I wonder if the moon didn't exist, what would the word for month be in all languages? Even in English the word month comes from the word for moon! :)
that doesn't make much sense as the concept of "month" wouldn't also exist :)
(Ian Boddison) I think yes, because it is used as the verb 'to be' here, so it means '(the) moon is yellow', and without that I think it would be 'moon yellow', that don't makes sense.