Evening star. [volume] (Washington, D.C.) 1854-1972, 1892-08-30
ON A FAR.OFF PLANET.
Prof. Pickering Tells of His Observation OF
Mars From Perm

Prof. Pickering Telis of His Observation Of
Mars FROM Peru.
Prof YIN, n p;cter;,, d;ro,.o -. r,,
~ ""eS'o' Va n~r'aru
0'"eSe ,, VINO is stationed at Are
qua, feru observing the opposition Of Mars,
has written as follows to dstronoo,v and A sf,o-
pbys;c;s the astronomical ,or.,
az -, --.,-,.,,,
P"3 'aheu "'ehuoh 10 tne
importan' enect OF our atmosphere In mislesd-
ing judgment as TO the true colors exhibited by
the heavenly bodies. A good illustration of
this may mo oh,,;,sd f,o,, ,,.... -.
Ill, a., ~, 'u.An,i'
'''' "a'- Inc Instant greens OF the
landscape are at once changed to gray either by
the passing over Of them of a cloud shadow or
by the passing of a very thin mist between them
and the nv. Tn .h. ,,I
darker aud !, Az ,a,t.- III. S... ny ooeouio
the ureenisb bue enti,a,x 5;s, 80 -. '"'o
..Ibe sudde, ,h.naas - ~ asn;,:., l..
some Of The s,n.,l.r 80. ,,ro,' ~, ,,ia. W
are sometirnes ,lrnost ~. H. $780, T..
was obtained sbortlv hsSora s,,nr;sa - a.
snowy region abnrt ,hs .o,,tl, - a,,...n,, -
n most br;osnn. gree, ou;ta onwoi;prp, ~ -
the rather narro1 oraen b,na s;tna,sa i,s, ~
the north ~ n Ia9er os tba orr c,r,o ~ Ar
color Of the snow chon,ed N . hr;nht rrciJow
the rest of the disc changing in the meantime
to orange Later the sae;nc ;mnroy.J sayoroI
of the canals became visible and the snow no
came nh co,orle.s no nnon our .urrU,,aino
mDuntains Tho tvo forrnar effecte were proh.
ahIv due % had vo.;ro tbo s,ctI,ot;ons ~ ar
own at,nosnbero snnar.nor;rc tbt coIors of tbo
surroundine regions pnon the snow We have
Ibid 1t down NJ a rule never to RELY greatly uuou
our color observations unless the enowcaps of
the planet appear perfectlv coIorlcss and the
canal system e we'll defined These conditions
we find ALWAYS combined with the bost seeing
For these delicate color observations II will
therefore be seen that not only do we REQUIRE n
telescope Of the best quality. but also the very
best oDtainable atmospheric conditions.
"In studying tine smaller dark regions, such
as the northwestern part of the Syrtis major,
great differences of color have been noted from
night TO night, and have colored sketches in
my possession taken at different times in which
it is represented as gray as green, Us blue az
brown and even as violet
The latter color was so extraordinary that
| endeayored to make that portion of the
planet appear to nv ewes of some other color.
but il was impossible and no other color but
violet lake could be made to match it, This
color upon the planet has been only seen by me
once since The brown color above noted was
undoubtedly due 10 bad seeing. At one time j
felt convinced that the real color of the darkest
spots upon the planet was deep blue. and this
may in reality be the case, but Of late under
favorable circumstances they have apr cared TO
me to be of an absolutely colo-less gray.
The most striking ma king upon the planet
and that most readily seen with small tcle-
SCOPE, IA tile NNEtlS major or 1 Uluck MS Is
nearly central i'll the sixth position of the
planet. This region in 1890 was interesting MS
containing the most conspicuous canal visible
upon the planet excepting the large one which
terminates the Syrtis major upon the north.
At this opposition these canals are too far
north TO be well seen. The fourth and third
regions OF the planet are both uninteresting
The second position is interesting as showing
the great southern ocean, which is nearly as
conspicuous as the Syrtis major itself
I'VE now come to a eurious feature of the
observations namely. the actual change in
color which. eliminating all probable sources
Of error. the planet really seems to undergo
When the Syrtis major IL central. before the
autumnal equinox of the northern hemisphere,
the region to the east is seen to be more green
ish than that to the wcst. As the season wears
on the difference in color grows less marked,
and the greenish hue is confined more closely
TO the region Immediately bordering the Syrtis
on the east. The two arms of Svrts are not
of equal breadth. the eastern arm being nearly
twice as wide as the western arm. Early in 1890
the entire region inclosed between the arms of
the Syrtis major IA far az the snowcap, was Of
a brilliant green color Eleven DAYS before the