Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1892-12-01
THE SKIES FOR DECEMBER.
WRITTEN FOR THE DISPATCH.

tion. And as we have not been knocked
into smithereens by Holmes comet or Bic
la comet or Jones' comet or Smiths comet
or Browns comet, nor yet by any comet be-
longing to any other gentlemen who care
lessly leave their property running around
loose where it is liable to bump into us, why
1 suppose DISPATCH readers may still be in
terested in the celestial sights which will
present themselves to our gaze this month.
But before We take q look at the skies for
December let US see what we know about
these wonderful things called comets. what
is comet anyhow? The name is derived
from the Greek word "kometes" Qong-
haired1, and a comet may be defined as
nebulous body revolving around the sun.
Comets, then, are bona fide members of our
solar system, and like the earth, Mars and
other planets, they are held in their orbits
by the suns attraction. This fact, however,
only became known after Newton's wonder
full discoveries, in which he affirmed the
universally of the laws of gravitation.
Previous to this comets were looked upon
as anomalous bodies whose motions it was
impossible to understand The suddenness
with which they blazed forth, their i'm
mense size, their great velocity, their &C.
centric motions, sweeping toward the sun
from all regions and all directions, made
them objects of superstitious dread and
terror, until finally the irresistible hand of
science swept away these mysteries and put
the strange bodies in their proper category
Of solar satellites.
Light on Live Topic.
The senseless and unreasoning terror
which seems to have been caused in some
localities by recent comets is only relic of
the superstition OF the Dark Ages. Authori-
ties agree on this at any rate, that there
was no danger. Even if we had struck the
comet the shock would probably not have
been noticed. About the best thing that
was said in regard to the recent scare was in
yesterdays DISPATCH, where Prof. Jacoby is
quoted. He said, II think great deal too
much was said and written about the
Holmes comet" But since so much was
said and written it is well to have a clear
idea of what we are talking and reading
about. To continue, then, comets revolve
around the sun like the planets do, but un-
like the planets their orbits are exceedingly
eccentric. For instance Eucke's comet
approaches to within less than 60, 1000, 900 miles
OF the sun, and its aphelion or greatest
distance from the sun is about 4O0, 600, 900
miles. Yet Encke's comet is one of the least
eccentric. Some comets approach even
nearer the sun and then retreat to q much
greater distance, the orbits of many of them
extending far beyond that OF Neptune, the
most distant plant. A comet approaching
the sun from a great distance comes more
and more under its influence, and SO moves
faster and faster, and soon dashes past the
attracting body with the most tremendous
velocity. When it once starts moving away,
however, the sun brings it up with short
turn, and the comet turns sharply around,
passes the sun on the other side, and whirls
away in almost the same direction from
which it comes, but with its speed con-
stantly diminishing as it recedes from the
SUMS attraction.
The comet of 1880 had a very eccentric
orbit. 1t came within less than 100 900 miles
of the sun, and swept around it at the fear
full rate of 100000 miles an hour. 1t has
never been seen since, and probably has
period of revolution of about 800 years.
Such a comet would or course retreat to a
vast distance from the sun, and near its
aphelion would move with velocity as re.
markably small as It's velocity when near
the sun was remarkably great. lG is likely
there are dozens of comets floating along
away outside OF Neptune at a regular snaiPs
pace oil not more than a mile minute. But
their turn Will come in time to be again the
express trains OF the solar system.
The Tail of the Comet Is Mysterious.
In regard to the tails of comets it would
take several columns to tell what is not
known about them. They are merely the
prolongation of the nebulous envelope sur
rounding the nucleus, and but very little is
known of their character. 1t is the tail,
though, that makes a comet cons piouous.
A comet without a tail. as many are, is of
little interest to the amateur observer. The
tails sometimes reach enormous size. One
attained length OF 120 000, 900 miles, or was
considerably longer than from here to the
sun. There are six comets recorded whose
tails extended 800, or from horizon to
zenith. Most readers of The DISPATCH will
remember the magnificent comet of 1882,
whose tail was 200 or 800 long.
The periods of comets naturally vary
greatly. Encke's revolveS around the sun
in about three years, while another has a
period estimated at about 5000 years. One
OF the greatest and most remarkA BILE comets
is Holley's. In the years 24S, 3}4, $780, 1905
l456, 1881, 1907 and 1882 remarkable comets
are recorded to have appeared, but Holley
was the first to suspect them to be one and
the same body with a period of 70 years.
He calculated its orbit and predicted its re-
turn in l75s. In that year, long after Rol-
ley's death the comet punctually appeared,
and also showed up on time in 1885. 1t is
consequently due again i'll ls years, and it is
about as sure as death and taxes that the
year 1910 will again witness the return OF
this magnificent sight. May we be there to
seel
What Can Be Seen In the Skies.
THE planets visible in December are
Jupiter Mars, Saturn and Venus At 9
o'clock this evening Jupiter is high up in
the south, far the most conspicuous object
in the sky, though not quite so bright as six
weeks ago, when he was in opposition.
Mars day is past, and he now shines
scarcely brighter than an ordinary first
magnitude star. At the hour mentioned the
ruddy planet may be seen rather low down
in the southwest Saturn does not rise till
long after midnight, and is not especially
noticeable. As LOT the unrivaled Venus she
is now the queen of the morning skies, and
those whose duties call them out before
dawn is over, may see this brilliant planet
glittering above the eastern horizon as
brightly as Jupiter did dozen hours
before. The moon is full on the Sd and the
new moon becomes visible on the goth.
The constellation for this month are the
finest of the year. At IL O'Clock December
!, 10 o'clock December Is and 9 o'clock De-
cember So the most brilliant constellation
in the heavens may be seen high up in the
southeast. This is the mighty Orion, the
only constellation that can boast two first
magnitude stars. These are Betelguese and
Rigel, the former marking the right shoul-
der OF the figure of the mighty hunter, and
magnitude stars midway between form the
belt. Almost in line with these three stars
and to the southeast is the brightest star in
the heavens, the famous Sirius, or DoI-star.
1t is in CAMS Major, or the Greater Dog.
Procyon, a first magnitude star in CAMS
Minor, is half way up from the
L., oil, n-fA hn