The Solar system is an arranged system, consisting of the central star, nine planets and a large amount of comets, asteroids and other objects. As you know, our planet, the Earth, is a part of it. It belongs to the four inner planets, which are often called terestrical. These all have a relatively low weight while having a rather high density and their surface is solid and rocky. Terestrical planets are surrounded by large planets, which consist of gas. The last planet is Pluto, whose qualities differ from both groups mentioned above. All of the planets go around the Sun in the same way in eliptic tracks with a small deviation from the ecliptic plane. However, each planet is unique in some way. You can learn the details about any of them by clicking the image the planet.