We've had a lot of questions like this. We decided that yours required an answer from a young scientist in the classroom near yours. G., room 3, did some research and this is his answer.

It is known that the history of the Earth stretches more than 4 billion years, although how the Earth formed is still not known for sure. Some scientists say that it formed from gas and dust changing forms and blending together.

Others think of it as having emerged from a cloud of meteorites or meteoric dust spinning around the sun. The forces of gravity caused the pieces to come together, or accrete, with heavier particles gravitating to the centre and lighter ones collecting outside. This coming together of the mass created heat, which caused melting and the gradual forming of three layers: core, mantle and crust.

There are lots of good books in your school library about the planets. Here are a few that we have looked at.

The Solar System

Robin Kerrod

523.2 ker

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My picture book of the planets

Nancy E. Krulik

523.4 kru

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