Maybe true, but... I thin the real "names" of the sun is sol, and of the moon is Luna. Just mankind is so pre-occupied with particular sun/moon(s) that the lan

Maybe true, but... I thin the real "names" of the sun is sol, and of the moon is Luna. Just mankind is so pre-occupied with particular sun/moon(s) that the language heavily leans into the context where "moon" refers to Luna, and "sun" refers to sol; unless the context explicitly implies otherwise. Hence "the moon" isn't just the proper title for Luna, but rather a reference to "some moon in particular", which has always been Luna for so long, that the term is now an idiom. In contrast, I think if you where on a planet in a different solar-system, "the sun" might reasonably refer to the local star, and "the moon" to the local moon, assuming just one prominent moon.