Gemini is a zodiacal constellation consisting of 85 primary stars that are visible from Earth without a telescope. The brightest pair of stars Castor and Pollux, which make up the heads of the twin-based shape. Gemini is the Latin word for ‘twins’ and it is this appearance that influenced the myths surrounding the constellation throughout human history. Most famous of these myths is the story of the brothers Castor and Pollux, Greek (and later Roman) heroes who gave their name to the two brightest stars in this heavenly formation.
The first great astrologers and astronomers, the Babylonian civilisation designated this constellation as The Great Companions. Individually, Castor and Pollux were known to them as Meshlamtaea, or “the One Who has Arisen from the Underworld” and Lugalirra, or “the Mighty King”. Both these names are alternative names for, or aspects of, the god Nergal, who was king of the Underworld.
In star maps of the time, the Great Companions are depicted as brave warriors ready for battle. Statues of the two of them were often found guarding entrances and doorways to important temples or houses. Prominent in the Summer sky over ancient Mesopotamia, the constellation of Gemini would have been seen as a defender warding off further catastrophe during the plagues and droughts of the hot and dry season.
The twins Castor and Pollux became associated with the constellation of Gemini around this time, and it is their stories that are best known today. Pollux was the son of Zeus and Aetolian princess Leda, while Castor was his mortal brother born from Leda’s marriage to Spartan King Tyndareus. Their twin sister was Helen of Troy, and they are mentioned by her in Homer’s famous Iliad.
The pair became famous for their hunting, boxing, horse-riding and other athletic skills. Eventually they joined Jason and his famous Argonauts, central to the myths of the constellation Aries, as they chased the Golden Fleece.
Castor and Pollux essentially met their fate cattle rustling. Caught whilst stealing the herd of their cousins Lynceus and Idas, Castor was killed in the ensuing brawl. Shortly after, Zeus stepped in and hurled a bolt of lightning down to end the fight and save his son. However, Pollux was distraught at his brother’s death and asked to be reunited with him for all time in the heavens. Zeus reluctantly agreed, and thus was born the two brightest stars in the constellation we know today.
In modern astrology, Geminis are considered to be strong willed and adaptable. This is because of two sides (sound familiar?) of their personality, that work in a harmonious manner to overcome any obstacle.
Modern astronomy has revealed a lot to us about the physical characteristics of the constellation Gemini. For example, to the naked eye the star of Castor appears as one point of light. However, it is actually made of three separate pairs of binary stars. Astronomers have also found an exoplanet in orbit around the orange-tinged giant giant star, Pollux.