SKIES OF VENUS

Evening Star, Issue 17977, 25 May 1922, Page 4

SKIES OF VENUS

PLAX KT.VRY '!"■! POP I IPS. Whether life, as we uncicisiaml it, can exist elsewhere in the universe lias oiten 1 been a .subject ill controversy ('.'.'rites tile astronomical correspondent of the ' London Morning Post’,. in the .-olar sy.-tem, a; any ialc, it. seems |-rolsiblf that- fur the most- pari, pia.nelary condition; are quite unsnilabie lor a rare of being.-; physiologically similar to ourselves. It lias, however, been aigueil tlial, of tlie planets of the sola;' system, it in not (he much discussed Mars, hut Venus that is likely to provide the nearest approach to terrestrial condition.-. It is si ill quite uncertain how long tlie " day" of Venus is. It may bo about, equal to ran- o'.vn ; or, on tile other hand, it may always keep the same face to the sun, as our moon always keeps the same lace towards Iho Kailh, except fisr small oscillations. A ihird alleniativc has recently been suggested by I’rnfessoi Pickering, who- thinks he has found evidence of a period of nearly three of our days. We can hardly conceive existence under perpetual sunshine nr perpetual darkness, so that we need no' envy any po-s;Me inhabitants of Venus if the second hyputiosis be (lie true one, however much the pr.■ t’,■>'oie- cloudiness o! the planets atmosphere may protect them. If Ihe first hvpothesis he taken, day and night will siiei ced as tlrev do with us, but toe smaiicv inclination of the axis o[ \tnius to the ecliptic will greatly diminish the seasonal variation. In the day sky, it clouds permit. the sun inu.-t be a make nificenfc object, with a disc twice as large in area, as it appears to us. Night conditions may. however, be much more interesting. Venus has no mouii of its own, and by far the most conspicuous object in its night sky must be the Karth when favorably placed. to an observer with sight no belter than onw exceptional mortals possess, the Karth in opposition should appear as a. disc, and not as a mere bright point. Moreover, the motion of our moon round the Karth would In; conspicuous, as iis greatest distance would he about equal to the. diameter of the sun or moon as seen from the Karth. The moon would, of course, be brightest when tin; K.iriii appealed "full,”’ but it is dilUcnlt to calculate j how bright, a star would bo to equal (lie lighi Hi' the moon. Inhabitants of the | moon might very likely have advanced | in their aslinnomieal knowledge much j further than was possible on the Karth ; before the invention of the telescope. j It has often been remarked how lucky | we are in possessing rein-lively the tineat j moon in the solar system. Jupiter cer- [ tainly lias four moons as large or larger j than* ours, but they do not appear larger as seen from Jupiter, and are quite small compared with the plnnet. The Karths moon is not large, but its radius is nearly a, quarter of the KarlhV radius, so that it is reasonably comparable in size. Mercury is the only planet known to us Hut would appear brighter from Venus, and | its eccentric orbit would bo on additional advantage to the primitive astronomers j of Venus, if .such there have ever been, j Mercury also has no moon, and though Mars has two iiiov are exceedingly Small, I and give practically no light. Bat urns i unique ring is the only other exceptional a-puondago in the system. Naturally all the outer planet? would he fainter as seen j from Venus. It must not lie forgotten i (hat it is probable Unit atmospheric conditions cm Venus are extremely bad for observing, ns it is considered likely that, its sky is permanently overcast: