The moon and the stars are always in the sky.

Question

[Why is 'the stars' used? Can we omit 'the'? Can we see the same stars in the sky? Can't we see new stars in the sky as time passes? Do we see the same stars in the sky as time passes?]

Answer 1

All your sentences are fine.

And, yes, you can use "the" with "stars" or not, as you wish.