If you go high enough, the night sky will surround every side of you, and the map will become more and more white until it's just a white plane expanding everywhere out below you. Keep going, and the night sky will start to shrink the edges of this plane/map into a circle, getting smaller, until the circle vanishes, and you're entirely surrounded by night sky. Or space, depending how you look at it.
I'm not even joking, this is what happens when you go high and keep climbing. At least in DCS 1
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