For centuries, wandering tribes in Babylonia and Assyria, guarding their flocks at night, watched in awe and fear as the sun sank below the horizon and the stars came up against the black dome of the heavens. They watched them slowly move across the sky, up to the zenith and then slowly down, disappearing finally below the horizon on the other side. This was not all. Some of the larger stars seemed to move independently, cutting diagonally across the path of the moving heavens. Frequently a star would dash from its place and come streaking down the sky, leaving behind it a trail of fire that threatened to destroy or engulf the earth. More terrifying than any of this was the great circle of cold light that moved periodically across the heavens, far bigger than any of the stars and with a path all its own. It came and went in cycles. The first night it would appear as a mere crescent sliver of light with a faint outline completing the disc; the next night the crescent would be larger and the darkened disc smaller until finally, no less than twelve times a year, it arose a fiery red ball, shrinking in size and turning golden as it approached the zenith. The phenomenon was an obvious sign from one of the gods; the priests called it Nannar or Sin, "the illumer," and in some regions it was En-zu, lord of wisdom. But regardless of what god was responsible for such a glorious display of power, it was clear that the heavens should be studied and if possible interpreted.

-Lloyd A. Brown, The Story of Maps