What will hapen to the sun?

Answer 1

Well, in about 500, 000,000,000,000 (fivehundred billion) years from now (when we are all dead) the sun will lose it's light and die out. Then it will explode like all the other stars in our universe.

EDIT: Actually - scientists reckon the sun will last about another 6,000 years in its present state before it transforms in to a red giant - swallowing up all but the outermost planets. After an undetermined period in this state, it will 'blow off' most of the gasses that make up the bulk of the suns mass - leaving behind a 'white dwarf' sun. This will die relatively quickly (in space terms) leaving a cold solid mass of iron.

Answer 2

The sun will eventually exhaust its nuclear fuel in about 5 billion years, swelling into a red giant and consuming the inner planets, including Earth. It will then shed its outer layers, leaving behind a dense core known as a white dwarf.