CHAPTER XI 

 LIFE IN OTHER WORLDS 



IF life was not brought to the earth from another 

 planet, then life was created, or originated, on the 

 earth. Some of the conditions which attended its 

 birth have been considered, and they amount to this : 

 that the temperature of the earth, the elements of the 

 earth, the conditions of the earth's surface, oceans, and 

 atmosphere were exactly those which favoured the origina- 

 tion, the continuance, and the development of living 

 things. The earth, among all the heavenly bodies which 

 we can examine at all closely, is probably the only one 

 on which life, as we know it, would have much chance of 

 survival. 



The Sun as an abode of life we may at once put out 

 of the question. Taking the planets in order of distance 

 from the Sun : of Mercury we know very little, but 

 astronomers like Schiaparelli and Lowell have pronounced 

 it to be an airless, dead planet with a surface cracked 

 in cooling untold ages ago. Venus is believed to be much 

 like the earth, not differing greatly in size, and probably 

 having an atmosphere of considerable extent ; x but its 



1 W. W. Bryant, A History of Attronomy (Methuen), 1907. 

 118 



