Gemini
Gemini is the third sign of the tropical zodiac, covering the 60°–90° sector starting at the March equinox, between May 21 and June 20. It is an Air sign, Mutable in modality, ruled by the planet Mercury.
Last reviewed: 2026-07-19
Historical fact
In ancient Babylonian astronomy (recorded in the MUL.APIN compendium, around the 7th century BCE), the sky sector now known as Gemini was called MASH.TAB.BA.GAL.GAL, 'the Great Twins,' linked to a pair of minor twin deities in Mesopotamian mythology, identified by some Assyriologists as Lugalirra and Meslamtaea. The Greeks reattributed the twins to the figures of Castor and Pollux (the Dioscuri) — one mortal, one divine, who chose to share immortality between them — a myth often cited as the origin of the sign's association with duality. Ptolemy systematized the order of the twelve signs, including Gemini as the third, in the Tetrabiblos, around 150 CE.
Interpretation — Western Astrology (Tropical)
In modern Western astrology, Gemini is read as the sign of curiosity and communication: Mutable energy (adaptable, versatile) combined with the element Air (intellect, exchange of ideas) under the rulership of Mercury, the planet associated with language, reasoning and mental agility. Commonly associated traits: curiosity, sociability, quick wit and ease adapting to new contexts. The shadow side commonly includes scatteredness, inconsistency and difficulty maintaining focus or commitment to a single direction.
Interpretation — Vedic Astrology (Sidereal)
In the Vedic system (Jyotish), the corresponding sign is Mithuna, also ruled by Mercury (Budha) and likewise the third of the twelve rashis. Because it uses the sidereal zodiac, which accounts for the precession of the equinoxes, Mithuna's date window is currently shifted relative to tropical Gemini — today falling roughly from mid-June to mid-July, varying by the ayanamsa (calculation method) used. Classical texts such as the Brihat Parashara Hora Shastra describe Mithuna natives as communicative, curious and versatile, with an inclination toward study and the arts — a characterization broadly convergent with the Western reading, despite the two systems developing independently.
This section presents one tradition's interpretation, not a verifiable fact.
Frequently asked questions
- Who are the original twins associated with the sign?
- In Babylonian astronomy, the sector was linked to a pair of minor twin deities, identified by some Assyriologists as Lugalirra and Meslamtaea. The Greeks later reattributed the figure to Castor and Pollux, the Dioscuri.
- Why are Castor and Pollux associated with Gemini?
- According to Greek myth, Castor was mortal and Pollux was divine; by choosing to share immortality between them, they became a symbol of duality and union — a central theme in the astrological reading of Gemini.
- Are Gemini and Mithuna (Vedic) the same sign?
- They correspond to the same position in the sequence (third sign, ruled by Mercury), but occupy different date windows, because the Vedic zodiac is sidereal (aligned to the constellations) while the Western zodiac is tropical (aligned to the seasons) — the gap today is roughly 24 degrees.
Sources
- Nicholas Campion. A History of Western Astrology (2009).
- Claudius Ptolemy. Tetrabiblos (c. 150).
- Maharishi Parashara (trans. R. Santhanam). Brihat Parashara Hora Shastra (1984).
- David Pingree. From Astral Omens to Astrology: From Babylon to Bīkāner (1997).