Why are the seasons changing?


There is a dark, dark misconceptions about the cosmos. And the most common of them is that it is supposedly cold in winter, because the Earth is farther from the Sun than in summer.

The scale of this misconception is astounding. I have heard this nonsense even from very educated people. The roots of this misconception grow from the once heard fact that the Earth’s orbit around the Sun is not a perfect circle, but rather an ellipse.

In fact, the difference in distance between the Earth and the Sun in winter and summer has little effect on temperature. Moreover, the Earth is closer to the Sun in winter than in summer!

In fact, the change of seasons occurs due to the fact that at different periods of the Earth’s orbital motion, its surface is illuminated by the Sun at different angles.

This is because the Earth’s axis of rotation is tilted at an angle of about 23.5 degrees. As a result, it turns out that for one half of the year the Sun illuminates the northern hemisphere of the Earth more, and the second half — the southern. Accordingly, when it is summer in the northern hemisphere, winter in the southern hemisphere, and vice versa.

This can be clearly seen in the picture. When the Earth is tilted with the North Pole towards the Sun, the Northern Hemisphere is better illuminated by the Sun. As a result, the northern hemisphere warms up well and summer is in it. And exactly the opposite in the second half of the year.