Explanation: No star dips below the horizon and the Sun never climbs above it in this remarkable image of 24 hour long star trails. Showing all the trails as complete circles, such an image could be achieved only from two places on planet Earth. This example was recorded during the course of May 1, 2012, the digital camera in a heated box on the roof of MAPO, the Martin A. Pomerantz Observatory at the South Pole. Directly overhead in the faint constellation Octans is the projection of Earth's rotational axis, the South Celestial Pole, at the center of all the...