Question

stars do not change shape why

Answer 1

Our friends at the Cable Natural History Museum in Cable, Wisconsin, ask whether constellations ever break apart or change. To answer this, first let's think about what the constellations are, and then we can see whether they change.

When we look at the night sky, we see distant stars shining like faint lights. Now we know they are really brilliant lights, like the Sun, that are incredibly far away from us and from each other. Astronomers have used some wonderfully inventive methods to discover the distances to the stars, but to our eyes, they all look as if they are pinpoints of light at the same distance. As an extreme example of this, the red planet Mars is tens of millions of times closer than the red star Antares (Greek for "Rival of Mars"), but you certainly can't tell that just by looking at them when they appear near each other in our skies.

It's normal for us to find patterns in natural arrangements of things. For example, most people can imagine they see faces or other familiar objects in some clouds or rock formations. It's the same with the stars. Ancient observers, without the benefit of our modern understanding of the nature of stars and space, saw these patterns and thought they might be important symbols. Cultures throughout history have created different names and descriptions for the arrangements of stars. The constellations most of us are familiar with were created by people living in the Mediterranean and the Middle East. Many of the stories of the constellations tell us about the myths and legends of the people who gave them names thousands of years ago, but they tell us nothing about the stars themselves.