That's no moon!
Just print the 2 parts and glue it together.
Print at 0.1 or 0.2mm, with an infill of 50% min, it's better if the ball is heavy.
The ring must be printed very slowly to be strong.
The design is not as neat as other DeathStars found here cause this one is designed to be printed as a small object, the lines has to be bold.
EDIT 04/2017 : The object has been updated with these modifications:
-The hook is fatter, it should be more sturdy
-Remove holes under the objects
-The scale is now 85% of the original version, it was too big for a keychain I think