The Scenery Of The Moon's Southern Hemisphere
:
To Mars Via The Moon
I now directed M'Allister to steer across the lunar equator into the
southern hemisphere, and our attention was soon attracted by a very
large walled plain on the eastward side of our course.
John asked me what it was called, and I explained that it was named
Grimaldi, being also well known to observers as the darkest tinted of
all the large lunar formations. As seen from the earth it appears a
nar
ow ellipse, but we could see its full width, which is 129 miles, the
length being 148 miles. It is also noteworthy as one of the few plains
which are convex in section, and it is so large that its area is equal
to the combined area of the whole of the counties of England south of
the line of the Thames, including Cornwall.
I showed M'Allister this formation on our map, where it appears only a
narrow ellipse in consequence of the moon's curvature, and pointed out
how very different was its appearance now we could see over its whole
extent. Other formations nearer to the moon's limb appear still more
foreshortened when viewed from the earth.
John here remarked that "these large ring-plains covered immense areas,
and, now that we could actually see them, their magnitude was more
impressive than anything we could have imagined from merely hearing or
reading about them."
"Yes, John," I said, "from our altitude of more than ten miles above the
lunar surface we command a much more extensive view and gain a better
knowledge of details than we could obtain even if we landed on the moon.
For instance, if we could stand down in the centre of one of those very
large rings, we should imagine we were in the midst of a boundless open
plain. The mountains all around us would be so distant that, owing to
the sharp curvature of the lunar sphere, they would all be below the
horizon, notwithstanding the fact that many of them are several
thousands of feet in height. So, for all we could see of them, those
mountains might be non-existent.
"In the case of somewhat smaller rings we might perhaps see, here and
there above the horizon, just the topmost peaks of some of the more
lofty mountains."
M'Allister was now struck with an idea, and exclaimed, "Professor, I
notice that many of these great walled plains are very flat, and I
should think they would make fine golf-links, for there would be plenty
of room to send the ball flying!"
"Undoubtedly," I answered, "you would have plenty of space for that; and
I can tell you that you would be able to send the ball flying six times
as far as you could on the earth with the same expenditure of force,
because the moon's gravitation is only one-sixth of that of the earth."
"That would be grand," said M'Allister. "I should like to have a few
turns at golf on the moon."
"Ah, but you would also have extra long tramps after your ball," I told
him, "so you would get plenty of exercise; but, for the reason already
mentioned, you would be able to get over the ground six times as
easily."
"Well, Professor, I should not mind the distance in those
circumstances," he answered jauntily.
"Perhaps you like jumping exercise too," I said. "Only fancy,
M'Allister, if you wanted to jump across one of those narrower cracks!
Why, if you could jump a distance of ten feet on the earth, you could
jump sixty feet on the moon just as easily! Some of our athletes have
jumped a length of twenty-six feet, so the same persons could with equal
ease jump 156 feet on the moon! What do you think of that for a long
jump?"
"Heh, Professor," he replied, looking rather bewildered, "what a jump!
Why, I should think the mon was never coming down again!"
"I say, though, M'Allister, after all I am inclined to think you would
not find golf on the moon altogether a pleasant game," said John.
"Why not, mon?" inquired M'Allister.
"Well," answered John, "I was thinking that if you sent your ball flying
into one of those cracks which are several miles deep you would find
yourself eternally 'bunkered,' for no niblick ever made would get you
out of that."
M'Allister laughed so heartily at this idea of John's that we both
joined in his mirth; then I recommended him to wait until we reached
Mars if he wished to enjoy a game of golf, for there he would be sure to
find enormous stretches of level ground.
CHART OF THE MOON, SHOWING THE PRINCIPAL FORMATIONS SEEN ON ITS SURFACE
The dark areas are termed seas, though there is no water on the moon.
The many small rings are ring-mountains and ring-plains. (The North Pole
is at the top.)]
