Kerbal Space Program

I'm not even sure they are supposed to do that, not even once this was ever mentioned anywhere. As far as gameplay goes, this has no effect other than visual. What really concerns me though is that the lights dramatically drop performance of the game since the new terrain shaders were introduced. You basically have the same graphics card as me, so you can test that yourself. Just shine a bunch of lights (10 should be enough) onto the surface and you will see the game slowing down. My game drops from 170 fps to 30 and even lower with just 12 lights. I think it definitely should be reported as its own thing.

dok_377: I agree, shadows are a very minor issue. I play with vsync on, 60 Hz monitor. I made a simple test craft as you suggested. I got 54 fps lights off, 53 fps lights on. I'm always CPU limited in KSP due to low CPU core utilization I believe (Xeon X5670 usually at 20 - 30% load). I often get the yellow clock for other real craft. Sorry - can't reproduce your issue.