Death of The Sun

Sun becomes a red giant before it's death

Sun is the source of life in Earth. Without it we wouldn't be alive here. It seems impossible to believe but it wouldn't be around forever. Eventually the sun has to die. It has a fixed amount of fuel in his core. It is undergoing fusion at a rate and it will be depleted about within 5 billion years.

Unfortunately sun will not go out with a bang. It is too small for erupting as a supernova. As sun exhausted Hydrogen fuel it will cool and gradually collapse under the force of gravity. Energy form this collapse will heat up the core again to 100 of jillions of degrees. This temperature is hot enough to start burning Helium. Under the extra heat of Helium burning the star will expand into a Huge Sphere called the red giant the outer layer of the sun will eventually become so unstable that they will fly off into space, leaving behind the small core about the size of earth.