Mythological Origin Based on Two Brothers: One Mortal, One Immortal The Gemini constellation represents the twin brothers Castor and Pollux in Greek mythology. According to the story, Pollux is immortal due to his divine lineage, while his half-brother Castor is mortal. When Castor dies, Pollux wishes to share his immortality with him. To reward this devotion, Zeus places them both in the sky as stars (the Gemini constellation). The sign's association with "dual nature" and "devotion" stems from this mythology. Represents the Hands, Arms, and Nervous System in the Body in Astrology In classical astrology, each zodiac sign governs a specific region and function of the human body. Gemini is the sign that rules the hands, arms, lungs, and directly the nervous system. For this reason, Gemini individuals using their gestures and body language very actively, having high manual dexterity, and feeling a constant need for mental stimulation are explained by this bodily alignment.