冬至的太阳与银河
2021年12月21日 Solstice Sun and Milky Way Composite Image Credit & Copyright: Stefan Seip (TWAN) Explanation: Welcome to December’s solstice, first day of winter in the north and summer for the southern hemisphere. Astronomical markers of the seasons, solstice and equinox dates are based on the Sun’s place in its annual journey along the eclipt...