I sent three messages yesterday which were bounced by the anti-spam
protection (I was using an email address other than the one under
which I was subscribed.)  I have remedied this now.  So in this
message I am resending them, combined and lightly edited.

Jim
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| Jim Cobb          | 540 Arapeen Dr. #100 | [EMAIL PROTECTED]      |
| Parametric        | Salt Lake City, UT   |     (801)-588-4632 |
|  Technology Corp. |           84108-1202 | Fax (801)-588-4650 |
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The trouble with most of us is that we would rather be ruined by
praise than saved by criticism.


------- Forwarded Messages

To: Arthur Carlson <[EMAIL PROTECTED]>
Cc: Jim Cobb <[EMAIL PROTECTED]>, [email protected]
Subject: Re: lunar eclipse 
In-Reply-To: (Your message of Tue, 26 Jan 1999 09:25:39 MST.)
Reply-To: Jim Cobb <[EMAIL PROTECTED]>
Organization: Parametric Technology Corp.
Date: Tue, 26 Jan 1999 12:06:33 -0700
From: Jim_Cobb <[EMAIL PROTECTED]>

I think I understand the situation now.  The definitions of the moon
phases are "the times when the apparent longitudes of the Moon and Sun
differ by 0, 90, 180, and 270 degrees," according to the 1999
Astronomical Almanac (p. D4).  (This seems to be becoming my favorite
book...).  The maximum eclipse occurs when the moon is closest to the
anti-solar point.  Now we know from my earlier messages that the Moon
is one degree south of the ecliptic at the time of the full moon, and
approaching crossing.  It must be the case that some movement of the
moon toward the ecliptic more than makes up the distance increment
incurred by moving away from 180 degree apparent longitude difference.
Thus, the eclipse occurs shortly after (11 minutes) the full moon.  It
makes sense to me now.

Jim

Art Carlson wrote:
> Well, that's interesting.  I would have defined "full moon" as the
> time when the moon is most nearly opposite the sun, which would be the
> same as the time of maximum eclipse.  How else can it be defined?
> There must be something like a projection into the ecliptic.
> 
> Art Carlson

------- End of Forwarded Messages

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