INDEX MAP TO CHART OF THE MOON
1. Bay of Rainbows
2. Plato
3. Sea of Cold
4. Alps Mountains
5. Great Alpine Valley
6. Cassini
7. Autolycus
8. Aristillus
9. Archimedes
10. Timocharis
11. Lambert
12. Euler
13. Sea of Showers
14. Aristarchus
15. Herodotus
16. Ocean of Storms
17. Copernicus
18. Apennine Mountains
19. Sea of Serenity
20. Haemus Mountains
21. Sea of Conflicts
22. Proclus
23. Sea of Tranquillity
24. Sea of Fertility
25. Hevel
26. Kepler
27. Grimaldi
28. Flamsteed
29. Bonpland
30. Gassendi
31. Sea of Vapours
32. Hipparchus
33. Albategnius
34. Ptolemaeus
35. Alphonsus
36. Arzachel
37. Theophilus
38. Cyrillus
39. Catherina
40. Sea of Nectar
41. Langrenus
42. Vendelinus
43. Petavius
44. Schickard
45. Wargentin
46. Tycho
47. Maurolycus
48. Clavius
49. Newton
50. Straight Wall
51. Sea of Moisture
52. Sea of Clouds]
Proceeding on our tour of inspection, we crossed the Ocean of Storms to
a point near the central part of the lunar surface, and I showed them
the fine walled plain called Ptolemaeus. This is 115 miles in diameter,
and contains an area as large as the combined areas of Yorkshire,
Lancashire, and Westmorland, its highest peak being 9000 feet in
altitude. It forms the most northerly of a line of walled plains, the
most southerly being Arzachel, which is sixty-six miles in diameter, and
has a very depressed floor; while one peak on the walls rises to a
height of 13,000 feet.
Passing farther west, we next examined another splendid group of three
ring-mountains, arranged in a line running nearly north and south, viz.
Theophilus, Cyrillus, and Catherina. The first is the most northerly,
and is about sixty-four miles in diameter, with several very high
peaks-one rising as much as 18,000 feet, and two on the opposite side
being 16,000 and 14,000 feet high respectively. Even the central
mountain is very large in area, and 6000 feet high. "That," I remarked
to M'Allister, "is nearly half as high again as Ben Nevis, the highest
mountain in Scotland, which is, after all, only 4400 feet high."
"Ben Nevis, Professor, is 4406 feet high!" corrected M'Allister.
"That's right, M'Allister," said John, clapping him on the back, "stick
up for bonnie Scotland, and don't let her be robbed of that six feet of
mountain!"
Proceeding, I then said that Cyrillus, the middle ring, was, as they
could see, very irregular in shape; and the walls were in some parts
very much broken and damaged.
Catherina is the largest of the three, being over seventy miles in
diameter, and its highest peak is 16,500 feet in altitude.
I should have liked to have shown them the splendid double-walled plain
called Petavius, which has a convex floor some 800 feet higher in the
centre than at the edges. We were, however, too late both for that and
Langrenus, another fine formation on the same meridian, for the sun had
set upon them and they were in darkness, so it was no use going any
farther in that direction.
We now directed our course over the Sea of Clouds till we arrived at
what is known as the "Straight Wall."
"M'Allister," I said, "that ought to interest you, for there is a
somewhat similar formation in Scotland. You see this is an escarpment,
or cliff, over sixty miles long, and varying from about 600 feet to 900
feet in height.
"This cliff is one of the best known examples on the moon of what in
geology is termed a 'fault,' indicating either that one part of the
general surface has been greatly elevated, or that the adjoining part
has been depressed. We have many examples of such 'faults' on the
earth-for instance, one runs a long way across Scotland, from
Stonehaven round to Helensburgh, between the Highlands and the Lowlands,
and is about 120 miles in length. That is about twice the length of the
Straight Wall; so you see that Scotland can beat the moon in that
respect!"
This brought M'Allister up to the scratch. "Scotland," he exclaimed
excitedly, "can hold her own in most things! Why, mon, the empire is
indebted to her for the finest statesmen, the cleverest lawyers, the
best engineers and scientists, and, allow me to say, the bravest
soldiers in the whole world! Scotsmen go everywhere, and can do
anything!"
"Oh yes, M'Allister," said John, with a laugh, "and a Scotsman has got
to the moon! but, please, do not forget that two Englishmen planned the
trip, and devised the means of accomplishing the journey!"
M'Allister smiled a rather wintry smile, and then subsided. John was a
bit too smart for him that time.
Passing on, we inspected the large cleft running parallel to the
Straight Wall, and the small mountain close by named after Birt, the
well-known selenographer. We then crossed the Sea of Clouds again, and
had a long look at the great system of straight clefts near Campanus and
Hippalus, together with the fine walled plain Gassendi, the floor of
which is at some parts 2000 feet above the lunar surface. I had often
studied this through the telescope, as it is a most interesting
formation.
"Well, Professor," remarked M'Allister, "I have travelled nearly all
over our own world, but in all my journeyings I have never seen such
wild and rugged scenery as I have during the few hours we have been
passing over the moon. The mountains seem to be split and rent in all
directions, especially where there are volcanic craters in the
neighbourhood-and, really, they seem to be everywhere; while landslips
are very numerous, and the mountain passes are extremely rugged and
gloomy."
"Yes," I replied, "my telescopic observations had prepared me for a
great deal, but the weird ruggedness of the lunar scenery exceeds all
my anticipations."
