What would happen if Saturn's course caused it to careen into Jupiter? Would Earth be in jeopardy?

About the only thing I can think of that might make this happen is if something mive from outside the solar system perturbed one or both of these planets into an improbable collision course. But if Saturn and Jupiter ran into each other, the impact energy would be around 2e37 Joules, which is the amount of energy radiated by the sun in 1656 years. So most likely all life on Earth would become extinct.