Astronomy

The word “astronomy” comes from a combination of two Greek words: astron, meaning “star” and nemein, meaning “to name.” Even though the beginnings of astronomy go back thousands of years before the ancient Greeks began studying the stars, the science of astronomy has always been based on the same principle of “naming the stars.” Many of the names come directly from the Greeks, since they were the first astronomers to make a systematic catalog of all the stars they could see. A number of early civilizations remembered the relative positions of the stars by putting together groups that seemed to make patterns in the night sky. One of these looked like a curling river, so it was called Eridanus, the Great River; another looked like a hunter with a bright belt and dagger and was called Orion, the Hunter (p.61). Stars are now named according to their placement inside the pattern and graded according to brightness. For example, the brightest star in the constellation Scorpius is called a Scorpii, because a is the first letter in the Greek alphabet. It is also called Antares, which means “the rival of Mars,” because it shines bright red in the night sky and strongly resembles the blood-red planet Mars (pp.48–49).