The Helena independent. [volume] (Helena, Mont.) 1875-1943, 1892-07-02

Which IL ~ Near ~ II VIII Ever Oct
The Moons Of other Planess-
Eclipsss.
Tho moons Of Mars were discovered 4 raw
years 4 through the telescope Of tho Ma
val observatory at Warrington BY Prof.
Asaph Hall. He will DO actively interested
in the observations Of that planet and its
new-found satellites which will be made in
August next. BY astronomers all over the
world. since the discovery Of the moor
In 1881, this il The first opportunity afforded
for examining them, inasmuch az they are
90 mail ~ TO be only %psrceptible at close
range. Once In svery fifteen years Mars
reaches its nearest point TO the earth.
Eight weeks hsnoe IL will be within 8b,0OO,-
GOO miles of az, whereas, ita greatest dis
tance IL 14l, 600. 900 miles. writes Rene Baehe
in the st Lolis Globe Democrat Great
interest attashss 70 the matter because this
sister world IL 10 much like our own in re-
spect to its climatic and other conditions
that il may reasonably be supposed to be
inhabited. perhaps BY human bsings.
When tho lover swears BY earth's ''incon-
slant" satellite it never occurs to him to
consider that there 1t least twenty moons
in the solar systsm. Saturn alone has
eight, the biggest Of them, Titan" being
nearly twice the size Of onr moon, and
Jupiter possesses four. ranging in dimsn-
sions upward from "Europs." just about
as large as the orb of terrestrial night, to
"Ganymeds," greatest of all known moons.
The latter has ! diameter OF $3.50 miles.
whereas the moon belonging 10 this world
10 only 2. 100 miles through.
Though our moon 10 supposed to be dead
n cold. similar conditions are not as
sumsd to govern all the satellites Of the
sister planets. .Some of those pertaining
to Jupiter+ar believed to emit light Of their
own. showing that they are still hot. How
ever. astroncmers are usually eager TO hnd
evidence Of life On other spheres. even dis
covering on tho earth's attendant orb ap-
parent traces of mighty works Of engineer
ing artiics-the imagined creations OF
races OF beings long sxtlnot-suCh a. the
s%tupendous bridge that appears to span a
crater OF tho moon volcano callsd "Eu-
doxus." sNs64
Eclipsea are everyday affairs on Jupiter.
Three Of ito satellites are collapsed at every
revolution OF that mighty globe, 30 that .
Jovian year 1900 eclipsss of moons and
about the same number of eclipses OF the
sun by moons. Under such conditions one
would become accustomed to a phsnom-
enon which ocoasionally appalls the, tsrras-
trial observer. Ihs Hindoos, whom they
over the sun, believe that the latter il being
swallowed by . dragon. Then they beat
gonRs and scream until the frightened
monster diagorges his fiery mouthful.
One Of Ssturn's moons, called Mimss.
about half the size of the sarth's. satellite.
10 80 close to the planet in it's oiroline that
it seems to Cross the face Of tho latter at an
astonishing rate Of speed. OF the seven
others, Titan, has ! diameter Of $500 miles,
Iapetus 1900. Rhea 1900. Dione and
Tethys each 500. while Enoeladus and
Hyperion are very little fellows. Several
of them in the sky together, with the fam
ing ring of star-dust stretched athwart tho
heavens. must make a gorgeous spectacle on
the Saturnian sphere. Through tho tels-
scope it is very interesting to watch the
shadows thrown upon Jupiter By that giant
planets moons. observation Of the ~eciipsss
of which furnished the first data for esti-
mating the velocity of light.
"Uranus has four little moons-"Ariel."
"umbrisl." 'Titania' and "Oberen"-
which. funnily enough. rise in the north
and act in the south. A single dimiuutive
one belonging TO Neptune traveraes the sky
from southwest to northeast. Neither
Mercury nor Venus has any satellite. But
the most interesting Of all moons are the
two that attend Mars, each sixty miles in
diameter. That planet is just one-half the
size OF the earth; its surface is divided into
continents and seas, having a. much land
as water; it las an atmosphere, clouds fire.
quently concsaling its face, and ito seasons
are about the same % here, though the vim
tors are colder. Because ono of is moons
travels around it three times az fast AZ
Mars himself turns. II appears to rise in the
west and set in the east. while the other.
really circling in the Same direction at .
speed comparatively slow, rises in the east
and sets in the west. Thus both moons are
seen in the heavens ct the samo time, going
opposite ways.
The most remarkable guess on record was
made by Dean Swift, who, = century before
the moons of Mars were discovered, made
Gulliver say OF the Astronomers Of Laputa:
''Ihey have found two satellites which re-
volve about Mars. whereof the intermost 10
distant from the planet exactly three diam
eters OF the planet; the former r~svolves in
the space of ten hours and the latter in
twenty.one and a half hours" In fact, the
inner moon il 10000 miles from Mars. )
whereas, the diameter of the plsnst being
1900 miles, Gulliver's estimate would place
IL at 10000 miles. For the outer moon he
kAVob SOsOOO AlO y tA0 ,ulhe8uO0s WHICH IL
really 10. ZOO miles. The time for rsvolu.
tion for the inner moon is actually seven
teen aud = half hours and for the outer one
thirty hours. Prof. Hall has nance. these
moons 'Deilnos IS" and ''Phobos,'' after the
attendants Of the god Mars, who are mon /
TONED in Homoi's ''Iliad."
Hundreds Of minor planets belonging to |
the solat system. which are only big enough
for moons, though not such. have been dis. /
covered during the present century. They
are called ASTEROIDS" and the three largest /
of them are 'Vesta,' - "Csres'' and '.Pallas."
Many of them are only of bout the bigness
of q good-sizsd farm. Life upon ono of
them, owing to the feebleness OF gravity,
would seemingly be attended with difficult
ties. One inRenius romancsr has described
an imaginary journey through space. in the
course Of which he lanped upon a small az.
teroid, finding it occupied by q single giant.
The latter. being displeased with some re-
marks made by his visitor, kicked him off
into space 10 far that he fell within the at.
traction of another sphere.
To solar planets yet undiscovered moons
may belonR-for example, to the mysterious
big dark sphere" beyond most distant
Neptune. which some astronomers assert
the existence OF. A similar hypothetical
world, alleged to have its orbit inside that
OF Mercury, is ''Vulonn.' Science has mot
accepted the latter. though two observers,
Swift and Watson, working Independently in
Colorado q few years ago. simultaneously
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