Showing posts with label Autumn. Show all posts
Showing posts with label Autumn. Show all posts

Sep 18, 2015

Autumnal Equinox

The Autumnal or Fall Equinox is a floating date around September 22-23 that marks the first day of autumn, when day and night are of equal lengths. The sun crosses the equator moving southward (in the northern hemisphere). The Autumnal Equinox marks the beginning of shorter days and longer nights and the passage into winter. On this day, the sun rises directly in the east and sets directly in the west; the sun will begin to rise at the South Pole after six months of darkness, to bring six months of daylight; and the zenith passes directly overhead on the equator, so the sun casts no shadows. For centuries, friends have gathered to celebrate the day and strengthen their spirits in preparation for the passage into winter.

Apr 11, 2014

Seven Spring Facts

The vernal (spring) equinox (‘equal night’) is the day when the center of the Sun is visible for exactly 12 hours. That is not the same as the ‘equilux’ (equal light) when there are 12 hours of daylight from the Sun’s first appearance and its going down. Australia and other parts of the Southern Hemisphere begin the first day of autumn at the same time and there is a movement to call this event the March Equinox or Northward Equinox to avoid a North Hemisphere bias.

Astronomically, spring officially begins on the spring equinox.

The spring and autumn equinoxes are the only days when the Sun rises directly due east and sets due west in the northern hemisphere.

The reason there is more daylight during the spring is the earth’s axis tilts toward the sun at this time of year.

We have used the word ‘spring’ for the season since the 16th century. Before that spring was used for centuries to apply to the source of a river and the spring season was known as Lent or Lenten.

The Slatina spring in Slovenia is alleged to have been discovered by the mythological winged horse Pegasus.

The earliest known use of the term ‘spring-cleaning’ was in 1857