Thanks for reporting. We've written up a task for dealing with the Jupiter and Sun collisions in that simulation... it's definitely not behaving like it should be.
That sim, however, is going to be a stress test for your system, as there's a lot going on with the dust trails, collisions, supernova, etc. It's not too surprising that it would reduce your frame rate, though we still don't want it to crash! That happens to me too when I have graphics set to High, though the simulation keeps chugging when on Low. We'll look into that as well, thanks.