There are nine planets in our solar system all circling the sun by a gravitational pull. The nine planets are in this order: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. (Pluto is actually a dwarf plant)
Earth is a smaller planet than others in our solar system and yet life has lasted longer here. That is mainly because all the other ones are to hot or to cold and some like Jupiter are made of gas. The way Earth protects itself from the heat is the O-Zone layer. Petrol and gases destroys the O-Zone layer and causes global warming.