Looking up into the sky at night you can see many stars and other objects. Early mariners used the stars for navigation. Today we know much more about the stars, planets, Sun, moon and other objects in our sky. The Universe is a near endless space filled with galaxies, stars, planets and other objects like asteroids and meteorites. Each galaxy can contain potentially billions of stars or suns. The Earth's sun is part of the Milky Way galaxy. The Earth's sun is at the center of our Solar System. The Solar System includes all the planets that revolve around the Sun, and the moons that revolve around the planets. Our solar system consists of 9 planets that revolve around the Sun. These planets, listed from the closest to farthest from the Sun, are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.