Board Thread:Naruto Discussions/@comment-26127155-20150326052215/@comment-25549954-20150417161756

That does not solve the problem even Naruto and his team were able to adapt so there is environment on the moon. Although it is not farfetched that they are not human beings look at the horns, also iirc when Naruto asked Hagoromo whether he was an alien, he didn't say no instead he said that makes sense, I didn't quite get that part but he was reluctant not to reveal where Kaguya's origin.