The history of the Earth explains the most crucial events and fundamental stages within the development of our planet Earth from its creation 4.578 billion years back to the current day. Almost all branches of natural science have got contributed for the understanding of the primary events from the Earth's past. Age of Earth is around one-third of age of the universe. An immense level of biological and geological change has happened that time span.
Earth formed around 4.578 billion years back by accretion through the solar nebula. Volcanic outgassing most likely created the primordial atmosphere; however it contained almost no oxygen and might have been toxic to humans and other living things. Most of the planet was molten due to frequent collisions and extreme volcanism along with other bodies. One huge collision is thought to have been responsible for tilting the planet earth at an angle as well as forming the Moon. With time, such cosmic bombardments ceased, enabling the planet to cool and form a great crust.
Geological and Biological change may be constantly taking place on the planet because the time of its creation. Organisms continuously evolve, dealing with new forms or perhaps going extinct responding to an ever-changing earth. The method of plate tectonics has played an important role within the shaping of continents and Earth's oceans, along with the life they harbor. The biosphere, in turn, acquired a significant impact on the atmosphere as well as other abiotic conditions on the planet, including the formation from the ozone layer, the proliferation of oxygen, as well as the development of soil. Though humans cannot perceive it because of their relatively brief life spans, this change is actually ongoing and can continue for the following few billion years.
Scientists are still trying to unravel one of the biggest mysteries of earth: When did life on earth begin and the way it happen. It's estimated that the very first life forms on the planet were primitive, one-celled creatures which appeared about three billion years back.