Rock Island Argus. (Rock Island, Ill.) 1893-1920, 1904-12-08

PROFESSOR WILLIAM H. PICKERING AND
HARvARDs PERUVIAN OBSERVATORY.
Dy- PROFESSOR Pickering In honor OF one
of Saturn's sisters. The eight other
members of the family are Japetus,
Hyperion, Tethys, DiOne, Titan, Enga.
lade Mimas and Rhea.
The newly discovered Phoebe has
some traits which distinguish her as
Just about the most erratic attache OF
q planet that ever came under an as
tronomer's telescope. Professor Pick
ering, who has recently mapped out
the moon and published an atlas by
which one can study the geography OF
the satellite of Mother Earth, has learn
ed that Phoebe plays game of peek
aboo' with inquisitive observers from
this planet. Not only so, but contrary
to the regulations of Saturn's numer-
GUS family she revolves backward.
To begin with, Phoebe is a very small
sphere, her diameter being only about
200 miles, as calculated by Professor
Pickering. That is minute in COM
parison with the earth's 5000 miles
and with the 73, 600 miles diameter of
Saturn himself. 1t is said that by
per1on. could that satellite be seen from
Saturn, would look about as large as
Jupiter does to observers on the earth.
But Phoebe would look only about the
size Of a star of the fifth or sixth mag
nitude. No resident of earth has seen
Miss Phoebe with the naked eye or
even directly through the telescope.
Professor Pickering has never seen her
except as a speck on n Photographic
plate, and even then it required sever
al photographs. locating her at differ
ent attitudes of her eccentric orbit, to
prove that what was seen was not
simply a speck of dust in the telescope.
Phoebe was discovered by Professor
Pickering through the twenty -four inch
Bruce telescope of the Harvard obser-
vatory ut Arequipa. PERU, March IA.
1899. The professor had been looking
for her for eleven years. Several pho
tographs We're taken and observations
made as to her characteristics when
suddenly she disappeared, and disap-
peared so completely as 70 make the
astronomer wonder whether he had
ever discovered her at all. But at
length she was located again. and it
was then found that her habit of going
backward accounted for her success in
fooling the curious star gaZers. Vari-
Gus explanations are offered for this
retrograde motion. One is that Phoebe
was originally a comet which was cap
tfreds by Saturn. In such case the
comet by passing OH one side of Sat
urn would have given direct motion
to the resulting satellite or ON the 9th
or retrograde.
Professor Pickering is an expert in
the business of photographing the
heavenly bodies He can tell when II
SHOWS in Mars, and, as for the moon,
he has that mapped out as accurately
as tract cut up into town lots. His
ATLAS of the Moon" tells everything
about the orb of night from its origin,
some hundreds of millions Of years
ago. to its present day vegetation and
snow. Professor Pickering is forty-six
years old He is n graduate of the
Massachusetts, Institute Of Technolo-
gy. When lie was twenty he assisted
in the observations made in Colorado
Of the total eclipse Of 1878. He be-
came connected with the Harvard OBJ
servatory in 1887. In connection with
his astronomical work Professor Pick
ering has climbed some tall mountains.
He has assembled over 100 peaks. in
Guiding Ell Misti, I'm Peru, which scars
to an altitude of 1900 feet. The Are
uuipa station Is located over 5000 feet
above sea level. and it has been found