF THE EARTH

ORIGIN OF THE EARTH

The earth is only one the nine planets and revolves around the sun through space. Nearly all branches of natural science have contributed to the understanding of the main events of the Earth's past. It has all favorable conditions required to sustain life. The earth is the only home for human beings, animals, plants and other organisms.  Scientist theories that the earth was born around 4.6 billion years ago out of the dust and gases. Volcanic outgassing probably created the primordial atmosphere, but it contained almost no oxygen and would have been toxic to humans and most modern life. However before coming into the present shape it was a fire ball surrounded by the clouds of hot gases. Much of the Earth was molten because of extreme volcanism and frequent collisions with other bodies. One very large collision is thought to have been responsible for tilting the Earth at an angle and forming the Moon. It took millions of years to cool down and the envelope of hot gases turns into clouds. These clouds rained for a long time and the rain water accumulated in the low lying areas of the earth which is turned into oceans of today. In the beginning, the earth was a gain land mass called Pangaea. This land mass gradually split into different land masses which are called continents today.

Mountains and volcanoes have resulted due to the upheavals in the interior of the earth. In the process of cooling, the upper surface of the earth became solid which we call as the earth crust. About 570 million years ago the life began on the earth in the form of micro-organism. Photosynthetic life appeared around 2 billion years ago, enriching the atmosphere with oxygen. The first 345 million years saw the development of adequate life. For the next 160 million years replies came into existence and subsequent 65 million year saw the development of mammals. The development of man is only an event of one million year old.  Biological and geological change has been constantly occurring on our planet since the time of its formation. Organisms continuously evolve, taking on new forms or going extinct in response to an ever-changing planet. The process of plate tectonics has played a major role in the shaping of Earth's oceans and continents, as well as the life they harbor. The biosphere, in turn, has had a significant effect on the atmosphere and other abiotic conditions on the planet, such as the formation of the ozone layer, the proliferation of oxygen, and the creation of soil.