When the earth revolves around the golden ball, the solar terms in the northern hemisphere are equal in length from day to night.

Look at the map and it shows (1) that the direction of the earth's revolution is from west to east. (2) When the earth revolves to position B, it is on the vernal equinox in the northern hemisphere, and the date is around March 2 1. At this time, the sun shines directly at the equator, and the world is equal to day and night. (3) When the earth is in position A, the sun shines directly on the Tropic of Capricorn, and the date is 650. At this time, there is an extreme night phenomenon in the Arctic, and the days in the northern hemisphere are short and the nights are long. (4) When the earth is in position C, the sun shines directly on the Tropic of Cancer, and the date is around June 22nd, which is the summer solstice in the northern hemisphere. At this time, there is extreme day in the Arctic, with the longest day in the northern hemisphere, the shortest night and the shortest day time in the southern hemisphere. (5) When day and night are equal around the earth, they are the vernal equinox and autumn equinox in the northern hemisphere. Around June 22, the sun shines directly on the Tropic of Cancer, which is the summer solstice in the northern hemisphere; From May 1 to June 1, the point of direct sunlight lies between the equator and the tropic of cancer, and the point of direct sunlight lies in the northern hemisphere and moves northward. (7) The period of revolution of the Earth is one year, with 365 days. When the earth turns from position A (winter solstice) to position B (vernal equinox) on the orbit of revolution, it is located in Zhangye, Gansu, China in the northern hemisphere. (2) vernal equinox; Equator; The length of day and night is equal; (3) Tropic of Capricorn; Solstice of winter; Extreme night; (4)C； (5) vernal equinox; Autumnal equinox; (6) the north; North; (7) One year; The days are getting longer and the nights are getting shorter and shorter; (8) Earth's rotation; The earth revolves around.