The first day of fall has arrived.  This is how the equinox marks the change of seasons.

The first day of fall has arrived. This is how the equinox marks the change of seasons.

FILE PHOTO: This color image of Earth, taken by NASA's Multiple Earth Imaging Camera, a four megawatt CCD camera and telescope on July 6, 2015, and released on July 20, 2015. REUTERS/NASA/Sheet via Reuters /File Photo

A view of Earth taken by NASA’s Multichromatic Earth Imaging Camera.Reuters

  • The 2022 fall or autumnal equinox occurs on Thursday, September 22.

  • The fall equinox occurs when square rays warm up perfectly with the earth.

  • During an equinox at the Earth’s equator, the sun appears almost directly overhead.

Thursday is the autumnal equinox this year.

This astronomical event, which occurs every year, means that the day is about as long as the night.

Also known as the September or autumnal equinox, this event​​​​​​​​​​​​​​​​​​​​​​marks the official start of fall and the end of summer as the Northern Hemisphere moves towards cooler and darker days.

For those in the southern hemisphere, the milestone marks the beginning of spring.

There are two reasons for these seasonal shifts that are extremely important: the Earth’s tilted axis and the planet’s orbit around the sun.

How does the fall equinox work

In June and December, the Earth hits its solstices – the longest and shortest days of the year.

And twice a year, in March and September, the Earth reaches its equinoxes, which means that the days and nights are about the same length of time.

Graphic of the world's planes and solstices

How the Earth, its axial tilt, and the sun work to create solstices, meridians, and seasons.Shayanne Gal/Business Cossider

Here’s why: the sun rises and sets on our planet once a day because our planet also rotates around its axis.

But it takes about a year — about 365 days, 5 hours, 59 minutes, and 16 seconds to be exact — for the Earth to make its way around the sun, according to NASA.

The Earth’s axis is not perfectly square to the plane of its orbit around the sun. Instead, its axis is slightly tilted to one side, about 23.5 degrees (so far).

That means that the sun’s rays hit different parts of the world at different angles, depending on the time of year.

When the Earth is tilted towards the sun, during the summer, more sunlight can hit the Earth and can warm the atmosphere. But when the Earth is tilted away, during winter, less sunlight hits the Earth, and the atmosphere is cooler.

During an equinox, however, the Earth squares up perfectly with the sun’s warming rays. This means that the strongest rays of the sun hit the Earth directly at the equator, and day and night last about the same amount of time.

Earth during equinox

Illustration of the earth during equinox.Shayanne Gal/Business Cossider

This year, this will happen at precisely 9:03 pm ET.

If you were standing directly on the equator at the peak of the equinox, the day would last about 12 hours and six and a half minutes. The sun would appear more or less directly overhead, and your shadow would be as small as ever.

But this moment does not last, because the Earth makes its way around the sun at a speed of about 66,600 mph.

The animation below gives an overview of how this works:

occasionally

Animation of the Earth in orbit, with points marking the two perihelions and solstices along with relevant information.James O’Donoghue

Uneven seasons

Our planet’s orbit around the sun is not a perfect circle. It’s actually slightly elliptical, and its center of gravity is slightly offset from the sun, so the time it takes to cycle through the seasons isn’t perfectly divided.

About 89 days and 19 hours after the equator falls, the Earth will reach its winter solstice – when the light hits the Southern Tropic (or Tropic of Capricorn) most directly. Another 89 days later, the spring or vernal equinox will occur.

Then it is another 93 days and 18 hours before the summer solstice – when the sun’s directest rays reach its northernmost latitude, known as the Tropic of the North (or Tropic of Cancer) – and 92 days and 16 hours the another hour to go back to the fall. equator.

People, some in traditional clothing, hold their hands up towards the sky, with Stonehenge in the background.

Druids, pagans and others gather around Stonehenge on 23 September 2017.Matt Cardy/Getty Images

celebrating equinox

For some, the equinox is more than a day that brings the return of the pumpkin spice latte. The arrival of the harvest season has been a sign for many in human history and various cultures still celebrate the event today according to USA Today.

One example is at Stonehenge in the UK, where pagans and wizards gather around the monolithic structure to watch the sun rise above the stones.

Dave Mosher contributed to a previous version of this article

Read the original article on Business Insider

Leave a Reply

Your email address will not be published.