You can derive morality from observation if you aren't looking for ontological "ought statements". Hume's position assumes that the religious approach to morality is the only one possible - that morality consists of these detached and universal "ought statements" that must be observable in the Universe somehow and take on the same form as Commandments from a God.

That's not how the Objectivist ethics works, at all. There are no "ought statements" because ethics, in Objectivism, is a system of judgement and reasoning. It's applied epistemology.

So, no, you won't find a mythological ethics in reality. But you can learn how to identify the nature of things and judge how they relate, positively or negatively, to human life. And that's the essence of Objectivist morality.