the sun will eventually 'die'. All stars have a reserve of hydrogen which is the fuel that drives the nuclear fusion that produces the heat and radiation we receive here on Earth. When a star exhausts this supply of fuel, it first swells into a red giant (for the sun, this means that earth will either be swallowed up in the inferno or left scorched and barren, much like Mercury) before its gravity causes it to collapse in on itself
Now about the moon becoming adrift im not sure.
So far how many exoplanets have been discovered???