Weekly journal-miner. [volume] (Prescott, Ariz.) 1908-1929, 1913-07-09
JUPITER IS CHIEF
ATTRACTION IN
THE HEAVENS
Saturn, Uranus, Neptune
New Moon, Earth In
'Aphelion. Milky Way.

The planet Jupiter is the central
attraction this month for observers
of the evening sky. 1t is the bril-
liant star seen in the southeast as
soon as it is dark enough. 1t rose
on the LIST at 7:30 p. m, and several
minutes earlier each succeeding even
ing. Tonight it is opposite the sun.
and rises before sunset after that
date. The quadriIateral of stars
below it forms the bowl of the
Milk Dipper' in Sagittarius. In the
course of the month the planet
moves toward the right or westward
with regard to these stars. Obserr-
ers who watch the movements of
the four bright satellites with a
telescope may see transits of a sat
elite and its dark shadow on the
evenings of the 3rd. 18th, 18th. 10th.
22nd, 18th. Satellite and its shadow
cross the disk on the 18th and 22nd,
satellite II and its shadow on the
18th and 10th. The shadow pre-
cedes the satellite | on the 3rd, in
all other cases the satellite is follow
ed by its shadow
The overpowering size of this
planet is one OF the astonishing facts
proved by astronomical study. The
sun has nearly ninety-nine and nine
tenths of all the material particles in
our group of heavenly bodies, and
all the planets are but pigmies in
comparison. But Jupiter has nearly
three-fourthS of all the particles
found in the planets, while our earth
has but about one-four hundred IF
tieth. Jupiter'S mass is 3l8 times
that of the earth. 1t is the king CT
planets, if size is the measure of
royalty, although a humble subject
OF the all-powerful solar king. 1t
shows its mass superiority by in
fuencing most powerfully the paths
OF the smaller bodies which pass
near it. The group of small planets
which are mainly situated between
Jupiter and Mars have their motion
modified by its attraction.
and comets which pass near him suf-
fer still greater disturgance One
of the most laborious parts OF the
of the orbits of planets !
and comets is that which takes ac-
count OF Jupiter's disturbing action. |
Halley's comet was observed in
1909 and 1910 several months earlier
than would have been the case had |
not Jupiter accelerated its motion. A !
comet first seen in 1889 had its per-
lod shortened from more than TWEEN
~ years to seven years because it |
went very near the planet A large
number of comets, nearly forty in
all, have been found to move in or
bits whose greatest distance from
the sunNis nearly that OF Jupiter's
distance. The fact that there are
many small bodies between Jupiter
and Mars, instead of one large body
as in other parts OF the solar system.
s probably Sae IN some way to his
great mass. The tabulation of the
orbits of these small planets shows
gaps in some regions and punches
places in others, which can be ex-
blamed as a result of Jupiter's at
raction, and there are at least four
small planets which move in such
way that the distance between sun
md Jupiter. sun and planet, and Ju-
'lter and planet are nearly equal 20
Zach other-a special case under the
aw of gravitation. Several of the
mall satellites of Jupiter are prob
lbly bodies which at some time have
been captured by him and COM
'elled to revoIve around him Jupi-
er's part in the gravitational theory
II planetary and .cometary motion is
therefore, very important in that
branch of astronomy.
Several other events in planetary
.nnals occur this month. Mercury
an be seen in the evening. about
hree-quarters of one hour after sun
let, in the first ten days. One
hould look above the sunset point
few degrees farther south. The
,lanet shines with about one-half its
greatest brightness and therefore
will not readily be found Venus,
N the 3rd, reached its greatest dis
ance west of the sun, and will grad
ally draw neearer the sun as the ,
mornings follow each other. 1t is ,
he brilliant star seen long before S
unrise in the northeast. On the
st 1t rose at IS a. M, and on the :
I Ct will risa 1T N a m