How does supervenience profit? (G.E. Moore)

There is a gap between fact and values and between "is" and "ought". Nevertheless, relations between facts and values or between "is" and "ought" obtain, since it is logically impossible to maintain that two persons could actually feel, think and behave in exactly same way but differ only in moral value. Moreover any "ought" seems to imply a factual "can". Is it possible to bring together these opposite ideas ? This is what is called the "problem of moral supervenience". I try to show how it could be solved by promoting a sort of nonnaturalistic version of moral realism, in the spirit of G.E. Moore.