One of the most wonderful traditions that has been passed down to us from our ancestors is the constellations. They grouped the brightest stars in the night sky into recognizable shapes and patterns. These patterns were a product of their imagination, and they were named after things that were important in their life.
Today most of us explore the constellations as a recreational pastime, but to our ancestors they were an important part of their daily lives. They used the constellations to navigate and as celestial calendars to mark the changing of the seasons.
Our modern constellations come to us from the Greeks, although nearly every culture on Earth has adopted their own star pictures. Ptolemy, the famous Greek scientist, published a book in A.D. 150 called “The Almagest.” This book contained a summary of Greek astronomical knowledge and included a catalog of 1,022 bright stars arranged in 48 constellations. However, these constellations can be traced even further back in time. Historians are not sure exactly where, when or by whom they were invented, but evidence points back to the ancient Babylonians and Sumerians 4,000 years ago.
In 1922 the International Astronomical Union, astronomy’s official governing organization, adopted our modern list of 88 constellations. This list covers the entire sky in the northern and southern hemisphere. It contains 14 men and women, 19 land animals, 10 water creatures, nine birds, two centaurs, a dragon, a flying horse, a serpent, one head of hair, a river and 29 inanimate objects.
The majority of these star patterns bear little resemblance to the figures they represent. The constellations are symbols of our ancestor’s favorite things placed in the sky.
The IAU also set definitive boundaries between the constellations. Astronomers today refer to constellations not for their patterns of stars but to define precise areas of the sky.