True story!...sort of. The sun will steadily grow larger until it becomes a red giant (most likely swallowing the earth). It won't actually implode/explode but instead it will expel its outer layers until a small, extremely dense core remains (white dwarf). In the meantime, the temperature of the sun will steadily increase and in about a billion years there will be no liquid water on the surface of the earth... Once that happens all life will die...of course this is assuming our core hasn't already cooled to a point where the earth's protective magnetic field is gone. Once that happens the solar winds (radiation) from the sun will carry away all our water and atmosphere. Most likely we won't have to worry about the sun dying in 5 billion years, because we will have already been killed when our water and atmosphere boil off, or killed by an asteroid...or the most likely scenario to me, killed by our own stupidity.