Arab weather - the earth revolves around the sun at a time when its axis tilts from the horizon by about 23.5 degrees, so the northern hemisphere tilts towards the sun during the summer months, and it tilts away from the sun during the winter months, and the opposite occurs in the southern hemisphere.
But twice a year it happens that the tilt of the Earth aligns with its orbit around the sun, so that there is no tilt of the Earth relative to the sun, and then the equinox occurs twice during the year, the day of the spring equinox in March, and the day of the autumnal equinox in September.
In the following, we will learn about the reasons why the autumnal equinox is a special day from the rest of the year:
- Autumn begins astronomically and officially on the day of the autumnal equinox in one hemisphere, and autumn continues for 91 days until the winter solstice, while spring begins astronomically and officially in the other hemisphere.
- In its apparent journey over the horizon, the Sun is perpendicular to the Earth's equator.
- Day and night are equal on the equinox day.
- The autumn equinox in the northern hemisphere is in September, and in the southern hemisphere it is in March.
- Spring begins in the Southern Hemisphere.
- An opportunity to determine exact directions because the sun rises in the true east (at an angle of 90 degrees with the horizon), and sets in the true west (at an angle of 270 degrees with the horizon).
- Sunset for the first time in the North Pole after a day that lasted 6 months
- The sun rises for the first time in Antarctica after a 6-month night
- The autumnal equinox does not necessarily mean the onset of cold or rapid changes in the weather.