The other is a microwave image, made by a satellite bouncing 85 GHz radar from space. On both of them, I can see a clear area to our east. The clear area on the images can't possibly account for the dark sky I see, because it is much too far away. I asked Dr. Li about the advantages of one type of image over another. He pointed out the obvious answer.
Microwaves can see through clouds and at night.
In Antarctica, there are lots of clouds and six months of darkness, which means a lot of times with no visible light image possible. For example, rough water can look like snow or ice, and vice versa. I can see this in the two images I have in front of me. They both show clear water in the same places. The microwave image shows ice detail in a large area covered by clouds in the visible light picture.