Wow, nicely done. Love the detail! But the clouds kinda do look like water. You might wanna blend them a little.
You should submit this to Equestria Daily . com.
This make a 'fine' wallpaper.
I especially like the stars.
But it 'does' look a bit like water. I would touch it up with a 'fluffier' & 'whiter' look.
I wanna thank you for suggesting that I submit this to EqD; I got featured! :D
Now THAT, is an awesome Luna! Nice job!