This section is about how our Earth came to exist & how it came to be covered in water.
How the Earth was Created
In its simplest terms the Earth was created from Elementary Particles and the force of Gravity. But, it wasn't as simple, or a quick as it sounds. It took billions of years before the Earth came into existence.
- When the Universe began it created all the matter, or the elements, it would need to make everything that exists in the Universe today.
- To start with the matter just floated around as a big cloud of gas and dust. This was no ordinary cloud though, it was over 14 billion miles across.
- Then, 4.6 billion years ago, gravity took hold and started to to turn it into everything we see around us today.
Our Sun & Solar System
- Part of this Universal cloud of dust fell in on itself as a result of the gravitational force & formed our Sun & Solar System.
- The cloud's own gravitational force had become so strong it started to pull the dusty elements into the middle. As it did this, the dust in the cloud began moving in a giant circle, like the water in a sink as it drains away. This forced the dust and gas in the middle of the cloud to pack itself into a tight ball.
- This ball was the beginning of our Sun. The ball got heavier and heavier as gravity forced the dust closer and closer together. This made a lot of heat and eventually it ignited. Our Sun had been created.
- 4.6 billion years later the you can still see the Sun burning in our sky today. It provides our planet with the light and warmth, which is essential to life on our planet.
At the same time a similar thing was happening to much smaller clouds of dust and gas around the Sun. These formed the Earth and all the other planets and moons in our solar system.
- The earth probably took as long as 200 million years to form. That's a very long time.
- To start with the earth was made of fiery lava. It was so hot you would not have been able to stand on it.
- The earth was like this for 500 million years.
- During this time big lumps of space rock called comets and meteorites crashed onto its surface.
- As amazing as it might seem, these rocks from space actually contained the water that would eventually fill our seas.
- But the seas would not form for another 300 million years. This was because the earth was too hot for the water inside the rocks to turn into liquid.
- Finally, the earth started to cool down. The surface became solid and the water inside the space rocks turned into liquid. It started to rain and the oceans, lakes and river filled with water.
- Although the earth's surface was now cool enough to walk on, if you had been there you would not have been able to breath the air. Instead of the oxygen we breath today, the atmosphere was a deadly mixture of poisonous gases. These gases were carbon dioxide, nitrogen, methane, and sulphur.
- Although deadly, if there had not been so much carbon dioxide in the air back then, life might never have begun on earth. This is because the carbon dioxide acted like a blanket around our planet stopping it from freezing into an icy ball forever.
- Carbon dioxide is a Greenhouse gas. This means that it traps some of the warmth from the Sun inside the earth's atmosphere keeping the planet warm. In the same way the glass on a greenhouse traps the heat from the Sun inside the greenhouse.
The Start of Life on Earth
- Although we could not have lived on the earth as it was 3.85 billion years ago, somehow life on earth began back then. The conditions on earth, although deadly to us now, were just right at that time for life to begin.
- The life that formed 3.85 billion years ago was very different to the complex life we know today. It was very simple. It didn't watch TV, it didn't go to school, it didn't drive a car, it didn't even walk, hear or talk. It was just one very small cell that did no more than it needed to just live.
Move onto our next section if you would like to know about how life came to be on Earth
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