Where does the sun go on the vernal and autumnal equinoxes? An introduction to the direction of the sun on the vernal and autumnal equinoxes.

1. On the vernal equinox (when the sun reaches 0° ecliptic longitude), the sun happens to shine directly on the equator. At this time, the dusk line passes through the north and south poles and coincides with the earth's meridian circle, bisecting all latitudes into two parts. , half is located in the day hemisphere, and the other half is located in the night hemisphere, so on this day the global day and night are almost equal.

2. On the day of the autumnal equinox (when the sun reaches 180° longitude), the sun shines directly on the equator again. The morning and evening lines also pass through the North and South Pole, coinciding with the earth's meridian circle, dividing all latitudes into two parts, so It is said that "the spring and autumn equinoxes, day and night equinox."

3. The difference is that after the spring equinox in the northern hemisphere, the direct sun point gradually moves northward, the solar radiation gradually increases, the weather gets warmer day by day, and the days get longer and the nights get shorter; after the autumnal equinox, The direct sun point gradually moves southward, solar radiation gradually decreases, the weather becomes colder day by day, and the days become shorter and the nights become longer. The Southern Hemisphere is just the opposite.