The visible sky
Have you ever looked carefully and curiously at the night sky far was from a city? If so,at first glance you may have found no order in the stars, and no way to judge their distances, except to say that they are far away.What patterns emerge from a careful long term scrutiny?
- Describe the daily motions of the sun, moon, stars and planets relative to the horizon.
Take the time to study the stars for a while; you'll find that they fall into patterns, designs imposed by your mind. Ancient skywatchers perceived stellar patterns and passed them on such patterns are called Constellations. Early named constellations marked a convenient group of stars, with ill-defined boundaries, that typically outlined a mythological or realistic figure. In Babylonian times the constellations came into use as signposts in the sky to mark the positions of the sun and moon. The constellations used today (there are 88 of them) are established by international agreement of astronomers.