The Coconino weekly sun., 1896-10-22
MERCURY AND VENUS.
Important Discoveries Relating {,
 These Planets Announced.

The observers at the Lowell Obser- vatory at Flagstaff, Arizona, find that Mercury and Venus rotate on their axis once during their revolution about the sun. Venus is not cloud covered. as has been supposed, but is yelled in an atmosphere, but Mercury is not.
 This official dispatch from MT. Low ell for distribution to astronomers is exceedingly interesting, since it sug- gests radical changes in the generally accepted opinions concerning the mo- tions of these planets and the atmos- pheric conditions existing on Venus. Of course the data from which the opinions have been deduced can. not as yet be stated, for the information has come to us by telegraph. Observa- tions of Mercury and Venus have al- ways been difficult, the reasons there. for in the different planets being, how ever, not the same. Mercury never leaves the company of the sun. it's greatest distance from it in the sky being not more than about 30 degrees. It is on that account enveloped in sun. light. which aims its brightness and makes the details of its surface diff cult to detect. Some fifty years ago astronomers thought they discovered motion about its axis and fixed the day at about five minutes less than ours. But this time, while generally accepted and given place in text books. has been without absolute proof. It has been conceded that little or no at- nosphere exists there, for if it did it would have been detected during the transits of the planet across the suns disk. The rotation period must in this case be determined from the ob- servation of the actual surface of Mer. cury. and hitherto no observer has been fortunate enough to get even glimpses of this.
 With Venus the case is quite differ- ent. The brightness of this planet is such as to obscure vision, so that the best observations have been taken at times when there was daylight present to tone down its brilliancy. It has been the general opinion that the sur. face of the planet was hidden from us by dense clouds in the atmosphere, while mountain peaks piercing these clouds on permanent spots have been lacking, so that the time in rotation has been in doubt. It has been set down, however, as about an hour longer than the day of the earth. Some observations of things which were supposed to give clew to the rota. tion have been recorded, but, like the satellite which was seen by the olde, astronomers to be in company w:::t the planet, the later astronomer with
 his powerful telescope has not been able 10 see them.
 The dispatch from Flagstaff suggests the curious fact that these planets have each of them only one day IT each year, and this will very readily settle the question of possible inhabi tants, unless indeed these are nomadit tribes which follow the sun and liv'
 always on the sunny side of the planet for the outer portions exposed to dark 3 ness and inter-planetary cold cal , hardly be able to support life. Witl 5 reference to the atmosphere of Venus it has been generally conceded tha , one exists which is denser than ours
 The reas ons for this belief are, briefly that at the time when Venus is a cres , cent the horns extend over more tha I half circle, which they could not d a were there no atmosphere to refrac @ the light; and, further, when durinI the transits of Venus portion of tn
 planet has entered upon the suns dis
 or remains upon it an illumination c the whole edge of the planet has bee seen. which could be accomplished i . no way known to us except the diffui ;. ion of the sunlight through au atmos . phere. The degree of this diffusio 'i being considered it is probable tho the atmosphere is quite deuse. Mi 6 Lowell is, however, assured that tn '' supposed clouds do not exist and a 5 that prevents our observation of tn n con6guration of Venus is the difficult
 of looking through its atmosphere
 Boston Transcript.