The Milan exchange. (Milan, Gibson County, Tenn.) 1874-1978, 1882-03-11
News From Jupiter.

across an eNpanse of space four hundred
million miles in breadth The Atlantic
cable with its tiny span of three thou
SAND miles Is nothing TO this. More
over, 1t IS news, not from another con-
tinent, but from another world. SO i'm
mensely'ifls therange of human thought
expanded'that men find it worth while
to spend their lives in trying to pene-
trate the mysteries of stars and planets,
sure that Whatever tales of genuine dis
covery among these distant suns and
worlds they may have to tell will find
generous and appreciative, listeners.
Men are beginning to clearly perceive,
not merely that the whole earth is akin
but that this world is only one member
OF aclosely connected system of worlds,
The other worlds of this system then
possess great Interest for us, and the
modern astronomer, with his telescope
and spectroscope, must be reckoned
among the news gatherers of the age
To understand the meaning of what
the telescope has recently been showing
in Jupiter, it will be necessary to recall
some facts previously known about that
giant planet. Jupiter is the largest body
in the solar system except the sun It.
SSiiS NhN CACCCuo IuO tdTbu III volume
about l, 800 times. The girth of the
earth at the equator is in round num-
bers $4,000 miles. Jupiter's equatorial
girdle measures 267 600 miles But Ju-
piter is light in proportion to his size
Ills specific gravity is a little less than
that OF water Therefore, if we can inn
agne an ocean big enough to try the
experiment, Jupiter dropped into it
would not sink. The belts of Jupiter
are well-kpown phenomena. They are
among the first objects upon which
the amateur astronomer who has hap
PLY become the possessor of telescope
tries its powers, and there is probably
nothing else in the whole heavens that
he views so frequently and with so much
satisfaction. Yet, although astronomers
have been watching these belts, and be-
holding the wonderful changes that
take place in their appearance, for more
than 200 years, they have not succeed
ed in satisfactorily explaining them
Within few months, however, great
deal of light has been thrown upon this
subject.
About four years ago the astronomical
world was interested in the appearance
upon Jupiter's southern hemisphere of
a huge red spot, some twenty-five or
thirty thousand miles long and seven or
eight Thousand broad. Half dozen
different theories were advanced to ac-
count for this appearance. Some said it
was an opening in the cloud-choked at I
mosphere of Jupiter, showing the red
hot ball of the planet beneath; others,
observing its permanence of form, sup
posed it to be portion of the solid body
of the planet heaved up and thrust
through the vaporous enyelope--a pre- /
cipitous and fiery continent. Still others I
imagined it to be an enormous Stag I
floating on the molten surface of the
planet. Most astronomers, however,
preferred to wait for more facts before /
forming theories, This spot has re-
manned visible ever since, and anybody |
can see it with good telescope of two /
inches aperture. 1t was soon perceived !
that the spot moved Slightly faster than
the rest of the luminous disk Suppos- T
ing it 10 be a part of the more solid !
body OF the planet, observations were
made upon it 10 determine the time of .
.Jupiter's rotation. The result obtained |
was about nine hours fifty-iye minutes
and thIrty-five seconds, showing that
thisgreat globe is whirling around its axis "
twenty-five times as fast as the earth. ,
Recently another phenomenon, not so
conspicuous but even more wonderful
than the red spot, has been perceived
on Jupiter. This is q brilliant white
spot which sometimes appears upward
of five thousand miles in diameter, and .
at other times is almost invisible IL
moves faster than the red spot, going
arpt1n1 n, oil, nina
minutes, so that in forty-four or forty +
five days it makes complete circuit .
of the planet with respect to the red .
spot There is reason to think that the .
white spot has been visible at times ever
since the summer of 1878, although it 4
has only recently attracted special at /,
tention. Mr.. Dennin9, of England, /
who has devoted much study to the sub |
ject, thinks that this spot shines with its |
own light, that it is part of, or pro- |
lection from, the actual surface of the
planet. That being the case, of course
it is to be depended upon for determin-
ing the rotation of the planet rather
than the red spot, the speed of which
has begun to slacken. Once in about
fiXty-siX days the luminous spot fades
until it is barely perceptible, and when
IL DllghtenS again lts speeu IL sllShtly
increased. Now comes a very interest
ing observation. On New Year night
Mr.. Denning observed that the spot was
almost invisible, and it remained in that
condition for several. days. A big
cloud had hidden it. This cloud had
been observed from the time of
its formation in Jupiter's atmosphere
ON December II. 1t was then some
distance behind the white spot, but as it
moved with even greater velocity than