Arizona republican., 1913-03-04

l SOldr IduldtlOnS dS uOtS dH equal hl Cct of the earths' surface, and the earth reflects 30 per cent or more of the suns rays So it would seem that Mer- cury's temperature must be constant 1 lv above the boiling point of water, ] and, without liquid water, as we know i it. cannot exist
 | It is true that the fleets of solar radiance may be profoundly modified 1 by atmosphere, but Mercury's low al bedo argues that the planet must pos | sess the thinnest of atmospheric Veils. l A cloud wrapped globe like Venus re- ] fleets fully 65 per cent of the light that reaches it. In all the planets 1 high albedo goes with a dense vapor- | freighted atmosphere. But Mercurys aIbedo is only IT, almost the same as that of the dead airless moon. Some calculations would make it even lower. | And yet Mercury is seemingly not en- tirely devoid of an atmosphere. Mark l ings upon it's surface are obliterated at times under the observers gaze as if by some aerfal screen. Besides there
 
 ones of the presence of water vapor in such atmosphere as may exist.
 Its Orbit and Rotation
 l The eCCentriCity of MerCuryS orbit l subjects it to great changes of tenn perature. At it's nearest approach it is within 2S1@ millions of miles of the sun. It's greatest distance is 43l2 mil lions of miles. This means that, in the course of it's SS-day year, Mercury receives sometimes only four times, at other times nine times as much solar radiance as the earth.
 | Does Mercury reVolve upon it's axis more than once in its year? Such ob- l servers as Schiapareli and Lowell say l it does not and that consequently the planet turns always the same face to the sun, just as the moon turns always the same face to us. Probably the ma jority of astronomers have accepted their conclusions as correct, but others are still sceptical If they are right. Mercury at once becomes. according to human standards, an unnhabitabIe planet
 For the succession of day and night upon a planet results from it's inde- l DeuUbnl dAldl IOidliOH ana, under the conditions described by SchiaparelH 1 Mercury would have no days, only years. And, so long as these years continue one side of the planet must be exposed continuously to the scorch-
 ing sun. while the other must be plunged into an endless night, with Venus and the earth as it's brightest luminaries It is true that, owing to the great eccentricity of Mercury's s orbit and the resulting liberation of the planet there would be two zones, stretching from pole to pole between the regions of perpetual day and night, where the sun would rise and set once in each Mercurial year. Each Of these zones would be about 1,200 miles broad at the equator and would follow the lines of longitude to their conveyance at the pole. and each would include about One-eghth of the planets sur v face. But for ree-eights the night . would never pass and, on the remain ing three-eighths, the sun would never set, only Oscillate east and west of . the zenith through an arc of 47 de grees once in every 88 days.
 Oceans Boiled, Then Frozen
 It would be hard to trace the cli- . matc effect Of such an arrangement It is conceivable that water might exists in it's liquid state in the zones of 1 liberation, but only for a short time at any one point, and that only at sunrise and sunet If oceans ever ex- isted on Mercury they must long ago have been boiled away and now exist as a sea of ice covering the dark side t,,f+ I,r a,Tn
 Mercury has a diameter of about 5000 miles It's surface is about one seventh that of the earth and it's vol ume one-eightieth Its mass and gray ity are uncertain. Probably a 200 pound man transported to Mercury would weigh not more than 50 pounds
 Because of it's nearness 10 the sun Mercury, seen through a telescope 1 presents the appearance of a little moon, running through all the phases from full to new and back again. The possessor of a three-inCh telescope should be able to see it as a crescent on the evenings of the 10th and 11th Theoretically it should present a half disc at it's greatest eIongation, but for some reason, probably weak illumina- tiOn along the terminator, it assumes the crescent form
 New Stars in the East
 BOOtes (The Huntsman and Virgo (The Virgin) are chief amo' 2 the new cancellations in the eastern field this
 month. Spica, the principal star ir Virgo, rises a little to the south of the east point It makes it's appearance at about 9 o'clock at the beginning Ot
 March and, by the end of the month
 is well above the horizon. It is a pure
 white star of rather less than the first
 magnitude and is a favOrite with mar
 inerS for determining longitude.
 Aroturus, principal star in Bootes
 affords fine color contrast with Spica
 It has pronounced ruddy hue. yellow
 with a tinge of red. Among stars wis
 ible in these attitudes Sirius alon
 surely surpasses it in brightness. Ca g bella, in Auriga, and Vega, in Tn
 Tyre (now below the horizon), are it
 only rivals north of the celestial equa - tor. But ArOturus is a far mightie
 sun than either of the others. one O