SCIENCE OF HOME AND COMMUNITY 



Is Mars inhabited? The most interesting of all the 

 planets is Mars. This is the only one which seems even to 

 make possible the existence of life at all similar to that 

 found on the earth. Some astronomers believe that Mars 



SMA LL 



o* 



MARS 



o 



EAffTH 



O 



rf/vt/s 



MERCURY 



FIG. 210. Relative sizes of planets. (Sun's diameter on same scale equals 

 length of cut.) 



is inhabited. Others think we have not yet secured enough 

 evidence to prove that it is inhabited. The reasons for 

 believing it inhabited are found in the appearance of the 

 surface as seen with the telescope. There appear straight 

 lines called canals, and sometimes these are in parallel pairs. 



