348 FROM NEBULA TO NEBULA 



THE MOON'S TOPOGRAPHY EXPLAINED 



Paradoxical as it may sound, the real surface of the 

 moon is as smooth as that of Mars! Equally paradoxi- 

 cal may ring the statement that the lunar oceans have 

 risen from their beds and taken up their permanent abode 

 on the dry land. In plain English, they have disap- 

 peared, not into outer space, but into SNOW, and the 

 mountains and craters that we see are nothing more nor 

 less than the fantastic sculpturings of one Jack Frost. 

 Like the man in the fable who could not see the woods for 

 the trees, so astronomers have been all along failing to 

 see the lunar oceans because of the heaped-up snow ! The 

 text books tell us that snowflakes are so exceedingly por- 

 ous, and absorb so much air in their creation, that a single 

 inch of rainfall is equivalent to a ten-inch fall of snow. 

 Fancy, if you please, some strange freak of Nature 

 whereby all the waters of our oceans and rivers and lakes 

 should be converted into the "beautiful" and settle upon 

 our continents and islands never to return again as 

 water to its ancient beds, what a wonderful and strange 

 sight our earth would present ! 



This is precisely what has happened to our moon. 

 This is why her surface is so magnificently sculptured, 

 why we see no rain-clouds or oceans upon her, why her 

 atmosphere has "disappeared" why, in short, she pre- 

 sents the curious aspect and asperities she does. 



Here you may interpose, ' ' Then how do you account 

 for the fact that the same sort of thing hasn't happened 

 to the earth and Mars I" Easily enough. With respect 

 to the sun, the moon does not rotate on her axis in just the 

 same way as she does with respect to the earth, but turns 

 completely round, so that every point on her surface ex- 

 periences a day one of our fortnights long followed by a 

 night of equal length. In short, her days and nights are 

 virtually two seasons, summer and winter. This strange 

 arrangement, as you can see, accentuates many fold the 

 contrast between the seasons, and causes us to ruminate 

 how the thing works out. We have only to use our eyes 

 and brains to satisfy ourselves. 



