When day on earth equals night. Spring and autumn equinoxes. One of the most important practical tasks of astronomy is the establishment of the date of the equinox

An equinox is such 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 on 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. The Sun also rises almost exactly in the east and sets 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, insert rowan tassels between window frames for amulets. And for the Celts, this is a harvest festival, a festival of autumn and wisdom. And they have their own rituals - they first demonstrate to everyone the best gifts of summer, and then eat them, which guarantees an abundance of food for the whole year.

Autumn breaks up with summer
She's crying, she's laughing
It suddenly pours rain
Then all of a sudden the sun will flood everything,
equinox of nature,
Variety of weather!
Day is equal to night
Tomorrow it will be shorter
But that's tomorrow, and now,
Happy equinox to all of you!
And though nature fades away
Don't let it 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 golden 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!

The day has become equal to the night,
Autumn sends us its greetings.
On a magical day I wish you
I am healthy, long life.

Equinox today -
The day is magical, difficult.
May a surprise be sent to you
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.

Day autumn equinox Today,
And there is no reason to be sad.
It's time to send the soul into flight,
She should soar for joy.

I want smiles on this day to see the sea,
Let the veil of lies come out forever.
For your families to flourish
Love let their hearts get drunk.

Today we celebrate the holiday.
After all, day and night are equal again!
Not far from winter
Don't borrow heat from us!

The equinox is now
Let the sun shine in the sky
To give us strength,
To live like in fairy tale dreams!

The day has settled on the scales
On the second night settled,
The universe is happy children,
Noisy son and quiet daughter.

Minutes split in half
Divided the hours for two
Autumn equinox day
You gave us today.

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

Outside the window plays autumn
She brushed the leaves from the apple tree,
Equinox visit us
Looked at the day.

Day and night do not argue at all -
This autumn day.
The sun rose above the earth
In the Quarter again takes the source!

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

Day and night converged already on an equal footing,
So we crossed the threshold
When the summer was full
And now it's autumn evening

We were reminded that frosts are near,
Cold, cold will soon be here
Autumn will take possession of a lush garden,
And shake off the confident arrogance.

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

Congratulations: 25 in verse.

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 duration of day and night is the same on the whole Earth and equals 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 the day would be equal to the night every day, - says Alexander Bagrov, a leading researcher at the Institute of Astronomy of the Russian Academy of Sciences. - No, the Sun moves along the ecliptic, slightly tilted. When the sun rises above the ecliptic, we have a long day. When it goes down, the nights are long. And only at the moment when the Sun passes through the celestial equator, the day is equal to the night. Therefore, 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 the longest day of the year - in summer. Or the longest night is in winter.

Since ancient times, the spring equinox symbolizes the beginning of a new cycle in nature. And yet - new beginnings in people's lives. From the point of view of astrology, 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 on the day of the vernal equinox really rose against the background of the constellation Aries, but over time, the equinox point has shifted, and now it is actually in the constellation Pisces. Since the signs of the Zodiac are not associated with the constellations, although they bear their names, the first sign of the Zodiac, as before, is 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 Boris Manevich, candidate of historical sciences, lecturer at Moscow State University. - This is a day of balance of day and night, light and darkness. In many cultures and religions, various holidays were dated for the day of the vernal 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 carefully and long looked after so that they would germinate and bear fruit. It was believed that with the appearance of fruits, wishes come true.

Magic is a product of human consciousness. Simply put - fiction, - skeptical astronomer Alexander Bagrov. - It is necessary to understand that people from ancient times were engaged in agriculture or hunting. Both were closely related to the seasons. Either the flight of birds begins, then it's time to plow the land - in general, time had to be counted somehow. Observations helped in this countdown. For example, on March 20, the day is equal to the night. Aha, there is a point of reference! From now on the day will be longer than the night, you need to get a plow, and after plowing, sow.

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

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

Yesterday, the Indian summer reached its culmination: in Moscow, the air warmed up to +21.6, according to Central Russia was up to +24.5. This is more in line with an ordinary summer than an Indian one. Today, the nature of the weather is beginning to change, but only in the northwestern sector of the Central District.

Sunny day in early autumn. © Tomasz Parys | Shutterstock.com
The anticyclone continues to control the situation, holding back the offensive atmospheric front from the west. Thus, for those who did not have time to enjoy Indian summer yesterday, nature gives another warm day.
Even in the northwestern regions, where the colors of the weather will be smeared with clouds and light rains, you can still catch the last notes Indian summer, with temperature +15...+20.
And in the east and south of the district, where the sky will remain sunny, you can again count on +25!

