The constellation Gemini (latin for twins) is named after the twins Castor and Pollux of the Greek mythology. The two brightest stars represent the heads of Castor and Pollux with smaller stars making up the bodies. Gemini is the third sign in the Zodiac and the constellation was described by the astronomer Ptolemy in the 2nd century AD.
How to spot Gemini
Gemini is easy to spot in the sky, it is located northeast of Orion and between Taurus and Cancer. You can locate it by first searching for the belt of Orion. Then look below the belt for the bright star called Rigel. Now look above the belt for the bright star called Betelgeuse. Join them with a line to locate the twins, two bright stars close together. For stargazers, Gemini is visible in both hemispheres. In the north, the constellation is visible in winter and spring. In December you can spot the Twins at around 9 pm as they move slowly westward until daybreak. From January to March it can be seen even earlier at around 7 pm. In the south, Gemini is visible during the summer season. In December, for example, it can be seen low on the northeast horizon at around 1 am. From January to March it is visible from 10 pm to 4 am when it sinks below the horizon, in April it appears at 8 pm and dips slowly to vanish at midnight. Like many constellations, the Twins appear upside down in the southern hemisphere.
The story of Gemini goes back to classic Greek mythology. The twin brothers, Castor and Pollux were born of the same mother, Leda, but different fathers. Castor’s father was the mortal King of Sparta. Pollux’s father was the Greek God Zeus who disguised himself as a swan and seduced Leda. The twins were handsome and adventurous and embarked on many hazardous adventures. Castor was a renowned horseman while Pollux was known for his great strength. When Castor was slain in battle, Pollux was inconsolable in his grief, unable to live without his brother. Since he was immortal, he begged Zeus to make Castor immortal too. His father fulfilled his wish and placed them both in the sky, united forever in the bonds of brotherly love.
The bright star Castor is actually made up of 6 stars and 3 binary stars. In China, the twin stars represent the dual forces of nature, the Yin and the Yang.