#### WTF_Seriously

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##### Why don't we see more solar eclipses?
« on: December 02, 2020, 10:30:38 PM »
The August 12, 2017 total solar eclipse was a marvelous thing to witness.  I was lucky enough to enjoy it while having a fine cigar in my backyard.

A few things I've discovered about it.  The center (my term for the exact longitudinal alignment of the sun and moon) of the eclipse occurred near the longitude of St. Louis, MO.  If you check https://www.timeanddate.com/moon/phases/usa/st-louis you'll find that solar noon and the lunar meridian crossing of the new moon occur at the same time as one would expect.

I appreciate @Tom Bishop for turning me on to the mooncalc website.  One can gather great data there. Using that site, I was able to iterate that at the time of the center of the eclipse the moon was directly above between 12 deg. 18'-20' N lattitude.  Just doing a little math with the sun traveling .26 deg/day, the sun would be approximately 8 deg. 30' N at that time.  That alignment was able to cast the umbra as far north as 44 deg.

Now according to the WIKI: "When the moon is below the sun's altitude and near it, the moon is dark and a New Moon occurs."

So this raises the following question.  Twice a year, the sun and new moon approach the equator at the same time.  Near the Sept. equinox in 2025 they are within a degree of each other and within a degree of the equator.  How could this alignment not cause a total solar eclipse at that time as well as the numerous other times the sun and new moon would align in locations nearer the equator and closer to each other than the nearly 4 degree difference witnessed in August 2017?
« Last Edit: December 02, 2020, 11:14:19 PM by WTF_Seriously »
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#### macattack

• 24
##### Re: Why don't we see more solar eclipses?
« Reply #1 on: December 03, 2020, 04:50:49 AM »
Waiting on that next total solar eclipse in 2024, maybe have to travel 40 miles for totality.  Had nice front row seat for 2"42" of totality in 2017.  I had that on my calendar since 2002.  I should be around for the 2045 one too.

https://eclipse.gsfc.nasa.gov/SEsaros/SEsaros.html#:~:text=The%20periodicity%20and%20recurrence%20of,to%20solar%20eclipses%20as%20well.

#### WTF_Seriously

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##### Re: Why don't we see more solar eclipses?
« Reply #2 on: December 09, 2020, 02:51:40 PM »
Got curious about the upcoming Dec. 14 new moon.  It occurs in northern Argentina.

It occurs at Lat. 23.5 S.  The sun should be 1.82 deg. north of this.

Above, we see that with a sun moon offset of just under 4 deg. the umbra cast in 2017 extended roughly 36 degrees north of the sun's location.  1st year geometry would tell us that the umbra cast by a 1.82 deg. offset would be less than that 36 degrees.  That would mean on Dec. 14 a solar eclipse should occur somewhere between 21.7 deg S and 57.7 deg S, but it doesn't.
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