TO KNOW THE STARRY HEAVENS 



243 



The Eclipses of 191 7. 



The four ecHpses of the sun will re- 

 spectfully occur on the morning of Jan. 

 23, during the forenoon of June 19, 

 during the late evening of July 18, and 

 in the early morning of December 14. 

 The first three are only partial eclipses, 

 so that from no station on the earth 

 will the sun be seen to be completely 

 hidden by the moon, while the fourth 

 is a so-called "Annular Eclipse," in 

 which the round, intensely black, ball 

 of the moon will be seen to move com- 

 pletely onto the bright disc of the sun. 

 At this time, however, the apparent 

 size of the moon will be slightly less 

 than that of the sun, the disc of the 

 latter will therefore at no time be com- 

 pletely hidden, but its edge will be 

 visible as an intensely bright ring of 

 light. The path of this annular eclipse 

 will pass exactly across the South 

 Pole of the earth. 



Unfortunately, none of the four so- 

 lar eclipses will be visible from any 

 station within the United States. But 

 two of the three eclipses of the moon 

 will be completely visible to us and 

 will furnish most interesting phenom- 

 ena for observation. Each of these oc- 

 curs after midnight ; the first during 

 the early morning hours of January 

 8, and the second before sunrise on 

 December 28. Their observation will 



cause the moon will at that time lu^t 

 have risen. 



***** '"") 



The Lunar Eclipse of January 8. 



In Figure 2, the shaded circle repre- 

 sents a section of the great shadow of 

 the earth, a shadow which always 

 stretches out into space in a direction^ 

 directly opposite to that of the sun. 

 During the early morning of Januarys 

 8, the center of the moon will be seens 

 to move eastward along the path A B 

 D E, and thus our satellite will plunge 

 completely into the shadow. 



The center of the moon will reach 

 the point A and the eclipse begin at o 

 hrs. 50.4 niin., (Eastern Standard 

 Time) ; it will reach B and the eclipse 

 become total at 2 hrs. 0.4 min., and it 

 will reach C and the moon be most 

 completely immersed in the shadow at 

 2 hrs. 44.6 min. The total eclipse will 

 end at 3 hrs. 28.8 min., the center of 

 the moon then being at D, and the en- 

 tire phenomenon will terminate, and 

 the moon leave the shadow at E, at 4 

 hrs. 38.6 min. Thus the entire eclipse 

 will occupy 3 hrs, 48.2 min., while the 

 moon will remain completely immersed 

 in the shadow i hr. 28.4 min. 



The Solar eclipse of Jan. 23 will be 

 visible throughout western Asia, north- 

 ern Africa and eastern Europe, but 

 from no region will more than three- 



Figure 2. Passage of the moon through the Earth's shadow, on the early morning of January S. 



thus call for some resolution on the 

 part of the amateur astronomer. The 

 third lunar eclipse will occur during 

 the afternoon of Independence Day 

 (July 4) and will be invisible to us be- 



fourths of the sun's diameter be seen 



covered by the moon. 



***** 



The Planets in 191 7. 



Jupiter now shines very brightly in 



