Archive for the ‘Earth’ Category
How Old Is The Earth?
The earth began to be formed over 4.5 billion years ago, but for millions of years nothing could live here. Gradually, the earth’s crust and atmosphere were formed and life could survive. There are two theories: the nebular hypothesis theory whereby a mass of white-hot gas whirled about in space getting smaller and hotter throwing of rings of gas which condensed to form a planet. And secondly the planetisimal theory: a huge mass of small, solid bodies called planetisimals. A greater star pulled on the sun and caused parts to break away attracting the tiny planetisimals. Astronomers have estimated that earth is 5,500,000,000 old!