TO KNOW THE STARRY HEAVENS 



305 



ward in the heavens. Still higher in 

 the heavens, the entire constelkition of 

 the Great Bear (of which the Great 

 Dipper is but a small part) is now in 

 excellent position for tracing out in its 

 entirety. Now, too, is the best time 

 of the year for the observer to become 

 acquainted Avith the Lesser Lion and 

 the Lynx, two faint little groups which, 

 with Coma Berenices and the Hunt- 

 ing Dogs, inclose the whole southern 

 border of the Greater Bear. 



The Planets in March. 



Mercury, Venus and Mars are all in 

 the same region of the heavens, neai 

 the Vernal Equinox, and all are much 

 too close to the sun to be observed dur- 

 ing March. Mercury passes to the east 

 of the sun on March 29, but will not at- 

 tain its greatest distance until nearly a 

 month later. Venus is still in the morn- 

 ing heavens, and though it will not pass 

 to the east of the sun until April 26, it 

 is already wholly lost in the sun's rays. 

 Mars, the first of the three worlds to 

 enter the evening heavens, passed from 

 the west to the east of the sun on Feb- 

 ruary 28, but it withdraws from the sun 

 so very slowly that by March 31 it sets 

 but twenty-three minutes after sunset. 



The two great outer planets, Jupiter 

 and Saturn, are still shining brightly, 

 however, in the early evenings of March. 

 The former glows low in the west, with 

 a steady, golden radiance, but it is now 

 too low in the heavens for the most sat- 

 isfactory observations with the tele- 

 scope. Toward the beginning of the 

 month this planet sets about 9 hours 

 30 minutes P. M., but by March 31 it 

 will sink below the horizon a few 

 minutes before eight o'clock. 



The beautiful Saturn shines high in 

 the evening heavens, almost on the 

 meridian. Ever since the beginning of 

 the year this planet has been moving 

 westward, or "retrograding," among 

 the stars, so that although two months 

 ago it was to the eastward of a straight 

 line joining Castor and Pollux, it is now 

 perceptibly to the right of this line. 

 On March 25 this backward motion 

 will cease and the planet will begin to 

 run eastward again. Its motion is, 

 however, always so slow that even by 

 the end of the present year it will have 

 only reached the eastern borders of the 

 faint constellation Cancer. 



Late on the night of March 3 the 

 moon will be seen drawing quite close 

 to the planet Saturn, and it will again 

 pass the planet at about an hour before 

 noon on March 31. Many observers in 

 the southern hemisphere of the earth 

 will see the planet hidden by the moon 

 on these dates. To observers in north- 

 ern latitudes, however, the two bright 

 objects so near together will merely 

 form an interesting figure in the heav- 

 ens. 



On March 20, 11 hours 38 minutes 

 P. M. (Eastern Standard Time), the 

 center of the sun will cross the equator 

 in its motion from the south to the 

 north, and at this instant spring will 

 begin. 



The Zodiacal Light. 



It is at this time of the year that the 

 strange, faint illumination of the wes- 

 tern heaven known as the Zodiacal 

 Light is best observed. It is very prob- 

 able that the great majority of persons, 

 even among those who are interested in 

 astronomy, have never had the pleasure 

 of tracing out this little-known object. 

 Many imagine it to be so difficult 

 that it requires an unusual eyesight or 

 very special methods for observing it : 

 when it is first pointed out to such per- 

 sons and clearly seen by them their first 

 expression is almost always one of sur- 

 prise that they had never seen it before. 



At this time of the year the Zodiacal 

 Light is seen as a faint, wedge-shaped 

 illumination in the western heavens, 

 just after the twilight has fully disap- 

 peared. The center of the base of the 

 wedge rests upon the horizon a few de- 

 grees north of the west point, its axis 

 as seen from our latitudes not extend- 

 ing upward but inclining toward the 

 south in the direction of the constella- 

 tion of the Bull. The center line of the 

 triangle of light lies very nearly along 

 the Ecliptic, A V B, Fig. i. It is be- 

 cause the seasonal change of the heav- 

 ens brings this line so much more di- 

 rectly upward from the horizon during 

 the month of March that the Zodiacal 

 Light is best seen at this time. 



To see this faint pyramid clearly the 

 observer must occupy a station well re- 

 moved from all sources of artificial light 

 and the moon must also be below the 

 horizon, so that the general background 

 of the heavens is as dark as possible. 



