Evening star. [volume] (Washington, D.C.) 1854-1972, 1892-07-23
OTHER MOONS THAN OURS.
Dean swin's Remarkable Cues. About th<
Satellites OF MarS.


From the Prcvidsnce journal
The moons OF Mars were discovered a few
wears ago through the telescope Of the naval
observatory at Washington BY Prof. AsAph.
He viii be actively interested in the osscrva-
lions OF that planet and its found satellites
which viii be made in August next by sstropo-
mers all over the world. Since the discovery
Of the moons in 1857 this is the hrut opportu-
nifty afforded for examining them. inAsmuch A
they are 80 small rs 20 be perceptible only at
close range Once in every fifteen years Mars
reaches lie nearest point TO the earth. Eight
weeks hence it will be within IS 900 900 mile. Of
US, whereas its greatest distance Is isi. 900 600
miles. Great interest attaches 10 the matter.
because this sister world IL 30 much like our
own IN respect 60 its climate and other con-
dlnoa' that It may reasonably be supposed 20
be Inhabited.
There are AZ least twenty moons in the .o,.r
system. Saturn alone has eight and Jupiter
possesses four. ranging from Europa lust
about as large a. the orb ~ terrestrial night 20
GanSricdc. gros.est OF al known moons, with a
disrnc r OF S.4s0 miles. whereas lho moon be-
longing to this world IL only 2.f0O miles
through.
Though our moon is supposed 10 be dead and
cold. similar conditions are not assumed 20
govern all the satellites Of the sister planets.
Some OF those pertaining 10 Jupiter are believed
I w ShA.N htAt ol tnClf oN n. showing that thew
are stall hot. However. astronomer are usually
eager - fnd evidence % lie on other srheros
even discovering On the earth's attendant orb
apparent traces Of mighty works Of engineering
run ,e-the imagined creations 81 races of be-
ines long eNtinct-such ~ the stupendous
ofiuee uiat appears 10 span crater Of the moon
volcano called Ludoxus.
Ecigses are everyday Affairs on jupiter.
Three of its satellites are eclipsef AZ every
revolution OF that mighty globe. 90 that q
spectator there might witness during the
Josisn wear 400 eclipses Of moons and about
the same u'imberof eclipses Of the sun by
moons. One of Saturn : moons called Nimas
abou; half the sine of the earths satellite /. 80
close TO the planet IN its circling that il seems 10
cross The face Of the latter at an astonishing
rate OF speed. or the seven others Titan has q
diameter Of $3.50 miles, lapetus, l. 500 miles.
Rhea, l.200 miles; Dione and Thetys each 500
miles. while Enceladus and Hyperion are very
little fellows. Several OF them IN the sky to-
gether, with the flaming ring % star dust
stretched athwart the heavens, must make a
gorgeous spectacle by night on the Saturnian
sphere. Through the telescope il l. very inter
esting 20 watch the shadows thrown upon
Jupiter by that giant planets moons observa-
ton OF the eclipses Of which furnished the first
data Tor estimating the velocity of light
lranus has four little moons-Ariel, Umbriel,
1itnnis and 0beron-which. funnily enough.
rise in the north and set in the south A siuS1s
dminutlve one, belongingso Neptune trsserses
the say from sou Midwest 20 northeast Neither
MercurN nor Venus has any satellites.
But the most interesting of all moons are the
two that attend Mars each about sixty miles in
Diane r. That planet is Just one-haif the size
OF the earth; It's surface is divided into conti-
nents and sens. having much land rs water
IL has an atmosphere, clouds frequently con-
cealIng its face, and its seasons are about the
same as here, though the winters are colder.
Because one of its moons travels around 10
three times as fast as Mars itself turns il sp-
pears to rise in the west and set In the east
while the other really circling in the same d.
rectlon a, speed comparatively slow rises in
the east and sets in tho west. Thus both moons
are seen in the heavens at the same time going
in opposite WAYS.
One OF the most remarkable guesses on record
was made by Dean Swift, who a century before
the moons OF Mars were discovered made Gull
liver say Of the astronomers Of Laputa: They
have found two satellites which revolye about
Msrs, whereof the innermost il distant from
the planet eNacdy three diameters Of the
planet; the former revolves in the space Of ten
hours and the latter in twenty-one and one-half
hours In fact, the inner moon lie 10 900 miles
from Mars. whereas-the diameter Of the planet
being 1000 miIes-Gulliver's estimate would
place il at 1900 miles. For the outer moon he
gives 10000 miles for the distance, which 10
really $1,000 miles. The time Of revolution for
the inner moon is actually seven and one-half
hours and for the outer one thirty hours Prof.
Hall has named these moons Deimos and Phobes
after the attendants of the god Mars. who are
mentioned In Homers "Iliad-'