Our sky in Ohio typically has enough water vapor that our "fair" days show
up as gray-blue rather than blue. This means it is hard to see Venus at
midday with eyes alone... the surrounding sky is just too bright.
But it is a piece of cake to see venus with a small telescope if you know
where to look. Binoculars also work if you have a steady hand and make sure
to stay away from looking at the sun.
The computer-guided telescopes with altazimuth mounts are not very good for
this... there is no good way to align them during the day.
I use an older telescope with equatorial mount and setting circles. I set
the mount angle to my latitude and point the polar axis as near north as I
can. Then I aim the telescope at the sun. I use a solar filter, but if you
don't have one you can cover the primary telescope opening (to avoid damage
to the scope) and put a piece of paper over the finder eyepiece and look for
the sun to project onto the the paper covering the finder eyepiece.
Once aligned to the sun, note the Right Ascension (R.A.) and Declination
(Dec.)readings. Having looked up the R.A. and Dec. for both the sun and
venus, move the telescope the proper delta-R.A. and delta-Dec. to aim it
where venus is supposed to be. With a fairly wide eyepiece in place there
is a good chance venus will be in your field of view (after you remove the
solor filter).
I did this with my astronomy class a few weeks ago when the elongtation
(R.A. difference) was only one hour. It worked like a charm.
We also let the sun slip behind the nearest building and tried to see venus
by eye alone. Be neither I nor my students could see it on that day... too
much water vapor.
Later in the day when the sun is almost down, it is easy to see venus even
slightly before sundown, but I don't think this is what this discussion is
about. I have little doubt we could pick up venus midday with our eyes if
we had a very dry sky.
Michael D. Edmiston, Ph.D. Phone/voice-mail: 419-358-3270
Professor of Chemistry & Physics FAX: 419-358-3323
Chairman, Science Department E-Mail edmiston@bluffton.edu
Bluffton College
280 West College Avenue
Bluffton, OH 45817