They move.........
I don't buy that as an excuse. I made a stepping motor from scratch using parts from Radio Shack and created a mobile scope platform for my 14" light bucket and recorded two hours of video focused on Mars' transit through a clear winter night sky. It cost me somewhere in the neighborhood of $20 to build.
You can't tell me that terrestrial scopes and/or orbital scopes couldn't do the same thing on a much more precise scale.