When day equals night

Twice a year, on the days of the autumn (September 22-23) and spring (March 20-21) equinoxes, the Earth turns towards the Sun in such a way that the sun's rays fall vertically on the equator. And then all over the globe - at the poles and at the equator, in temperate latitudes and in the tropics, the length of day and night becomes the same. It is curious that in Latin this event is called "aequinoctium", which translates as "equinox". In this sense, the Germans, who use the word "Tagundnachtgleiche" ("equality of day and night"), turned out to be more logical.


Autumn in the northern hemisphere. © Artens | Shutterstock.com
On the day of the autumnal equinox, the Sun crosses the equator and moves into the southern half of the celestial sphere. From this moment on, astronomical autumn begins in the entire northern hemisphere of the Earth, and darkness takes more and more minutes from light every day! The shortest day of the year, which falls on December 21 or 22, marks the beginning of astronomical winter. After that, daylight hours gradually increase and by the beginning of the third decade of March it becomes equal to the night. On the day of the vernal equinox, autumn comes again on our planet, only this time in the southern hemisphere...


Yellowed leaves. © Calin Stan | Shutterstock.com
An interesting fact is that autumn and winter in the northern hemisphere is a week shorter than the autumn-winter season in the southern hemisphere. Since the number of days from the spring equinox to the autumn equinox is 186, and the time interval from the autumn to the spring equinox is only 179 days! The fact is that in the winter of the northern hemisphere, the Earth moves around the heavenly body somewhat faster than in the winter of the southern hemisphere. Because in January Earth passes the point of the orbit closest to the Sun - perihelion. And at perihelion, as you know, line speed the planet is growing! Therefore, we residents northern latitudes, we are in a more favorable position than the inhabitants of the southern latitudes, whose dark and cold season is longer by as much as 7 days!


Spring is coming to Australia. © Bui Viet Hung | Shutterstock.com
However, the moment is approaching when we are forced to pass the baton of spring and summer to the inhabitants of the southern hemisphere. This will happen tomorrow. In the meantime, let's enjoy the last hours of the outgoing astronomical summer, especially since the weather is conducive to this!

The spring equinox, or the time when the day is equal in duration to the night, falls annually on March - and in 2018 this day will come on the 20th.

The equinox, that is, the time when the length of day and night are equal, occurs twice a year - in spring and autumn. Change of times in modern world determined by the calendar, and in ancient times these days were considered the change of seasons. Scientists consider the spring equinox to be the astronomical beginning of spring, which lasts three months, until summer solstice- in 2018 falls on June 21.

Therefore, since ancient times, people considered the day of the vernal equinox a long-awaited and mystical event.

When day equals night

The spring equinox is when the sun moves from the southern hemisphere of the celestial sphere to the northern. The Earth at this time, moving along its orbit, will overcome a quarter of a year's path. The equal duration of the light and dark times of the day is explained by the fact that the two hemispheres will be exactly half illuminated by the luminary.

The seasons of the hemispheres change from the day of the spring equinox. Since that time, in the northern hemisphere of the Earth comes astronomical spring, and in the south - astronomical autumn. And so it goes until the summer solstice.

Six months later, when the Sun, continuing its movement, moves from the southern hemisphere to the northern, the equinox will again come, but the Sun at this time is on the opposite side of the orbit.

March 21 is historically considered the date of the spring equinox. On the first Ecumenical Council in 325 it was on this day that general rule by definition of the day of the celebration of Easter.

According to the rule, Christians celebrate the Bright Resurrection of Christ on the first Sunday after the spring full moon, but not earlier than the spring day of the equinox.

The spring equinox falls every year on different dates, since it does not have a fixed day and hour and shifts by almost six hours every year. Due to the fact that astronomical year different from the calendar, the spring equinox can fall from March 19 to March 21.

IN leap years the earliest dates of the equinoxes are observed, and the latest in years that precede leap years. In a leap year, the time is adjusted and the equinox returns to its original date.

Traditions and customs

Many peoples of the world day of spring equinox since ancient times it was considered a great holiday - magical and ritual. Spring festivals in ancient and medieval times were celebrated with gaiety and rituals that called for the fertility of the land and the well-being of the people.

The Great Sphinx was erected by the ancient Egyptians so that during the spring equinox it pointed directly to the rising sun. Many nations have kept this holiday in their calendar to this day. To the tradition of ancient farmers Central Asia and the Middle East, the roots of Navruz, which in Farsi means "new day", have their roots. For many peoples who profess Islam, the holiday has become an integral part of their culture - the day of the equinox as National holiday Kyrgyz, Kazakhs, Tajiks, Tatars, Uzbeks, Bashkirs and many others celebrate.

