328 



THE GUIDE TO NATURE 



by no means certain. As to the intricate 

 network of lines or bands of the same 

 color as the "seas" which cover the plan- 

 et, these interesting but mysterious fea- 

 tures are far beyond the power of a 

 smaller telescope. 



Figure 3. Drawings of the planet Mars. The Syrtis 

 Major, or Hourglass "Sea," at A, the Lake of the 

 Sun, at B, and the South Sea, at C, as well as the 

 Polar Caps, at P, can be seen under good conditions 

 in comparatively small telescopes. 



Though ^Nlars passed nearest to the 

 earth on February 9, and although it has 

 moved but a little way along its orbit 

 since then, the present is unfortunately 

 not a very favorable opposition. The 

 reason for this will be evident from an 

 examination of Figure 2. The sun is no 

 less than thirteen millions of miles out- 

 side the center of the nearly round orbit, 

 so that if the earth passes Mars when this 

 planet is at the most remote part of its 

 path the two worlds will be twenty-six 

 millions of miles farther apart than when 

 their approach is the most favorable. In 

 this year Mars passes aphelion — or is 

 farthest from the sun — on March 13. 



The Zodiacal Light. 



As a new moon occurs on March 3, 

 the last days of February and the first 

 week of March will afford the observer 

 excellent moonless nights on which to 

 look for this most interesting object. He 

 should go out of doors as soon after sun- 

 set as the western sky has become dark, 

 and having fovmd a station away from 

 all electric and other artificial lights, he 

 should face directly toward the western 

 point of the horizon. He will then see 

 this great, faint pyramid of light, its base 

 resting on the western horizon and its 

 apex probably extending almost to the 

 Pleiades. It will probably be consider- 

 ably fainter than that bright part of the 

 Milky Way which is above it, though the 

 brightness of the Zodiacal light often 

 varies suddenly and capriciously. 



This faint light at which w^e look is a 

 real, material object, being nothing less 

 than a great flattened cloud of very small 

 density, which surrounds the sun and ex- 

 tends out into space beyond the orbit of 

 the earth. It is probable that its sudden 

 changes of brightness are electrical in 

 character, and they are probably due to 

 great electrical disturbances on the sun. 

 If so they should be especially marked 

 during the present year when sunspots 

 are most numerous. 



The Planets in March. 



Mercury reaches its greatest distance 

 west of the sun on March i, and during 

 the first part of the month may be seen 

 in the dawn for about an hour before 

 sunrise. It will not pass to the east of 

 the sun and become an evening star until 

 April 14. 



A^enus is the most beautiful object now 

 in the evening heavens. The observer will 

 notice that this planet is now moving very 

 rapidly eastward and northward among 

 the stars so that by the end of the month 

 it will set far in the northwest and shine 

 in our evening skies until four hours after 

 sunset. It will attain its greatest distance 

 east of the sun on April 24. and through- 

 out the entire spring it will grow con- 

 tinually more brilliant, not attaining its 

 greatest brightness until May 27. In the 

 telescooe Venus now resembles the moon 

 when this is a little more than half full. 



Tupiter, which has shone in our evening 

 skies for so many months, is now lost 



