Two months a year the Sun at the south-pole goes right over the horizon and it will be registered by the Earth System Research Laboratory's camera. Their time-lapse video of March 2013 is very interesting, as a black dot or eye in the sun is registered. Other days and years the camera is never pointed at the sun, as they probably don't want us to know what is out there. If you zoom in on that dot structures get visible, which normally shouldn't be visible. What can this be, can it be a Sun simulator and if so, why would they do it?
At the South-pole in March and October the sun will be going over the horizon, of which you can see movies at the website of Earth System Research Laboratory. Per month you can find a time-laps movie (probably automatically made), so that everybody can judge how it looks. Of the available online material is "March 2013" very interesting. It is the only evidence available from the South-pole in which you can see a black dot. The following screenshots have been taken from the Earth System Research Laboratory, regarding the time-lapse movie of March 2013. Specifically it is of 03-03-2013 at time-lapse time 0.13/1.13.