Page:In the high heavens.djvu/125

Fig. 15.—The Seasons in Mars. May 27, 1890.

distance from us it is still not one-hundredth part of the distance by which we are divided from Mars when that planet is at its nearest. Yet we can never look on the moon as a neighbouring world in the same sense in which we look at Mars. The moon is a globe of quite a different order from the earth. Its want of air and water in any measure comparable with the abundance of such elements on the earth at once establishes so profound a difference between it and the earth, that we naturally relinquish the supposition that our satellite can have any resemblance whatever to the earth when considered as the abode of organized life.

But there is another planet with which, in all probability, we have much closer affinities than we have even with Mars. Fig. 16.—The Seasons in Mars. August 4, 1892.The planet Venus happens to be almost exactly of the same size as the earth. If models of the two globes were inspected, it would require careful measurement to say