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When will Halley's Comet be visible?
------------------------------------
First some bad news! The very best
viewing of Halley's Comet from planet
Earth will be from south of the
Equator (South America, South Africa,
Australia, etc.), due to the current
positioning of the Earth's axis rela-
tive to the comet. In the Southern
Hemisphere, the comet will be, on the
average, higher in the sky for longer
periods of time than in the Northern
Hemisphere.
But, don't despair! Comet Halley
WILL be in fairly good sky positions
in North America at certain times
during its visit. However, this leads
to...
MORE BAD NEWS!
When Halley makes its closest and
brightest approach to Earth in late
March - early April, it will be in
very poor position on the southern
horizon, making it barely viewable
from the southern states, and almost
completely unviewable from the Great
White North.
-----------------------------
Timetable for Halley Watching
-----------------------------
For North American observers, there
will be 4 primary observation
'windows' during which Halley will be
viewable with the naked eye, assuming
the comet achieves anticipated levels
of brightness. The 4 periods span
from December of 1985 to April of
1986.
Halley's Watch Period #1
------------------------
December 1 - 15, 1985
Inbound toward the Sun
This period marks the first time
Halley's Comet has been seen with the
naked eye since July, 1910. The comet
will appear as a faint, fuzzy speck in
the region of Pisces, just south of
the Great Square in Pegasus. It can
be found in the southwest sky about
half-way between the horizon and the
zenith (straight overhead), within an
hour after sunset.
If a tail has started to form, a
pair of binoculars or a small
telescope should be able to pick it
out.
Halley's Watch Period #2
------------------------
January 1 - 25, 1986
Still inbound, ready to turn the
corner
The first 12 days of January will
find Halley in the west-southwestern
evening sky free from interference
from the Moon. From the 12th on, the
Moon will begin to increase in
brightness, thus making observing
more difficult.
At the first of the month, Halley
will be approximately 30 degrees above
the southwest horizon (90 degrees
being directly vertical), and should
then be showing a short tail. It
will be visible for about 2 hours
after sunset. However, with each
passing night, the comet will set 6
minutes earlier, thus allowing only
30 minutes of decent viewing by the
12th.
By the end of this period, Halley
will be located in the western sunset.
It will actually be only 2 weeks from
reaching 'perihelion' on February 9,
its close encounter with the Sun in
which it swings around and starts its
outbound leg.
Halley's Watch Period #3
------------------------
March 8 - 21, 1986
Outward bound, heading our way
Halley re-emerges from its swing
around the Sun and begins to appear
low in the southeastern morning skies
just before sunrise. However, the
comet will be only 5-10 degrees above
the horizon, sadly making it difficult
if not impossible to view. Neverthe-
less, it is likely that Halley will be
supercharged from its recent encounter
with the Sun and will be sporting a
bright tail. Viewers in the mid- and
southern U.S. may get a fair glimpse
of the comet or part of its tail low
on the horizon as it makes a gradual
sojourn towards the southern horizon
during the month.
By the end of this period, the Moon
will begin to dominate the sky, hin-
dering what little chance of viewing
is possible.
During this period, 6 different
space probes will be making close ap-
proaches to Halley's Comet, performing
a wide assortment of data collecting
and picture taking. We will discuss
the details of these probes in an up-
coming issue of LOADSTAR.
Halley's Watch Period #4
------------------------
April 2 - 13, 1986
Close Encounter of the
Extraterrestrial Kind!
On April 11, Halley's Comet will
reach its closest point to the Earth
during this visit, being approximately
37 million miles away. This is a far
cry from the stunning visit in 83
A.D. when Halley came within 3-4
million miles of Earth, exhibiting a
double tail that stretched from one
horizon to the other, shining
exceedingly bright!
During this period, Halley should
be readily visible on the southern
horizon from the southernmost
latitudes of the continental U.S.
The farther north you live, the less
your chance of seeing the comet at
all! The tail may be as long as 25
degrees and, therefore, may be seen
sticking up over the horizon in some
places.
The comet will be at its highest
point above the horizon (8-10 degrees)
starting at sunrise at the beginning
of the period, backing up 30 minutes
with each subsequent night. By the
13th, Halley will be at its highest
point around midnight.
By the 13th, the Moon will begin to
brighten the night sky. However,
Halley should remain distinctly
visible in spite of the lunar
interference.
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