THE MOON.
Come, and let us pay a visit to the moon. We seem to feel a personal
interest in her, just because she is, in so peculiar a sense, our own
friend and close attendant. The sun shines for us; but, then, he shines
for all the members of the Solar System. And the stars--so many as we
can see of them--shine for us too; but no doubt they shine far more
brilliantly for other and nearer worlds. The moon alone seems to belong
especially to ourselves.
Indeed, we are quite in the habit of speaking about her as “our moon.”
Rather a cold and calm friend, some may think her, sailing always
serenely past, whatever may be going on beneath her beams; yet she has
certainly proved herself constant and faithful in her attachment.
We have not very far to travel before reaching her,--merely about
two hundred and forty thousand miles. That is nothing, compared with
the weary millions of miles which we have had to cross to visit some
members of our family. A rope two hundred and forty thousand miles
long would fold nearly ten times round the earth at the equator. You
know the earth’s diameter--about eight thousand miles. If you had
thirty poles, each eight thousand miles long, and could fasten them all
together, end to end, one beyond another, you would have a rod long
enough to reach from the earth to the moon.
Let us take a good look at her before starting. She is very beautiful.
That soft silvery light, so unlike sunlight or gaslight, or any other
kind of light seen upon earth, has made her the darling of poets and
the delight of all who love nature. Little children like to watch
her curious markings, and to make out the old man with his bundle of
sticks, or the eyes, nose, and mouth of the moon--not dreaming what
those markings really are. And in moods of sadness, how the pure calm
moonlight seems to soothe the feelings! Who would suppose that the
moon’s beauty is the beauty rather of death than of life?
[Illustration: APPEARANCE OF THE FULL MOON.]
The stars have not much chance of shining through her bright rays. It
is well for astronomers that she is not always at the full. But when
she is, how large she looks--quite as large as the sun, though in
reality her size, compared with his, is only as a very small pin’s
head compared with a school globe two feet in diameter. Her diameter is
little more than two thousand miles, or one quarter that of our earth;
and her whole surface, spread out flat, would scarcely equal North and
South America, without any of the surrounding islands.
The reason she looks the same size as the sun, is that she is so very
much nearer. The sun’s distance from us is more than one-third as many
_millions_ of miles as the moon’s distance is _thousands_ of miles.
This makes an enormous difference.
We call our friend a “moon,” and say that she journeys round the earth,
while the earth journeys round the sun. This is true, but it is only
part of the truth. Just as certainly as the earth travels round the
sun, so the moon also travels round the sun. And just as surely as
the earth is a planet, so the moon also is a planet. It is a common
mode of expression to talk about “the earth and her satellite.” A no
less correct, if not more correct, way would be to talk of ourselves
as “a pair of planets,” journeying round the same sun, each pulled
strongly towards him, and each pulling the other with a greater or less
attraction, according to her size and weight. For the sun actually does
draw the moon with more force than that with which the earth draws her.
Only as he draws the earth with the same sort of force, and nearly in
the same degree, he does not pull them apart.
The moon, like the other planets, turns upon her axis. She does this
very slowly, however; and most singularly she takes exactly the same
time to turn once upon her axis that she does to travel once round
the earth. The result of this is, that we only see one face of the
moon. If she turned upon her axis, and journeyed round the earth in two
different lengths of time, or if she journeyed round us and did not
turn upon her axis at all, we should have views of her on all sides,
as of other planets. But as her two movements so curiously agree, it
happens that we always have one side of the moon towards us, and never
catch a glimpse of the other side.
And now we are ready to start on our journey of two hundred and forty
thousand miles. An express train, moving ceaselessly onward night and
day, at the rate of sixty miles an hour, would take us there in about
five months and a half. But no line of rails has ever yet been laid
from the earth to the moon, and no “Flying Dutchman” has ever yet plied
its way to and fro on that path through the heavens. Not on the wings
of steam, but on the wings of imagination, we must rise aloft. Come--it
will not take us long. We shall pass no planets or stars on the road,
for the moon lies nearer to us than any other of the larger heavenly
bodies.
