Kathy Beatie, age 11, of Visalia, Calif., for her question:
How are the constellations formed?
If you often look at the stars, you soon notice that they are arranged in certain patterns, The earliest star gazers noticed these starry groups. They noticed too that most of them change with the seasons and most of them rise and set like the sun.. For a long time, almost everyone believed that the star designs, the constellations, moved around and around the earth. They were quite sure that our world was the center of the universe and everything in the heavens was perpetually revolving around it.
The true fact that our little world was not the center of the universe was very hard to swallow. But people have been getting used to the idea for the past 300 years or so, We know now that our world is but a small speck in the vast island. universe. What's more, our vast universe is but one of thousands, perhaps millions, just like it, scattered throughout the wide oceans of space.
Our universe is called the Galaxy. Basically it is a wheel of stars with various clouds of stardust and almost certainly other planet systems like our own. Our Solar System is Old Sol with his family of planets and other small bodies. It is situated about two‑thirds of the way from the hub of the Galaxy towards the rim.
All the stars we see belong to the Galaxy, and the Galaxy revolves like a wheel. As this happens., the stars parade around in a more or less orderly fashion. The chances of two stars colliding is very very remote,
Our little world has a splendid view of the stars scattered throughout our corner of the Galaxy. When we gaze at the Milky Wpy, we even get an overall panoramic view clear across the Galaxy. The individual stars we see there are those in our own back yard, as it were.
Visalia is more or less 30 miles from giant Mount Whitney in California. His towering peak is to the northeast, When you face south, southeast or any direction other than northeast, you do not expect to see the big fellow. So it is with the constellations. ‑!is the earth turns, we get first one view and then another view of the vast heavens around us. In one patch of space we see a group of stars shaped like a ladle. We call this constellation the Big Dipper. In winter we see the constellation Orion. The stars in a constellation are those visible in a certain area of space at which we are looking.
We cannot tell the distance of a star by its brightness. One star in a constellation may be quite near, as stars go, and another one far, far away. Through countless ages, the stars of a constellation may change formation. But this process is too slow to observe in a lifetime. The constellation patterns are formed by accident, It is merely the group of stars you see when looking in a certain direction at the heavens.