When the night sky is dark and clear, it presents a dazzling spectacle. Myriads of stars, glowing patches of gas, a planet or two, the Moon in its phases, perhaps a meteor shower, an eclipse of the Moon or even a comet, all such sights are there for the taking by anyone who cares to look up.

Even when dimmed by city lights and smog, the night sky is worth a long look. The panorama is constantly changing, with the view never quite the same, even on successive nights. There is always some thing of interest, some sight to appreciate, whether you are viewing with binoculars, a small telescope, or just with your unaided eyes.

Astronomy, the science of the stars, is perhaps the most ancient form of methodical human knowledge. To track the paths of the celestial lights today is to retrace the steps of the first observers many thousands of years ago.

Starting with the stars

Most of the things we see in the night sky are stars, vast balls of glowing gas similar to our Sun but so far away from us that they are reduced to mere points of light, scattered mostly at random across the heavens. The unaided human eye can detect about 6000 stars under dark, clear conditions, but less than half of those are visible at any one time.