Please help explain the ecliptic and the white road ~ ~ ~

Erosive

The great circle where the earth's orbital plane around the sun intersects the celestial sphere. Seen from the earth, the ecliptic is very close to the annual apparent motion of the sun on the celestial sphere. Because the earth's revolution is perturbed by the moon and other planets, the orbit of the earth's revolution is not a strict plane, that is, it produces irregular continuous changes in space, which includes many short-term and a slow long-term movements. Short-period motion can be averagely eliminated in a certain time, and the orbital plane with periodic motion eliminated is called instantaneous average orbital plane. The strict definition of the ecliptic is: the great circle where the instantaneous average orbital plane of the center of mass of the Earth-Moon system revolves around the sun and intersects the celestial sphere. The ecliptic is the base circle of the ecliptic coordinate system on the celestial sphere.

The orbit/path of the moon

lunar

path

The great circle where the orbital plane of the moon around the earth intersects with the celestial sphere.

The ecliptic and the white road intersect at two points.

The intersection of the moon moving from the south of the ecliptic to the north of the ecliptic is called the ascending intersection, and the opposite intersection is called the descending intersection. The intersection angle between ecliptic and white varies from 4 57' to 519', with an average of about

5 9', the change period is about 173.

Jesus Christ. Because of the attraction of the sun to the moon, the straight line connecting the two intersections moves westward along the ecliptic opposite to the direction of the moon. This phenomenon is called intersection regression. The intersection moves 19 2 1' every year, which takes about 18.6 years to complete a week. This phenomenon has an important influence on the nutation and tides of the earth.