The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1900-01-24
PLANETS AND STARS.
How to Tell Them Apart-Test for
Naked-Eye Observers.

New York Evening Post.
We do not know what man first discov-
cred planets in the sky. 1t may have been
some shepherd, tending his focks, perhaps
upon the plains of Chaldea, surely in the
far-away. misty early beginnings of man.
kind upon the earth. And yet to this day
the test by which the unaided eye can most
easily distinguish planet from star re-
mains the same as that which must have
revealed the first planet to the earliest of
astronomical observers. The very name
planet tells the history of an epoch-mark-
ing discovery just as surely as though
written record of its making had been
handed down to us through successive gen.
erations of men. PLANET" signifies wan
derer." 1t comes from an ancient Greek
word of that meaning. And in truth, to an
unlearned, unettered shepherd of to-day
the planets must appear just as they
did to his long-paSt forerunner of Chaldea,
aimless, lawless wandering stars within
the serried array of heavens night.
1t is ever the characteristic of genius to
disentangle the simple basic phenomena of
nature from among the complex results ex-
hibited to the eye of a casual observer. So
we shall not err in ascribing genius to the
man who first noted the planets peculiari-
ty of travelling among the other stars, and
in designating his discovery an epoch
making one. The whole sky is thickly
studded with the so-called fixed stars. So
far as the naked-eye observer can tell they
all retain precisely the same relative po-
sitiOnS with respect to one another from
year to year and from generation to gener-
alton. If you select a certain triangle
quadrangle of stars as they rise in the
east, you will see them slowly climb the
sky and again descend and set in the west,
always forming precisely the same geo.
metrical figure Nor is this ALL If the
ancient records of naked-eye observations
were searched with care, just the same
triangle or quadrangle of stars would be
found described as having always been
seen to rise and set, then as now, so long
as men have watched the sky.
But suppose there were planet within
the center of our triangle of stars. AS we
watched night after night we should see
the planet slowly change its place within
the triangle. By imperceptible degrees but
with q continuous and cumulative motion
the planet would approach of the tri-
angles sides and at length would pass far
beyond and away. 1t is thus that the first
planet must have been differentiated from
the stars, and thus again the naked-eye
astronomer of to-day can best proceed to
elementary planetary study Note care
fully the heavenly bodies you suspect of
being planets. Fix in your mind, or on a
diagram. their positions with respect to
neighboring stars and you will speedily
come into possession of evidence as to the
planetary nature of the body under obser-
walton. One planet detected in this way
will afford more satisfaction and encour-
aging instruction TO the beginner in as
tronomy than much study by the aid of
books or teachers.
1t is true chat other characteristics of the
planets will help in their identification by
the unaided eye. I In the first place, the
planets are usually very bright, though not
often SURPRISING the most lucid of the fixed
stars. again, the planets are said not to
twinkle. Many observers would not con-
slider this strictly accurate, though il is
certainly a fact that the twinking of the
planets is less than that of a majority of
the stars. But in the absence of a tele-
scope the only sure test is the presence of
such motion among the stars as We have
| described. Into the causes of this motion
| 1t is not our intention to enter. Suffice IL to
say that IL is due to the planets revolution
| in their annual orbits about the sun. This
makes them change their positions in
space. and so we see them projected on diff
| ferent parts of the distant vault of the sky
at different dates of observation.