A Close Look

Those astronomers who specialize in planetary lore are enjoying a treat since Mars is now at its closest point to the earth. The actual date of nearest approach is Aug. 23. At this time the planet is only 35 million miles away as against a possible distance of about 63 million miles when the two planets are at opposite sides of their orbits. These approaches, such as the present, occur every 26 months or so, but there is a variation of some 2 million miles in the nearness depending on what part of their eliptical orbits the two planets may be at the moment of juxtaposition. When the two planets are "in opposition," as this is called, in last August the very best opportunity for observation is offered, although at that time only the south pole of Mars can be seen.

As usual the flood of newspaper buncombe about Mars and its inhabitants appears. The actual knowledge of the planet is considerable, as astronomical knowledge goes, but the amount of conjecture, most of it baseless, is 10,000 times greater.

Mars is the planet whose orbit lies just outside that of the earth. Its mass is about one-ninth that of the earth. Its atmosphere has probably less than one-seventh the density of that of the earth. Because of its smaller mass, its gravity is much less and objects on its surface weigh only about one-third as much as the same objects would on the surface of the earth. It has also distinct polar caps, which increase and decrease with seasonable variations. It has also no marked clouds in its atmosphere. It has no surface elevations probably not over 2,000 or 3,000 feet in altitude. It has no oceans. Its year or period of revolution is close to 687 days; its day is about 24 hours and 37 minutes. It has two satellites, very small, and very close to the planet, one of which rises and sets twice a day, one every other day. Because of the structure of its orbit there is a difference of about 40% in the amount of solar heat received by the planet in Summer and in Winter. Aside from this, on account of its light atmosphere, its temperature variations are great.

And then there are the canals. The presence of the major canals are fairly well established by a number of observations. The late Prof. Percival Lowell at his observatory at Flagstaff, Ariz., claimed the discovery of as many as 585 canals. Some of these are doubted as optical illusions. These supposed canals were estimated at 30 to 100 miles in width and Prof. Lowell believed them to be belts of irrigated country close to canals. He believed further that they were supplied with water by the melting of the polar caps, and thought he dectected changes in the darkness and color of the canals indicating the coming and going of the water and its effect on vegetation. The whole supposition that there is animal life on Mars rests on the fact that the alleged canals are absolutely straight, running along great arcs of the planet's surface. "How," it is asked, "could these canals have been made unless by intelligent beings?"

Those who doubt the existence of life on Mars are skeptical of the existence of the canals which Prof. Lowell so carefully mapped, an'd they point out that the light atmosphere, the extremes of heat and cold, the comparative absence of water (even if the polar caps consist of snow--and it is suggested that they may be congealed carbon dioxide--it is estimated that there is less water on Mars than there is in one of the larger of the Great Lakes) make life such as we know it impossible. But like the argument for "life," the argument against "life" is not conclusive.

This year astronomers are given an opportunity for an unusually close look, and we may hear new wonders.