Objects are illuminated by default, I don't think it can be turned off. In a previous version (don't know which one), I think it used to be dark in the simulation until a star was added, but I can't remember very well (don't quote me on it). As for real-time lighting? I don't know about that. This game is quite intensive as it is without a fancy lighting system, but its not out of the realm of possibility. Giant Army just wants to get down the performance and the bugs before attempting big game changing features.