GLORY OF THE STARS

New Zealand Herald, Volume LXXVI, Issue 23284, 1 March 1939, Page 20

GLORY OF THE STARS

THE HEAVENS IN MARCH SURFACE OF OUR PLANET ITS APPEARANCE FROM SPACE BY CRUX AUSTSiALW 'V When one is familiar with the telescopic appearance of the surfaces of the planets that are the Earth's neighbours in space, and with the great variety they disclose to the eye, it is perhaps natural to wonder what the Earth must look like as seen from the other planets through human eyes. There is scorched and barren Mercury, for instance, on which very little detail can bo seen even in the most powerful telescopes, f . and brilliant Venxis, on which no detail at all can be discerned, for the simple reason that its disc is for ever hidden from our eyes by a thick, impenetrable mass of cloud. . ... ■ ; Beautiful Mars, so like our Own globe, with ruddy regions, pale blue areas, a, criss-crossing of what we have termed canals, and polar ice 'Caps .which wax and wano with the seasons, Eeems most likely to mirror our terrestrial image. Further off in space, when we reach the giant planets Jupiter and Saturn, we find these bodies completely cloud-covered, but they are distinguished from -Venus in that tiheir clouds are beautifully and variously coloured and are drawn out by the planets' rapid rotation into parallel bands of light and shade. Appearance from Moon If man ever succeeded in ins king the hazardous rocket journey to the Moon and found time, in the midst of its strange new landscape, to look back upon the planet he had left, hanging in the black lunar sky four times as big as the Moon appeairs to ■us, what would he see? The most conspicuous feature presented to his gaze ■would be the clouds, which, like those of Venus, would ,be brilliantly • white. [Unlike the other planets, however, the terrestrial clouds would cover only about half the visible surface. There

■would be an equatorial belt of cloud, shifting in. latitude with, the seasons, - flanked on either side by nearly cloudless belts over the desert zones near the tropics of Cancer and Capricorn, beyond which brighter, partly clouded regions would extend to the poks. The cyclonic storms of temperate latitudes would -be conspicuous in the wealth of ever changing detail as white areas of cloud followed by dark areas of clear sky, through which tho surface could be seen. They would all ha re an eastward motion and last three or four • Except in desert belts there .would rarely be an area of a thousand miles free.from cloud.-.Even apart from this a'study of the surface ieatures would £ be difficult to make, for the whole would be shrouded in a blue atrnosr pheric veil, transparent only when the ail' was free from dust or haze. ,r Features of Disc

' The most conspicuous details j would be the reflection of the Sun ia the oceans, snow-covered areas and deserts. The oceans normally would be the darkest parts of the. disc,/but' when the Sun became reflected in them they .would become the most brilliant. The great forest regions would appear dully blue and cultivated regions of a lighter Sreen tone, but only their broadest outnes would, be visible. Observers on Venus, our nearest planet, provided they could see through the dense clouds that surround their globe, would be able to see telescopically objects 50 miles in diameter, but Would have great difficulty in distinguishing the permanent surface through the ever-shifting terrestrial clouds. ; From Mars the situation would be much worse, because the Earth, being Bearer to the Sun, would appear to move from side to side of that orb, always presenting a crescent-like disc .to the Martians, as Mercury and Venus $ do to us. Terrestrial twilight effects •would probably be much more prominent to the Martians than those we can seo on Venus. , : /] From the more. distant Jupiter and Saturn the Earth would be Visible only occasionally at the times of its greatest elongation from the Sun, and even then would be only a star-like point oi: light. Inhabitants 'of Uranus, Neptune and Pluto, would probably- never -know that the Earth existed,, because it; would ;. be for them always * hidden ra the Sun's light. - .. s Phenomena in March The Sun will be in the constellation [Aquarius until March 11, when it will pass into Pisces. Its noon altitude at Auckland will decline during the month from 61. degrees to 49 degrees:. The autumnal equinox 'will occur this year ■■ on March 21. . The Moon, in. the course of its circuit of the heavens, will be in conjunction with the various naked-eye planets as follows:—Mars, 13th, 5 p.m.; Venus, 17th, 9 p.m.; Mercury, 22nd, 11 p.m.; Saturn, ,23rd/;& a.m. :Mercury, in the evening sky at present, will attain its greatest elongation from the Sun on March 17, after which it will draw in toward that orb. .Venus remains in the morning sky and is visible only to the very early riser.

Mars is also in the morning; sky, ."where .it can be seen rising in the east ah hour after midnight, being below the sweep of stars in Scorpio. .Jupiter •will be in conjunction with the Sun on the 6th, and is therefore invisible. Saturn may still be seen in the western evening twilight.