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2 minute read
Farewell, Winter; Hello, Spring!
BY DENNIS MAMMANA
Week of March 19-25, 2023
Spring is about to... well, spring! At least in the Earth’s Northern Hemisphere, anyway.
Springtime officially arrives this year in the Earth’s Northern Hemisphere, and autumn in the Southern Hemisphere, Monday, March 20.
Many folks know that around the first day of spring (and, of course, the first day of autumn) the sun rises due east and sets due west. At these times, it’s wise for people who drive in those directions around dawn and dusk to be extra careful, since the rising and setting sun can make it difficult to see oncoming traffic and pedestrians along east-west roadways.
This whole change of seasons business comes about not because of our varying distance from the sun as many people mistakenly believe, but rather because our Earth’s axis is tilted relative to its orbit around the sun.
During wintertime, we in the Northern Hemisphere see the sun cross our daytime sky low in the south; in our summertime, it crosses high overhead. At some point during the year, however, the sun has to cross the equator on its way northward, and that occurs at the exact moment known as the vernal equinox, which, this year, occurs on March 20 at 2:24 p.m. PDT (5:24 p.m. EDT).
On that day our sun lies directly over the Earth’s equator and, if you were standing there, you would see the sun pass directly over your head around noontime. A few days or weeks earlier, the sun would have appeared in your southern sky, and a few days or weeks later it would appear in your northern sky. But on that day, the sun stands directly over the equator and would appear to pass directly overhead.
It is also around this time of year we may notice that our days and nights are of nearly equal length, and it is from this that we get the term “equinox,” which derives from Latin and means “equal nights”. And, as long as we don’t concern ourselves with the fine details of our sun’s position, those are both fairly true statements.
For billions of years life on our planet has become accustomed to seasonal changes, but did you ever wonder what conditions might be like if the Earth’s axis were not tilted and we had no seasons? Would life on Earth be different?
With no tilt, the Earth would have a more moderate and stable climate. Flora and fauna might have become quite specialized, creatures of different sizes and types might intermingle more, and the ecology of our world would likely be quite different than we know today.
And if Earth’s axis were tilted even more? Seasonal changes would be more extreme; winds would blow more strongly, storms would be more powerful and common, and local temperatures would vary dramatically throughout the year.
So, as we begin to see the changes around us as springtime arrives, be sure to enjoy them all. We owe to them our very existence.
And as our temperatures gradually become more pleasant once again, I’m glad to be done with the cold and dreary days of winter, and I’m reminded how happy I am for our changing seasons!
Visit Dennis Mammana at dennismammana.com. COPYRIGHT 2023 CREATORS.COM