Constellations

© 1995 by Robert C. Moler

Astronomy is a diversified field of study. It ranges from astrophysics at the frontiers of quantum and relativistic physics to constellation study, a pursuit of the heavens with the unaided eye and ancient tales of heroes and gods.

The stars were always there. During the long ascent of the human race from the caves to the moon we have tried to make sense of the random patterns of those sparkling points of light.

For the most part the points of light seem to stay in the same patterns, but they all move in unison as if attached to a huge dome of sphere. Five of those stars, however don't stay in patterns, but wander along a band of the sky. Then there are those two other objects, not points of light, but large and round. One governs the day, the other changes its appearance and position from night to night in a monthly cycle. Both of these objects keep to the same band as the five wandering stars.

What was the purpose of all these things? One ancient culture of which we are all quite familiar, though most of us are not descendants of records the following:

Then God said: "Let there be lights in the dome of the sky, to separate day from night. Let them mark the fixed times, the days and the years, and serve as luminaries in the dome of the sky, to shed light upon the earth." And so it happened: God made two great lights, the greater one to govern the day, and the lesser one to govern the night; and he made the stars. God set them in the dome of the sky, to shed light upon the earth, to govern the day and the night, and to separate the light from the darkness. God saw how good it was. Evening came, and morning followed - the fourth day.

(Genesis 1, 14-19 The New American Bible)

Thus our ancestors believed that everything in the heavens had a purpose. for them. The purpose of the sun is obvious. The moon's function was time keeping, giving rise to the time unit we call a month. The Hebrew and Islamic calendars are still based on the moon.

The wandering stars, whose motions were hard to decipher became the roulette balls of chance in astrology, supposedly governing the fates of kings and princes. Nowadays these oracles of the wandering stars, cast horoscopes for the common folk from the comic pages of our daily newspapers. Isn't democracy wonderful?

The world's cultures each invented their own constellations, with liberal borrowing from neighboring cultures. Constellations were imagined images of people, animals and things that more or less fit a particular pattern of stars. The most important constellations of ancient times were those of the Zodiac and the Lunar Mansions.

The Lunar Mansions are mostly forgotten today, but they were is many cultures the 27 or 28 stopping places where the moon spent each night on its circuit of the sky each month . The constellations of Zodiac are the twelve constellations the sun passes each year. The Zodiac is also the abode of the planets and the moon.

The constellations of the Zodiac are the most important and well known and were developed in Greece and the Middle East. Most of the rest are also Greek, though given Latin names. The constellations to the far south, out of sight of Greece are of more modern origin, though a few to the north with faint stars are also modern. One favorite deep sky object hunting ground of mine lies in Scutum, between Aquila the eagle and Sagittarius. Scutum the shield is the armament of John Sobieski, king of Poland who broke the Turkish siege of Vienna and ended the advance of the Turks in 1693. Scutum has no bright stars, thus was unnamed by the ancients.

Today astronomers have taken many of these constellations and marked them out as areas of the sky, rather than just star patterns. The boundaries were fixed in 1930. Thus we have, today 88 official constellations recognized by the International Astronomical Union (IAU).

Nowhere on the official list can one find the Big Dipper or the Summer Triangle. These are two of a great number of unofficial constellations, called asterisms. Asterisms are important because these are the most noticeable star patterns, and when you're new at star gazing, these patterns stand out in the randomness of the stellar dome.

While the study of constellations and their lore may not seem very scientific, compared to the findings of the Hubble Space Telescope, it is for many, like myself, a starting point to the pursuit of astronomy. How can we be afraid of the dark when watched over by Hercules, the seven sisters of the Pleiades, the soaring eagle of Aquila, and Orpheus playing his harp Lyra.

They are now all very old friends of mine.


Questions? Send Email to me at bob@bjmoler.org

Uploaded: 07/14/96