THE MYSTERY OF MARS — WILKTNS 235 



white color. The yellowish clouds which have attracted the attention 

 of the best observers are thought to be sand storms, in which the sandy 

 surfaces of the deserts are whirled aloft by air currents. There must 

 be winds on Mars; but judging from the manner in which clouds of 

 any kind tend to rise and hang over the same region, without drifting 

 far, it seems that the atmospheric currents are usually ascending or 

 descending, probably associated with temperature variations. 



The mean temperature on Mars must be much lower than that on 

 the earth, because the planet is so far from the sun and also on 

 account of its rarefied atmosphere. The best authorities believe that 

 the maximum temperature at noon on the equator is somewhere be- 

 tween 50 and 60 degrees Fahrenheit. From this maximum it must 

 fall rapidly as the poles are approached, and also both in the early 

 morning and the late afternoon for places on the equator. Mars is 

 certainly a cold world, but it is also a dry one; to this it may be 

 added that Mars is a smooth world. 



Despite Mars being a small, dry, and cold world, there seems to 

 be some analogy between the conditions on Mars and some of the 

 more arid regions on the earth. A mysterious thing about the red 

 planet is the fact that although it is smaller than the earth but larger 

 than the moon, and thus fits in between them, it is much more smooth 

 than either. The moon clearly tells us that smallness of a planetary 

 globe is no bar to its having a rough and mountainous surface, but 

 on Mars it is doubtful whether there are any mountains higher than 

 the Welsh hills or the highlands of Scotland. Some authorities have 

 set the maximum height much lower, around 2,000 feet, and talk 

 about the featureless horizon on Mars and how, owing to the sharp 

 curvature of its surface, the ground must seem to rise up like a huge 

 convex shield, especially in the desert regions. 



The great barrier to increasing our knowledge of Mars is an insur- 

 mountable one, namely distance. This, together with the limitations 

 imposed by our atmosphere, renders it certain that the largest tele- 

 scope man can ever construct will fail to solve the problem of the 

 type of Martian life. It is possible that we will eventually learn more 

 about this alien form of life by radar than by visual or photographic 

 means, unless such means are located somewhere comparatively close 

 to the planet, perhaps on one or either of its moons. 



Every time that Mars comes to opposition, and is therefore most 

 favorably situated, enthusiastic and hopeful people "tune in" with 

 powerful radio sets in the hope that they may pick up signals from 

 the Martians. In 1924 and again in 1926 reports appeared in the 

 press of certain unidentified "pips" which might, but almost certainly 

 did not, originate from Mars. Assuming that intelligent beings exist 

 and attempt to contact us, the difficulty here would be to make any- 



