On a clear night you can see a large golden band in the sky, like a cloud. This cloud is actually made up of millions of stars, and is what we call the Milky Way System, or simply the Milky Way. We can only see a part of the Milky Way in our sky. The whole thing looks like a big wheel. It is thick in the middle and becomes thinner and thinner towards the outer edges. This part is call 'star mist'. Like everything in space the wheel is always turning.

Where does the Earth fit into it all? Imagine the Milky Way as a windmill which never stops turning. ON the end of one sail there is a light. This light is the sun. Next to this light is a much smaller one: the Earth. Around the light buzzes a bee: the moon. The moon turns around the Earth, both turn around the sun., The sun, the Earth and the moon turn around the axis of the Milky Way. It takes 200 million years for the Milky way to complete one turn. Astronomers believe that there are millions of Milky Ways in the Universe; at least 400 million galaxies are detectable from Earth. Each Milky Way is made up of millions of stars.