Frater Benedict
I know about the HYMN 'Ave maris stella' (It was probably written in the 7th or 8th century somewhere in western Europe) but not about the piece of art with the same name that you mention. The moon is mentioned in Revelations 12, so whenever an artist chose to depict a moon together with Mary, we know from where the artist got the idea. Waite who grew up with a Roman Catholic mother must have known some of this.
An interesting difference between Waite and the Wirth deck (which Waite must have known about) is that in the Wirth deck The Empress is depicted with the moon at her feet and twelve stars around her head. It seems that Wirth and Waite didn't have exactly the same ideas about the Popess and the Empress, although they have some iconographical details in common.
An interesting difference between Waite and the Wirth deck (which Waite must have known about) is that in the Wirth deck The Empress is depicted with the moon at her feet and twelve stars around her head. It seems that Wirth and Waite didn't have exactly the same ideas about the Popess and the Empress, although they have some iconographical details in common.