ASTRONOMICAL NOTES.

Manawatu Standard, Volume XLII, Issue 1014, 6 November 1917, Page 6

ASTRONOMICAL NOTES.

Mr U. r l. Salmon, honorary astronomer to the. Palmerston Philosophical Society, supplies the following interesting astiononuca! notes for this month ;

“To many people the planet Venus, at present a rosplendanr- object in the southern evening sky, is simply a bright- star, )nd (hero the matter ends. But -although ;o astronomers Venus is a planet, of ;ib.sorbing interest, and of nu little, actual use to us on earth, this magnificent luminary lias also claims to much popular inlercst. In its size it is very nearly the same as our own* globe, the diameters be-

ing 7600 and 7900 miles respectively, while as a light, reflector it. is unrivalled. The planet; possesses a clear and extensive atmosphere, about; twice as dense as our own, and apparently somewhat, n-s.-mblfiig it in composition, although the iln-ory has ftoen advanced with a certain show of reason that carbon di oxide gas U iis mam constituent. The year of Venus is ?'J 4 of our days in length, and. like or; - moon, its year and its day eo-incicle in time. It revolves onco on its axis in its year, and hence presents always the same hmiis]>!)• ■ e-• to the sun and to our observation. As its axis is almost vertical to the pi. -mo ol its ecliptic, Venus has no seasons, and tins, added to the fact of the absence of day and night, precludes the possibility of liie existing upon it. The plaiu-t varies in distance from us vety greatly, being disunit only 25,000,000 miles, <>r roughly a quarter of our distance from the sun, when ar, its nearest, approach: whereas when at IXI,I opposite pole it is separated from our earth by the vast abyss of 160,000,000 miles. Being an itinfir planet, that is, its .orbit lying within that of the, earth, Venus exhibits .phases as does ihe moon, and lor tho same reason ajipears now an evening, now a morning star, and first climbing higher in tho heavens, it suddenly arrests its n-scent and recedes. Markings are clearly visible upon the planet’s surface, and the American astronomer, the late. Professor Lowell, ascribes these to chasms cut by the roaring hurricanes which must inveep from the cold, night-enshrouded surface to the arid desert, produced by the blast of tho sun’s perpetual rays upon the opposite hemisphere. As to the use of Venus to us, the transit of the planet across the sun’s disc affords u„ one Of our surest, and most accurate methods of measuring tlio distance of the latter frcmi the earth. Those transits tire rare and of great as tronomical interest, and few of the present generation arc likely to witness one. Ihe last, occum'ii in December, _ 1882, and tin; next is due and will infaHtal)!}’ occur on Juno 8, 2004.”