On a Rainy
Day
November bows to December, and Fall to Winter.
The Oregonian
claimed that there were only two clear days
in October, and if it is
possible, this month has been even more cloudy.
We deserve the rain, for
drought has plagued our region for years. This
is merely a year of
above-normal precipitation, not a disaster. Still,
it is difficult to look
out the window without cursing. When will the
skies clear again? I missed
most of Fall's astronomical events: the
Orionid and Leonid meteor showers,
Saturn's ring crossings and transits
of Titan, and several planetary
conjunctions. Last winter's sketches of
Mars and Jupiter stare at me from
the back pages of my notebook,
whetting my appetite. However, this
astronomical thirst is itself
denied by the moisture-providing clouds. I
am drawn to observing logs
from my past, and electronic news from areas
with clear skies. I know
that I can hold on until an
East Wind
comes shooting down the Gorge
once again, driving the clouds back to the
coast and drying everything up.
On that night, bitterly cold though it
may be, I know that I will be outside.
Full Moon. Bad seeing. High relative
humidity. Limiting magnitude no
better than 4.5 at the zenith in a
light-polluted sky. In short, the
conditions make for a deep-sky
observer's nightmare. When there hasn't
been a clear night in over a
month, a true amateur astronomer can't be
picky. There is the
obligatory view of Saturn with its rings and
moons. On a night like
this, enjoy it fully. There is no reason to
rush to another object.
Planets survive the poor transparency, although
bad seeing detracts from
detail and resolution.
An 8" telescope makes the Messier objects easy
targets, if the sky is
halfway decent. With the Moon's glare centered
in the southern sky near
Taurus, no object is easy. M1 is gone, M35 a
washed-out collection of a
few dim stars. M74 and M76 are on the very
edge of visibility. The
Andromeda Galaxy is stripped of its dust lanes
and outer regions. Small
objects with high surface brightnesses, like
M77 and NGC 2392, are the
only ones that really hang in there.
Why
look for these objects on such a poor night? One answer is: "A
bad
night skygazing is better than a good night watching TV." The clear
weather, as ill-timed as it may be, will probably go away before the
Moon departs from the evening sky and is therefore precious. The
artificial and natural sky glows combine to send a warning. Unless we
control light pollution, this may be as good as the sky ever gets. M35
would normally be a showcase object, a textbook example of an open star
cluster for beginning astronomy students. Tonight, it is distinctly
unimpressive. Already, Portland's lights drown out the excitement that
should go with a first view of the Great Cluster
in Hercules or the Ring
Nebula. Forget about seeing spiral structure in
galaxies from the city.
Central and Eastern Oregon still offer dark
skies, but not everyone can
be persuaded that the trip is worth it.
Even when the weather is good,
few people will leave an introductory
astronomy class with an
appreciation for what can be seen in the night
sky.
These thoughts are sobering, but a view of the Moon lightens my
mood. I
forgo the polarizing filter, instead projecting the image onto
a sheet
of paper held behind the telescope. If it works with the Sun,
why not
with the Moon? I trace Mare Crisium and the rays of Tycho and
Copernicus, enjoying a new perspective from which to observe our
satellite. I shut down the observatory, and notice that the conclusion
of my observing run coincides with the arrival of the night's first
clouds.
11/28/95
Observations of
"Object Y"
12/6/95