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Aardvark Communications:

A Practical Guide to Astronomy


Earth Bound


Life Forms on Earth

One and a half billion years after the creation of the Earth, amino-acids began to form into proteins in the deep and warm oceans of this planet. These proteins began to form 'stromadelite' colonies in more shallow waters. Amphibians then came onto land where plant life was waiting for them. Then 225 million years ago, the dinosaur ruled the planet. The most common theory to the extinction of dinosuars is that a huge asteroid crashed onto Earth, poisoning the atmosphere.

What's the Earth Made Of?

Above ground, the Earth's atmosphere reaches 400 km (250 miles). The atmosphere is made of 78% nitrogen, 20% oxygen and traces of carbon dioxide. Our planet's weather relies on this atmosphere, along with the oceans and the air, hence our concern for the environment and ozone depletion.

Below ground, the Earth rests on 'tactonic plates' -when they move we get earthquakes. These plates float on 'magma' which is liquid rock. For more information on this check out Aardvark's Volcano Web.

What Could Happen to the Earth?

There are a number of ways we could see the end of the Earth, not counting by our own hands. We could be suffocated by poisonous clouds brought apon by a crashing asteroid, like the dinosaur. Or our sun could expire, leaving us in a deep freeze. Or perhaps we could be sucked into a giant black hole at the center of our galaxy. Any of these could happen, but not likely in our lifetime.

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