Fill in the blanks choosing from the words/phrases: light, heavy, terrestrial, gas giant, gravity, temprature, hot, cold, rock and metal, water ice (Check spelling before submitting!) You may use an answer more than once. The primary reason we have two different types of planets is because decreases with distance from the Sun. Close to the Sun it is too to condense from the nebula so are made out of rock and metal. Far from the Sun it is enough for to condense and being mort t than rock and metal forms larger planets..