The Waterbury Democrat., 1934-02-01
BY DIR CLEMENT S. BRAINKN Of the Columbia University
 Observatory Staff


 The most favorable opportunity of the year to observe Mercury
 will be afforded us this month as
 this small planet reaches. greatest eastArn eIongation from the sun
 or, fine i3t1a. At that time it will bo about twenty degrees away from the sun and about the same digtance above the horizon at sum down. Because Mercury is the nearest to all the planets to the, sun and its average distance from the latter is only tl4irty-six million
 miles. it can never be seen in the slxJ very far from the sun and from these attitudes is never seen axainse q really dark sky. This makes 1t difficult of observation not only for amateur but for pro- feanioual aStroiiomers as well. A c0nphfatiVely small number O1
 Deoy1le have ever Knowingly 0n- served this planet in spite of the fact that it was weil-known to man from the earliest days of primitive etar-gazinR. It will be well to start observing about . week pes fore the 18th, the exact date ~ best opportunity, and observatlons may be, continued for week ps- Horia this date. Look Tor " elInea with the rnaided eye or with tne help of q small field glass, opera prnrimate uoint of the horizon where the sun has just set. Mer- c,irv has a slightly ruddy tinge ana the brightness of a first-magnituae star. ,.,s.,, tv of observing Mercury, very nt- tIA is really known about it's pnys- ical conditions. We know some thing Of it's motions and dimenSl sions. We know that 1t revoives oho,,t ffa sun in about S8 days and that its diameter IS apouL tree fhoisand miles and that lts noass Is only about ofie-twentietn, +het If the earth. From It's low rnfIectinx power of solar light we infer that. 1t like the moon, eau have no atmosphere; this IS con- Nrroea also by the clear-cut ap- neararce of it's disk as 1t crosses inc collar disk at the time or fransit. without reaching nne noirt of certainty up to the pres. ant. all indications point to tne nrohability that Mercury rotates on ita s,is once in exactly the same lime that 1t takes to complete an orbital revolution about the sun This means that 1t must alwayss keen the same face turned toWaLu fhe sdf. Approximately hall or s surface iS In perpetual nignt; L remainder in perpetual dayhsnS There is no succession or oay a night such as we have oh
 earth and as there Is also on Mat .h. AS a result the temperature on en ersmsJv fith. about $50 degrees Y ana nr, fhe dark side 1t approxi- ,nates fine lowest obtainable !ap- oratorv temperatures, colder than that of liquid air. ,xo
 Taiescol,ic observation of Mer- crirv shows that the palnet runs through a phase-cycle similar " that of the moon in many respects when 1t is between us and the sun' inc dark face only is turned to- ward ,is and we have the spnase enmivaierit to that of the new moon. TAter. when it's orbital motion nas navrinA it 10 the other side of the rim. so that the latter Is between fha earth and Mercury we nave st iu the full phase. Between 4hese two 1t runs through all cres- cent. quarter, and gibbous phases;
 Venus. which has been prn- liant evening star for the past aSw months. is Invisible at the Desin ming of February because oI ,ss proximity to the sun; It IS ll cV the function with the latter on @ 1fh. After this date it raplugg moves westward from the sun anu by the end of the month IS asa visible to the naked eye, pu. u.,.,an lo time as @ morning star, pVsi.4T 4Tn which it will maintain uhIm ,,tar @ taTe. the place of Venus as the ,eren,,er planetary object in the evening sky; 1t rises now at about ,nsn-tirne and remains Tn the SKY all night. Neither Mars nor Sa- turn. however, are in gooq posi- lion for observation. ,,u
 A total eclipse of the sun VIII take place on February l S-I4. Niss ;hia only over a watery track VI the pacific Ocean running rom ,,nint north of the island or boI pso fo an end in the ocean OH tne cosst of Vancouver Island. severn t,rv islets only will be favoraply located for observation, among tbem Wake Island, a Pacific pos sestsen of the United States:
 Tn February the wonderful orion ,rea of the sky occupies the mos. Tavorable position for observatio" af o,,r conventional map-time, N ing directly to the southwaru across the meridian. Sirius, .n Greaf Dog star, is just east of the ,naridian. about one-third of the way from the horizon to the zeo "itk. It is the brightest star ln the entire sky with stellar mag