北天与南天的星像迹线
2020 February 12 Star Trails of the North and South Image Credit & Copyright: Saeid Parchini Explanation: What divides the north from the south? It all has to do with the spin of the Earth. On Earth’s surface, the equator is the dividing line, but on Earth’s sky, the dividing line is the Celestial Equator — the equator’s projectio...