A while back, Maxis updated the moon in Granite Falls, Glimmerbrook and Forgotten Hollow to a much better texture:
They didn't bother to apply the same high quality texture to the rest of the worlds though, so every other world is left with that shitty, poorly made moon.
I accidentally found GF moon texture while looking for other things... I've been looking for it for months and finally... I applied it to all the worlds:


It looks weird when it's cloudy, but it's better than the horror we have.