What is the date when the earth is closest to the sun?

When the earth is closest to the sun in a year, the perihelion is the winter solstice, 65438+February 22 or 23.

The farthest time from the sun in a year is the summer solstice, June 22 or 23.

The earth revolves around the sun, the orbit is an ellipse, and the sun is at a focus of this ellipse, so the distance between the earth and the sun is related to the position of the earth in the orbit. During the summer solstice, the earth is at perihelion, and the earth is farthest from the sun. During the winter solstice, the earth is at perihelion, and the earth is closest to the sun. From the perihelion to the apohelion, that is, from the solstice in winter to the solstice in summer, the earth rotates and moves away from the sun. From summer solstice to winter solstice, the distance between the earth and the sun is getting closer and closer. It can be seen that the winter solstice is closest to the sun. This is from the perspective of a year. If you look at it from one day, how does the distance between the earth and the sun change with time?

If the earth has no other movement except rotation, and the rotation axis is perpendicular to the straight line between the sun and the earth, then at the same time, people on the equator are closest to the sun and people on the polar regions are farthest. The earth rotates obliquely at an angle of 23.5, so the difference between the morning and evening sun on the equator is relatively large. The greater the latitude (that is, the farther away from the equator), the smaller the difference between the noon sun and the morning and evening sun.

If the earth is completely stationary, the noon area is closer to the sun than the morning area. But the earth is not completely stationary, but in constant rotation and revolution, so the distance between the sun and the observer is related to the shape of the earth, the latitude of the earth, the time of sunrise, the slow change of the direction of the axis of rotation of the earth and the slight influence of planetary gravity on the orbit of the earth, but the change of this distance is very small compared with the linear distance between the sun and the earth.

It can be seen that the sun is far away from people on the same day, at different times and in different places. It's just that this distance is too small to be considered, just like the weight of a few hairs on a heavy elephant can be ignored. Therefore, in a day, in the same place, the distance from the sun to the earth should be the same in the morning and at noon.