The Nautical Almanac # 21 --- Pollux (and Castor), the Twins

 

Gemini The Twins is the third constellation of the Zodiac. Astronomically, the sun is presently in Gemini from June 30th to July 30th. 

 

As an asterism, Gemini is dominated by the stars Castor and Pollux. The two stars are visual companions lying virtually side by side in our night sky. They actually are at a relative angle to each other in space, some 14.35 light years apart. 

Pollux is a single orange giant approximately 34 light years from Earth. Pollux is about nine times the radius of the Sun, but only twice the mass.It is 43 times as bright as the Sun, and burns at 8000 degrees F., about 2000 degrees less than our Sun. It is just over 700 million years of age. It is the 21st star in the Nautical Almanac. 

Castor is a sextuple star system of white giants, white dwarfs and at least one red dwarf. The Castor system is 51 light years away, and Castor A is about 2.75 times the mass and 2.5 times the radius of the Sun. Castor A has a temperature of about 18,000 degrees F. The system as a whole has an age of between 250 - 450 million years. Castor has no main listing in the Nautical Almanac, but its proximity to Pollux in the night sky makes the pair essentially a dual listing.

Just as they are disparate stars, the "twins" they represent are at best fraternal. Gemini is an ancient constellation, but its identity has often changed. 

Gemini has been identified in the Lascaux Caves as "The Wounded Bird-Man" a human figure apparently gored by a bull (Taurus?) as a wounded rhinoceros (possibly Leo?) wanders off. The figure has dropped his bird-headed totem in his death throes. 

Gemini --- "The Wounded Birdman" of the Lascaux Caves, 30,000 years ago. Gored by a Taurus-figure Gemini has dropped his protective totem (the second twin?) in his agony.

Although Gemini was called Mashtabagalgal "The Great Twins" in early Sumeria, the asterism itself was divided into two parts, The Greater Twins and the Lesser Twins (Mashtabagurgur). The Lesser Twins later vanished from the star charts.

As the Sumerians were succeeded by the Akkadians, the Chaldeans, the Assyrians, and the Babylonians, the identity of the twins in the sky shifted. For awhile, the figures were identified with Anu the sky god and Ki the earth mother, the parents of all the gods (Annunaki). Later, they became Enki and Enli, the twin god-brothers. Still later, they were one god, Nergal the lord of the underworld in two aspects --- the god of battle and the god of pestilences. 

The Twins were still later identified as the two sword-wielding godlets who guarded the gates of the underworld and kept the dead from escaping back into the world of the living (and if you don't know the story of the two angels with the flaming sword who barred Adam and Eve's path back to Eden this might be a nice time to learn about it). 

Adam and Eve being evicted from Eden. A Mesopotamian legend says that the angels guarded the gates of the Underworld against escapees.

A very late Babylonian designation had them as Shammash the sun god and his wife Ninharshaga the goddess of green living things who engaged in perpetual intercourse to keep the earth fertile. Being a Mesopotamian deity apparently had its perks, and the image of the god and goddess lying side by side in the sky must have indicated a smoke break; I wonder if they walked a mile for a Camel?

Shamash the Mesopotamian sun god with what looks like a menorah above his head. Note that it has 12 lights, reflecting Sumer's fascination with multiples of six. Today, the tallest candle on a Chanukah menorah is called a Shamash, the usual translation of which is "servant."

The image of a copulating couple eventually made its way into the Egyptian Zodiac, though at first the Twins were the god Set who killed his brother, the god Osiris. 

Osiris (seated) and Set. Set killed his brother, who was eventually resurrected.

One of the more interesting aspects of the Mesopotamian Zodiac is that there was, for a time, a double Zodiac, one of deities (used by the priesthood for divining) and one of mundane farm animals (used by farmers for the planting). Gemini seemed to shift back and forth between one and the other for centuries. 

In Greek myths, Castor and Pollux were the magical twin sons of Leda (with the god Zeus and with the man Tyndareus of Sparta). Pollux was immortal, but Castor was not. When Castor died, Pollux begged his father to raise Castor from the dead. Zeus did so, and placed them both in the heavens. 

The Greek myth is the one we remember best. But like most of the Gemini legends except where sex is involved, the heavenly twins seem to encapsulate dissension with a hint of violence or death.

Ed White was the first American to "walk in space."

In the mid-20th Century, the United States named its second manned space program Gemini, reflecting the fact that two astronauts were sent aloft in what was an amazingly cramped capsule.

The Project Gemini spacecraft was twice as large as the Project Mercury ship, but it had twice the crew. An amazingly versatile ship, it had an adaptive design to allow it to touch down on land, and "Big Gemini," which carried a crew of up to 12, was the first spacecraft considered for moon flights or as a "working" craft. NASA decided to go with Apollo, and the Rogallo Wing, a kind of parasail, was never actually used. The Space Shuttle took its place as a cargo hauler. "Big Gemini" never got beyond the prototype stage.