French words are gendered. Soleil/Sun is masculine. So it's 'cirque du soleil' But Lune/Moon us feminine, so it should read 'Cirque de la lune'. Saying "Cirque du lune" is not only improper, but makes it obvious you just googled Soleil/sun -> moon/lune and did a lazy word replace. Makes you look uneducated and lazy... Like being fat does...