Space is interesting!
Look at the sky. It seems that it is very close-reach out and touch the sun or the moon, well, if you climb to the top of a tall tree, you will find yourself next to them. But actually it is not so. Neither we can reach the sky with our hand, nor the trees with our tops. The sun, moon and stars are very far from us. This is a large planet to which you want to fly in a spaceship.
There are 8 planets in the solar system. All of them are circling around the Sun, and constantly on the same path, which is called the orbit. And one of these planets is our Earth.