"What is the explanation of it all?" M'Allister inquired.
"I should think, M'Allister, that much of it was originally caused by
the extreme violence of volcanic outbursts," I answered; "but the
excessive expansion and contraction, resulting from the alternate spells
of intense heat and intense cold to which the moon is continually
exposed, will account for the formation of many of those tremendous
chasms and precipices which we see everywhere around us, as well as for
the huge mounds of dislodged rocks and debris, which are piled up in
such chaotic confusion on the ledges of the mountains and round their
bases.
"On the earth such debris would very soon have become smoothed by
atmospheric erosion, the interstices would have been filled up with dust
and soil, while the growth of vegetation would have added a new charm to
the effect.
"You have seen the great landslip in the Isle of Wight! When it fell all
was wild desolation, but it has become covered with such a luxuriant
growth of vegetation that it now presents a scene of beauty.
"On the moon, however, there is neither atmosphere, rain, nor moisture
to produce weathering of the rocks or to encourage the growth of
vegetation; so the rocks remain just as sharp, rugged, and bare as they
were ages ago when they were first split off from the mountains.
"No doubt very large masses of rocks are still frequently being
dislodged, and if we could see them falling from the upper part of a
mountain, rebounding along the spurs, with fragments flying in all
directions and ultimately dashing to pieces at the base, it would seem
to us most uncanny not to hear the slightest sound arising from all this
apparent commotion. Without an atmosphere, however, no sound could be
produced, no matter how many thousands of tons of rock might fall to the
ground.
"Tremendous changes of this nature may be happening on the moon, but our
telescopes are not powerful enough to enable us to see the results. They
would have to cover an area of miles to be noticeable, unless they
presented some particularly striking configuration."
"Professor," exclaimed M'Allister, "how is it that all the shadows on
the moon are such a dense black and so sharply defined at the edges?"
"That," I exclaimed, "is entirely owing to the absence of the
atmosphere. On the earth, even at night time, some light is diffused by
our atmosphere, and shadows are never dense black even when thrown by a
bright sun. On the moon it is black darkness everywhere outside the
direct rays of the sun, and there is no gradual diminution of the
darkness about the edges of shadows such as we see on the earth. The
only mitigation of the blackness is seen where some light is reflected
across from the rocky walls on which the sun is shining.
"In those deep recesses down at the bases of the mountains the cold must
be most intense and the darkness truly awful. It all looks very nice
when the sun is shining, but appearances are often deceptive, and do not
improve on a closer acquaintance."
We could not have landed upon the moon if we had desired to do so, for
no provision had been made for a supply of air by means of helmets and
other apparatus. I kept my own counsel in this matter, as I had very
good reasons for discountenancing any proposal to investigate the lunar
scenery too closely.
By a curious coincidence, not long after this conversation we had ocular
demonstration of the fact that the moon is liable to changes from other
agencies than those of expansion and contraction.
We were looking at some distant mountains which were in the full
sunshine. Suddenly a dark shadowy looking mass shot across the sky and
struck one of the mountain peaks some distance down from the top. The
peak seemed to be immediately demolished, and vanished from our sight!
M'Allister gazed spellbound; but John excitedly exclaimed: "Did you see
that, Professor? One moment the peak was there, and the next moment it
was gone!"
"Yes," I said. "Undoubtedly that dark shadow was a large meteoric stone.
Many have fallen on our earth at various times, some being tons in
weight. Usually, however, they are so small that on entering our
atmosphere they become fused by the friction and changed to dust. Larger
ones are partially fused, and often split into fragments in the upper
air. The moon, having no atmosphere, is quite unprotected in this
respect; and meteorites moving at enormous speeds, probably over forty
miles in a second, travel unchecked and unaltered in character until
they strike the lunar surface. It is estimated that immense numbers
constantly enter our atmosphere and are destroyed; but the moon must be
continually exposed to bombardment by meteorites of considerable size.
"Many of our ships have been lost at sea in calm weather, and their fate
has remained a profound mystery; but it is not at all improbable that
some of them have been destroyed by large meteorites, for several
instances are recorded of ships having very narrow escapes from these
dangerous missiles from outer space."
Passing on towards the south-west, we had a long look at the magnificent
formation named Tycho. It is a ring-plain nearly fifty-six miles in
diameter, the mountain walls having some peaks over 17,000 feet in
height. I drew their attention to the long bright ray-streaks which
radiate in all directions for many hundreds of miles from the
neighbourhood of this formation, to which I alluded when we had been
looking at the rays from Proclus. Tycho and these bright streaks can be
seen from the earth when the moon is full without the aid of a
telescope, if one possesses good eyesight.
