THE PLANET MARS.

Hawera Star, Volume XLVIII, 20 August 1924, Page 10

THE PLANET MARS.

NEARER THE EARTH THAN FOR YEARS PAST. lhe long anticipated opposition of Mars will occur on the 24th of this month at 4.30 a.m., when the sun, earth and Mars will lie in a line. Mars will then he closer to the earth than it has been since some years before 1800 A.D. or than it will lie until after 2000 A.D.. It will he distant on the *4tii inst. 34,630,000 nates from the earth, its minimum distance. Galileo was the first to examine the planet in 1610, and he noticed that it 'was subject to phases, though it never departed very much from the circle. In 1636 Fontana noticed dusky markings on it, and the first drawing of these marks was made by Huvghens in 1659. In Hl9 Maraldi noticed white patches at the north and south poles, and these are evidently polar caps similar to those on the earth. At the present time several local telescope owners have seen the caps. The southern cap is very large; it is evidently winter in the Martian southern hemisphere; a fortnight or so ago the northern polar cap was just visible, but durincr the last few nights it lias totally disappeared—the approach of midsummer m the northern hemisphere. In 1877 the Italian, Schiaparelli, startled the world with his discovery of the socalled “canals,” and these were confirmed by Percival Lowell, of the Flagstaff Observatory, Arizona. There can be no doubt of the objective fact of these ‘‘canals,” but whether they are the result of intelligent beings is open to doubt. That life once existed on Mars and still exists in perhaps lowly forms is quite probable, but most scientists disagree with Lowell that these “canals” were the work of intelligent beings made for the purpose of bringing water from the poles 'to the dry areas. Mars is certainly endowed with an atmosphere and water exists on its surface, and it would be unwise to assume that plant life fitted to its environment could not have been evolved in the Martian past and suitably modified to survive as the conditions of existence became less and less favourable. At the present time several local observers have seen what appeals like a great dark equatorial cloud belt stretching round the planet, different to any marking shown on any past, drawings of the planet, .and areas of what look like green or dark vegetation are often seen. Mars, like the earth, is a globe somewhat flattened at the poles. Its equatorial diameter is 4215 miles, compared to the earth’s 8260 miles. The force of gravity at its surface is only one-third of its value at the earth’s surface. . A man weighing 12 stone on the earth would weigh only 4 stone on Mars. The axis of Mars is not perpendicular to its orbit; it is tilted from the perpendicular by an angle of 24 degrees (very much like the earth, which is tilted at an angle of 234 degrees). Like the earth, it rotates on its axis, taking a little over 24 hours, or a little longer than the earth. Professor Waterfield, writing in the “Splendour of the Heavens,” says: •■Herschel’s suggestion at the end'of the I.Bth century that the pole caps consist of snow is now almost universally accepted. All our experience tells us that the chemical elements which are found in the sun and stars are, with practically no exceptions, found on the earth.” When the snow caps have dwindled considerably (as r they do with the incoming of summer in each respective hemisphere) - dark i rifts appear in them, extending in- [ wards from the polar sea, and later I breaking them up into several isolated parts. These rifts always appear in j Lhe same places. Mr Jarry Desloges 1 thinks that they are irregularities in the level of the ground. But Lowell ' found that they were identical with | certain polar canals which ate visible ! when the snows have disappeared, and believed them to be strips of vegetation that tend to hasten the melting of the snow beneath which they are buried.

| It was: at one time thought that Mars being so much, further from the sun than the earth, life as we know it could not. exist there, but Watevfiold replied to this as follows; “Since Mars is at a greater distance from the sun, the heat which it receives is only about 45 per cent of the amount of heat received by the earth. Its atmosphere. however .is abnormally clear, so that the heat which actually penetrates the air and, escaping absorption, reaches its surface is but slightly less than that which reaches the earth’s surlaee after passing through its much denser atmosphere. The day temperatures of Mars should Hot therefore lie greatly different from our own. while the larger number of cloudless days would tend yet further to diminish this difference and to raise the temperature. On the other hand the rarity of the atmosphere would favour the more rapid escape of heat, and cause a much bigger fall of temperature at night. There is now, however. reason to believe that this escape of hear is largely penetrated by a very considerable formation of cloud during the Martian night. Tf that is so, the night temperatures also should not be very much lower than those on the earth.” All this, of course, considerably strengthens the view that there is life on Mars.

Mars has two small moons. The noaier one. Phobos. is 5800 miles from the centre _of the planet, and therefore only 3700 miles from its surface. U revolves round Mars in 7hrs 39min, levs than one-third of a Martian day. Tti this respect it is unique, for we know of no other body which revolves round its primary in a period shorter than that of the rotation of the primary on its axis. It is. therefore, most interesting to note that more than ]:>9 veers before the discovery of '-■■o' ->x mi 1877) Dean Swift in his “Gulliver s Travels” tolls of the detection bv the astronomers of a fictitious race, of two satellites of Alans. •me ei whidi possessed this very unprecedented nrooertv! One would ai-

m'd th'*ik the old satirical ’Dean was possessed of the nrooertv of second ; To an inhabitant of Mars n h'd'.>x, onlil'e all other heavenly bodies, rises in the “west.” travels liiiekl' - across the sky. and sets four hours later m the “east.” changing in that short time from new to full moon and from foil to new moon. The outer satellite. Deimos. is scarcely less unconventional. At a distance of bl/iO'i mdos it moves round the nlnnot is 30hrs 18min. Since this period is not very much longer than that of Mars’ rotation. Deimos remains above the Martian horizon for nearly three davs without setting, and during that tune goes through all its phases from new to full moon twice over. At the fiixt opposition in 1922 Deimos was seen in one of the local observatories in Hawern. Neither moon has a diamote' - exceeding op miles. so cpiite nrobahlv they are not round. It is known that manv of the smaller asteroids and satellites are not round. One satellite of .funiter is thought to be shared like a cottage loaf.

Tt might, he added that the experiment of Professor Todd to study this onpos.ition of Mars, by using a mirror of meveuvy in a mine shaft in South America as a reflecting telescope has

been abandoned. The project was too ambitious; it was to bring Mars in vision within a mile or so of the earth. It was not found practicable, however, to obtain a revolving bowl of mercury to give the necessary parabolic curve. Mars is the bright red star which rises in the east about 7 o’clock in the evening or a little earlier. Jupiter is the bright star nearly overhead in the north about 7 o’clock, and Saturn at that hour is further to the west. Mercury is also visible in the west, and on Monday night was visible at 7 o’clock in the reflection of the zodiacal light setting in the same region as the sun. Uranus is near Mars, hut is not visible except in a telescope. Venus is a morning star, and can he seen in broad daylight.