This isn't rocket science, the reason you see the color blur is that the camera uses 3 seperate color paths (RGB) that must have some delay just like a DLP projector. They are going to take a long exposure anyway because of the distance and losses through all the atmosphere. A moving object would blur, and if they are in fact using a color wheel, you would see the rainbow effect. I'm sure there is a lot of post image processing that attempts to make the picture sharper, and that is what makes the "ghost" plane seem more transparent since the software knew to remove the extra leading and trailing images of the plane, but the area under the plane was there the longest so it bleeds through in the image processing. Cheap digital cameras do the same thing in lower light conditions because they must take a longer exposure to get the brightness needed in the image.