HALLEY'S COMET.

Dominion, Volume 3, Issue 711, 10 January 1910, Page 5

HALLEY'S COMET.

T ' ■ TRANSIT OVER THE DISC OF THE SUN. THE INTRUDER'S DENSITY.' Ily Telegraph—Proas Association-Copyright ' __ (Hoc. January 9, 5 pnj , ' • London, January 8. Tho '■jreenwich. Observatory estimates that Halley's comet will make the transit over the sun's disc on May 9 The phenomenon .should be visiblo m Australia and Asia, but not m Europe, \ Though it is improbable that the comet 1 will be of sufficient density to be soon siloouetted on the sun's disc, the spectro- , scope or'the. spectro-heliograph may dek -tact its presence, , PREPARATIONS TO OBSERVE THE „ TRANSIT. . SPECTRUM OBTAINED AT LICK. When tho last English mail left it was 'etated that "expeditions were bomg equipped m .England and' America for taking observations of Halley's comet during the total eclipse of the sun in May, ,1910, which will be visible in the Antarctic and partly viable m Australia. Mr. M'ljean, a well-known English observer, is going to Tasmania to watch the transit of the comet over the sun's <fosc He will remain thero from May 8 to May 19 An American observer will proceed to Honolulu for tho same purpose and to observe the comet whon it l's an evening object after the transit" i A strange consequence of the motion of 1 the earth round the 6un is that while a,t present the earth is travelling towards Halley's comet, m a short .while it will be travelling away from it "As a result of this (says an English paper) the comet is approaching the earth at a much higher velocity than"l,l6C,fiGG miles per day, the rato with which it is approaching the sun; and on December 20 it will !' be but 120,000,000 miles distant , | "After it has reached that point it will ' , for some tuno become more distaut from i the earth until at length it ncars tho v earth's orbit. It will be a fine evening A object from May 21, and, naturally, this ,}' will be the best time for observing it ' * "But the problems which engage tho ] minds of astronomers have already rei caived sufficient light to seem to give the I answer to some pregnant questions. It has,long,been a.matter of dispute as to i how far the light with nhich a comet i shines is independent, ol 1 how far it is merely reflected sunlight. ' "Lick Observatory, California, has been 'i successful in obtaining a spectrum of Hal--1 ley's comet, a feat which has never been vjt .ii/v.afloomplishedjivithv.sov faint -'ah : object be-v {■[' v.'-'.fore, jand'ithoyspeclinmuwas'cbhtiiiuous;' - if:;'/; showing? the =;presencev of : ■; ;.j'^i. : .:\pnly.-:^v,Np":'indicationf : ;was given' of■the ''■ : .-[:'.: ": -. comet's^composition."^- ; JyS 'Ji■:-^'i ; .;-T-,f>