New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1892-08-08
THE OBSERVATION OF MARS.
WORK AT THE NATIONAL OBSERVATORY
AN INTERESTING TALK WITH PROFESSOR HALL
WHO DISCOVERED THE PLANETS
SATELLITES.
10y TELEGRAPH TO THE TkIBUsE.l


Washington, Aug. 7.-WhiIe in his present opposi.
ton to the sun. Mars is being more cioseS "a'n7 W
the astronomers the Naval Observatory IN thl' cy
than mt any previous time In his history. Whether
any new or important discoveries will be MADE IL Is VI
course impossible say mt this time, the aihrma've
hope being about balanced by the negative oouo"
still no opportunity to observe whatever may appear
on Mars has been will he lost by the as'roho'ne'
OF the Naval Observatory, where nightly VisiiS ais
being maintained with the greatest zeal ana attehu'9
ness The observations, usual, are uhder 'he oreo
ton OF Professor Asaph Hail. the dscoverer oi tho
two moons OF Mars and this fact lends aduiuohai In
terest and Importance TO the work now pehs oohe ~
the way Of verifcation and further discovery 49,
There are two principal telescopes In use az tns
Naval Observatory. one Of them Is the sre'. $500
sixnch equatorial with which Professor han, N
1877 discovered the two Marian sateih'cs' D
and phobos This instrument has been USED uuiins =,
long series OF examinations of double stars, alu "
now being used steadily though not at lts ec"'o''
power in the observations on Mars. IL Is Wen A
that smaller instruments give better "'"i'' " 90.
ordinary examination OF planets, for the reasoh IN"
the high power telescopes magnify atmospheric VIC
turbances surrounding the earth at the same f"s
that they magnify the object observed, so inc az,
reme power of the great equatorial. 1,sOo tines WIZ
-, b.. resort.d 10 500 times probably being tho
greatest mognfying power used at the present umo'
The other glass at the Naval Observatory Is thc 'n
inch equatorial which is in charge of FrolesSor Hue
r,shv ono of Professor Halls able assistants This
nineinch instrument IS used chiefly in the ooserVa'
of comets and asteroids OCCUPATIONS Of stars py ''
MOON and miscellaneous observations ot s'ars "no0'
nositions appear to need Identification or rathcau'h'
mi, c,oss g. also be,ng turned nightly on Mars
ubs fact that the present position OF Mars is tno
most favorable for purposes Of observation since 1917
when the two satellites, Deimos and PhoDos' were W
covered is keenly appreciated by the as'rohone' "
work on Georgetown Heights, and the speciai %
.fn,notons OF the planet during ITS perlod OF opp
tion begun June 90. will continue until september 90
General observations also being MADE high''s' an"
h interest and enthusiasm OF the Observers concern
ing the valuable data possible to De oDtahen nav
much increased since the work began. ~ - "'ue'
stood by astronomers, however that "iate'er 10 Nv"
done will be in the nature Of preliminary "orh if
frture real labor rs the nenrness OF Mars Is 'ou"
balanced in n sense by his being so far south ana
therefore so low down in the heavens ana subject !"
afmosnhenc disturbances and the results OF the oo
sorvatons now going on will he chiehy valuable 10
material for comparisons upon the next la'oaD
opposition OF Mars In 1894, when the planet Will o'
seen at a greater altitude and be more readily scdp
in spite of the greater distance. The Immediate OBJECT
OF the present observations Is therefore to get material
for ultimate use in determining the most important on
all ouos,Ions concerning the panet-that is how nearly
Mars resembles the earth in his physical condiilOhs'
and whether life, as it is known here can ana uoes
exist on his surface. .
The theory that Mars may have another moon III
the space outside Of the known satellites mas Deeh
closely kent in mind BY the astronomers at the Naval
Observatory and although signs Of this additional
satellite have been discovered great care Is mantaned
in the watch for its appearance. The fact thae s'AS
wears had passed after the discovery Of saurS seven
moons when two Observers simultaneously discoVerea
an eighth not inside the satellites before knp"h p"'
in An orbit between those Of other satellites is con
cover another moon in MarS's neighborllood
80 far Professor Hall has been unable to discover
any new facts OF value abopt Mars but u" mas fhy
succeeded in verifying the I.sLlts OF previous eAand
tons, According to his latest observations he again
finds the satellites which he gave to the world OF
ASTRONOMY so TO speak. revolving In their pecullar
oTay around Mars one OF them is about eight miles IN
diameter and revoves at a distance OF 1000 miles from
the planet and the other, about twenty miles IN
diameter, revoves at Il mean distance OF 12ooo miles
from the planet. These moons have been seen by
their dlscoverer since 1877 in 1879 ISL, 1so4 looo
1888 and 1890, well as during the present opposi
ton. The smaller satellite makes one revolution 10
little less than eight hours while the larger one doe
not complete IT. revolution in less than thirty hours
The satellite appears to reverse the motion @
the earth. Through the Naval Observatory telcscop
these moons 10 be mere points Of light in the
sky and from their planet they are about onefth tM
sire OF the earth's moon.
in reply to request today for Information about
the present series Of observations Mars Professor
Hall said Nightly since early day I'm July have
been closely observing The phenomena of Mars. hoping
not only 10 verify former discoveries but TO make
ones | have succeeded in the first mentioned effort.
but not I'm the II is not unlikely that Mars has
another moon, and | would naturally be greatly graft
fed TO It. With references TO DeimoS, the OUTER
and Phobos the inner satellite. have made particular
-rvations with the object If getting the distances
from the centre Of the planet and the times Of the
revolutions around 1t by the satellites. this being.
think the best way 10 determine the mass quantity
OF matter OF Mars These observations Of the satellites
will continue until about september 10. when the in
strumchts here will have TO be moved TO the new
Naval Observatory. which rapidly nearing complexion
In addition to close observation Of Deimos ana
PhoboS have carcfIl;' examined the surface of the
planet. watching the spots or markings, AS We call
them. There great variety OF these marx
ings. Of which. being OF rudy reddish color,
are supposed he land. willie other markings seen Of
a dark blue color are supposed to be water. BY OBJ
serving when the spots markings begin and close,
and by comparing their positions With those of former
years get the length Of the Martial days with
good deal Of accuracy. You may be interested TO
know that the length OF day in Mars Is "a hours ~
minutes and - seconds.
"In connection with examinations OF the surface
OF Mars we generally look for little line markings,
commonly referred to as the >chaparelh canals
and while we have been able to many Of these
line lines, all Of them found 10 be single, none
double II should be said mere. however, that the
present position OF Mars is not favorable for minute
or delicate observation, the planet Is far south.
But, even considering its position, the planet IL
so near the earth say withn about 36.OOOOOO miles
one OF the favorable distances knOwn-lt seems 10
me that II double lines existed
ought 10 be able 10 them.
Another thing upon which steady observation &c
this Institution is kept up Is "A distinctly white spot
near the south pole which, turns around that POLE
OF Mars 10 revOlves, just Greenland on our
earth does pun pose being X the position OF the
axis Of rotation Of the planet test Of the theory
OF astronomers that its axis has changed IN
position. In addition To careful special observations
general observations carried on from nihit 10
night. and Mars begins to rccede nom the
earth the present is the best season for our work.
When asked 10 his opinion OF the theory of