Zodiac signs are based on the Earth’s orbit around the Sun and are rooted in astrology, an ancient system that divides the sky into 12 sections, each linked to a constellation. Here’s a detailed explanation:  

How Zodiac Signs Are Determined  

1. The Ecliptic Path:   The Earth revolves around the Sun, and from Earth’s perspective, the Sun appears to move across the sky through a path called the ecliptic.   Along this path, the sky is divided into 12 equal sections, each associated with a specific zodiac constellation.      

2. The 12 Zodiac Signs:   Each sign covers 30 degrees of the 360-degree ecliptic.   The signs are associated with different dates based on the Sun’s position during the year:      

3. Elements and Modalities:   Elements: Fire, Earth, Air, and Water describe the core nature of the signs.   Modalities: Cardinal (initiators), Fixed (stable), Mutable (adaptable) explain how signs react to life events.      

4. Astrological Chart:   In a full astrological chart, other planetary bodies like the Moon, Mars, and Venus also play a role, reflecting deeper aspects of personality and life events.      

5. The Precession of the Equinoxes:   Due to Earth’s axial tilt shifting over thousands of years, the constellations’ positions have moved. This phenomenon means the zodiac constellations in astronomy don’t align exactly with the zodiac signs in astrology.