the birth of the earth
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4.6 billion years B.C Collision of Rocks A long time ago millions of asteroids collided with each other so there were many rocks floating around in space. Scientists think that around 4.6 billion years B.C, these rocks began to collect together and then heat up. They formed a sphere that is not a perfect ball shape and is what we call Earth. |
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Toxic World
This was just before the first purple bacteria appeared. There was very little oxygen and UV rays were able to reach the surface of the Earth. So they were hundreds of times stronger than they are now. The atmosphere was toxic and it was full of methane and sulphur dioxide. Out of the gases in the air, only twelve percent of it was oxygen. The land, which was one giant supercontinent, was barren and lifeless. Victoria was under the ocean and nothing lived there yet. The ground would always erode off the continent, because no plant roots held together the sand. The sky was not blue. |
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Green Sunscreen
Green bacteria made a lot more oxygen than purple bacteria. It also made the sky blue. Then it made ozone which acts as a sunscreen. Plants can now start to live on land because of the ozone. |
2.5 billion years B.C
Purple Ocean 2.5 billion years B.C all life lived in water because of the toxic rays coming from the sun. The water changed colour because purple bacteria evolved making the water look purple. The purple bacteria gave a little O2 but not as much as the green bacteria which was to come. 
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