Far, far behind us lies the earth, and beneath our feet, as we descend,
stretch the broad tracts of moonland. For “downward” now means towards
the moon, and away from the distant earth.
What a strange place we have reached! The weird, ghastly stillness
of all around, and the glaring, dazzling, cloudless heat, strike us
first and most forcibly. Nothing like this heat have we ever felt on
earth. For the close of the moon’s long day--on this side of its
globe--is approaching, and during a whole fortnight past the sun’s
fierce rays have been beating down on these shelterless plains. Talk
of sweltering tropics on earth! What do you call _this_ heat? Look
at the thermometer: how the quicksilver is rising! Well, that is not
a common thermometer which we have brought with us. The mercury has
stopped--three hundred degrees above boiling water!
Not a cloud to be seen overhead; only a sky of inky blackness, with a
blazing sun, and thousands of brilliant stars, and the dark body of
our own earth, large and motionless, and rimmed with light. Seen from
earth, sun and moon look much the same size; but seen from the moon,
the earth looks thirteen times as large as our full moon. Not even a
little mistiness in the air to soften this fearful glare! Air! why,
there is no air; at least not enough for any human being to breathe
or feel. If there were air, the sky would be blue, not black, and the
stars would be invisible in the daytime. It looks strange to see them
now shining beside the sun.
And then, this deadly stillness! Not a sound, not a voice, not a murmur
of breeze or water. How could there be? Sound can not be carried
without air, and of air there is none. As for breeze--wind is moving
air, and where we have no air we can have no wind. As for water--if
there ever was any water on the moon, it has entirely disappeared. We
shall walk to and fro vainly in search of it now. No rivers, no rills,
no torrents in those stern mountain ramparts rising on every side. All
is craggy, motionless, desolate.
How very, very slowly the sun creeps over the black sky! And no
marvel, since a fortnight of earth-time is here but one day, answering
to twelve hours upon earth. Can not we find shelter somewhere from
this blazing heat? Yonder tall rock will do, casting a sharp shadow
of intense blackness. We never saw such shadows upon earth. There the
atmosphere so breaks and bends and scatters about the light, that
outlines of shadows are soft and hazy, even the clearest and darkest of
them, compared with this.
When will the sun go down? But he is well worth looking at meanwhile.
How magnificent he appears, with his pure radiant photosphere, fringed
by a sierra of dazzling pink and white, orange and gold, purple
and blue. For here no atmosphere lies between to blend all into
yellow-white brightness. And how plainly stand out those prominences
or tongues of tinted flame, not merely rose-colored, as seen from
earth, but matching the sierra in varying hues; while beyond spreads
a gorgeous belt of pink and green, bounded by lines and streams of
delicate white light, reaching far and dying slowly out against the jet
background. The black spots on the face of the sun are very distinct,
and so also are the brilliant faculæ.
We must take a look around us now at moonland, and not only sit gazing
at the sun, though such a sky may well enchain attention. How unlike
our earthly landscapes! No sea, no rivers, no lakes, no streams, no
brooks, no trees, bushes, plants, grass, or flowers; no wind or breeze;
no cloud or mist or thought of possible rain; no sound of bird or
insect, of rustling leaves or trickling water. Nothing but burning,
steadfast, changeless glare, contrasting with inky shadows; sun and
earth and stars in a black heaven above; silent, desolate mountains and
plains below.
For though we stand here upon a rough plain, this moon is a mountainous
world. Ranges of rugged hills stretch away in the distance, with
valleys lying between--not soft, green, sloping, earthly valleys, but
steep gorges and precipitous hollows, all white dazzle and deep shade.
But the mountains do not commonly lie in long ranges, as on earth. The
surface of the moon seems to be dented with strange round pits, or
craters, of every imaginable size. We had a bird’s-eye view of them as
we descended at the end of our long journey moonward. In many parts
the ground appears to be quite honeycombed with them. Here are small
ones near at hand, and larger ones in the distance. The smaller craters
are surrounded by steep ramparts of rock, the larger ones by circular
mountain-ranges. We have nothing quite like them on earth.
