The equinox is the time when day is equal to night. At the moment when the Sun crosses the equator from south to north - this is the day of the spring equinox, and from north to south - the autumn equinox. At this time, the Sun is directly above the Earth's equator. The word comes from the Latin equi or equal and the Greek nyx or Latin nox, meaning equal night.

Equinoxes and solstices

The equinoxes occur at the intersection of the ecliptic and the celestial equator. On September 23, the Sun moves down from the celestial equator and crosses it - the autumnal equinox, and on March 21, when it moves upward, it is the spring equinox. On these days, the Earth's axis is not inclined towards the Sun or far from it, and therefore the circle of illumination cuts all latitudes in half, which leads to the same length of this day throughout the Earth.

In both cases, the solar circle of illumination conventionally bisects the equator. The equator is an imaginary line with a latitude of 0 degrees that divides the planet into the Northern and Southern Hemispheres. This is the only place on earth where day is equal to night always, every day of the year.

The Earth is tilted, the maximum angular deviation towards the Sun is 23.5 degrees. The day June 21 with a positive deviation of the Sun relative to the celestial equator is called the summer solstice, and December 21 with a negative deviation is the winter solstice.

Simply put, the equinox represents the days when day is equal to night (March 21 and September 23), the solstice is the shortest (December 21) and the most long days(21st of June).

The equinoxes, together with the solstices, are directly related to the seasons of the year.

Equinox - the name is deceptive

If the Earth's axis were perpendicular to its orbital plane, the entire Earth would have equal lengths of day and night. A real sunny day has different durations, with fluctuations of up to 15 minutes.

There are three reasons for this timing difference:

1. The movement of the Earth around the Sun is not a perfect circle, but eccentric.
2. The apparent motion of the Sun is not parallel to the celestial equator.
3. The phenomenon of precession of the Earth's axis.

In addition, the Earth carries out two different types movements:

• around the Sun in a fixed orbit, a journey that takes exactly 365.26 days (year);
• around its axis - forming day and night.

To complete one daily revolution, it takes not exactly 24 hours, as we used to think, but 23.93 hours.

The Earth is spherical, so the half facing the Sun is illuminated, while the other half is at night. The day/night cycle is continuous, except at the Earth's poles, where day and night are thought to last for half a year.

In fact, this is not true, they are not equal. Just as the generally accepted opinion regarding the equator, where day is equal to night, is wrong all year round, then at the equator one would expect the Sun to rise at 6:00 am and set at 6:00 pm. In fact, it rises at the equator at 6:03 am in July, 6:11 am in February, 5:53 am in May and 5:40 am in late October.

This phenomenon of actual "non-equinox" is caused by the fact that the Earth's axis is tilted at an angle of 23.4 degrees. The “inequality” of day and night is also influenced by the phenomenon of refraction. Refraction is the refraction of sunlight through the atmosphere, which visually lengthens the day. Because of this phenomenon, the top edge of the Sun can be visible even if it is just below the horizon. For example, it is usually visible in the morning a few minutes before the actual sunrise. This phenomenon is influenced Atmosphere pressure and temperature.

Therefore, the real duration of the “day” for the North Pole reaches 193 days, and the night - up to 172 days and, accordingly, for the South Pole - day lasts 172 days and night lasts 193 days.

Earth's Precession Movement

Due to the very slow movement of the firmament (actually the earth's axis moves), the equinoctial Sun, when day is equal to night, moves from one zodiac sign to another approximately every 2160 years, completing its entire revolution in approximately 25,920 years. This very slow movement of the sky is called the precession of the equinoxes. The precession of the equinoxes is the movement of the Earth, which results in a change in the orientation of the rotation axis.

The first estimate of earth's precession was made by Hipparchus in 130 BC. e.

The Earth's axis precesses due to the superposition of such factors:

• Its shape is not completely spherical (it is an oblate spheroid protruding at the equator).
• The gravitational forces of the Moon and the Sun acting on the equatorial protrusion try to return it to the ecliptic plane.

Consequences of precession:

• shift of the equinoxes;
• movement of the celestial poles;
• displacement of astrological zodiac constellations.

