The autumnal equinox takes place every year on the 20th or 21st of March in the southern hemisphere, where Brazil is located.
This year the autumnal equinox will take place on the day March 20, 2021, as in the years 2022 to 2025.
This astronomical phenomenon is the exact moment when the Sun passes through the celestial equator. When it happens, the southern hemisphere begins to receive less sunlight. As the Earth is tilted on the other side, that is, in the northern hemisphere, the Earth starts to receive more sun.
This explains why the day the equinox occurs in March in Brazil, autumn begins. In the northern hemisphere, in turn, the equinox that takes place in March begins spring.
What is Equinox?
Equinox is an astronomical phenomenon that happens twice a year: in March and in September. This phenomenon is the moment when the Sun crosses the celestial equator. From that moment on, one hemisphere starts to receive more sunlight than the other.
In the southern hemisphere, where Brazil is located, the autumn equinox takes place in March, beginning autumn. In September, the spring equinox occurs, giving rise to spring.
As the earth is tilted, the opposite happens in the northern hemisphere, that is, in March there is the spring equinox and in September there is the autumn equinox.
Definition of Autumn Equinox
On the day the equinox occurs, the length of day and night are practically the same. Hence, the word equinox means “equal night”. Of Latin origin, it is the junction of two words: aequus (equal) + nox (night), aequinoctiu.
Before the autumnal equinox happens, it's summer and the days are longer, but as the days go by they get shorter, until the autumn.
The autumnal equinox heralds that the days will get shorter and the nights longer. Likewise, the temperature will decrease.
With decreasing sunlight, we tend to feel more lazy and less energetic. For nature, the autumnal equinox represents the beginning of a period of rest. After all, trees lose their leaves, many animals stock up on food, and some species hibernate.
In countries with a tropical climate, however, the changes are not so great, but temperatures drop a little.
spring equinox
The spring equinox takes place in the southern hemisphere in September, on the same day as the autumn equinox in the northern hemisphere.
This happens because of the Earth's tilt. Thus, while September begins spring in the southern hemisphere, autumn begins in the northern hemisphere.
Read too:
Equinox
Solstice
