For thousands of years people have been looking at the sky and wondering what those objects are all about. The glittering stars and the Sun have always hid a certain amount of mystery and beauty.
For astronomers, the Sun is just a dying star. For everyone else, however, it is a huge burning ball that gives us light, warmth and life. So far so good.
But what really burns our Sun? It is a well-known fact that there is no air in the cosmos. Accordingly, there is no oxygen to burn. Our everyday experience tells us that burning is a sequence of exothermic chemical reactions between a fuel and an oxidant. However, this is not the only kind of reaction. The sun really burns – but there is a nuclear rather than a chemical reaction.
Our star burns hydrogen. And in huge quantities – a few hundred millionths of a second. Do not worry – it has enough fuel that will allow it to exist for another 5 billion years.