User blog:Nickslasher4/Astros keep spawning!

Hey guys it's me again, I have one question here... I know it sounds dumb but, every time I create a new moon and wheter its at max. Or min. World settings, Astros keep spawning no matter what world settings you made, and I think I heard mrob27 that he said that some moons have no Astros, but they keep spawning no matter how many times, I just wanted a peaceful world, no Astros,just the passive mobs,so is there any way to get rid of them besides of killing them with turrets?

And I don't want them cus im building a city u see, but if they shoot at the brown mob, they could explode and destroy some of my works, so yeah I just want peace and quiet no Astros at all, thanks