The Ways of the Planets

by Martha Evans Martin

SURFACE ASPECTS OF MARS

Seen through a telescope, Mars is not so red as it appears to the naked eye. One of the best observers of it has compared it to an opal, and it surely has some of the qualities of an opal in the diversity of aspect that it shows to different observers from different points of view. No other planet has been so subjected to controversy over what appears on its surface. This is partly due to its being the only planet whose surface is without doubt open to our view and in a situation where it can be minutely studied, and partly to the fact that the controversy involves questions concerning life and intelligence, which are always of intense human interest. Matters of this vital sort are never accepted without dispute. That is one way of getting at the truth. In the intensity of the discussion the question of the existence of the phenomena and that of the meaning ascribed to them are sometimes unnecessarily made to depend upon each other. In the case of Mars it may well be that there is less difference of opinion as to what is really seen on its surface than as to the meaning of the phenomena.

There are recorded observations made of Mars as early as 272 B.C., more than two thousand years ago, and it has been nearly two hundred and fifty years since the snow-caps were first seen. Through the telescope not only the snow-caps are plainly visible at the proper seasons, but there are also visible dark patches over the surface, showing a variety of color, and in certain parts changing somewhat as the seasons change. It is one of these patches, the outline of which suggests a somewhat twisted eye, that is known as the “eye of Mars.” The main surface of the planet is reddish yellow in color; the patches on it are variously described as gray, grayish green, or blue, colors which in combination could easily take on a tone of any of them according to the eye of the observer, and this portion of the planet’s surface does, in fact, show first one and then the other of them predominating.

When the planet’s differences of color were first observed, the reddish-yellow portion was supposed to be land, and the areas of varying bluish-green and gray were thought to be the waters of the ever-changing seas. A little after the middle of the last century some keen eyes saw a few streaks or markings of some sort across the land areas, and in 1877 a close study of the planet by an eminent Italian astronomer, Schiaparelli, brought to his view many greenish streaks, all directed toward the so-called seas, and sometimes seeming to intersect there. In publishing this discovery Schiaparelli called these streaks canalli, which is properly translated “channels,” but appeared in English as “canals.” Since “canal” with us means artificially constructed waterways, the discovery became at once one of universal interest; for artificial waterways mean human beings to construct them, and it was an intensely interesting thing to know that Mars was probably inhabited with beings at least somewhat after our own kind. It was a new world. The little planet became a topic of absorbing interest to all of us. And thus began the controversy over the habitability of Mars, and the meaning of its surface features, in which astronomers, seeking only for the truth, have taken a much more dignified part than they have sometimes been more or less sensationally represented as doing. The discoverer of the so-called canals himself believed them to be natural waterways cutting through the land after the manner of our straits and channels, and had very little to say in explanation of them. But his work gave a new impetus to the study of this little brother world of ours.

In our own country the observatory at Flagstaff is the one the best known among those doing research work on Mars; but it is not the only one. The observatory there is finely situated in the thin, clear atmosphere of Arizona, the mechanical facilities for such work are good, and there seems no doubt that there are there some observers who have eyes that were made for seeing. All that the sharp vision of Schiaparelli saw has been seen there, and much more. Several hundred canals have been discovered, and at certain seasons many of them have appeared to become double. Their courses have been followed, and their appearances and disappearances have been watched. Somewhere near six hundred of them have been mapped. According to these maps, the canals seem to be laid out with a geometrical precision such as nature is not likely to follow; they run across some regions that were formerly supposed to be water, and they have points of convergence every here and there, forming at such points large dark areas.

Naturally, when a person has discovered any new and curious phenomenon in nature he seeks to determine the exact meaning of it. It would have very little interest for him if he did not, and it would be a dry lot of facts that did not arouse a desire to do this. The interpretation put upon what has been seen at the observatory at Flagstaff is, in brief, about as follows:

The surface of Mars has no oceans or mountains. The reddish areas, which form the larger part of the surface, are deserts. The blue-green streaks are ribbons of vegetation along each side of artificially constructed waterways, which are of immense length and cross and recross each other until they somewhat resemble a network of lines over the desert surface of the planet, and are used for irrigating this arid region. The points where the canals converge and form the large dark spots are oases made by the water carried by the canals. The water is supplied by the melting of the caps of snow at the poles during the Martian summer, the expanding of the lines of vegetation seeming to occur at periods corresponding to the time required for the water of the melting snow to reach the oases. The presence of this vast system of artificial waterways covering a large part of the surface of Mars makes it seem probable that “Mars is inhabited by beings of some sort or other,” that these beings are not men such as we know anything about, but that “there may be a local intelligence equal to or superior to ours.”

These conclusions concerning what is seen on Mars are not held by any one to be completely proved, but are thought by their author to follow reasonably from the phenomena as observed. By persons of a different temperament they are regarded as too complete an explanation, particularly as the data upon which they are founded are not undisputed. Some of the best astronomers have not been able even to see the multitude of fine lines, much less to give any explanation of them. Others do not regard it as certain that they are so geometric in their outlines as to suggest anything more than cracks or clefts in the surface of Mars, such as might be made by nature, and consider that, instead of indicating life, human or other, they may be the marks of age, such as similar lines or cracks which have been observed on Mercury seem to be.

Also, it is not at all certain that there is sufficient water vapor in the slight atmosphere of Mars to furnish the snow necessary for this great irrigating system, nor the heat to melt it at the proper season. The natural temperature of Mars would be, as we have seen, very low, and unless it is modified in some way not yet indicated everything points to a frigidity too intense to permit the continuance of life and growth of any sort known to us.

These things must all be reckoned with before anything certain can be known of the surface of Mars. The difficulty of pronouncing upon the minute details is impressively indicated by Professor Moulton, who says that, even under the finest conditions and with the best telescopes, it is like viewing “a perfectly accurate relief map of the whole United States made on such a scale that it would be only three inches in diameter and held at a distance of three feet from the eye.” Under such a near limit of vision, we can well see that differences of opinion might arise.

The mere fact that some astronomers have not seen the lines on Mars does not mean that they deny their existence. Some eyes have greater defining power than others, as well as some telescopes, as every one knows. But while all the lines and patches of color that are claimed to have been seen on Mars doubtless have been seen by some persons, yet it is not necessary to accept the interpretation of them given by lively-minded observers when it is not convincing. There may be vegetation on Mars, and even intelligent beings. We do not know; and thus far there is not much to support, even by inference, the view that there are. If we want the truth, we are brought no nearer to it by giving full credence to a speculative theory simply because it is interesting and pleasant; and thus far all theories advanced as to the nature of the surface markings on Mars are speculations, though there is no doubt that the marks are there. It is pleasing, however, to contemplate the idea of there being on Mars, or on any other planet, an active intelligence of any sort resembling what we have here on earth, and it is not strange that such a wide-spread popular interest should attach to Mars, in view of what has been suggested by the markings on its surface.