The autumn equinox on September 22 will mark the beginning of astronomical autumn in the Northern Hemisphere of the Earth, TASS reports with reference to the press service of the Moscow Planetarium.
An equinox is a unique phenomenon when the length of day and night equalizes across the globe. It occurs when the center of the visible solar disk crosses the celestial equator. This astronomical event occurs twice a year: in spring and autumn.
After the autumn equinox, the Sun moves into the Southern Hemisphere of the celestial sphere, which leads to interesting consequences for different parts of our planet. In the Northern Hemisphere, the nights begin to prevail over the days in length, marking the arrival of astronomical autumn. At the same time, for residents of the Southern Hemisphere, this moment means the onset of astronomical spring, and the nights there gradually become shorter.
It is worth noting that the vernal equinox, which occurs in March, has the opposite effect: it brings astronomical spring to the Northern Hemisphere and autumn to the Southern Hemisphere.
