Wolf, I would hazard a guess as follows: The Torah is the moral code of all society, the code that defines what is good and what is bad. Even for non-Jews, it defines what is good and bad. All moral judgements point one way or the other ONLY because the Torah says so.
Therefore, if you have a society that does not have any connection with the Torah as they are on another planet, then for them by definition the concepts of good and bad and moral judgements cannot exist. This is as opposed to all humankind on Earth for whom the Torah’s giving through Moshe at Sinai (on Earth) constituted the message from G-d of a definitive moral code – Jew (613 mitzvos) and non-Jew (7 mitzvos) each on their level.
To pre-empt an obvious question on what I have just written; surely there are some commandments in the Torah that are ‘Mitzvos Sichliyos’ i.e. commandments that could be arrived at by simply using an innate sense of right and wrong e.g. the prohibition of murder? The answer I think I once heard to this is that in truth even these type of commandments are in essence rooted in the Torah’s definitive moral code. Thinking that we would arrive at the commandment without the Torah’s existence is an illusion. (See Rabbi Keleman’s book Permission to Believe for more on this last point.)