4 jo ] Recognizing the Stars 



moving at a rate of 186,000 miles a second, takes four years to 

 travel from the nearest fixed star other than the sun to our 

 earth. This impressive figure is a useful one to remember, for it 

 involves the "light-year" previously mentioned, which is used as a 

 unit of measurement in astronomy. (A light-year is the distance 

 light travels in one year.) 



Looking at the night sky, we have the illusion that all the 

 stars are the same distance from us, with some larger than others. 

 However, their apparent size is partly dependent on their location. 

 Some of these stars are hundreds of thousands of light-years away! 



How STARS SEEM TO MOVE 



When we talk about "fixed" stars, it is a good idea to 

 remind a child that the earth rotates on its axis. It is this real 

 motion of the earth that explains the apparent motion of the stars. 

 The youngster should also bear in mind that the axis of the earth, 

 if it could be extended, would pierce the northern sky a short 

 distance from the North Star, or polestar, known also as Polaris. 



Polaris, the North Star: Polaris is the only star in the sky that never 

 seems to move. While it remains nearly stationary, the other 

 constellations seem to move around it. If we look for Polaris from 

 a position just north of the equator, we will locate it barely above 

 the horizon. As we travel northward, it seems to be higher and 

 higher in the sky. If we went as far as the North Pole, we would 

 find Polaris directly overhead. 



The North Star has guided sailors for centuries in determining 

 their position at sea. In the southern sky, where the earth's axis 

 would touch if extended, there is no star bright enough to serve 

 as a comparable guide to seamen. 



The heavens look different depending on what part of the earth 

 you view them from. Thus, from the United States and Canada 

 we cannot see the stars that circle the South Pole; and the people 

 who live in Australia, southern Africa, or South America, cannot 

 see the stars around the North Pole. It is only from locations along 

 the equator that all the stars can be seen. 



