The New York herald. [volume] (New York [N.Y.]) 1840-1920, 1877-08-23
ABOUT THE MOON OF
MARS.
From the Philadelphia Evening Telegraph. Ausust

From the Philadelphia Evening Telegraph, August
201
Tho following despatch from Washington has an in
terest that Is not merely scientific Tho great tsle
scope OF tho Naval Observatory has inst sgnaizcd
ITSELF In tho hands Of Professor Hall, by Of tho
most remarkable additions 10 modern astronomy
nothing less in fact than the discovery OF ono satc
lite, and probably two, to tho planet Mars About
eleven O'Clock Thursday night Professor Hall
noticed very small following Mars few seconds
and made an es mate OF its distance from the planet.
Two hours later he looked again. aud surprised to
lind that the star seemed 10 DO still following tho
pInnct. As the distance had not Increased, while tho
planet was moving away at tbs rate Of fifteen second
AN hour no therefore madco careful serios Of mea.
sures which showed that the satellite was eighty
SECONDS from shc planet An. hour laicr II st
there, but Mr. Hall made further observation,
hardly cred,ing the great discovery no had made
On Friday m"rnng he showed hts observations TO
Professor Newcomb, who con6dent that tho
OBJECT must be satellite that be calculated roughly
eight hours, or little less This showed that tho
object would pass behind tho planet some time
during the following night and shat II not in
early evening u would reappear before daylight In
the morning. In the evening II WAS invisible. hut
reappeared, rne to tho prediction, about ono O'Clock
cssor Hall had now little doubt OF the reality Of
tue object that he made tho discovery known to
though, best to wat for ano,nsr loo. s,ors s or
mally announcing tho discovery, especially AZ Pro-
lessor Newcomrs calculation showed thst iJ would DO
on tho opposite side Of tho planet on saturday
Ing Hardly was the telescope turned on Mara when
the satellite was seen and its position determined
ny several OF the astronomers. In the course
OF the evening an object which might DO another
satellite, much closer to tho planet, found by Mr.
Todd but nothing could DO detcrm ned Respecting the
time OF its revonion The observations Of the nrst
satellite showed its time Of revolution TO DO about
thirty hours, but several weeks observation will DO
required to settle this exactly
scientific authorities here regard this as ranking
among the greatest telescope discoveries Of the CEN
asteroid group In 1871 and of tho planet Neptune in
1916 Professor Hail. the fortunate discoverer Of the
1867. When Professor Newcomb resigned tho charge
OF the great telescope, In 1875 he succeeded TO IT, He
Is an abio and learned mathematician and unostsn
tatious and conscientious observer Professor Now
comb tcicgraphed tho discovery OF tho satellite the
morning TO tho European obscrvasorios, and 1t Is
hoped that the weather thcre will permit Of further
observations Professor Hail. who has kept cont a.
Gus watch NJ tho instrument Tor week. aud who was
fortunate enough TO mako this remarkable discovery
furnishes the following statcment--
The first satellite OF MFRS discovered ut the
Naval Observatory in Washington ON tho night Of
August IT, 1t was first seen at tortytwe minutes past
eleven. II has been observed the nights Of tho
10Th, 17th and 18th OF August The time oi tho revo
hours It's greatest apparent distance from the centre
Of Mars IL eighty seconds of arc think l saw
another satellite on Saturday morning, about four
O'Clock, but OF Tho existence Of this satellite
am not absolutely certain. l believe, however that
there are two, and expect to DO able determine
this to night, Ms commence observations again about
midnight Tho satellitein It's appearances is iniht
object of about tho szc Of Of III. thirteenth or
fourteenth magnitude and II possible 10 discover
II only by putting Mars which rs now exceedingly
bright. out OF tho fold OF tho telescope TO get
rid OF the brilliant light Of that planet.
The distance OF the first satellite IRON the planet IS
between $4,000 ard ID, 900 miles, which Is less than
that Of any other known satellite from It's primary
only about one-sixtecntn tho distance OF the moon
from the Garth The inner one 10 tho existence OF
which tho astrologors not yet abs0 ccrain
stu closer. Tho diameter Of tho satellite very
small, probably not more than 0fty ono hundred
miles Tho following despatch announces of1c,ally
the discovery OF the satetcs:- .g1ii So! 7
WASHINGTON, August r. 1877.
Two satellites of Mars hsvc been discovered by Hall
Washington. First, elongnt0n west, August 49, eleven
hours Washington time Distance eighty seconds PERIOD
thirty hours. Distance Of second, dfty seconds.
JOSEPH HENRY.