The information for the following story is from Scholastic Canada's Atlas of the World.

The Earth's Interior

A few years ago, astronauts blasted off through the Earth's protective atmosphere of gasses. They passed through the ozone layers and into outer space on their first trip to the moon.

From their spaceship, we can only imagine their excitement as they looked with awe at the huge globe of rock and metal – our Planet Earth.

The astronauts could see the exterior of our planet – the large continents and oceans. But what they observed was just the very thin covering or "skin" of the Earth.

On the outside of the Earth we see continents and oceans, plants and animals, but what is going on inside our Earth?

For a great number of years, scientists have done a lot of research to find out what's inside this huge mass of material. They've learned a lot about the interior of the Earth by studying patterns of movements of earthquakes waves.