The daytime and nighttime equinoxes are not the same length; their dates vary depending on latitude.

The forces of nature are harmonious and consistent. Ancient peoples were very attentive to the seasons and the position of the Sun in the sky because their lives depended on timely planting and harvesting.

Our ancestors have long celebrated the days of the solstice and equinox, when day is equal to night, as special holidays. Many great Orthodox holidays and are now in close proximity to these dates: Christmas ( winter solstice) and Easter (spring equinox).

An equinox is an astronomical period when the center of the Sun “crosses” the celestial equator, while it is completely perpendicular to the Earth's equator. If we talk about the northern hemisphere, then at the autumn equinox, namely on September 22 or 23, the Sun moves from the northern hemisphere to the southern. And at this time the day is almost equal to the night, which is why it got its name. And the Sun rises almost directly in the east and sets directly in the west.

Each nation celebrates this day in its own way, having its own traditions. For example, in Rus' it is customary to bake cabbage or lingonberry pies, organize festivities, and insert rowan tassels between window frames as a talisman. And among the Celts it is a harvest festival, a holiday of autumn and wisdom. And they have their own rituals - they first show everyone the best gifts of summer, and then eat them, which guarantees enough food for the whole year.

Autumn breaks up with summer,
She sometimes cries, sometimes she laughs,
Then suddenly it starts to rain,
Then suddenly everything will be flooded with sunshine,
Equinox of nature,
Variety of weather!
Day today is equal to night,
Tomorrow it will become shorter
But that's tomorrow, and now,
Happy equinox to all of you!
And although nature fades away,
Don't let this scare you,
She needs to rest too
Gain new strength, take a nap,
And I, in autumn bad weather,
I wish you LOVE and HAPPINESS!

Autumn is in the yard,
The leaves are gilded with a brush,
And today is day and night
Exactly the same!

The equinox has arrived
A star fell from the sky,
Let her bring you
Happiness, joy for the whole year!

Today the day has become equal to the night,
Autumn sends us its greetings.
I wish you a magical day
I wish you health and many years to come.

Equinox today -
A magical day, not an easy one.
May a surprise be sent to you
By wayward fate.

On the autumn equinox,
I congratulate you,
Peace, harmony
I wish in my heart.

Let the foliage cover
From troubles and insults,
And the path to balance
Will be open.

The day of the autumnal equinox is today,
And there is no reason to be sad.
It's time to send your soul into flight,
She should soar with joy.

I want smiles on this day to see the sea,
Let the veil of lies disappear forever.
So that your families prosper,
Let their hearts drink in love.

Today we will celebrate the holiday.
After all, day and night are equal again!
Winter is not far away,
Don't borrow heat from us!

The equinox is now
Let the sun shine in the skies
To give us a reserve of strength,
To live like in fairy-tale dreams!

The day has settled on the scales
The second night settled in,
Happy children of the universe,
Noisy son and quiet daughter.

The minutes were divided in half,
The two divided the hours,
Autumn equinox day
You gave us a gift today.

I wish that nights and days
You filled me to the brim with happiness,
So that we can live in harmony
And the minutes of love were not counted.

Autumn is playing outside the window,
I brushed the leaves off the apple tree,
Equinox to visit us
Stopped by for a day.

Day and night do not argue at all -
On this autumn day.
The sun rose above the earth,
The Quarter takes its source again!

May you achieve it in life
You're the same height
Let it be like the sun at its zenith
You always shine for people!

Day and night have already come together as equals,
So, we have crossed that threshold,
When summer was full,
And now it’s an autumn evening

Reminded us that frost is near,
The cold, the cold will soon be here,
Autumn will take possession of the lush garden,
And shake off his confident arrogance.

Give me your hand, let's sit with you,
On a park bench by the stream,
We are always - in summer and winter,
We'll be together - just you and me!

Congratulations: 25 in verse.

When is the autumn equinox in 2018 / 1zoom.ru

Those days when day is equal to night are called the equinox - spring or autumn. We will meet the autumn equinox this week.

Autumn equinox 2018: when - what date and what time

In 2018, the autumn equinox fell on September 23. It will start at 4:54 Kyiv time.

