moon bases will have siege mechanics, i do believe it was Lauri who said it, or possibly one of the notes(progress or ptu), but basically moon base sieges will happen after the release of station sieges. until then the moon has 2 safezone formats, be near the city, or stay within your 150m area of your own base. once your outside either one, which you probably have to be to farm ore to build your moon base, you have to consider people may be waiting on you to leave your safety.