Is There Life on Mars 1925
WHY ARE WE KEEN ABOUT MARS?
WHY SHOULD MARS ATTRACT so much interest as it does? “asks Dr. Robert G. Aitken, associate director of the Lick Observatory, in a recent leaflet issued by the Astronomical Society of the Pacific (San Francisco). It is by no means the largest of the planets; on the contrary, it is next to the smallest. It has only two tiny moons, as compared with the nine each that revolve about Jupiter and Saturn. It is not even the planet that is nearest the earth, for at its least distance it is 35,000,000 miles away, whereas Venus comes within 26,000,000 miles of us every other year. Dr. Aitken goes on:
“So far as astronomers are concerned many answers could be given, but in my opinion the chief, if not the only, reason for the great popular interest in Mars is that, more than any other planet, it has become associated in our minds with the question of the possibility that life may exist on other worlds than on our little Earth.
“What evidence have astronomers secured on this question, and, in particular, what gain in knowledge has resulted from their study of the planet at the opposition of August, 1924, when it was nearer to the earth than it had been for over a century or than it will be for a century to come?
“Briefly, we know that the Martian day is practically equal to our own; that on Mars the seasonsâ€”spring, summer, autumn and winterâ€”closely resemble our own, except that they are nearly twice as long because the Martian year equals 22 1/2 of our months. These facts are beyond dispute. Astronomers almost unanimously agree also: that there is an atmosphere on the planet which contains water vapor; that the polar caps, which grow as the Martian winter deepens and shrink as the summer comes on, are frozen water in some form; that a large number of the markings seen on the planet are permanent and, therefore, on the actual surface; but that there are no permanent bodies of water on Mars resembling our oceans or even our great lakes. Here agreement ends. There has been great diversity of opinion as to the extent and character of the atmosphere, as to the temperature and range of temperature, and, above all, as to the nature and interpretation of the surface markings. This difference of opinion is not surprizing, for the image of Mars even in a powerful telescope is hardly larger than the disk of the moon as seen with the naked eye; and the very largest direct photographs that I have seen (before enlargement in the dark room) are much smaller than a silver dime. Further, our own turbulent atmosphere, as well as whatever atmosphere exists on Mars, interferes sadly with all our views of the planet’s surface.
“The question ofÂ life onÂ Mars turns upon the points in dispute; for the facts on which all are agreed (except the non-existence of oceans and lakes) are all favorable to the view that life may exist there. The recent observations have done something to clear up the situation.