China Naming Network - Naming consultation - Where is the direct point of the sun at the vernal equinox?

Where is the direct point of the sun at the vernal equinox?

The direct point of the sun at the vernal equinox is on the equator.

First, the direct point of the sun in vernal equinox.

The fourth of the 24 solar terms is usually around March 20 every year. At this time, the time of day and night on the earth is equal, that is, day and night are each 12 hours. At this time, the sun is above the equator and points directly at the equator.

Second, the position of the direct point of the sun at the vernal equinox.

At the vernal equinox, it is caused by the inclination between the earth's rotation axis and the common rotation axis. When the earth revolves around the sun, its inclination makes the sun shine directly at different positions on the earth at different times of the year. At the vernal equinox, the sun shines directly at the equator because the axis of the earth points to the sun at this time, which makes the sun shine directly in the middle of the earth.

Third, the significance of the direct point of the sun at the vernal equinox.

It is of great significance that the sun shines directly on the equator at the vernal equinox. The vernal equinox is a day with equal time between day and night all over the world. On this day, the length of day and night on the earth is equal. It is also the same day of sunrise and sunset all over the world. These characteristics make the vernal equinox an important moment for the world to observe and study the earth, the sun and astronomical phenomena.

Variation of direct solar point

1, law of motion

The position of the direct point of the sun on the earth is influenced by the revolution and rotation of the earth. During the year, the direct point of the sun moves between the Tropic of Cancer and the Tropic of Capricorn. Move from north to south, reach the Tropic of Cancer around June 22nd, move south, and reach the Tropic of Cancer around February 22nd.

2. The length of day and night

The location of the direct point of the sun determines the length of day and night in different areas. When the direct point of the sun is above the equator, the world is equal to day and night. When the direct point of the sun moves north or south, the length of day and night will change. In the northern hemisphere, when moving northward, the day time becomes longer and the night time becomes shorter; In the southern hemisphere, when moving south, the days are shorter and the nights are longer.

3. Seasonal changes

The position of the direct point of the sun determines the seasonal changes in different regions. The inclination of the earth's orbit and the position of the direct point of the sun are different in different seasons, which leads to seasonal changes in different regions. In the northern hemisphere, the direct point of the sun is near the Tropic of Cancer in summer and the Tropic of Cancer in winter. In the southern hemisphere, the situation is just the opposite.