Castor and Pollux: the picture behind Gemini

On clear winter evenings two stars of almost equal brightness stand close together, high in the sky, a little way above Orion. They carry the names of two brothers from a Greek story, and a twelfth of the zodiac is named after them. Where the picture of Gemini comes from is written up there – and not in the lists of traits.

Two brothers, one life divided

Castor and Polydeuces, Pollux to the Romans, are held in the tradition to be the sons of Leda, but not the sons of the same father: Pollux comes from Zeus and is immortal, Castor from a mortal king. They grow up together, they set out together, and then Castor dies in a quarrel over a herd of cattle.

Pollux then asks not to have to live on without his brother. The immortality is divided: from that point the two spend their time by turns, one above for as long as the other is below. That is the picture inside this sign – not two faces, but two halves that belong together and are never in the same place at the same time.

The patrons of seafarers

In antiquity the two were not figures for those who studied the stars, but helpers in an emergency. Sailors called on them in a storm, and the bluish glow that can show up on mastheads in a thunderstorm counted as their appearance; two flames were a good omen, a single one was not. In Rome they were given a temple of their own in the middle of the Forum, of which three columns still stand today. So the picture was not a marginal note for scholars, but something people counted on when it mattered.

What is actually in the sky

The two points can be told apart with the naked eye. The brighter one is Pollux, an orange giant star a good thirty light years away. Castor beside it looks fainter and sits around fifty light years off, although astronomy has assigned it the first letter of the constellation. A telescope breaks it into several points; in all there are six suns circling one another in pairs. So the two brothers in the sky have nothing to do with each other – they only stand side by side from where we look.

And then the confusing part: in precisely the weeks when Gemini birthdays fall, you hardly get to see these stars. In early summer they sit in roughly the same direction as the Sun and set shortly after it, in the middle of the bright dusk. They become properly visible only half a year later. That holds for every sign: the group of stars that gives your birth month its name is, around your birthday, exactly the one you cannot find.

Why a double picture changes things

Among the twelve pictures of the zodiac, Gemini and Pisces are the only ones made up of two identical beings; the rest show a single figure or a single object. That is more than a curiosity, because every interpretation works from the picture in front of it. An Aries can be described by what he does. A double picture forces the interpretation to fit two things in at once – and that is why it regularly ends up at change, mobility and contradiction.

What travelled from the story into the interpretation

Of everything told about Castor and Pollux, only a part made it into the descriptions of the sign. What was taken over is the doubling: two who appear together and take turns. What was also taken over is the inequality of the two – one mortal, the other not – which in the interpretation becomes two sides set beside each other that do not carry the same weight.

The rest was not taken over: the quarrel over the herd, the death, the revenge. And what actually holds the story together is almost never taken over. Pollux could have lived on by himself and did not want to. The story is about two who cannot get free of each other, not about one who cannot make up his mind.

What astrology has made of this stretch of the year comes out of that imagery: out of a piece of early summer, out of the element air and precisely out of two brothers who relieve each other. You can read what portrait came of it under the zodiac signs; and what else belongs in a birth chart besides the sun sign begins with the ascendant.