An enormous number of ring-plains and ring-mountains exists all over the
southern half of the moon's disc; in many cases there are rings within
rings, and others where they have overlapped or cut into previously
formed rings.
Moving almost due south, we passed the large but partially ruined walled
plain known as Maginus. This ring has a floor which is no less than
14,000 feet below the lunar surface. We then arrived at that favourite
object for telescopic observers which is named Clavius. This is an
enormous ring-plain, being over 142 miles in diameter, and encloses an
area of 16,000 square miles, thus being half the area of Scotland. It
has a very depressed floor, and some of the mountains are 16,000 to
17,000 feet in altitude.
Farther on, and close to the south pole, we saw the very deepest of the
lunar walled plains, which is named after Newton, who possessed probably
the deepest intellect of any of our astronomers. A smaller formation
south of Plato was originally named after him, but was not considered
worthy of a man of his scientific eminence, so the name was transferred
to the formation we were looking upon. It is about 143 miles long and
very irregular in shape, and its depth is about 24,000 feet-so deep, in
fact, that the sun's light never reaches to the bottom; thus, when we
look at it from the earth, the floor is always in shadow.
The Leibnitz Mountains, unfortunately, were not visible, as the sun had
set upon them. I, however, mentioned that this range comprises several
peaks which are believed to be the highest on the lunar surface,
reaching as they do an altitude of 30,000 feet, and, according to some
measurements, 40,000 feet. They are very difficult to measure, owing to
the fact that they are really situated on the farther side of the moon,
extending east and west of the south pole, and are only occasionally
brought into view by the moon's libration; even then they are seen in
profile, and so situated that they cannot be measured with certainty.
They are, however, so high that they blunt the southern cusp of the moon
when it is in crescent form.
I now directed M'Allister to turn the vessel in a north-easterly
direction, and we moved across to the last objects which I proposed to
examine. One was the large walled plain "Schickard"-about 135 miles in
diameter-which encloses several other rings; the other, which lies to
the south-east of it and close to the moon's south-eastern limb, is
probably the most unique object on the lunar surface. As we gazed upon
it I explained that the formation, which is known as "Wargentin," would
probably in the usual course of events have been a ring-plain about
fifty-four miles in diameter, but it really is a high plateau of that
size, with very low ramparts. It is evidently a ring-plain which became
filled to the brim with lava, or mud, that welled up from the interior
of the moon; and the mountain walls, being exceptionally strong and
without any breaks or gaps, withstood the enormous pressure of the lava,
which therefore solidified and formed the great plateau as we now see
it. The low ramparts, which we noticed here and there, are really the
isolated peaks and ridges of the mountains forming the walls. This is
the only known instance of such a formation; but probably others would
exist had not the walls of the rings given way under the pressure of the
lava. The walls of several ring-plains have been quite carried away,
and, in some cases so obliterated, that it is now difficult to make out
the original shape of the rings.
Having taken a last look at this unique object, I directed M'Allister to
set the machinery in motion and rise for the purpose of quitting the
moon.
"But," interposed John, "are you not going to have a look at the back of
the moon, Professor?"
"No, John," I answered, "only a small portion of it is now in the
sunlight, the rest is in the blackest darkness, so we should not be
likely to learn much more about it than we know at present."
"Do you think the moon is inhabited?" he then asked.
"No, I do not think it is; no sign of life has ever been discovered, and
we have seen nothing to indicate its existence here. The prevailing
conditions seem to preclude the possibility. Think, John, if there is
any life, what must it be! Without any atmosphere-therefore, not a
sound to be heard, for all would ever be in the most deathly silence-no
breath of wind; never a cloud nor a drop of refreshing rain, nor even
dew; intense heat in the sunlight and the most intense cold everywhere
in the shade! If any life does exist, it is most probably down in those
gloomy, dark and cold recesses at the bottom of the ring-mountains,
where there may possibly be some remains of an atmosphere. It would,
however, be life in such a dreadful and debased form that I would rather
not think about it at all.
"For a somewhat similar reason, I have directed M'Allister to keep the
Areonal at least ten miles above the lunar surface all the time we
have been passing over it. When we saw it from a distance it was, as you
know, an object of surpassing beauty; and as we have seen it from here
it has still been pleasant to look upon. This is truly a case where
distance lends enchantment to the view; for, if we went down close to
the surface, we should find it a scene of the weirdest and wildest
desolation-more horrible than anything seen during a nightmare, and
more terrible than anything imagined by the insane!
"No, John," I concluded, "let us retain our memory of the moon as a
thing of beauty, and leave it at that."
"I quite agree with your view of the matter, Professor," John replied;
so I gave the signal to M'Allister, who was awaiting the result of our
discussion, and we soon left the moon far below us.