The vernal equinox happens when?

Answer 1

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 the Southern Hemisphere is 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.

Astronomy

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.

Answer 2

On the vernal equinox the sun is directly over the equator which happens on or about March 21

On the autumnal equinox the sun is directly over the equator which happens on or about September 22

Answer 3

This question is unclear. Is the user asking for times, equinox dates for upcoming years, or a definition?

Answer 4

The time of daylight and nighttime is equal.

Answer 5

The hours of darkness are longer than daylight hours.

Answer 6

the first day of spring

Answer 7

mar 21