The morning news. [volume] (Savannah, Ga.) 1887-1900, 1891-12-04
JUPITER AND ITS MOONS.

Some Interesting Scientific Facts
About the Earth's Big Neighbor.
Prof. Otis Ashmore. teacher of astronomy
and other sciences at the high school, is
always ready to talk on astronomical sub
jects to appreciative listeners, and what be
says is always interesting.
els there anything in the astronomical
field that may prove of interest to the pub
lie during the present month"; MORNING
NEWS reporter inquired of Prof. Ashmore
yesterday.
Nothing of special nature such as an
eclipse, or transit he replied, shut to the
astronomer, or even to an ordinary OBJ
server, there are several features worthy of
note. The planet Jupiter has recently passed
its opposition, and, being at this time near
est to US, fine opportunity Is
now presented for observing this gigantic
world. 1t is now the brightest star In bhe
heavens, and passes the meridian about 6
o'clock p. m. A telescope or opera glass Of
moderate power will now reveal its four
moons revolving around 1t as our moon re-
wolves around our earth. The planet itself
is more than 1900 times as large as the
earth and rotates upon its axis In
about 1913 hours. Its year is twelve times
as long as ourC. The telescope reveals sew
eral dark bands OF changeabie cloud hke
form surrounding the planet near its equa-
I0eoe dT6 pTOUdOA1 COu0ou6eu NdpOro
in its atmosphere similar to the cloud
masses surrounding our earth near the
tropics and are caused by enormous trade
winds setting from the poles toward the
equator. There Is very strong evidence
that Jupiter, while much older than our
earth, is much younger in point OF cosmical
development. The light emitted by the
planet is more than it receives from the sun,
aud this circumstance, together with several
other facts, leads us to believe that Jupiter
is yet red-hot, and that many ages must
elapse before it will be fit for animal or
vegetable life."
fare its moons ever collapsed, and are
they ever of any practical importancep
Every frequently. Scarcely a day passes
without one or more ecllpses. Sometimes,
too, the satellites pass between us and the
planet, making transit across its disk and
dragging their dark shadows behind them.
These eclipses are used by sailors in de-
termining their longitude at sea, sud they
constitute one of the most practicable as
we'll as the most reliable means for this pur-
pose"
"What is their size and distance from
Jupiterp
Taking them in order from the planet the
first, or 10, is 1850 miles In diameter, and is
$4,000 miles from the planet; the second
(Europa) is 2, 300 miles in diameter and 412,-
coo miles from the planet; the third (Gany-
mede) is 3,T00 miles in diameter and 658 900
distant: and the fourth (Callisto) is 3 200
miles in diameter and is distant
1.l56O00 miles from the planet.
The FIRST makes revolution
In ebout forty-two hours, and the fourth in
about seventeen days. These little moons,
it will be remembered, was the first dis
covery made with the telescope, and Galileo,
their discoverer, and the inventor of the
telescope, came very near losing his life on
If In RI a
the people Of the world believed that the
earth stood still while the sun and moon and
stars revolved around it Calico taught
that the sun Is IN the center and the earth
and all the planets revolved around it, and
that Jupiter and its moons were living
witness of this fact. This view was held TO
be contrary to scripture and many refused
to look through the telescope for
fear they might be convinced.
Galileo was arraigned by the
church for heresy, and was forced to reoant
what he had said with reference TO the
earth's motion. But Galileos teachings
finally prevailed, despite the prejudice and
prosecutions of his enemies. and science by
the aid of the telescope has finally estab-
lished his views In the place of the cumber-
some Ptclemaic theory, which was taught
Tor l 400 ysars. We are now rapidly reced-
ing from Jupiter at the rate Of $4,000 miles
per hour.n
What other objects In the evening skies
ore of interest to the observersN
1.-THE planet Venus is just beginning to
appear as evening star in the west, and near
by and little below it the planet Mercury
may be seen at dusk about an hour behind
the sun. Mercury is 80 near the sun that
he is not often visible, and but few persons
ever recognize him when seen. For the
next few days only, can we see this shy
planet. Neptune he's just passed its opposi-
ton, and hence is In the most favorable
position for observation, but it requires a
good glass to reveal his position near the
large, red star, Alde6aran, now well up In
the east at O'clock"
What aspect do the consultations and
nxed stars present at this season.
The most magnificent of all the year
Orlon, with its marvellous array of suns
ana nebulR. through the telescope presents
grand appearance. The evening skies in
TACT are now ablaze with natures grandes5
works, and dull indeed must be the mind
mat does not feel the sublimest inspiration
In contemplating them."