THE HABITABILITY OF VENUS, MARS, AND 

 OTHER WORLDS. 



By C. G. Abbot. 



[With 3 plates.] 



In considering the probability of the existence of intelligent life 

 on other heavenly bodies than the earth, it will be convenient to 

 take up these heavenly bodies in several groups, dealing first with 

 those in which conditions are so very different from ours that the 

 existence of life seems impossible. 



THE MOON, THE SUN, AND THE OUTER PLANETS. 



The moon is our nearest neighbor and coplanet with ourselves. 

 Astronomers usually call the earth the planet and the moon merely 

 a satellite. Except for unequal size one is as much a planet and 

 as much a satellite as the other. They revolve together around the 

 sun, and rotate together about their common center of gravity. But 

 as the earth is of 4 times as great diameter as the moon, and is 81 

 times as massive, it is the controlling member of the partnership, 

 and swings the moon as the big boy at school does the little one in 

 the game of " crack the whip." 



At 240,000 miles distance the moon is beautifully seen and studied 

 by the aid of a telescope. It is a waterless, airless, mountainous 

 desert. There is no probability whatever that intelligent beings can 

 be there. 



What of our great benefactor, the sun ? No living thing, scarcely 

 even the hardiest chemical compound, can exist there because of the 

 intense heat. On earth the hottest thing is the electric arc, which 

 not only melts but turns into gas every substance. The spectroscope 

 and the heat-measuring appliances show that the solar temperature 

 is nearly twice as great as that of the arc. Hydrogen would not 

 burn in pure oxygen on the sun, but water, if it could ever reach 

 there as steam, would be instantly separated into these component 

 gases. 



Circling the sun, beyond the orbit of the earth, lie five great 

 planets: Mars, Jupiter, Saturn, Uranus, and Neptune. Within the 

 earth's orbit there are two: Venus and Mercury. 



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