Never mind, I have them too. I guess I just never looked hard enough lol. I noticed they only appear when the "distance" is close enough for the ground objects to be drawn. I have my bottom slider for visible ground objects or whatever it says set to 3 miles (max distance). I can actually see a line rolling across the ground as the detail level changes and things come into that range. I watched last night as a group of these artifacts came into view, right behind the detail line. Outside my 3 mile line there was no artifact, inside it they were there.
