The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1892-08-02
THE TINY MOONS OF MARS
Wonderful Discoveries with the Giant
Telescope at Lick Observatory.
The Interest lag Planet Brought So Near that
theEcliIs of Its Little Satellite. Or Eight
Mills in DIAMETER. Can Be Measured.

LICK OBSERVATORY. CAL. Aug. 1.-The
| giant telescope presented to the Univer-
sity OF California By James Lick 10 making
| record for itself during the present oppo-
sition of Mars. For several days observa-
| tions OF most valuable character have
been obtained by the Mount Hamilton
| astronomers. The near approach of the
| planet and Its consequent brilliancy and
| size at this time have enabled observers to
utilize the full powers of the Instrument
with most interesting results. Drawings
| by all the astronomers EXHIBIT numerous
changes In its principal characteristics
since the celebrated sketches made by the
Milanese astronomer. Schiaparelli. Many
| of his almost fancIful details are shown to
have no existence in reality. None of the
so-called canals" can be verified. All
these curious streaks. whatever they may
be, are broad strips and not narrow lines,
| just as they were seen through tho Lick
telescope two years ago. This will be
bitter disappointment to many visionary
theorists. who have found in the existence
| OF these canals, and particularly in tho an-
nouncement that oil were seen to be
| doubled, most indisputable evidence that
Mars vas inhabited by human beings.
The most startling of all the Mount
Hamilton observations thus far are those
made on the two tiny moons OF tho planet
which were first discovered by Asaph Hall
| In Washington during the opposition of
| 1877, and which have since beeD seen at
brief intervals and only in the very largest
| telescopes. Not only have these little at
| PENDANTS (by long odds the faintest planet
airy bodies to be seen any where In the sky)
been in plain view for the best part of the
month, but OF late astronomers have regu-
| Iarly observed their eclipses IN the shadow
| of Mars. The news of this work will be
received with the greatest astOnishmeDt at
scopes large and powerful enough to show
| the moons. for at most of them IL has only
been possible to glim pse the tiny bodies by
the most persistent efforts and astronomers
are loath to believe that the Lick telescope
enables these minute specks of light to be
| steadily followed right up to the limb of
the planet.
INSTANTANEOUS ECLIPSE.
The director of the observatory states
that the satellites are seen to disappear in
the eclipse upon reaching the line of the
shadow with almost the same instanta ne-
Gus effect which is seen when the dark limb
| of the moon passes over a bright star in the
sky. Within space of only two-tenths of
a second tn Q whole body of the moon is
| seen to be immersed in shadow cast out
| into space by tho globe of Mars. 1t is al
| most i'm possible to convey q proper idea of
| the insignifioant size of these little satei-
lites or the extraordinarily small scale upon
which their orbits are drawn. The inner
| satellites are probably only about eight
miles in diameter, and the outer one about
| twenty. The first is less than four thou
| sand miles from the surface of the planet,
and the other about three times that dis
tance
They revolve so rapidly about the planet
| that the inner one appears to move through
the sky from west to east, and consequent
| ~ rises in the west. ltcOmpletes one revo-
| luton in less than eight hours. so that it
| seems to be new" three times day. In
| one evening this little attendant passes
| through all four quarters of she moon. The
light which they give the planet at night
| the giant refractor they appear to be two
| points of light with no sensible disc. 1t
! has only been possible heretofore to esti-
| mate the size of these bodies by comparing
| the amount OF light reflected by them with
| that reflected from the planet Mars itself
whose size is known. but now by means of
| their eclipses we have q direct measure of
| their size. since it Is found that each of the
satellites moves Its own diameter in about
! two.tenths of q second, and we can easily
tell from our know ledge of their orbits inst
| what space in miles each of them moves
through In that time. 1t Is quite certain
! that the Lick Observatory studies of the
| planet Mars during the opposition of 1892
| will pass into history.
ONLY 25.O00,O00 MILES AWAY.
| Until 1890 last evening the sky was en-
| tirely overcast, but the observations of the
| planet Mars were resumed as it cleared up.
| During the moments of cloudy weather
Professors Campbell, Schaberle and Bar
nard furnished the following additional
particulars regarding the pending Opp0si-
| ton:
At 10 O'Clock on the evening of Wednes-
| day. Aug. 8, Marswill he in opposition with
| the sun. His distance from the earth APP
proximates rs. 600, 600 miles. and will be then
nearer than at any time since 1877, when
| Hall discovered the two satellites and
closer to US tnan 1t will be again until 1909.
| During the past month Mount Hamilton
| astronomers have been observing Mars dur
| ing two hours OF each night when the
planet Is on the meridian. and they Will
| continue these observations tor at least
| one month more. The highest magnIfying
| power that it ia practicable to employ Is
| seven hundred diameters, equivalent to q
distance of the planet of only fifty thou
sand miles. The planet. at best, is now
| very low in the skv and with low altitude.
| The planets unsteadiness is due to the at
| mosphere causing all markings at times to
disappear.
The two satellites of Mars, the smallest
| two objects known to the whole solar sys-
| tenn, are just visible TO observers with
| twelve-inch telescope. They are cOnsplcu.
and have been seen by all visitors to Lick
| Observatory. The eclipse of the inner
| satellite In the planets shadow is easily
| observable. Since the outer satellite does
| not suffer An eclipse At the present time, it
ia necessary 10 obtain the positions OF that
| satellite by mirrOTetrical measurements,
which are made regularly, in order to prop
| erly determine the orbit. The south polar
| cap of Mars was unusually brilliant and
| large month ago. but 10 rapidly diminish
| ing In size and brightness.
| This variability of the polar caps has led
astronomers to believe that they Are COM
| posed of snow and Ice. The south polar
cap diminishes accordingly as summer in
| that hemisphere comes ON and increases
| time there are numerous dark markings
| within the polar cap as If there were large
| areas from which the snow had disap-
peared. These markings had not been seen
| before at any observatory. The region on
the surface know as the Lucns Soils is now
| seen nearly as it appeared through the
| thirty inch telescope urIng the opposl-
| ton of 1890. and very different from its ap-
pearance as shown in the drawings of
ScnIapsrellI. The Fons Auventi Fountain
of YOUTH. the large dark region heretofore
seen single now appears double through
the large refrnctOr.
But the most remarkable of all the OBJ
served phenomena are three or more prom
inent bright projections on the eOuth west
limb of Mars. visible for several nights for
short time each evening. about three
weeks ago.
They will be visible on the sOathern
4 4. - h. -knvx o