Recognizing the Stars [421 



As it shoots through the sky, a meteor may give off sparks or 

 appear to have a bright train; and it may travel in a straight or 

 wavy line. You are most likely to see one that appears white or 

 yellow; but there are also very bright ones, red or green, and these 

 are called "fireballs." 



The light given off by meteors is produced by the terrific speed 

 at which they race through the atmosphere, and the resulting 

 friction. Their average speed is anywhere from seven to nearly 

 fifty miles a second! 



"Meteor Showers": At certain times of the year meteors appear in 

 such numbers that we talk of "meteor showers." You can look for 

 a shower about the tenth of December in the eastern sky; another, 

 about the sixteenth of November. There are others in August and 

 October, but as they do not occur until after midnight, it is not 

 practical to keep young children up to watch for them. 



Two Thousand Meteors a Day: Some meteors are no larger than 

 a small pea; others may weigh thirty tons or more. The small 

 ones burn themselves out by the friction they create, but many 

 of the larger ones land on earth. About two thousand meteors 

 hit the earth every day! After landing they are called meteorites. 

 About fifteen hundred of them have been found (the biggest 

 weighs fifty tons) , and a number of them are on exhibition in 

 museums throughout the country. 



When a big meteor strikes the earth it may smash a gaping hole, 

 or crater, in it. The largest meteor-made crater in the United 

 States, known as El Diablo (the Devil) , is in Arizona. It is more 

 than four thousand feet across, and 575 feet deep. For years pro- 

 spectors have hunted in vain for the meteorite that created El 

 Diablo. Despite all the evidence of huge meteorites and the 

 discovery of some big ones, it does not seem that anyone has ever 

 been injured by a meteor. 



"FLYING SAUCERS" OPTICAL GHOSTS 



The baffling challenge of unsolved mystery confronts us in 

 the provocative reports of these strange objects which are supposed 

 to have been seen from time to time in the sky. The first accounts 