On the day of the spring equinox, New Year in many eastern countries, including Afghanistan and Iran. Among the Germans and Celts, the vernal equinox was associated with the rebirth of spring and indicated the beginning of the agricultural season. Mistresses, in order to please the goddess Ostara (one of the most "old" goddesses, who was worshiped at the end of the 2nd millennium BC) and celebrate spring in a special way, dyed eggs and baked wheat buns. Slavic holiday Shrove Tuesday is also timed to coincide with the spring equinox - on this day people said goodbye to winter and welcomed spring, which embodies the rebirth of nature. In the old days, people believed that the more fun the holiday was, the nature would be more generous to them.

The day of the vernal equinox in Rus' was called "Magpies" since at that time many birds flew in, namely 40, and the lark, which returned first, was considered a symbol of the holiday. On this day, according to an old custom, they baked cookies in the form of a bird and gave them from the whole village to the one who first saw the lark. Then the remaining sweets were handed out to the children so that they would invite the larks in their turn, which, according to legend, will bring spring with them. In many countries, this day is magical, as it is the only time of the year when spring meets spring. Usually, at this time, they tell fortunes and solemnly burn an effigy of winter, meeting the long-awaited spring.

Signs

On the day of the spring equinox, according to signs, they monitor the weather, and if it is warm on this day, then there will be no cold and frost until the summer. The day of the spring equinox is best spent with family or with a loved one - on this day you can not quarrel, get upset, sort things out with loved ones. To the whole next year spend without worries and not think about the bad, the day of spring balance should be met with fun. People believe that the wish made on this day will surely come true.

On the day of the spring equinox, they tell fortunes about love - they guess on Tarot cards, classic cards, runes, oracles. And in order to get an accurate answer, at the moment of divination, you should concentrate and ask a specific question. Since the holiday was preceded by Maslenitsa (in 2017 from February 20 to February 26 inclusive), many girls use similar fortune-telling. So, for example, pancakes were also baked on that day, and if the first pancake was not lumpy, then they believed that they would get married this year. On the spring equinox, the girls guessed at the gender of the first child, for this they followed the one who holiday table take the first pancake. If a man, then they were expecting a boy, and if a woman, a girl.

People considered dreams for the spring equinox to be prophetic, so the girls guessed at their husband before going to bed. To do this, two aces were placed under the pillow - spades and tambourines, as well as a ten of clubs, a ring, a key and a piece of pie, after wrapping all the items in a white scarf.

The future was already judged in the morning, depending on what was dreamed of: a ring for an imminent wedding, a key or bread - for success in work, a pie - for good luck and joy, a card of spades - for trouble, diamond card- to wealth, clubs - to moving.

The spring equinox is a magical period, a time for the manifestation of feelings, and if you have long wanted to confess your feelings to your loved one, you need to do it on this day.

Equinox, implies at least a basic knowledge of astronomical terms, because the equinox itself is a phenomenon studied by this particular science.

Required knowledge of astronomical terms

Our luminary makes its movement along the ecliptic, which is, speaking in unscientific terms, the plane of the earth's orbit. And the moment when the sun, making its way along the ecliptic, crosses the celestial equator, which is big circle air and parallel to the earth's equator (their planes coincide, and both of them are perpendicular to the axis of the world), is called an equinox. (also an astronomical concept that has nothing to do with Schwarzenegger) is a line that divides any celestial body into a part illuminated by the sun and into a "night" part. So, on the day of the equinox, it is this terminator that passes through the geographic poles of the Earth and divides it into two equal semi-ellipses.

The salient feature in the name

The name itself contains the concept that on the day of the equinox, night and day are equal to each other. WITH scientific point view, the night is always a little shorter, and the sun rises and sets not exactly in the east and west, but a little bit to the north. But all the same, since childhood, we know that June 22 is not only the day the war began and school proms (this was the case in Soviet time), but also the summer equinox. However, December 22 is also called the summer and winter solstices. This happens because the sun in these periods of time is either in the high point above the horizon, or at the lowest, and farthest from the celestial equator. That is, on the day of the equinox, the light and dark parts of the day are almost equal to each other.

