Gemini , is one of the constellations of the zodiac known as "the twins". It is part of the winter sky, lying between Taurus to the west and the dim Cancer to the east, with Auriga and the near-invisible Lynx to the north and Monoceros and Canis Minor to the south. The Gemini program is named for it.
Mythology
Since this constellation is easily viewable as two parallel stick figures, considering faint stars visible to the naked eye, it was associated with the myth of Castor and Polydeuces (also known as Pollux), collectively known as the Dioscuri. A myth of these twins heavily concerns cattle theft, and may be connected to early views of the Milky Way, as a herd of dairy cows or cattle, by which they are situated.
The orientation of the constellation can vary (since they readily form stick figures whether leaning right or left), though the twins are usually viewed as left leaning. However, when right leaning, one of the twins resides in the Milky Way, and the other outside it, a situation making it appear that one of the twins is stealing the cattle, and the other is observing. In this situation, together with the area of the sky that is deserted (now considered as the new and extremely faint constellations Camelopardalis and Lynx), and the other features of the area in the Zodiac sign of Gemini (i.e. Orion, Auriga and Canis Major), this may be the origin of the myth of the cattle of Geryon, which forms one of The Twelve Labours of Heracles.
Astrology
In tropical astrology it is associated with the decorated floral profusion of late spring and early summer. In sidereal astrology it is associated with the constellation Gemini and the Greek myth of Castor and Pollux.
Gemini is associated with the classical element Air, and thus called an Air Sign (with Libra and Aquarius). It is also one of the four mutable signs (along with Virgo, Sagittarius, and Pisces). Its polar opposite is Sagittarius. It is the domicile of Mercury. Each astrological sign is assigned a part of the body, viewed as the seat of its power. Gemini rules the nervous system, the lungs, the hands and arms. The symbol for Gemini is the twins. Gemini are communicators of the Zodiac. They are also the nonconformists of the Zodiac.
Graphic visualization
The stars of the constellation Gemini can be connected in an alternative way, which graphically shows a pair of twins holding hands.
The twin to the right is Castor, whose brightest star is alpha Geminorum (more commonly called Castor), is of the second magnitude, and represents Castor's head. The twin to the left is Pollux, whose brightest star is beta Geminorum (more commonly called Pollux), is of the first magnitude, and represents Pollux's head.
Pollux's torso is represented by star upsilon Geminorum, Pollux's right hand by iota Geminorum , Pollux's left hand by kappa Geminorum: all three of these stars are of the fourth magnitude.
Pollux's pelvis is represented by star delta Geminorum, Pollux's right knee by zeta Geminorum, Pollux's right foot by gamma Geminorum, Pollux's left knee by lambda Geminorum, and Pollux's left foot by xi Geminorum. Gamma Geminorum is of the second magnitude, while delta and xi Geminorum are of the third magnitude.
Castor's torso is represented by the star tau Geminorum, Castor's left hand by iota Geminorum (which he shares with Pollux), Castor's right hand by theta Geminorum: all three of these stars are of the fourth magnitude.
Castor's pelvis is represented by the star epsilon Geminorum, Castor's left foot by nu Geminorum, and Castor's right foot by mu Geminorum and eta Geminorum: epsilon, mu, and eta Geminorum are of the third magnitude.
