The morning call., 1893-11-25
CAPTURED COMETS
Lecture on the Planet
Jupiter.
Professor Barnard Says We See Not
Jupiter, but Vaporous Atmos-
phere-Five Satellites.

"The Planet Jupiter and the Phenomena
of his Satellites was the subject of Pro-
fessor f. E. Barnard's second lecture on
astronomy at the First Unitarian Church
last evening"
The lecture was illustrated with stere-
opticon views and charts. which made all
the phenomena described extremely clear
to the audience.
The reasons for concluding that Jupiter
Is OF much less density than the earth
were fist explained and then the lecturer
went on to describe the surface OF the
planet and the reasons why so little Is
actually known about the materials OF
which its surface consists.
"The spectroscope gives US little intor-
nation about Jupiter. When we examine
the spectrum Of Jupiter like that OF the
moon it is only reflected sunlight. Ger
tain elements, however, lead US to beileve
that the planet is surrounded by dense
atmosphere.
1--WE can observe great difference be-
tween Jupiter and Mars. The latter mas
well-marked features. which in all proba-
bilities are seas and continents. Jupiter's
markings are not like those of Mars.
Dark bands like belts surround the planet.
No markings were discovered till 163O,
when two prominent ones were located on
each side of the equator. Other belts
were afterWard seen crossing the poles.
These belts consist apparently of clouds"
The lecturer went on to describe other
markings of Jupiter's surface. especially
the bright spots prominent in the planets
southern hemisphere anu the black spots
in his northern hemisphere. the locations
and forms of which are changing all the
time. "All these markings have different
motions. A year is long time for spot
to remain visible.
"The phenomenon of bright red spot
was first noticed on Jupiter's surface In
1874. 1t was calculated to be about $4,000
miles long and about 1000 miles wide. In
1880 it was still visible, but in 1882 it had
begun to fade and be Obscured with
white mist. Ten years later it became
clearer. and is still visible. although little
difficult to see.
"There are various theories to account
for these phenomena. 1t is supposed that
Jupiter is in an intensely heated condition
midway between the temperature Of the
earth and that of the sun. All the water
on the planet is converted into steam. and
we look not upon Jupiter, but upon
steam vapor."
The professor further stated that his
own observations led hun to the conclusion
that it was not the actual surface of the
planet itself that could be seen through
the telescope.
The rest Of the lecture was devoted to
an interesting account OF Jupter's five
satellites. The existence of four OF these
bodies has long been known-jDdeed the
velocity of light was first determined by
the eclipses of Jupiter's satellites. The
fifth moon, which was recently discovered,
is only 100 miles in circumference. II is
so small as scarcely to be visible and re-
wolves around the planet with immense
velocity.
The last subject touched upon was the
comets captured by Jupiter's attraction
out Of their original orbits and brought
within the solar system.
At the conclusion of the lecture Rev. DR..
Ste bbins rendered a warm vote of thanks
to Professor Barnard.