Das ist kein Moon.
I could understand maybe if this was a line from an obscure Bosnian art-house limited-release film... but REALLY? REALLY?
One of the most famous lines in the WHOLE OF CINEMA
'That's no moon'
and yet a good few dozen people give the literal translation instead of the film quote.
The German line is there as a translation of the English film quote- so convert it back to the original English! Simple!
This seemingly small criticism is part of a wider plea to please use a bit of common sense with translations - literal word-for-word translations don't often work very well, you must always think about the wider context - read the original article if you can access it! - and don't be afraid to use resources outside of duolingo! You're not here to be good at gaming duolingo (bots and fetishists excepted) you're here to learn German and to understand the communication of the German speaking peoples...so don't be half-arsed about it... THINK!