The vernal equinox is March 20. Spring begins for the northern hemisphere at the precise moment when the Sun is centered on the celestial equator, zero degrees in declination, the midpoint between the north and south celestial poles. Every location in the world will experience 12 hours of daylight and 12 hours of nighttime…. except the North and South … Continue reading
During March, as winter draws to a close, the Sun rises to the south of due east and sets to the south of due west. By the end of the month, after spring begins, the Sun rises to the north of due east, at an earlier time than at the beginning of the month. Similarly, the Sun sets to … Continue reading
Due to the Earth’s annual revolution, the line of sight between the Sun and the background constellations is constantly changing. This appears as the Sun moving east through the constellations of the zodiac. During March, the Sun appears to be moving from the constellation Aquarius to Pisces. In the process, the Sun crosses the celestial equator, an invisible circle … Continue reading
During March, the days grow significantly longer. The Sun rises earlier and sets later, and is now quite high in the sky at noon. As a result, by month’s end, the length of daylight is three hours longer than on the shortest day, back in December.
The days have grown noticeably longer through February. The Sun increases 9 degrees in declination over month, a total of 15 degrees since the winter solstice, and the noon Sun is higher in the sky by that amount. As a result, by month’s end, the length of daylight is two hours longer than on the shortest day, with sunrise … Continue reading
The days begin to get longer in January as the Sun increases in declination, rising higher in the noon sky and having a more northerly amplitude at sunrise and sunset.
The winter solstice is this Sunday. What does that mean, exactly? It means several things, actually.