The San Francisco call., 1904-10-04

- URING these weeks the Jovian
planet, now so conspicuous in the
/ east, fully justifies its prehistoric
II name. Temporarily at least, it is
the monarch of the starry sky. Not
since the autumn of 1892 has it sh0ne
so brilliantly as at present, surprising
even Venus going down in the west as
the great planet rises. On october 10,
when our earth. speeding onward In
it's orbit, comes between the sun and
Jupiter, the latter will not be many
degrees past the point Of its elliptical
path nearest to the luminous central
orb. The combined results Of opposi-
ton and of Jovian perihelion bring us
within about 37O,O00,0OO miles of Jupi-
ter, which is 46,O00, 900 miles nearer
than in March, 1898, when opposition
occurred, not far from the point of
Jovian aphelion.
These OppOrtune seasons recur at in
tervals of about twelve years, in which
time Jupiter completes a revolution
around the sun. On the last occasion,
September, 1892. Professor Barnard dis
covered a fifth satellite with the 36-
inch Lick refractor Only a hundred
miles in diameter, it goes around the
planet twice a day, and was undis-
covered heretofore, though since recOg-
nized in a few large telescopes This
great discovery may not be rfvaled dur
ing the present season, but neverthe-
less, the mediums sized and the small
telescope. the opera-glass' and even the
naked eye can be used with effect at
the time of nearest approach For
large instruments the chief investiga-
tion will be as to the condition Of the
Jovian surface. Unlike the moon, Mars
and our globe, the surface of Jupiter
is a scene of such frequent change that
it is considered to be in a sun-like con-
dition, though cooled and no longer
seIf-luminous. The great size Of the
planet, which is $1,000 miles in diameter,
would necessarily prolong the process
of cooling beyond that of smaller bod
les, while expansion. caused by fierce
internal glows, would maintain the i'm
mense volume in contrast to its light
mass, which is only 316 times that of
the earth.
Though sharply outlined, the colos-
sal sphere is now regarded as a mass
of heated vapor, nearer to the consis-
tency of water than to that of air, of
various densities, not only in the up
per strata, but at depths visible
through it's nearly liquefied substance.
1t may have no solidity even at it's
center.
Such body cannot be readily lik-
ened to the crusted earth, with it's shall
low, transparent atmosphere imme-
thodically cloud-strewn. The coldness
of space and sunlight affect the differ
ing densities of the Jovian surface
more symmetrically and its tinted belts
extend parallel to it's equator, though
rarely intruding on that brighter zone.
Thus, to telescopic vision, Jupiter is a
pale golden orb, oval in form and pro-
fusely garlanded with crimson hues.
The rapid rotation Of the still plastic
mass has compressed the polar diam
eter to the extent of 5000 miles. It's
tinted aspect may be due to alternate
zones of different density, the belts be-
ing translucent spaces Of great depth,
suffused with sunlight and rejecting
only the red rays. Frequent changing
in number and in form, their gnarled
edges and their tendency to spotted
ness indicate that turbulent motion