General Knowledge

[cornelia 1]

55. What astronomically ends the "vernal Equinox"

[Buenchico]

The first day of spring.

[Kidas]

Slightly odd question.

The Vernal (springtime) equinox takes place at a very specific time, when the axis of rotation of the earth is in the same plane as the plane that is both perpendicular to the orbital plane of the earth and tangential to the earth's orbit.

(think that explains it)

In 2018, that will be at 16.15 GMT on Mar 20.


I guess that means it ends when the axis of rotation of the earth is no longer tangential to the orbit of the earth around the sun...

Or am I over-thinking this?

[1581960]

The sun crossing the equator

[andres]

The vernal equinox marks the beginning of spring but the question asks what ends it? The 'autumnal equinox'probably.

[Flonska]

The vernal equinox lasts until the summer solstice (June 20 or 21 in the Northern Hemisphere, December 21 or 22 in the Southern Hemisphere.

[Kidas]

Sorry Flonska, that's not right.

Each of the two equinoxes and two solstices takes place at a specific time

https://greenwichmeantime.com/equinox/

Those four astronomical events mark the beginning/end of seasons (by some definitions). It may be that the season of Spring lasts for the period between the vernal equinox and the summer solstice, but the vernal equinox is an instantaneous event. Loosely, it is when the length of the day is the same as the length of the night.

I suspect that the question is missing a word:

"What astronomically ends [on] the vernal equinox".

In which case it would be the Winter season

[Flonska]

Yes, Kidas, it is the Spring which lasts until the summer solstice, I forgot to include that point. Thank you for the realignment ;-)

[Tilly2]

♫ This is the dawning of the age of...♫

[cornelia 1]

Thank you for all that information