Several theories offer explanations as to how began. Of course we believe the big bang was actually the beginning of all masses that represent the planet's the stars and all other heavenly bodies.
However the earth itself may have formed as a result of the many fragments from this big bang colliding together with forces that generate such intense heat that the end result is a mass of molten rock.
Over millions of years as the planet began to cool, gases from within the earth began to form what we now consider our atmosphere . The gravity of the earth held these gases in place and in time as the earth began to cool , the surface hardened to form what we now consider land . The earth still in its infancy, continued its violent beginnings to form areas that would solidify as it continued to cool.
The gases in the atmosphere began to collect which formed huge clouds which contained many elements that began to fall in the form of rain , which nonstop continued for thousands of years .
This was as a result of the rain falling on this hot surface causing steam to rise back into the atmosphere which began to collect as clouds which in turn became more and more like we have today as rain clouds, unlike the early formations of clouds which contained extremely harmful chemicals whereas human life could not be sustained . And as this process continued , the constant rain began to cool the service even further, thereby allowing rain to begin to collect in areas that were cooler so that it would not evaporate back into the atmosphere .
As these rains continued, the water continued to collect more and more as the surface was cool enough, so that vast amounts of water would collect until there was so much it formed what we now have as oceans. However life still was not a part of this process . Not until millions and millions of years was the earth hospitable to begin to form life in its most simple list forms .
Once life began to take hold it was a matter of time before the planet was suitable for the inhabiting of life as we know over the past thousands of years . Today we still see some of the violent events but at a much smaller scale . These events can still change the conditions for which life as we know it can survive . Our planet is one of a delicate balance with its place in relationship to the sun and other planets . The earth itself is still continues to evolve , and the changes are something we witness today .