It is sought in the following pages to give a simple account of what
may now be said to be known of the character of the planets, and to
describe with as little technicality as possible their movements and
aspects and relations. An endeavor is made to impart concerning each
one of them not, surely, profound learning, but just a good, every-day,
practical notion, so that the mere name will call up a definite object,
with its own attributes, appearance, and behavior, entirely distinct
from any other planet or from any other object in the skies.
An endeavor is made also to so simplify and direct the observation
that any one, after a little practice, will know almost without
hesitation, on seeing a planet in the sky, that it is a planet, and
not a fixed star, and exactly what planet it is. The situation and
aspect of it will then as quickly and clearly pronounce it to be
the individual planet that it is as the sight of a person of one’s
acquaintance proclaims him to be that person, and no other. The very
name of Venus, for example, and still more the sight of Venus, will
call up a conception of Venus, with the particular atmosphere and light
and movements and wanderings which make her what she is. On looking
at her the observer will at once know why she occupies the special
position in the sky in which he sees her, why she is not so bright as
she was when she was last in view, or is so much brighter than she was
then, about how long she is likely to remain where she is, and when she
goes what will become of her.
For far off and truly mysterious as the planets are, it still is with
them as with most other objects in nature: a very little knowledge
of their aspects and their ways begets a sense about them that makes
the most casual observation of them interesting and, as far as it
goes, intelligent. The slightest glance at them betrays some shape, or
position, or light, or other quality, which at once makes recognition
of them unmistakable. They disclose themselves oftentimes, one can
scarcely say how, just as persons with whom we are intimate do by some
half-caught outline, motion, or posture; or just as the trees do to an
observer who knows, for example, an oak-tree from an elm, whether they
are covered with their own peculiar verdure, or whether they stand with
bare branches stretched out and colored in their own peculiar way.
This instant recognition of the planets is, of course, not to be had
by simply reading about them. Such practical familiarity with them is
attained only by seeking them out over and over again and looking at
them with attention, with eagerness, and with all one’s faculty. With
them, as with other natural objects, it requires observation truly to
know them. But then, observation, when one gets a little started in it,
is a great deal more interesting, a great deal more absorbing, than any
reading about them can ever be. It is also a very easy thing to begin,
for, after all, it is not much more than looking and then looking
again. In doing this one can hardly tell just when an object ceases to
be strange, and then becomes familiar, and finally is so much a part
of every-day knowledge that one knows it at a glance. But this is what
happens in the case of any natural object when we observe it often and
with true attention.
In the case of the planets, if one is interested at all, every stage
in the cultivation of such an acquaintance is full of pleasure. Even
to one who regards them only as a part of the general aspect of the
sky, they are the most beautiful objects in it and always the first to
attract special attention. Nine times out of ten, when any one asks
what a certain star is, it proves to be one of the planets. When one
of them is visible a person can hardly glance at the heavens without
noticing it, even if he does not stop to think about it. But if he
does stop to think about it and notices that it is far larger than any
star he has noted before, that it hangs low in the western sky early
in the evening, and shines with a brilliant silvery light, and if he
then learns that it is Venus, will he not always have a pleasant thrill
of recognition when he again sees such a star in such a position and
knows it as Venus, among the planets as surpassing in beauty as the
goddess of that name was among the immortals? Or, if in the east, at
the same time in the evening, he sees a brilliant, solid-looking,
unblinking star shining with a white light, but pinkish white, not
silvery, and finds it to be Jupiter, will not such a star in such a
situation be to him ever after a pleasant acquaintance that he can call
by name? Not that Jupiter and Venus are always in these positions, or
shine in just this way at all times. These are their places and aspects
at certain times, frequently recurring, and at such times always
unmistakably distinguish them.
It is, then, merely the matter of a little more and yet a little more
observation, in order to come to know any one of the visible planets in
all its varying aspects and situations. Of course, at the start some
guidance is necessary, but only a little; and that little, if it is of
the right sort, should not be irksome. To provide such guidance is one
of the aims of this book. That is, indeed, its main aim.
