[quote=@Melo]
[@Romanaria] Just to be certain. Is the theme THE moon (as in our/the earth's moon) or simply a moon. Could I, for example, write a story about the second moon of Jupiter and still be considered relevant to the theme? :P 
[/quote]

The answer is 'yes.' 

Wherever 'the moon' takes you, that's where you should go. Liberal interpretations are absolutely welcome.