How do you say beautiful moon in German?

Answer 1

"schöner Mond" or "schöner Trabant" the later being the astronomical term.

Trabant means moon in the sense of satelite, e.g. Jupiter has 63 moons - Jupiter hat 63 Monde/Trabanten. In normal usage, Germans would not use the term Trabant when referring to our Moon in the same way that English speakers would not refer to it as a satelite. Its name is the Moon and therefore unless you are actually referring to the fact that it is a satelite then it should only be translated as Mond.

When referring to Earth's Moon it should be capitalized as it is the name of the body and therefore a proper noun

The Moon - Der Mond

a moon - a satelite = ein Mond - ein Satelit - ein Trabant