It is a member of the Milky Way galaxy. It is believed to be over 4 billion years old. The volume of the sun is 1,300,000 times the volume of the earth. Its density is 1.41 times the density of water. Its mass is 333,000 times the mass of earth. The sun spins slowly on its axis as it revolves around the galaxy. The centre or core of the sun is very hot. The sun is by far the largest object in the solar system. 98% of all matter within the solar system is found within the sun. Sometimes immense jets of flame erupt from the sun’s surface and shoot out into space. These are known as solar flares. The sun appears to have black areas on its surface. These sunspots are places where the surface is slightly cooler. Sunspots can be as big as the earth. This means that all the planets, moons, asteroids, minor planets, comets, gas and dust would all combine to make up only 2% of all the matter in the solar system. Because the sun is so large compared to everything else, it is easily able to hold on to the rest of the matter, causing everything else to orbit around it. There are eight planets in our solar system. All these planets travel around the sun. Planets are always spinning. A day is a time it takes a planet to spin around once. The time it takes a planet to travel around the sun once is called a year. This journey is called its orbit. The sun is at a distance of 150 million kilometres from earth. The diameter of the sun is 13, 92,530 kilometres. The temperature at the surface of the sun is 6000 degrees Celsius and at its core, it is 15 million degrees Celsius. The Sun is our closest star.