Are comets permanent members of our solar system?

   There are many theories as to what happens at the end of a comet's life. The most common is that the comet's nucleus either splits or explodes, which may produce a meteor shower. It has also been proposed that comets eventually become inactive and end up as asteroids. Yet another theory is that gravity or some other disturbance causes a comet to exit the solar system and travel out into interstellar space.