This is Chase136.
A0751 man in the moon
A0759 moon once visited earth occasionally
Baer cites Cherokee myth from Mooney about Sun and Moon as lovers (I think I have seen that story in other tribal traditions also...?) -- and it has a motif: A0751.5.2 dung/ashes on moon's face smeared there by sun, with a citation for India
conclusion: "It seems likely that the Uncle Remus tale is an Afro-American version of a North American Indian myth, but so bowdlerized as to be almost pointless. Whether the storyteller deliberately attempted to clean up an incestuous theme or misunderstood the tale he heard is impossible to determine."
I found very brief reference to surprising the moon like this in Hurston's Every Tongue Got to Confess.
I'm not sure I want to go with Baer on this conclusion about it being the Native American story retold...the story has some inner dynamics of its own that have nothing to do with that other story IMO.