TO KNOW THE STARRY HEAVENS 



21 



that furnished by the rapid motions 

 and close approaches of the three 

 bright worlds — Mercury, Mars, and Ju- 

 piter. These are now, however, all very 

 close together in the morning sky, so 

 that in order to study them the obser- 

 ver must go out in the early morning 

 hours a short time before sunrise. 



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The Morning Planets. 



J he sun in its slow apparent jour- 

 ney among the stars has now passed 

 to the east of Mercury, Mars and Jupi- 

 ter so that as we look at these planets 

 in the southern heavens we see the 

 sun to the left of them. Consequently 

 these planets now set before sunset and 

 arise before the sun rises ; that is, they 

 are all morning stars. As Mars moves 

 eastward among the stars far more rap- 

 idly than Jupiter, the sun draws away 

 from the former planet much more 

 slowly than from the latter one. The 

 result is that the latter planet seems to 

 climb upward into the morning sky 

 much more rapidly than does the more 

 swiftly moving world. 



All three of these bright worlds are 

 now close together and moving east- 

 ward through the constellation Taurus. 

 Both Mars and Jupiter move quite 

 steadilv eastward, the former alone- the 

 path AB, Figure 2, and the latter along 

 the path CD. But the motion of Mer- 

 cury is peculiar. On June 1. it is at 

 the position E, but its motion is then so 

 slow that it is passed by Mars when 

 the former planet is at K and the lat- 

 ter at C. Its motion then quickens ; it 

 passes Jupiter (HV) on June S. and 

 overtakes and again passes Mars (RS) 

 on June. 1 1. One hour later it reaches 

 the point T, at which time it is at its 

 greatest distance from the sun. 



During each of these three conjunc- 

 tions of Mercury the two planets are 

 unfortunately rather far separated in 

 the sky owing to Mercurv'- path lying 

 si 1 far to the southward among the 

 stars. A far more striking sky figure 

 is that afforded by the close approach 

 of Mars and Jupiter (at the point V) on 

 the morning of June 8 ; the two planets 

 will then appear separated by but forty- 

 one minutes in the sky. 



To observe these most interesting 

 motions the reader should turn toward 

 the northeastern horizon in the very 

 earlv dawn. On June 1 the three plan- 



ets will rise about one hour ten minutes 

 before sunrise, while by the end of the 

 month Mars and Jupiter will rise two 

 hours before the sun. The dates of the 

 conjunctions are: Mercury with Mars, 



Figure 2. The paths of the mornirg planets from 

 Tune 1 to June 3d. Ai! is the path of Mars, CD that 

 of Jupiter and EF that of Mercury. 



June 5 and June 1 1 ; Mercury with Jupi- 

 ter. June 8, 9 P. M. ; Jupiter with Mars, 

 June 8, 7 A. M. Mercury reaches its 

 greatest distance west of the sun on 

 June II. The contrasting colors and 

 appearances of these three worlds, so 

 near together in the sky, will be ob- 

 served to much greater advantage if 

 the reader can use a small telescope in 

 their observation. 



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The Partial Eclipse of the Sun. 

 The third eclipse of the present vear 

 will occur on the forenoon of June 19. 

 This is a partial eclipse of the sun, but 

 it will unfortunately be invisible from 

 almost the whole of the United States. 

 The only part of our country from 

 which anything of the eclipse can be 

 seen will be from the stations lying 

 north of the line MN, Figure 3. From 

 practically all of Alaska, Western Brit- 

 ish North America. Northern Green- 



