I'm new to Blender and I've downloaded a 3d file with this earth object showing. In the picture I can see the light being cast onto Earth and if I move the yellow dot around the light moves, but movement is restricted to <180 degrees between north and south of the light facing side of earth, no idea why it's restricted and how to unrestrict it.
What is strange is that no light source is visible on the screen, where is this light source and how do I select and show this on the screen?