Are they volcanoes? So it would seem; only no life, no fire, no action,
remain now. All is dead, motionless, still. Is this verily a blasted
world? Has it fallen under the breath of Almighty wrath, coming out
scorched and seared? Is it simply passing through a certain burnt-out,
chilled phase of existence, through which other planets also pass, or
will pass, at some stage of their career? Who can tell?
We will move onward, and look more closely at that towering mass of
rugged rocks, beyond which the sun will by and by go down. Long jetty
shadows lie from them in this direction. No wonder astronomers on
earth can through their telescopes plainly see these black shadows
contrasting with the glaring brightness on the other side.
A “mass of rocks” I have said; but as, with our powers of rapid
movement, we draw near, we find a range of craggy mountains sweeping
round in a vast circle. Such a height in Switzerland would demand many
hours of hard climbing. But on this small globe attraction is a very
different matter from what it is on earth; our weight is so lessened
that we can leap the height of a tall house without the smallest
difficulty. No chamois ever sprang from peak to peak in his native
Switzerland with such amazing lightness as that with which we now
ascend these mighty rocks.
[Illustration: ONE FORM OF LUNAR CRATER.]
Ha! what a depth on the other side! We stand looking down into one of
the monster craters of the moon. A sheer descent of at least eleven
thousand feet would land us at the bottom. Why, Mont Blanc itself
is only about fifteen thousand feet in height. And what a crater!
Fifty-six miles across in a straight line, from here to the other side,
with these lofty rugged battlements circling round, while from the
center of the rough plain below a sharp, cone-shaped mountain rises to
about a quarter of the height of the surrounding range.
It is a grand sight; peak piled upon peak, crag upon crag, sharp rifts
or valleys breaking here and there the line of the narrow, uplifted
ledge; all wrapped in silent and desolate calm. There are many such
craters as this on the moon, and some much larger.
The sun slowly nears his setting, and sinks behind the opposite range.
How we shiver! The last ray of sunlight has gone and already the ground
is pouring out its heat into space, unchecked by the presence of air
or clouds. The change takes place with marvelous quickness. A deadly
chill creeps over all around. A whole fortnight of earth-time must pass
before the sun’s rays will again touch this spot. Verily the contrasts
of climate in the moon, during the twelve long days and nights which
make up her year, are startling to human notions.
But though the sun is gone we are not in darkness. The stars shine with
dazzling brightness, and the huge body of the earth, always seeming to
hang motionless at one fixed point in the sky, gives brilliant light,
though at present only half her face is lit up and half is in shadow.
Still her shape is plainly to be seen, for she has ever round her a
ring of light, caused by the gathered shining of stars as they pass
behind her thick atmosphere. She covers a space on the sky more than a
dozen times as large as that covered by the full moon in our sky.
[Illustration: THE EARTH AS SEEN FROM THE MOON.]
It would be worth while to stay here and watch the half-earth grow
into magnificent full-earth. But the cold is becoming fearful--too
intense for even the imagination to endure longer. What must be the
state of things on the other side of the moon, where there is no bright
earth-light to take the place of the sun’s shining, during the long two
weeks’ night of awful chill and darkness?
It seems probable that a building on the moon would remain for century
after century just as it was left by the builders. There need be no
glass in the windows, for there is no wind and no rain to keep out.
There need not be fireplaces in the rooms, for fuel can not burn
without air. Dwellers in a city in the moon would find that no dust
can rise, no odors be perceived, no sounds be heard. Man is a creature
adapted for life in circumstances which are very narrowly limited.
A few degrees of temperature, more or less; a slight variation in
the composition of air, the precise suitability of food, make all
the difference between health and sickness, between life and death.
Looking beyond the moon, into the length and breadth of the universe,
we find countless celestial globes, with every conceivable variety of
temperature and of constitution. Amid this vast number of worlds with
which space teems, are there any inhabited by living beings? To this
great question science can make no response save this: We can not tell.
Time for us to wend our way homewards from this desolate hundred-fold
arctic scene. We have more to learn by and by about our friend and
companion. For the present--enough.