The autumn equinox 2022

 

The autumn equinox 2022 in the northern hemisphere is on Friday 23 September. The autumn equinox marks the first day of astronomical autumn, and the precise time of the autumn equinox in 2022 will be at 3:04am BST.

 

For the two hemispheres, the equinoxes are opposite each other. When it’s the autumn equinox in the northern hemisphere, it’s the spring equinox in the southern hemisphere. For the purposes of this article, when we refer to the autumn equinox, it is from the perspective of the northern hemisphere, and we are referring to the September equinox, unless stated otherwise.

 

What exactly happens during the autumn equinox? Put simply, the autumn equinox is when the Sun crosses the celestial equator (this being an imaginary line in the sky above Earth’s equator), going from the northern hemisphere to the southern hemisphere. It's caused by the cyclical tilt of Earth's axis, and at the equinoxes, this tilt aligns with the orbit around the Sun.

 

At the equinoxes, the Sun is exactly above the equator, and both hemispheres receive (nearly) equal amounts of sunlight. In other words, day and night are (almost) equal in both hemispheres. After the autumn equinox, we start to receive more darkness and less daylight.

 

The word ‘equinox’ derives from the Latin words aequi, meaning ‘equal’, and nox, meaning ‘night’. Taken together, 'equinox' translates as ‘equal night’.

 

The September equinox denotes the start of astronomical autumn in the northern hemisphere, and the start of spring in the southern hemisphere. From our perspective, the Sun moves to be south of the equator, in the western portion of the constellation Virgo.

Link:

https://www.sciencefocus.com/planet-earth/autumn-equinox/

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