The number characteristic of the equinox and solstice

On the days of the solstices, one of them - either day or night - maximally exceeds the other. The equinoxes and solstices are also notable for the fact that they serve as the beginning of the seasons. These dates are very remarkable, and always one of the family members says that, they say, today is the longest or shortest day, or that today the day is equal to the night. And this distinguishes him from a series of consecutive days. Almost always, the date of these moments becomes the 22nd, but there are also leap years, and other moments and phenomena of astronomy that affect the date shift by the 21st or 23rd. The months of March, June, September and December are those in which the equinoxes and solstices fall.

Holidays that came from ancient times

Of course, they have been known since ancient times. Our ancestors observed them and connected their lives with these dates, dozens of witnesses will accept this. For the ancient Slavs, a certain holiday is associated with each of these days, and it usually lasts a week (Carols, Rusalia, Maslenitsa week). So, on the winter solstice, Kolyada falls, a holiday later timed to coincide with Christmas. Velikden, or Komoyeditsa, she is Shrovetide - these names mark the spring equinox, the birth of the young sun. From this day, the astrological solar year begins, and our luminary passes into from the South. Maybe that's why March 20 is the holiday of astrology. Kupala (other names Ivan-day, Solstice), or summer opposition, - big summer holiday of the ancient Slavs, covered with legends, glorifying the brave people going that night to look for a fern flower. Ovsen-Tausen, the day of the autumn equinox, after which winter slowly begins to come into its own, and the nights become longer. Therefore, our ancestors in Svyatovit (another name) lit candles - the most beautiful was put in a place of honor.

Earth's Special Climate Zone

All these dates served as starting points for the start of certain activities necessary for life - seasonal types of farming, building or stocking up for the winter. The days of the spring and autumn equinoxes are also characterized by the fact that the sun gives off its light and heat equally to both the Northern and Southern hemispheres, and its rays reach both poles. These days it is above the territory of such climate zone Lands like the tropics (translated from Greek means turning circle). In different directions from the equator to 23 and a few degrees, parallel to it are the northern and southern tropics. characteristic feature The area enclosed between them is that over them twice a year the Sun reaches its zenith - once on June 22 over the northern tropic, or the tropic of Cancer, the second time over the southern, or tropic of Capricorn. It happens on December 22nd. This is typical for all latitudes. North and south of the tropics at its zenith, the Sun never appears.

One of the consequences of the shift in the direction of the earth's axis

On the days of the equinox and solstice, it intersects with the celestial equator at points located in (spring) and Virgo (autumn), and on the days of greatest and least distance from the equator, that is, on the days of the summer and winter solstices, in the constellations of Taurus and Sagittarius, respectively . From zodiac constellation Gemini in Taurus, the summer solstice moved in 1988. Under the influence of the attraction of the Sun and the Moon, the earth's axis slowly shifts its direction (precession is another astronomical term), as a result of which the points of intersection of the star with the celestial equator also shift. Spring dates differ from autumn dates, and if September falls on the 22nd-23rd, then the question “When is the day of the vernal equinox?” The answer will be - March 20th. It must be noted that for the Southern Hemisphere, the dates will change places - autumn will become spring, because everything is vice versa there.

The role of the zodiac constellations

As noted above, the equinox points are the points of intersection of the celestial equator with the ecliptic, and they have their own zodiac symbols corresponding to the constellations in which they are located: spring - Aries, summer - Cancer, autumn - Libra, winter - Capricorn. It should be noted that the period of time between two equinoxes of the same name is called a tropical year, the number of solar days in which differs from approximately 6 hours. And only thanks to the leap year, which repeats once every 4 years, the date of the next equinox, running forward, returns to the previous number. With the Gregorian year, the difference is negligible (tropical - 365.2422 days, Gregorian - 365.2425), because this modern calendar is arranged in such a way that even in the long term, the dates of the solstices and equinoxes fall on the same numbers. This happens because it provides for a pass of 3 days once every 400 years.

One of the most important practical tasks of astronomy is the establishment of the date of the equinox

Dates range from 1 to 2, no more than days. So how to determine for the coming years when the day of the equinox? It is noticed that as a result of the presence of small fluctuations, the earliest dates, that is, the 19th, fall on leap years. Naturally, the latest (22) falls directly on the preceding leap years. Very rarely there are earlier and later dates, the memory of them is kept for centuries. So, back in 1696, the spring equinox fell on March 19, and in 1903, the autumn equinox fell on September 24. Contemporaries will not see such deviations, because the record of 1696 will be repeated in 2096, and the latest equinox (September 23) will occur no earlier than 2103. There are nuances associated with local time - a deviation in a figure from world time occurs only when exact date falls at 24:00. After all, to the west of the reference point - the zero meridian - a new day has not yet arrived.