The sun is a star located at the center of our Solar System, and takes up most of the mass of out solar system (99.86% of the solar system). In fact, the sun is so big that about a million earths could fit inside of the sun. the sun controls the climate and weather of the earth, and is about 4.6 billion years old. The surface temperature of the sun is about 5500 degrees Celsius. Hydrogen makes up 74% of the sun, helium makes up 24% of the sun, and other heavier elements like oxygen and carbon make up the rest.