Algodoo

This is pretty cool, but if you made the core only the magnet in Jupiter, it may have been alot more realistic (if you were going for a realistic feel.) It also may make big planets (if you are still using the magnet all thing) very unstable, and will most likely explode. Now dont get me wrong, if you make the core a magnet it also can be unstable; but it all depends how much strength you give the magnetic core.

only magnet* also your method still works too im just sayin