Universe - Daily course of the Sun during the year

978-3-14-100890-6 | Page 10 | Ill. 4
Universe | Daily course of the Sun during the year |  | Karte 10/4

Overview

The illustration of the daily course of the Sun shows the movements of the Sun from an earthly perspective. The perspective is that of the middle latitudes; in the low or high geographical latitudes the Sun's orbits appear differently.

Height of Sun in the sky

Due to the Earth's own rotation, all celestial objects appear to move on parallel circles around the north celestial pole. At the time of the equinox, on 20 March and 23 September, the Sun rises exactly in the east and sets in the west. The day and night last exactly twelve hours each. At noon on these days, the Sun can be seen at an angle of 37.5 degrees to the horizon plane (90 degrees minus latitude). At the summer solstice (21 June), the altitude at noon changes to 61 degrees. At this time, the day lasts 17 hours, but the night only 7 hours. At the winter solstice (21 December), the altitude at noon is only 14 degrees. In this case, the day lasts 7 hours and the night 17 hours.