Meteors and meteorites

   Every few months newspapers tell their readers to watch the sky for a big shower of meteors. Meteors by the billions travel around the Sun. They are chunks of rock or iron which, as a rule, are no bigger than peas. The Earth on its travels comes close to many meteors. The Earth's gravity pulls them in. They glow white hot as they fall through the air. Most of them are changed to vapor or dust before they touch the ground. People call these meteors that flash through the air and are destroyed shooting stars, or falling stars.
   Meteors are not scattered evenly in the space around the sun. Instead there are great swarms of meteors. The big showers of shooting stars come when the earth runs into one of these swarms.
   Shooting stars puzzled the people of long ago. An old Egyptian record tells about a night when the stars all jumped about like grasshoppers. Of course, the true stars were not jumping about. There were simply a great many shooting stars that night. The Romans believed that a shower of shooting stars meant that their gods were angry.
   There are millions of shooting stars every year. Although there are more of them at some times of the year than at others, one is likely to see a shooting star or two on any clear night. The dust from shooting stars is making the earth a tiny, tiny bit bigger every year.
   It is fortunate that most shooting stars are destroyed as they plunge through the air. They are traveling very fast. Being hit by a shooting star would be like being hit by a machine-gun bullet.
Some meteors that fall from the sky are not completely destroyed during their journey through the air. They are too big. On their journey through the air they are called fireballs. After they hit the earth they are called meteorites.
   Fortunately there are not many fireballs. Fortunately, too, many of them fall in the sea. On land, if they were common, they could do a great deal of damage. In Ari-zona there is a huge hollow, or crater, which scientists think was made by a group of fireballs. In a forest in northern Russia a group of these big meteors fell not very long ago and knocked down all the trees for miles around. But in modern times no one has been hit by a fireball. There is, however, an old Chinese record telling that one killed ten men.
   There are many meteorites in museums. The biggest one now in a museum was found lying on the ice in the Far North. It was found by Peary, the explorer who first reached the North Pole. This big meteorite weighs 36½ tons.
   Some meteorites are made of stone. Others are made of iron. Probably the first iron people used came from meteorites.
   Scientists think that the big swarms of meteors come from broken-up comets. They follow paths just like the paths of comets. At least once when a comet did not show up on schedule the earth had a shower of meteors instead. Where the meteors that are not in the swarms come from is still a puzzle.