Happy March Equinox!
Before I forgot… Happy Equinox, everyone!
The word “equinox” derives from the Latin words meaning “equal night” and refers to the time when the sun crosses the equator. At such times, day and night are of nearly equal length everywhere in the world.
While the March equinox marks the beginning of spring in the northern hemisphere, it is the start of autumn in many parts of the southern hemisphere.
During the equinox, the length of night and day across the world is nearly, but not entirely, equal. This is because the day is slightly longer in places that are further away from the equator, and because the sun takes longer to rise and set in these locations. Furthermore, the sun takes longer to rise and set farther from the equator because it does not set straight down – it moves in a horizontal direction.
Moreover, there is an atmospheric refraction that causes the sun’s disk to appear higher in the sky than it would if earth had no atmosphere.
How high the Sun gets in your sky, and how long it is above the horizon during the day, depend not only on the season, but also on your latitude.