About 4.6 billion years ago our Earth looked very different than it does today. Instead of the beautiful blues, greens and whites of today, it would have looked red and orange. The surface of our planet was covered in oceans of hot lava. Instead of breathable oxygen, the atmosphere contained a mix of deadly poisons.
For the first 500 million years, the Earth would remain as a giant lifeless ball of fiery lava. For another 300 million years after that, it would be too hot for liquid water to form. Finally, after 800 million years, an unimaginably long period of time, our home planet cooled enough for liquid water to begin to form. Everywhere rains began to fall, filling the lower portions of the Earth with water, forming lakes, oceans and rivers. |
Still, there was no life. No fishes to fill these oceans, no plants to cover the rocky surface, no animals to graze the wilderness. Just a barren wet rock, orbiting the Sun. The Earth's atmosphere now contained a mix of very poisonous gases, including carbon monoxide, carbon dioxide, nitrogen, hydrogen sulfide, methane, and cyanide. Breathing this air would cause death to most lifeforms as we know them.
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