This is something that Frontier are working on changing.
Currently the dark side of planets brighten up in an artificial manner when you approach the dark side. Partially this is for gameplay reasons, and partially it is to simulate ambient light. However the current method for this system is essentially a temporary measure and is far from ideal.
What is being worked on by Frontier, is a system that will actually calculate light based upon the local star field, and use the correct level of ambient light to illuminate the planetary surface. This means that some planets will have some pretty dark surfaces on the dark side. It also means that closer to the galactic core, then these dark sides of planets will be a lot brighter.
No idea when this new system will be introduced though. There is a quote somewhere, where one of the devs explains all of this - but at the moment I don't have it to hand.
Currently the dark side of planets brighten up in an artificial manner when you approach the dark side. Partially this is for gameplay reasons, and partially it is to simulate ambient light. However the current method for this system is essentially a temporary measure and is far from ideal.
What is being worked on by Frontier, is a system that will actually calculate light based upon the local star field, and use the correct level of ambient light to illuminate the planetary surface. This means that some planets will have some pretty dark surfaces on the dark side. It also means that closer to the galactic core, then these dark sides of planets will be a lot brighter.
No idea when this new system will be introduced though. There is a quote somewhere, where one of the devs explains all of this - but at the moment I don't have it to hand.