Why all the comments just angry at Ayn Rand? Is signaling how angry you are at someone accepted as a refutation of their arguments, and the arguments of anyone else who is somehow loosely associated with something named after them?

Bringing up Hume dismissively doesn't work either. Science can obviously study some facts about ethics, for example what people say about ethics under what situations, or what oughts children usually learn and when, even if it can't directly tell anyone what they ought to do. And once someone has some oughts, new ises can get you to make different decisions, and science can give you plenty of those. If you were omniscient, surely that would help you make morally better decisions, if you wanted.

Finally, if you want to understand morality, you should have some knowledge of the variety of naturally occuring morality, and ideally explanations of why it came to be that way. It's easy to make untrue generalizations that exclude behaviors (or patterns of behavior) that aren't merely hypothetical but already exist somewhere.