But in addition to what, as a help in observation, it may find to
say regarding the appearance and movements of the planets, it will
endeavor to give also ample information concerning their character and
constitution.
It is hoped that this may be done without weighting the narrative
with figures, though some of the peculiarities of the planets must be
expressed by means of numbers. Certainly no mathematical problems will
be presented. But it will be profitable to remember that every one of
the intimate things we know about the planets has come to us through
the long and laborious mathematical work of astronomers. To them we owe
the extinguishable debt that we owe to all special workers who put us
in possession of the facts that interpret life to us.
For the astrology and poetry and romance of the planets one must
go elsewhere. Nearly every book on the subject of the planets--and
there are many of them--has some information about these things; and
properly, too, for every genuine emotion and every real fancy has its
value. But neither curious lore of the planets nor the sentiment and
emotion they have produced in others is what the author of this book
is striving to set forth. It is something much more vital than this.
What we wish to contemplate here are the plain facts, the knowledge of
which enlivens and enriches one’s mind and nature. If the contemplation
of them kindles one’s fancy or excites one’s emotions, these results
at least will not be second-hand. If the bare facts, simply and
plainly told, and the view of the planets themselves as they wander
through their courses in the sky, do not awaken one’s understanding
and imagination, no amount of poetry or romance that other people have
built up around the planets will arouse anything more than a factitious
interest in them. It is when our own faculties are at work and our
own fancy plays over a subject that we become genuinely and lastingly
interested in it.
The facts themselves are in the main quite simple, and will not be
given here as anything else than that. They have been fairly wrested
from that mysterious thing called space by the mighty power of mind
and unceasing labor. Our knowledge of them is due to long nights of
watching and long days of calculating; to long and careful testing
and considering of theories, only to find that something else must be
tried; to courage to begin all over again, to sudden inspirations, and
sometimes to those lucky discoveries that seem almost like miracles.
The subject of the planets has in some respects a greater interest even
than that of the stars, because we know, after all, more about them.
We sometimes have a feeling, though, that we know more of the stars,
although the stars are so much farther off. Why we have this feeling
it is easy to explain. Knowing them to be so far removed from us, we
really approach the stars with a different expectation. The few things
that we have learned about them have in themselves such a magnitude
that it makes them seem a greater body of knowledge than they truly
are. The stars are indeed so far away, and what we know of them has
to be expressed in such large terms, that the mind does not demand in
that information the minute exactness that it seeks for in the case of
nearer objects.
In the case of the stars, we seek mainly to know their distances, the
direction of their motions, the speed with which they travel, and
their probable connection with each other. The fact that in computing
the distance of a single star, many trillions of miles away, the
result may be a little less than exact does not keep us from learning
what ones are sufficiently near for their distances to be measured
at all and what ones are immeasurably remote. Whether they travel at
the rate of exactly three or three hundred miles a second, we can
learn that some are traveling at somewhat the same rate of speed as
our sun travels, and some incredibly faster; that certain groups are
going in one direction and certain groups in another; that some are
approaching us and some are receding from us. And thus we can classify
them and learn the significance of these facts, and, little by little,
gain a definite understanding of the construction and meaning of the
entire universe. Their very remoteness gives a certain compactness to
the information we have about the stars, by making it necessary to
generalize more than we would if they were near enough to yield more
details; and we are in a way satisfied with this more general sort of
knowledge of them.
But the very fact of our knowing so much about the planets extends
our curiosity concerning them and makes us feel that we ought to
know more. The mind is provoked into more minute speculations about
them, and we demand more exactness of information and knowledge of
a more specific or intimate sort than would satisfy us in regard to
the stars. Atmosphere, habitability, exact size, seasons, and day and
night, are the kind of things we most seek to know in reference to the
planets. These are such definite things that conclusions concerning
them are subject to close criticism, and differences of opinion in
regard to them thus sometimes occur which tend to give one a more or
less confused notion of what is really known. As a matter of fact, our
information about the planets is much fuller than our knowledge of the
stars, as we would naturally expect it to be. Much of what we seek to
know about the stars has long been common knowledge about the planets.