Washington standard. [volume] (Olympia, Wash. Territory) 1860-1921, 1881-02-11
Jupiter and His Spots.


giant planet Jupiter. The markings
upon his belts have for soma time
been attracting the universal atten-
ton Of astronomers and amateur OBJ
servers. Always enigmatical, this
planet has, since the appearance of
the great red spot in its southern
hemisphere, become still more pr
picking to the astronomer. 1t was
at first supposed that this prominent
object would form a ready means of
determining the true period of the
planets revolution, but that result
has not been realized. On the con-
tlary, if anything, it has rendered
that problem still more doubtful.
Soon after the great" spot was
discovered, two or three other small
sr, but still plainly discernab'e and
permanent spots were observed near
by the large one. Close and con-
tinued observations of these several
spots during the past Summer, ac-
cording to the published reports of
Prof. Barnard, OF Nashville, Ten
nessee, have revealed the most sir
gular fact yet developed, that these
spots are not Identical in their revo-
lutions, as would be the case if they
were absolutely fixed in the central
nucleus of the planet. On the 25th
of last July, the center of one of the
small spots preceded the center OF
the large spot by one hour and 35
minutes. On the 22d of November
the center of the small spot preceded
the center of the large one by three
hours and II minutes. The large
spot had thusapparently moved back
ward one hour and AZ minutes be-
tween July 25th and November 22d,
showing u daily difference of rota-
tion of 0.439 minutes per day. At
this rate the small spot would gain
an entire revolution in about 23
months. There is quite difference
in the motion of the spots to be
seen on the planets disk.
In letter to Science, dated No
vember 29th, Prof. Barnard writes
in regard to this planet as follows
" The region occupied by the equa-
torial belt is subject to constant and
qrits. rapid change, being filed at
tint s,'ith the most delicate soft,
plumy forms. Brilliant white spots
are not unfrequent in this zone. X
* All the objects in the equa-
torial zone move with very great
velocity in the direction of rotation,
but invariably in q contrary direc-
ton to that pursued by tho (great)
red spot, which is really the only
object on the planet which has a
backward motion. Indeed, it would
not be bad comparison to compare
the red spot to o mighty city built
on the shore of vast and swiftly
flowing river, which is constantly
being filled with drift, and an occa-
sional glistening mass of ice tearing
its way past the city with velocity
of not less than 5000 miles a day.
In such comparison the city would
be as great an area as three-fourths
of our entire earth, and the river
fully 10000 miles in breadth"
Jupiter passed its perihelion on the
25th of September last. That great
planet then reached its neare st
point to the sun, and was also, at
the same time, within few days of
its nearest point to the earth; so
that .he rubicon of it's perihelion
and its nearest approach to the
earth and sun has already passed.
At it's perihelion, Jupiter is 46, ,OO0,-
600 miles nearer the sun than at its
aphelion. The difference between
the two intervals of distance is about
half the entire average distance of
the earth from the sun. Yet Jupi-
ter, at its nearest approach, is 45O,-
100000 miles from the great CEN
trail luminary. Nearly II years
must elapse before Jupiter will be
as favorably situated for observation
as he is at this time.
With the exception of Saturn,
nothing in the heavens affords a
more interesting subject for study
than Jupiter and his moons. 1t is
delightful to watch those four little
diamond-points as they move in rap
id succession around the parent
body, passing now as dark spots
across his disk, then behind and
eclipsed by it. A glimpse of its
moons may be had even through a
good opera glass, and in an excep-
tionally clear atmosphere, at con-
siderable elevation above the sea,
they have been seen by the unassist-
cd eye. The large spot may be seen
with fve-inch telescope. When
this spot is just beginning to appear
at the eastern portion Of Jupiter's
disk, so rapid is the rotation of that
planet that in little over two hours
it will have reached the center, and
in less than FIVE it will again be out
of sight, having passed around its