, 1876-10-20
An Astronomical Event.
| SATURN, WITH NEIGHBoRLY TURN, RUN
MING DOWN TOWARD OUR PLANET.

MING down TOWARD OUR PLANET.
On the sixth of August there was an
oecultation of the planet Saturn by the
moon, and unusual interest was excited
among astronomers, by reason of the
beautiful scene which the telescope re-
vealed on that occasion. On the third
of September there was another occulta-
ton by the moon in the morning. On
the twenty-seventh of August Saturn
was in opposition to the sun; that is,
the sun, the earth and the planet were
in the same line, the earth occupying
the middle place. 1t is somewhat re-
markable that all the occultations were
on Sunday.
The use which the opposition of the
twenty seventh will be made to serve. Is
to test certain Conclusions deducted by
the French astronomer, Trouvelot, in a
memoir on the physical aspects Of the
planet Saturn. This memoir was pub
llshed, with illustrations. in Sillimaa's
Journal. One of these conclusions was
that the inner margin of Saturn's outer
ring has for several years shown Jagged
forms near the handles, which would in
dictate irregularity of structure; another
Is that the thickness of the whole ring
system is increasing, and that the inner
ring is not entirely transparent, al
though more nearly so than the planet.
This system of rings renders Saturn an
unique member of the planetary family;
and, as modern Investigations tend
somewhat to show that we have in it an
evidence Of the truth OF Leplace's hy-
pothesis Of the original formation of our
system, the importance attached to a
careful observation of the latest opposi-
ton by astronomers may be readily ap-
preciated.
Saturn is now only about 1872 900 900
miles from the earth, instead of 829,-
500 900 miles, its greatest distance. It
is this difference of 183, 600, 900 miles
which makes the period of an opposi-
ton so important to theastar-gazers.
Saturn is the oldest of the worlds
that compose the known system of the
universe. He is sixth in the order of
distance from the sun. When viewed
through a strong telescope, his disc APP
pears striped with dark belts, which,
from their parallelism to the equator of
the planet, are believed by some scien-
fists to have been determined by cur
rents similar to our,trade winds. He is
attended by eight satellites, who have
been, since the beginning of time, pune
tual and regular in their attendance.
He is changable in character, and never
presents the same appearance twice in
succession. For this apparent eccen-
tr1city, the astronomers give the reason
that, since the' earth's mean distance
from the sun is 81 ,OO0, 900 miles, Sat
urn, when in opposition to it, is distant
732, 600, 900 miles when nearest the sun,
and $50, ,000, 900 miles when furthest
from it. AS the plane of his rings is
inclined to the ecliptic, and maintains
its parallelisms during the revolution Of
the planet, the angle at which it is pre-
sented to the sun is continually chang
ing; the appearance which it represents
to the earth are, therefore, also continu-
ally changing,
The ring is visible only when the
sun and the earth are on the same
side Of it, but it becomes invisible when
its plane passes through the center of
the earth, as well as when it passes
through the center of the sun. On this
account, says Sir John Herchel, two or
three disappearaDces Of the ring may
happen in q very short space of time.
The disappearances take place about
every fifteen years, or half the time of
Saturn's revolution in his orbit, and the
two sides of the ring have alternately
fifteen years of sunshine and fifteen years
of darkness.
Saturn rises in opposition when the
sun sets, and may be readily found early
in the evening coming up in the south
east. It will be the prominent evening
star for some time to come, and after ten
O'Clock, when Jupiter sets. the only visi-
BILE planet during the night. The star
gazer cannot mistake Saturn. He has
no bright neighbors, and If he had, the
lurid, dirty yellow that he sheds would
be sufficient to mark him.
A WESTERN JUsT1cE.-when illinois
was young, and her towns were few and