What would the best way about going about this. I have looked everywhere and I can’t think of where to start. Should I write a shader? lots of small lights on the planet? I tried a very crude method before where I had 2 models, one was slightly off center and had dark side textures but it created very jagged lines where they met and it was a very sudden change.
Haven’t got a response for any of my questions on so long…
Have a look at http://wiki.unity3d.com/index.php?title=Earth/Planet
With the additional information supplied, it sounds like you’re looking for this shader from the wiki.