Planet Earth is a very large place, so it has a large number of characteristics, as different as they are equal to each other. It is for this reason that they have been classified, to know with enough specificity the conditions in which life operates in certain areas. The meridians, meanwhile, are a series of great circles (a circumference that cuts a sphere into two hemispheres, and that preserves its diameter), whose main function is to determine the time zones and the date. In addition to these, you can find parallels, circular lines that help to establish latitude, that is, the location of any point in relation to the equator.
It is from the last one that the polar circles become known. It is a parallel that has the coordinates of "66º 33 ″ 46 '", which correspond precisely to the Antarctic Circle and the Arctic Circle. In addition, it has been determined that the latitudes of the polar circles are modifiable, this depending on the axis of rotation of the earth with respect to the ecliptic. They have one day a year in which the sun remains for 24 hours in a row and another in which it sets for the same amount of time.
The Arctic Circle is characterized by determining, in the extreme south, the day of the summer solstice and, in the north, the date of the winter solstice. While the phenomenon occurs, within the polar circle the sun does not set during the traditional 24 hours, and, while the second takes place, the flaming sphere does not rise. Various investigations have shown that this circle is moving north, about 15 meters per year. The Antarctic Circle, in the same way, has characteristics similar to those of the Arctic, but in this, the sun can last up to 24 hours; they have no nearby nation or inhabited territory.
