Well stars do no last for ever.Stars are full of different gases, most of the star is helium and hydrogen.When the star runs out of helium, star shuts down. Every planet blows up in to the million huge piece.These piece are dangerous for some another planets.Planets as earth.These piece are full of carbon, oxygen, nitrogen, iron, gold and the rest.Pieces are called COMETS and ASTEROIDS.Chemists and astronomers are trying to find out what else is in the star that makes star to blow up. (In next chapter we will talk about Comets and their affects on the Earth.)