The vernal equinox is the day in spring ("vernal") when the daylight and nighttime portions of the day are the same length ("equinox"). It's officially the "first day of spring", though in terms of the actual weather it's usually more like "about a third of the way into spring-like conditions".
There are two days every year where the daylight and nighttime portions last 12 hours each: the vernal equinox and the autumnal equinox. You should be able to guess what the autumnal equinox is, since unlike vernal, "autumnal" is fairly close to (one of) the English words for the season.
The word "vernal" refers to the season of spring, as the word autumnal refers to the season of autumn, or fall. The vernal equinox for one half of the Earth is the start of the Spring season, and one of two times a year when the day and night are roughly equal in length for most of the planet. At these times the Sun crosses the plane of the Earth's equator. The vernal equinox for the Northern Hemisphere is the March equinox (March 20). The vernal equinox for theis either September 22 or 23, the day termed the autumnal equinox for the north.
Every year the Earth goes once around the Sun; that is, after all, the definition of a year. The Earth spins on its axis, and this axis happens to be tilted about 23.5 degrees relative to Earth's orbital plane. As a result, for half of each year, the northern hemisphere is tilted toward the Sun for the other half the southern hemisphere tilts toward the Sun. This causes the different seasons of the year.
When the north is tilting toward the Sun, the Northern Hemisphere experiences longer days and warmer temperatures, beginning in the spring. When the south is tilted toward the Sun, then the southern hemisphere generally experiences the warmer weather.
As the earth revolves around the sun there are two moments (not whole days) of the year when the Sun appears exactly above the equator. At these times neither pole tilts toward the Sun. These moments are called "equinoxes". One occurs in March as the northern hemisphere starts to tilt toward the sun. In the north, that equinox is called the "vernal" or spring equinox, the beginning of spring. The other, in September, is the autumnal equinox and is the first day of fall (autumn). In the southern hemisphere, the March equinox is autumnal, and the September equinox is vernal. Around the time of either equinox (which means "equal night") the daylight period of the day is about the same length of time as the night time period.
The term Vernal Equinox has another meaning in astronomy: the point in the heavens which is the location of the Sun at the moment of the northern vernal equinox. This point is useful as an astronomical marker, but because of something called 'precession' it moves very slowly. At one time this point was called the "First Point of Aries", because it was located just over the boundary of the constellation Aries. It is no longer there.
*The actual distance from the Earth to the Sun is not the cause of the seasons. During the northern winter, the Earth is actually a little closer to the Sun than it is during the northern summer.
There is nothing about the vernal equinox which is an intrinsic source of headaches. I could hypothesize that there is something you do in celebration of the vernal equinox that is not good for you, or alternatively, your mere expectation of having a headache at that time of year is enough to cause a psychosomatic headache.
How do you get 1000000 robux for free?
A teacher walks into the Classroom and says If only Yesterday was Tomorrow Today would have been a Saturday Which Day did the Teacher make this Statement?
Give me food and I will live give me water and I will die what am I?
How do you spell water with 3 letters?
What countries have only three syllables in their name?
What is 8 divided by 2(2 plus 2)?
What does ckcd debit mean on a bank statement?
Are Danny Devito and Joe Devito related?
WHAT IS THE EXPECTATION ON THE SUBJECT NSTP AND TO THE INSTRUCTOR AND CLASSMATE?
Why do you think planners and designers of curriculum include the subject humanities in your chosen field of study?
What patterns are involved in multiplying algebraic expressions?
What are the advantages of using a two-way chart?
Bakit hindi kasama sa pinagpilian si andres bonifacio bilang bayani?
Why the story entitled origin of fair complexion and fair hair?
Who is the official channel for the DoD engaging the news media?
BE-4 For a powerboat to be operated in compliance with the law in addition to registration number what else is required?
Copyright © 2020 Multiply Media, LLC. All Rights Reserved. The material on this site can not be reproduced, distributed, transmitted, cached or otherwise used, except with prior written permission of Multiply.