MARS

Evening Star, Issue 18729, 3 September 1924, Page 5

MARS

ME E. CHRISTIAN’S LECTURE. A general meeting of the astronomical branch of the Otago Institute was held last evening in the Museum. Professor D. R. White occupied l the chair, and the illustrated address was given by Mr E. Christian, who took as his subject ‘ The Planet Mars.’

Mr Christian prefaced his remarks by stating that the chief astronomical event of the year 1924- was probably the opposition of the planet Mars, that body of mystery which for the last fifty years had created more controversy in astronomical circles than had perhaps any other branch of the science. Mars was the one planet on which conditions comparable to those on the earth were found. The planet had a mean diameter of 4,215 niiles, slightly more than half the earth’s diameter, and it was only one-ninth of that of the earth. Gravity at the surface of Mars, therefore, was only one-third 1 of the force’s value at the earth’s surface A weight of 91b on the earth would register on Man. only 51b, weighed in a spring balance. Except for Mercury, Mars was the smallest of the eight principal bodies of the solar system, and the planet required 687 days to complete the circuit of its orbit, whereas the earth’s revolution occupied only 565 days. Very favorable oppositions between the earth and Mars occurred at long intervals. These were such as took place on August 23, when Mars was about 36,000,000 males distant—closer than it had been for many years past. All astronomers had eagerly awaited) the opposition, but it was yet rather early to know the results. Martian discovery dated from the invention of the telescope, and in 1610 Galileo had observed that the planet was not always round, but was subject to a slight phase equal to the moon when about ten days old. The speaker then spoke of the first traces of dusky marking ob served on a bright orange-colored surface. The first drawing of these had been made by Huyghens in 1659, further cli coveries- were then made until 1892, when it was discovered that the canal! (channels) were not confined to the bright-colored portions, but crossed dark and light areas in unbroken lines. Drawings of these canali by different astronomers were screened, and showed,a, wide divergence of opinion. Also, in 1892 it was pointed out that the dusky regions shown by the telescope underwent seasonal changes, which suggested 1 that they were areas of vegetation. It was found, too, that these changes occurred in the canali. Traces of water in Mars were found only on the polar ice caps, where the chief canali had origin. Perhaps these channels were really strips of vegetation flanking the course of water. In some cases the channels ran for hundreds of miles in straight lines, sometimes for thousands. The canali could in no way be accounted for as natural phenomena. The lecturer then dealt with various theories on the channel question, stating that it appeared to be almost definitely proved that the polar caps were water.

Continuing, the speaker referred to the atmosphere of Mars, and said' tl an atmosphere existed could be proved beyond doubt. Sufficient proof of this was the fact that clouds were seen floating above the Martian surface, for they could exist only in an atmosphere. Various arguments to prove the contention were brought forward, and the question of the. atmosphere in relation to the possibility of Mars supporting life akin to that we know was discussed. It did not seem impossible that other slightly different forms of life might bo evolved to withstand the not greatly inferior pnissure at the surface of Mars. A much greater fall in the night temperature would be favored by the rarity of the Martian atmosphere. Considerable frost was in evidence during night. Going bade to the canali, the lecturer quoted the opinions of several famous astronomers, and said 1 that, although no satisfactory explanation of the canali existed, they had no proof of their artificiality, and until such proof was forthcoming they had not the least right to assume the existence of intelligence. After dealing with the two minute moons on Mars, and speaking of tidal forces, the lecturer concluded by saying they would take away with them the memory of some things seen certainly mists and l clouds, snow, water, vegetation, and desorts. There was something else they could not forget—a something seen as through a glass darkly—for, outlined upon the sands of the desert and stretching away into the regions of fertility, they had seen strange tracts—the footprints maybe of an unknown intelli* gence. t Mr G. Hoffman said that he considered it would be rash to conjecture that no form of life existed on Mars. They knew that given possible physical conditions some forms of life grew; but what life, if any, existed in Mars could also only be a matter of conjecture. A vote of thanks was carried by acclamation to Mr Christian.