The autumnal equinox falls on the same date in 2019 (at 9:50 Kyiv time). But in 2020 – on September 22 (15:31 Kyiv time).

Autumn equinox: signs

This day is considered the beginning of a real, “golden” autumn. By folk signs, what the weather will be like on this day, you should expect such weather for the rest of the fall.

Day of the autumnal equinox among the Slavs

For our ancestors, this was a time for summing up results and celebrating the harvest. Thanks were offered to the gods for a successful year and a rich harvest, and they were also asked for intercession for the coming winter.

During this period they stocked up forest mushrooms and medicinal herbs for the winter.

Autumn equinox: rituals

Some rituals of the ancient Slavs can easily be repeated in our time. For example, a ritual for family prosperity: apples from the new harvest (preferably from your own garden, but purchased ones are also suitable) - there should be as many of them as there are members in the family - each family member should hold in his hand. Then the fruits, imbued with the energy of each family member, are placed on a dish and placed on the table. In the evening, a candle is lit and the names of all family members are repeated. Then you need to focus on the apples, imagining the worries that are troubling the person, and say the spell: “Pourable apples, warmed by the Sun, grown by the power of the Earth, picked in the fall, ending the year. Each apple takes away adversity, attracts prosperity to the family. Good luck will accompany us (names), and adversity will bypass us.”. After which the apples are eaten by each family member, and the cores are thrown away as far as possible from the house.

This year March 20 is the vernal equinox. At 13:29 Moscow time, the Sun crosses the celestial equator in its apparent movement along the ecliptic. The length of day and night is the same throughout the Earth and is equal to 12 hours. The celestial equator is a projection of the earth's equator onto the sphere of fixed stars infinitely distant from us.

The sun does not move along the celestial equator, otherwise day would be equal to night every day, says a leading researcher at the Institute of Astronomy RAS Alexander Bagrov. - No, the Sun moves along the ecliptic, slightly inclined. When the star rises above the ecliptic, we have a long day. When it goes lower, the nights are long. And only at the moment when the Sun passes through the celestial equator does day equal night. That's why the event is called the equinox, in contrast to the summer and winter solstices.

During the last two events, as the astronomer explains, the Sun is as far as possible from the celestial equator. And then it turns out to be the longest day of the year - in the summer. Or the longest night is in winter.

Since ancient times, the spring equinox symbolizes the beginning of a new cycle in nature. And also - new beginnings in people's lives. From an astrological point of view, for example, the date of the vernal equinox is the day when the Sun enters 0 degrees Aries. This point is the beginning of the Zodiac. Once upon a time, the Sun actually rose against the background of the constellation Aries on the day of the spring equinox, but over time the equinox point has shifted, and now it is actually located in the constellation Pisces. Since the signs of the Zodiac are not associated with constellations, although they bear their names, the first sign of the Zodiac is still called Aries.

In the Northern Hemisphere, the vernal equinox marks the beginning of spring, and has long been celebrated as a time of rebirth, says the candidate historical sciences, teacher Moscow State University Boris Manevich. - This is a day of balance between day and night, light and darkness. In many cultures and religions, various holidays were dedicated to the spring equinox. On this day it was customary to hold all kinds of magical rituals. For example, after a number of preparations, plant seeds in a pot and make a wish. Then the seeds had to be cared for carefully and for a long time so that they would germinate and bear fruit. It was believed that with the appearance of fruits, wishes come true.

Magic is a creation human consciousness. Simply put, it’s fiction,” astronomer Alexander Bagrov is skeptical. - We must understand that people have been engaged in agriculture or hunting. Both were closely related to the seasons. Either the birds began migrating, then it was time to plow the land - in general, time had to be counted somehow. Observations helped in this count. For example, on March 20, day is equal to night. Yep, there is a starting point! From now on, the day will be longer than the night, you need to get the plow, and after plowing, sow.

As the scientist explained, science even now, unfortunately, does not know everything. And in ancient times she knew even less. Therefore, people made all sorts of guesses, supported them with rituals, which filled the void of scientific knowledge.

Easily explainable events now - for example, the same spring equinox - were given a certain magical meaning, people believed their own inventions, Bagrov explained. - But we cannot repeat their mistakes.