When your parents take you out to look out at the stars, have you ever noticed what shapes they look for in the sky? Some of the favorite ones to find are little and big dippers. The star found in the end of the handle of the Little Dipper is called Polaris or the North Star. The Big Dipper circles around this star throughout the year. Polaris is used like a compass by all kinds of travelers, because it seems to point to the North Pole. Will this always be true? Although pictures of Earth make it look like a perfectly round ball, in fact it bulges out a little at the equator and is a slightly squashed at the poles. Because of this, the earth, like a skater wearing baggy clothes, doesn't spin perfectly, it wobbles. After thousands of years of wobbling the earth will move enough that the North Pole will be pointing at another star! Can you guess what one it might be?

Opposites Attract

Have you ever played with the strong magnets that you use to fasten your artwork to the refrigerator? If you try to bring the backs of them together, you can feel the magnets pushing away from each other. If you move them to one side you'll find that they cling to each other. What you are seeing and feeling are called magnetic lines of force. This same type of energy also flows from the North and South Poles of another huge magnet we call Earth. For years people have tried to understand what made the world magnetic. When you brush your hair in the winter, you can usually hear electricity moving through it. This electricity we call static is made up of charged particles called ions, which are always ready to travel from one place to another, if conditions are right. Sending electricity through iron or rubbing iron across a permanent magnet can create a new magnet. Scientists believe that the earth has a melted iron core that spins in the center of it. As the earth moves, the electricity from these charged particles also moves around, just like static electricity in your hair. This movement of electricity causes the iron core to become magnetic. Electricity and magnetism work together and can move in waves throughout the universe.

They're All Around You!

The weird thing about electricity or magnetism is you can't see it. A few of the other electromagnetic waves that you can't see are radio, television, X-ray, ultraviolet (UV), and microwaves. One form of the waves that you can see is sunlight. The sun is also creating magnetism. If you want to see pictures of its magnetic lines of force that escape from the surface of the sun, you can look at a book about the sun or type in “sun & magnetic lines” in the search box of your Internet!Maybe you have one of the many toys that use magnets that allow you to draw pictures or write your name, then you can make it disappear as quickly as you made it appear. In most of these toys the magnet is in the wand that you hold in your hand, and your drawings appear when chunks of metal are pulled up toward the drawing board by the magnet. You may have also used magnetic letters or pictures that cling to metal surfaces like your refrigerator. Each dark sunspot, an enormous magnet that can be as big as the Earth, has a North Pole where its lines emerge from the surface of the sun and a South Pole where they reenter it. Sometimes people can't use their cell phones or watch shows on satellite TV because a cycle of sunspots is sending too much magnetism toward Earth. Scientists who have studied the sun believe that the sun reverses its magnetic poles about every twenty years. They also believe the earth may do the same thing, but there could be many thousands or millions of years between them. You might think that all the objects in the solar system come equipped with a magnet, but there is no magnetism on the moon, Mercury has very little, and none can be found on Venus or Mars!

Go to Jail

About 400 years ago, the astronomer Galileo proved something very important about the stars and planets. Because of this discovery, other scientists and many important leaders of the day thought Galileo was “dangerous.” He was arrested and sent to jail! Use the numbers to read the words around the border in order. You will learn what it is that Galileo proved!