The movement of the sun through the constellations
The sun seems to pass in front of numerous constellations as Earth revolves around the sun. The sun’s position about distant background stars drifts in an easterly direction from day to day, while the moon appears in a little different spot in the sky each night. It’s not as if the sun isn’t moving, and its movement is fictitious, owing to Earth’s rotation around our star.
The sun seems to be in front of, or “in,” different constellations throughout the year. The sun appears in Gemini one month and Cancer the next. The dates in the newspaper’s horoscope indicate when the sun is in a specific astrological sign. For example, the symbol Aries is represented by the period between March 21 and April 19. However, your astrological sign does not always indicate which constellation the sun was in when you were born.
Why don’t the zodiac constellations usually correspond to astrological signs?
We need to know more about how the Earth moves to explain why constellations no longer coincide with their respective characters. We must also discuss how we measure time.
Time is a fiendishly difficult concept to grasp, especially if we insist on using the sun and stars as our point of reference. For better or worse, our calendar is based on the seasons. The day the sun appears at its most northerly position in the sky is June 21 – the approximate date of the summer solstice north of the equator and the winter solstice south of the equator. The North Pole is most inclined towards the sun at the June solstice.
The North Pole does not always point in the same direction as the background stars complicate things. Our world whirls around like a top, and the Earth, like a top, wobbles! The North Pole traces a circle on the celestial sphere due to the Earth’s wobble. The wobbling is gradual; it takes 26,000 years to complete one rotation. However, as time passes, the impact becomes more pronounced.
The direction of the Earth’s axis drifts somewhat throughout one orbit around the sun, which means that the solstice’s location and our trajectory change by a very modest amount. The solstice happens around 20 minutes before one full journey in front of the background stars!
Our strewn calendars
Because we base our calendar on the solstices and equinoxes (and astrologers on the signs), the Earth does not complete an orbit in a single year. The tropical or seasonal year is a fraction of a second shorter than one complete circle (sidereal year). This implies that the sun’s position relative to the stars on any particular day – say, June 21 – wanders each year slightly.
However, after 2,000 years, the sun will be in a completely other constellation!
The sun was about halfway between Gemini and Cancer on the June solstice 2,000 years ago. The sun was between Gemini and Taurus on the June solstice. In 4609, the June solstice point will move from Taurus to Aries, leaving Taurus behind.