Origin of the Earth
Origin of the Earth The universe is between 10 and 20 billion years old, and the common accepted age is 15 billion years. This is a very long time. To appreciate its depth, we'll map the history of the universe into one of our twelve-month calendar years. Our cosmic year begins with the formation of the universe at midnight. Although a lot goes on in the first few months, our galaxy, the Milky Way, doesn't form until May 1 and our solar system is absent until around September 9. Earth forms on September 14 and life originates in late September or early October. The Eukaryotes, the first cells with nuclei, are flourishing by mid-November but most of what we know about the history of life occurs in December. December opens with an increase in oxygen in our atmosphere, a by product of oxygen-producing algae that destroy themselves by overproducing oxygen. The first worms appear in mid-December, and plants begin colonizing the land around December 20. Life enters middle ag...