How to find the winter solstice, autumnal equinox, vernal equinox and summer solstice in Earth orbit?
Winter solstice: it starts when the sun reaches 270 degrees of the yellow meridian, which is about 1 day within 30 days before and after the Gregorian calendar 65438+February 22nd or the lunar calendar1month15th (full moon).
On this day, the sun shines almost directly on the tropic of Capricorn, with the shortest day in the northern hemisphere, the extreme night in the northern hemisphere and the extreme sun in the southern hemisphere. Later, the position of direct sunlight moved northward and the days became longer.
The autumnal equinox is the midpoint of three months (about 90 days) in autumn. "Fen" in "Autumn Equinox" means "half". The autumnal equinox is around September 23rd of the Gregorian calendar every year, when the sun reaches 180 degrees. On this day, the sun shines almost directly on the equator of the earth, and the length of day and night is equal all over the world.
The vernal equinox is one of the 24 solar terms, and the vernal equinox is the midpoint of 90 days in spring, which is generally around 2 1 every year. The direct point of the sun is on the equator, and the world is divided equally day and night.
In the time period, it refers to the position where the sun is located between 0 and 15, that is, from March 20th to April 5th. But in fact, it usually refers to the day when the sun is really at 0 degrees of the yellow meridian: March 20 or March 2 1. On the vernal equinox, the sunrise and sunset time is 6 o'clock all over the world.
The solstice in summer is the longest day and the shortest night in the northern hemisphere. On the day of the summer solstice, except the south pole of the Antarctic circle and the polar night area, the sunrise direction in all parts of the earth starts from the northeast and sets in the northwest.