In ancient cultures, those who studied the natural world and used their knowledge to practice their craft, were revered, sometimes feared. They wielded power with their knowledge and abilities. To most if not all the “commoners” their craft seemed magical. But it wasn’t magic, it was knowledge, with some theatrics thrown in for effect. These practitioners studied and were the original nerds of society, albeit powerful nerds.
They studied a lot about the natural world in order to practice what appeared to be supernatural feats. Studying the heavens, these practitioners created two disparate disciplines, Astronomy and Astrology. They used their knowledge of astronomy to produce a scheme for predicting events (astrology) that gave them power, sometimes rivaling their monarchs.
Two astronomical events were of particular importance. Equinox and Solstice. Practitioners of astronomy used their knowledge to predict the coming seasons. They had temples and monuments constructed to worship the Sun and its apparent position in the sky during these events. The structures were designed and orientated so that sunlight would shine through small openings, onto sacred objects on the spring or fall equinoxes, signifying the beginning of planting or harvesting season. Similarly, shrines were built to result in similar magic on the summer and winter solstices. These temples, monuments, or shrines were considered holy and treated as such.
Equinoxes and solstices are natural phenomena that simply happen because of Earths orbit around the Sun and being tilted on its axis. Other than Mercury, with no axis tilt, all the solar system’s planets have equinoxes and solstices.
An equinox means the day and night lengths are approximately equal. Unequal length of day vs night is due to Earth’s axis tilt. Twice per year Earth’s position in orbit eliminates the tilt affect, so daytime and nighttime are pretty equal. Neither pole is pointed in the Sun’s direction, so the daytime is the same as the nighttime. Planets like Mercury, with no rotation axis tilt, have equinoxes all the time. Another way to think about it is the Earth is halfway between solstices.
A solstice means that day or night is the longest it will be for the year. The axis of rotation pole is either pointing most toward or away from the Sun. For a summer solstice that pole is pointing the most toward the Sun’s direction for that year. For a winter solstice just the opposite.
Also, because of this axis tilt the northern and southern hemispheres experience opposite conditions. Spring equinox in the northern hemisphere is fall equinox in the southern hemisphere. Summer solstice in the southern hemisphere is winter solstice in the northern hemisphere.
After a solstice, daytime hours start to either increase or decrease each day past solstice. The equinox, as I mentioned, marks the halfway point between solstices. Repeat.
What’s in the Sky?
Our vernal equinox and first day of spring occurs on March 20th, at 10:33 am Central Daylight Time.
Keep an eye on the pre-dawn eastern sky as planets Venus, Mars, and Saturn give us a show.