Expert: Tom Whiting - 12/14/2004

Question
-------------------------
Hi Tom
Thanks for your prompt reply. I've been having trouble getting a detailed
answer to my question but I'll find it somewhere.
I'm sorry you missed the 1991 eclipse, we almost missed it too. If the captain didn't get some advance weather information and take the ship 70 miles west of the original predicted spot, they would have heard the groans
in Mexico!
By the way, we used to go to Erie to swim at Presque Isle.

best regards     wraskin411@yahoo.com

Followup To
Question -
Hi
I have a question, but first I would like to say how lucky you are to have seen 5 eclipses. I saw only
one but it was over five minutes long. Could you
possibly have been on the same cruise, it was off Mexico, in 1991?

My question is "how does one calculate the direction
of sunrise at the equanox and solstice for a given
latitude?"

Answer -
Hi Walt.....
Never been on a ship, so no,  no cruises (180 combat missions in Nam in KC-135 tanker aircraft but I hate, and am leary of ships...weird, isn't it?  And I'm even an excellent swimmer too.....Eagle Scout, swimming, rowing, canoeing, lifesaving merit badges, but just don't like big ships.  Although, in 2009 I may have no choice....you know...1991 + 18 years).
We actually flew to, and were in Mazatlan Mexico for the 1991 event...clouded out.

Well, as a general rule, except for the extreme polar regions
say above 50 N Latitude or 50 S Latitude,
the sun basically rises due East at the equinoxes, and at
the solstices basically 23.5 degrees either north or south
of due east for the respective solstices. So that puts the
sunrise in the ESE on December 21for us Northern
Hemisphere observers, and in the ENE for June 21.

But if you want exact compass degree direction from a
given degree of Latitude, I'm afraid the mathematics is
beyond me...I can only think in general terms.

Although considering that there would be little parallax
involved....a distant horizon with the sun out there 93
million miles, I think those would be accurate statements
up to about 45 N. Latitude....sun would rise at about
90 + 23.5 = 113.5 Azimuth (ESE) on the horizon on Dec. 21 and
90 - 23.5 = 66.5 Azimuth (ENE) on the horizon on June 21.

Of course, in extreme polar regions, there is no daily sunrise
or sunset, as the sun just circles the entire sky daily, rising and setting only once every 6 months.  I've never seen it,
but I assume it begins to come above the horizon in the
south.

Hope all this helps,
Clear Skies,
Tom Whiting
Erie, PA  

Answer
Hi Walt,
Yes, well you win some and lose some, on total solar eclipses....
It was clear on P.E.I. for the 7/10/72 eclipse, my first, and for
the Winnipeg eclipse on 2/26/79, but cloudy for the Mexico
one.  Then we got to see the Aruba eclipse on 2/26/98
(no relation of course, to the 1979 eclipse of the same date-
just co-incidental), and we were also clouded out on the
European eclipse of 8/11/99 as was almost everyone in

Europe that day.....so I'm 3 for 5....not a bad
average.  Oh, it was also clear here in Erie for the annular
(ringed) eclipse on 5/10/94 where we saw 5 min 44 seconds
of annularity.   So actually I'm 4 for 6 on major solar eclipses.

BUT we saw an even rarer event on June 8 this year...a transit of Venus was perfectly clear in Erie for the 90 minute
time frame as we saw Venus depart the sun's disk.  I also
saw the Mars- Epsilon Geminorum occultation back in....
was it 1976 (?) and they say that that event was a once
every 500 year event of a star that bright by Mars (3rd
magnitude).   Plus I've seen every major comet from
Arend-Roland 1957 to Hyakutake and Hale Bopp back in
2001 (?)....plus we all saw comet  Shoemaker-Levy 9 slam into
Jupiter back in 1994 (?)....a super-rare event.  The only
thing left I'd like to see (before dying) is a supernova in the Milky Way....as the last one was 1604 (Kepler's Star) so its been 400 years....we are long overdue!

Oh well, I'll get off my soapbox now.
BTW Walt, feel free to write me directly at
bwhiting@velocity.net  if you so wish,
and please visit our Erie club website at
http://www.velocity.net/~bwhiting/
for some great picts of my new 30 inch portable
DOB truss scope....in fact, I spend almost
every new moon weekend at Cherry Springs
State Park, 15 miles SE of Coudersport, PA
(after the severe winter weather breaks)
if you happen to live somewhere in the PA,
MD, W. VA , NY region.

Clear Skies,
and nice chatting with you,
Tom Whiting, Major, USAFR (Retired-- KC-135 pilot
with 180 combat missions in Nam)
Pres.... ECMOG
Erie, PA