The sun has about another five billion years of life ahead of it, as it turns hydrogen into helium in its core. When the hydrogen fuels runs low, it will burn some of the helium nuclei, fusing those into heavier nuclei. But at the same time it will swell into a giant red star, whereupon the Earth will be destroyed. Only a few million years after that, the sun will puff off some of its out layers and then shrink into a white dwarf, with an intensely hot surface, but so small that it gives out little light. It will then cool off for the rest of time.