SOMETHING TRUE ABOUT THE MOON.
THE FULL MOON.
THE FULL MOON.
THE FULL MOON.
In another part of this book I told you something about the moon, which did not even pretend to be true. No body can go to the moon, although very many people have traveled more miles than the distance between the earth and its lunar companion. Any one who has sailed from New York to Liverpool and back forty times has gone over a greater distance than that from here to the moon, which is less than 240,000 miles away.
Many a sea-captain has sailed more miles than these. A ship came into New York Bay very recently that had sailed, in one voyage over 110,000 miles.
But we cannot visit the moon because there is no atmospheric air between that planet and the earth. If air existed in this vast space in which a balloon might float, and which a man might breathe, I think that some of us would manage to get to the moon before any one reaches the North Pole. The journey would be longer, but there would be no ice to block up the way.
But notwithstanding the fact that we cannot go to the moon, we know a great deal about that planet, especially as it affects the earth. And with the great telescopes that have been constructed, in late years, we can see much of the general configuration of that side of the moon which is turned towards us, and it appears very like the picture at the head of this article. Here we see depressions and elevations, and plain surfaces which may be, and probably are, mountains and beds of dried up oceans and vast plains, which, in all probability, are barren and desolate.
For scientific men feel quite certain that the moon has no atmosphere, and of course if there is no air, we have no reason to suppose that there is any life there.
But our principal interest in the moon relates to its effects upon ourselves, and our own planet, and therefore we should all understand it as we see and enjoy it from our stand-point.
We all know that sometimes the moon is full and bright, flooding the earth with its lovely light, and that, at other times it is quite dim, just a curved strip of light in the sky, and at still other times it seems to be absent altogether.
Though we have noticed all this, it is very probable indeed that some of us do not entirely understand these changes, and so I shall briefly explain them.
When we cannot see the moon at all, which is the case for two or three days every month, it is because the sun is not shining on that side of the moon which is turned to us. And we might as well remember that although the moon moves around the earth once every four weeks, it always turns the same side to us. We never have seen the other side, with telescopes, or in any other way.
When the moon is between us and the sun, the side towards us must of course be dark. Then it is that we do not see the moon at all.
But as the moon moves gradually to one side we begin to see a little strip of the bright portion as you notice in Fig.1. This represents the moon in its first phase.
I suppose you have noticed at such times, when the new moon is very small, that we can often see the whole disk of the moon, although the principal portion of it is very dim indeed. Still we can see a faint light shining upon it which makes it comparatively easy for us to discern its outlines.
FIG. 1. FIRST PHASE OF MOON.
FIG. 1. FIRST PHASE OF MOON.
FIG. 1. FIRST PHASE OF MOON.
This pale light is “earth-light.” The earth is then “full” to the moon-folk, (if there be any such creatures who can live without air,) and its brilliancy is partially reflected back to us from the surface of the moon.
The bright portion of the moon now grows larger and larger until,in about seven or eight days, we see it as it is shown in Figure2. Then it is said to be in its first quarter.
At this time the spots and various markings on its surface are generally seen very distinctly.
For seven days the bright portion of the moon continues to grow larger and larger, and during a part of this time it presents the appearance shown in Figure3.
FIG. 2. FIRST QUARTER.
FIG. 2. FIRST QUARTER.
FIG. 2. FIRST QUARTER.
At last, after about fifteen days of active increase of bright surface the moon reaches that point where the sun shines directly upon the side presented to the earth, and then it is “full moon.” Of course it must, at this time, be on the side of the earth farthest from the sun so that the sun can shine on it, and at the same time, we can see it.
FIG. 3. BETWEEN FIRST QUARTER AND FULL MOON.
FIG. 3. BETWEEN FIRST QUARTER AND FULL MOON.
FIG. 3. BETWEEN FIRST QUARTER AND FULL MOON.
Figure4is a small picture of the full moon.
But the moon does not remain full very long, as many of us who delight in moonlight rambles, and boat-rides, know to our sorrow. It soon begins to wane, and then assumes very much the same forms that it presented when on the increase, with this difference; its lighted portion is always turned the other way.
FIG. 4. THE FULL MOON.
FIG. 4. THE FULL MOON.
FIG. 4. THE FULL MOON.
It now rises later and later. When it was full it rose at about the time that the sun set, and set about sunrise. But now it rises later and later until at last it rises just before the sun, and is of course soon invisible in his brighter rays.
Figures5,6and7will give you an idea of the various phases assumed by the moon when in its wane, or decrease.
So now we have seen the moon in its various phases, which is nothing more than we can see in the heavens when the sky is clear, but it is better always to understand what we see.
We should remember, then, that one half of the moon is always bright. When it is between us and the sun (not on an exact line, however, for that would make an eclipse of the sun) we cannot see it at all, and then we say “there is no moon to-night.” When it moves around so that we can see a little of the bright side, it is “new moon,” and when it gets around behind us, so to speak, so that we can see the sun shining full upon one side of it, it is “full moon.”
If one of us could live upon that part of the surface of the moon that is always turned toward us, he could see the same changes taking place upon our planet as we see on the moon.
There would be “new earth,” and “quarter earth,” and “full earth,” which last would be truly grand!
Think of a bright orb of light in the heavens fourteen times larger than the full moon, and you will have an idea of how our earth would sometimes appear to observers on the moon,—were there any one there to see.