Recognizing the Stars [ 407 



However, these observers feel more certain about a connection 

 between sunspots and the northern lights (aurora borealis) often 

 seen from Alaska, Canada, and northern Europe, and also between 

 sunspots and the so-called magnetic storms that sometimes inter- 

 fere with radio reception. These storms and the northern lights 

 have never been traced to any particular sunspots, but they have 

 been most numerous during years when the sun was heavily 

 "spotted." 



"Granules" Hundreds of Miles Across: You would need to use 

 a large telescope to discover that the sun's surface is not smooth, 

 but apparently made up of countless grains (usually called "gran- 

 ules") that are believed to be rising streams of hot gases. Though 

 they look small to us, they have been estimated as anywhere from 

 about four hundred to a thousand miles across! The sun probably 

 contains the same chemical elements as its daughter, the earth, 

 but these remain in the form of gas because of the intense heat. 



ECLIPSES OF THE SUN 



When the moon is in a direct line between the earth and 

 the sun, we have a total eclipse of the sun. This kind of eclipse 

 does not happen often; hundreds of years may pass between total 

 eclipses in any one part of the earth. Sunlight is so taken for 

 granted that even the prospect of an eclipse is of wide interest 

 and appeals not only to scientists, but to all people, young and old. 

 We can see an eclipse of the sun from only a small area for a 

 total eclipse the area is about sixty miles wide while an eclipse 



EARTH 

 SUN'S RAYS 



MOON 



THE MOON, BETWEEN SUN AND EARTH, MAKES A SOLAR ECLIPSE 



When the moon passes between the earth and sun, the sun is eclipsed. However, 

 we see a fora/ eclipse of the sun from no more than a small portion of the earth 

 that area on which the tapering shadow of the moon falls. From a much wider 

 area the sun is only partly hidden and here observers see a partial eclipse. 



