Hey, agree with reducing the banding. Try adjusting your pallet, adding a few more shades, or better - dithering. Also, the moon is your focal point, it shouldn't be cut off by the edges of the frame. Bring it in full view (corner is fine). Another thing, zooming on on your moon, there are a lot of unnecessary colors and shades there. You should pixel it from scratch instead of converting a full-color painting of a moon.
