Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1891-10-01
THE PLANETS IN OCTOBER.

Conjunction of Saturn with Mercury and
Mars-Mercury at His Greatest Brilliancy
disappearance of Saturn's Ring-Con-
junction of Neptune and Aldebaran.
WRITTEN FOR THE DIsPATCHJ
The only planets that will be visible to
the naked eye throughout the present month
are Mars, Jupiter and Saturn. Venus is yet
SO close to the sun as to be completely over
whelmed by bis superior light, and she will
not be in the least conspicuous before De-
cember. On the evening of the 1st she sets
but 13 minutes later than the sun. and on
the Slst the time OF her setting is $50, or 32
minutes after sunset. She is in the constella-
ton Virgo, the Virgin, and will be in con-
junction with spica, the principal star of
that constellation, on the 9th.
Mercury may be seen just before sunrise
the first few mornings in October. He will
be in conjunction with Saturn on the Sd at
2:C4 A. NJ, the distance between the two
planets being but 49, minutes OF arc, Saturn
being that distance north of Mercury. At
the precise time of conjunction both are be-
low the horizon of Pittsburg, but three
hours Ia ter they may be seen in practically
the same positions relative to each other.
They are then of about equal brilliancy,
Mercury being at less brilliancy and far
together on the morning of the Sd, Saturn
appearing above the morrison at 4:3l:0 and
Mercury at 1923. Both planets may then be
seen in the same field of view through the
telescope, and Mercury will be found to be
gibbous or similar in appearance to the
moon three or four days before or after its
full phase.
Mercury Will BE Illuminated.
Seven tenths of Mercury's disk Is illumi-
mated at that time and he is then at about his
greatest brilliancY. Merculyis the smallest
of the majOr planets, his diameter being
only 2,992 miles, or less than half that of the
earth. The force of gravity at the surface
of Mercury is less than half that at the sur
face of the earth. In other words a man
weighing 200 pounds on the earth, would
weigh but 81 pounds in the planet Mercury.
The length of the Mercurian day is about
the same as on the earth, but the seasons
are much shorter, being only p days instead
of three months, as on the earth.
Mercury is also the swiftest moving
planet. darting through space with the
meteoric velocity of 80 miles a second-a
speed which can be better comprehcnded
when it is considered that an object moving
at that rate would cross the American con-
tinent in less than two minutes. Mercury is
now in the constellation Virgo and his angu
lar diameter as seen from the earth is 6" 2.
Mars is slowly gaining in brilliancy, but is
still very faint. Tomorrow morning he will
be seen four degrees higher up than Mer-
curry and to the right OF that planet. He will
be in conjunction with Saturn on the 18th
The approach will be close one. but not so
close as in the case of Mercury and Saturn,
the two planets being 80 apart, with Saturn
farther to the north. Mars is now in the
constellation Leo, but he will reach the
boundary of that constellation on the Sth
and will enter Virgo, where he will be at the
close of the month. He arose this morning
at 400, and on the 3lst will rise at BAT. His
apparent diameter at present is 40, but by
the last of the month will have increased to
E2
Jupiter Is the Main Attraction.
Jupiter continues to be the main planet
ary attraction. He is gradually becoming
less brilliant, however, though this is not
yet apparent to the naked eye. On the 10Th
inst. his diameter is 44'S, while on the 5th of
September, when he was at his brightest, his
diameter was 47'.4. He is on the meridian at
9:06 P. NJ. the 18th and at sol on the 3lst
He will be in conjunction with the moon on
the 14th $50 A. NJ. and his geocentric distance
from the moons limD is then 80 81, but, as
seen at the surface of the earth, the distance
between them will be about 80.
Saturn will be an object OF more than Or
binary interesG this month. Besides his
conjunctions with Mercury and Mars, which
have already been alluded to. another occur
interest," befalls him-the reappear-
ance of his ring on the Both, after an entire
invisibility of IS days. That event, how
o-ess--iu- he devoid of interest to anyone
withouta telescope of sufsoient power, to
observe it. Saturn is now in the constella-
ton of the Virgin and rises on the morning
of the 18th at 35l. His angular diameter is
1912.
Uranus Is Not Visible Yet
Uranus is too close to the sun to be
visible except with the aid of powerful
telescope. He will be in conjunction with
the sun on the 25th.
Neptune may be seen on clear evenings
with telescope of small power. He is now
in the constellation Taurus the Bull, i'll
north declinat ton 300 12. His motion is SO
slow that it requires on an average II years
to traverse each constellation. As he is now
in about the center of the constellation
Taurus, it will be nearly seven years before
he passes beyond the limits of that division
of the Zodiac. Veptune rises this evening at
s:31 He will be in conjunction with the
bright star Aldebarar on the 9th and they
will cross the meridian simultaneously at
3:l9 A. NJ. on that date, Neptune being 50 So
higher up than Aldebaran.