I think the problem is
In reailty
The dark part of the moon is still there - it doesn't become transparent and the stars shouldn't be seen as the moon would block them out.
So it should look like this (courtesy of @Chuck):
(There are a few other extra details being pointed out such as the fact that the outer moon is lighter than the inner moon - but I’d say this is the biggest an most obvious problem so I haven’t included the rest)