SNOWFALL ON MARS

Dominion, Volume 13, Issue 295, 7 September 1920, Page 8

SNOWFALL ON MARS

A POSSIBLE ABODE OP LIFE. Professor W. H. Pickering,'at the Harvard Observatory Station in Jamaica, states a "Morning Post" correspondent, has just observed the first extensive autumnal Martian snowfall, which serves to focus attention again on tho planet Mars, which of >all the planets bears the strongest resemblance to the earth.

Tho most serious force militating against tho observers of Mars is tho effect of our own atmosphere, the irregularities and vagaries of which on most nights preclude "good seeing." Tho surface details of tho planet are bo faint and fugitive that it is only on a few nights of the year in tho comparatively perfect atmospherical conditions of the tropical observatory stations that much useful and reliable information can bo obtained.

If we consider tho points of resemblance between the earth and Mars from which the physical significance of Mars is derived, we are led to the conclusion, as* a result of the recent investigations of tho planet, that Mai's is, or has been, a possible "abode of life." The first feature of importance is that Mars (with a surface area one-quarter that of tho earth) does undoubtedly possess an atmosphere. It is true that the Martian Atmosphere is now much less dense than our own, but this is what one would »x----ueet in accordance with Dr. Storey's theory of tho escape of an atmosphere from a planet which he advanced some years ago. The tenuous and almost-van-ished atmosphere of the Moon, the absence of free hydrogen from our own atmosphore, are in "accordance with this theory. It is (he presence of the Martian atmosphere, with occasional banks of cloud, that makes, in addition to the obscuring of our own atmosphere, the observation of surface markings of Mars so difficult and 'trying. Tho evidonco of water on Mars rests on a pretty substantial basis. The most imposing features of the planet aro the polar snowcaps corresponding on our earth to tho Arctic and Antarctic ice fields. As the Martian summer advances, the polar ice-cap decreases in extent, and in the height of'summer almost disappears. This gradual melting of polar snow-caps is a phenomenon that is readily observed. But tho formation of the snow-caps occurs under conditions unfavourable for direct observation, nnd has hitherto escaped detection. Professor Pickering's achievement is for this reason all the more noteworthy, and may be the prelude to far-reaching discoveries. The result of his observations has now made definite tho modo of formation of the polar enow-caps. Isidis—the region where the phenomenon look place —is almost 50 degrees from the Martian equator, and the whitening of that region can only be attributed to an extensive snowfall. Tho latitude of the region rules out of the alternative hypothesis of tho formation of the polar caps through the agency of frost, and it is interesting here to note that tho phenomenon just observed at Jamaica confirms the expectations of Professor Pickering himself on this point.