EXPLORING THE GLORIES OF THE FIRMAMENT 



169 



Photograph from Mount Wilson Observatory 



THE NEBULA IN COMA BERENCTS 



A little poleward from a line drawn between Regulus and Arcturus is the constellation 

 Coma Berencis (see the chart on page 170). The nebula shown here is a part of it, and is 

 thought to be so far away that a light ray leaving it today will not arrive* on the earth for 

 thirty thousand years. It is the fastest-moving object yet discovered in the heavens. Travel- 

 ing at the speed it is going in its headlong flight through space, we could go around the earth 

 in one minute. 



chart of the whole sky is being prepared 

 by the observatories of the world. This 

 chart requires the taking of 22,000 photo- 

 graphs, each covering four square de- 

 grees of sky (see page 178). 



MAPPING A UNIVERSE 



Each photograph has in it several stars 

 whose positions have been fixed by direct 

 observation. From them the position of 

 every other star shown on the plate can 

 be fixed by measuring, with a machine 

 employing high-power microscopes, their 

 exact places in the photograph. The 

 completion of this work will record the 

 position of at least eight million stars. 



When we consider the solar system — 

 with its great sun, its eight planets and 

 their twenty-seven moons, and its eight 

 hundred asteroids — as occupying an area 

 whose diameter is nearly six billion miles 

 (some six million times as far as from 

 New York to Chicago), it is amazing to 

 think that there may be millions of other 



solar systems as large or larger than our 

 own, comparatively close to us as star 

 distances go, though so remote that their 

 planets could not be seen bv the astrono- 

 mers of the earth, even with telescopes 

 as much more powerful than the biggest 

 ones now in use are stronger than the 

 naked eye. 



THE ACME OF ISOLATION 



So careful an astronomer as Agnes 

 M. Clerke tells us that a skiff in a vast, 

 un furrowed ocean could not be more ut- 

 terly alone than is our solar system in 

 its little corner of the universe. She 

 continues : 



"Yet the sun is no isolated body. To 

 each individual of the unnumbered stars 

 strewing the firmament, down to the 

 faintest speck of light, ... it stands 

 in some kind of relationship. Together 

 they master its destiny and control its 

 movements. Independent so far as its 

 domestic affairs arc concerned, it is 



