Our Earth and Its Fellow Planets [ 395 



straight down on June 21 (beginning of summer). On December 

 2 1 (beginning of winter) they come to us on more of a slant than 

 at any other time. 



We notice, however, that we have our hottest weather in July 

 and August, and our coldest in January and February. This lag is 

 explained by the fact that the earth takes time to grow warm 

 again after the cold of winter, and to become fully cooled off 

 after the accumulation of summer heat. 



Winter in June: On the day that summer begins in the Northern 

 Hemisphere, winter begins in the Southern Hemisphere; at the 

 stage of the earth's journey around the sun where the North Pole 

 is tipped farthest toward the sun, the South Pole is tipped farthest 

 away from the sun. Thus we see that the seasons in the Southern 

 Hemisphere are the reverse of those in the Northern Hemisphere 

 at the very same time. This shows that winter and summer are not 

 caused by the earth being farther away from, or nearer to, the sun. 

 It is the tilting of the axis that produces the changes of the seasons. 



Jupiter Largest of the Planets 



This planet is often one of the brightest objects in our night 

 sky, and this may give us the impression that it is at least as close 

 to the earth as Mars. The fact is that Jupiter is hundreds of mil- 

 lions of miles further away from us than Mars is; however, the 

 tremendous size of Jupiter enables us to see it clearly. It is the 

 largest of all the planets (perhaps that is why the ancients named 

 it for the king of their gods) , with a diameter about eleven times 

 that of the earth. 



AN ATMOSPHERE THOUSANDS OF MILES DEEP 



With only a small telescope you can get a closer view of 

 Jupiter, making out soft shades of red, yellow, tan, and brown 

 that form bands across the distant white planet, parallel to its 

 equator. These bands are actually clouds, composed in the main 

 of two poisonous gases ammonia and methane. Their presence 

 rules out any possibility of life as we know it on earth. Scientists 



