Classical Astronomy - Blood Moon: Round 2

Published: Sun, 10/05/14

Give the king thy judgments, O God, and thy righteousness unto the king's son... 
They shall fear thee as long as the sun and moon endure, throughout all
generations.  He shall come down like rain upon the mown grass:
as showers that water the earth.  In his days shall the righteous
flourish; and abundance of peace so long as
the moon endureth.  - Psalm 72: 1, 5-7
 
IN THIS UPDATE:
 
Dance of the Planets
  Two October Eclipses
  The Second "Blood Moon" of the Tetrad
 
Dear Friends, 
 
We have a lot of ground to cover in this newsletter, as I will attempt to make clear the astronomical circumstances of the current tetrad of lunar eclipses, which have been sensationalized as "Blood Moons" in the Christian media. 
 
At this writing, the second "Blood Moon" is less than three days away, and there has been nowhere near the hype this time as there was with the first one.  I hope everyone will note this closely, and consider that we should not get caught up in media hype, nor allow ourselves to get "blown around by every wind of doctrine," especially the sort that sells books.  Rather, we should "prove all things" and "hold fast to that which is good" (1 Thess 5:21).
 
It should also be noted that the "Blood Moon" craze has been mostly popular among those who have never previously paid much attention to the Moon or lunar eclipses.  Veteran skywatchers like myself are not impressed, since we understand that lunar eclipses are very commonplace natural phenomena, and that most years usually include one or two.  Further, there is nothing unusual about lunar eclipses occurring during the Jewish feasts, as this can happen every six years or so, on average.  The only difference this time is that there is a lot of media hype. 
 
Hopefully, after reading this newsletter, you'll be better prepared to understand these issues and discuss them with others.  Also, if you have any other questions, send me an email, and I'll try to answer them and share any explanations in this newsletter when the next lunar eclipse comes along, at Passover in 2015.     
 
Meantime, I hope you all enjoy the upcoming eclipses!  If you happen to observe them and take pictures, please send them along and I'll include them in an upcoming newsletter.
 
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In August and September, there was an unexpected upsurge of sales of our  Signs & Seasons curriculum.  In case anyone is inclined to send along congratulations, please consider that I do not sell books for a living, and when it gets crazy like that, it creates problems and cuts into my "day job" time.  I'd just like to understand the causes of this upsurge, so if anyone is aware of any recent positive reviews from prominent sources, or other recommendations, perhaps within a homeschool network, I'd be very grateful if you could send me an email with any information.  Thanks. 
 
* * * * *
 

 For more information about topics from Classical Astronomy discussed in this newsletter,
please check out Signs & Seasons, a
homeschool astronomy curriculum
(but popular with adult readers too!)
  
 
Visit our archive of previous editions of the Classical Astronomy Update newsletters, going back to 2007.
 
 If you haven't already done so, find us on Facebook and follow @JayRyanAstro on Twitter. 
 
Visit this page to subscribe to the Classical Astronomy Update and the Northeast Ohio Astronomy (NEOastro) newsletters.   
  
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Dance of the Planets
  
Two October Eclipses
 
There will be two notable eclipses in the month of October, 2014:
 
Wednesday, October 8 - Total Lunar Eclipse
Favoring the Pacific Ocean, including Hawaii and New Zealand.
Western USA and Canada can see the entire eclipse after midnight.
Partial stage commences at 5:14 AM EDT (2:14 AM PDT)
Totality begins at 6:25 AM, EDT (3:25 AM PDT)
Totality ends at 8:35 AM EDT (5:35 AM PDT)
 
Most of the USA and Canada can see the Moon beginning after midnight setting in mid-eclipse before sunrise.  Note that this eclipse is seen over the USA on Wednesday MORNING, and NOT Wednesday night.
 

 
Thursday, October 23 - Partial Solar Eclipse
Favoring North America, particularly the USA
Points east of the Mississippi can see the Sun setting in a state of eclipse
Eclipse commences at 3:38 PM EDT (12:38 PM PDT)
Greatest eclipse at 5:44 PM EDT (1:24 PM PDT)
Eclipse ends at 7:52 PM EDT (4:52 PM PDT)
 
You will need special solar viewing glasses to observe this eclipse, or else #14 welding glass.  (Note: our website will NOT be selling Eclipse Shades this time around, as with previous solar eclipses.)  You can also make a pinhole camera, especially for during the early afternoon hours for your location.
 
As a special treat, most of the USA will observe the Sun setting in a stage of eclipse.  This is always a lot of fun, as the Sun sets with a "bite" taken out of it by the Moon.  You can safely look at the eclipsed Sun while setting, just like a regular sunset, as its reddish orange color is not bright enough to hurt your eyes.  You will need a flat, unobstructed horizon to properly see the setting Sun, clear of trees and buildings, preferably over water.
 
Those living near longitude 86 degrees will see the Sun setting at a maximum stage of eclipse.  This line extends from around Grand Rapids, MI down through Indianapolis, IN, Louisville, KY, Nashville, TN, Montgomery, AL and to the western Florida panhandle.
 

 
This sunset eclipse will be especially visible for those along the shores of the Great Lakes who have a shoreline facing the southwest.  The entire western shore of Lower Michigan is favored, along with the southeastern shore of Lake Erie, from about Euclid, Ohio through Buffalo, New York.  The eclipse will also be visible from the east coast of Lake Ontario, northwest of Syracuse, NY. 
 
If we can hope to be blessed with clear weather along the Lakes in that season, this will be quite a sight!  Weather permitting, we will have a Classical Astronomy group gathering at Mentor Headlands beach in Mentor, OH.  Drop me an email for more info if you would like to be notified.

 
The Second "Blood Moon" of the Tetrad
 

The lunar eclipse of October 8 has been hailed as the "second Blood Moon" of the current tetrad of lunar eclipses.  We discussed this in a previous newsletter in which we analyzed the circumstances of this eclipse tetrad and expressed doubt as to this being a meaningful event with respect to  eschatology and Bible prophecy.   Please review that previous newsletter for more information. 
 
Briefly, the current tetrad of total lunar eclipses during 2014 and 2015 is deemed significant by some since they occur during the Jewish feasts of Passover and Sukkoth, or "the Feast of Tabernacles," and previous recent instances such an eclipse tetrad purport to coincide with significant events in the history of Israel.  However, a comparison of dates shows that the related events actually occurred BEFORE the eclipses of the tetrad.  I therefore concluded that there is no precedent for seeking an upcoming significant event in the history of Israel that might occur AFTER this current eclipse tetrad, since the other events (mostly) preceded the eclipses themselves, as follows:
 
1948 May 14 (Israel established)
1949 Apr 13 (Passover - total eclipse)
1949 Oct 07 (Sukkoth - total eclipse)
1950 Apr 02 (Passover - total eclipse)
1950 Sep 26 (Sukkoth - total eclipse)

1967 Apr 24 (Passover - total eclipse)
1967 Jun 05 (Six Day War)
1967 Oct 18 (Sukkoth - total eclipse)
1968 Apr 13 (Passover - total eclipse)
1968 Oct 06 (Sukkoth - total eclipse)

1492 Mar 31 (Jews expelled from Spain)
1493 Apr 02 (Passover - total eclipse)
1493 Sep 25 (Sukkoth - total eclipse)
1494 Mar 22 (Passover - total eclipse)
1494 Sep 15 (Sukkoth - total eclipse)
 
 
Timing of the Hebrew Feasts
 
The previous newsletter includes links to articles that explain the astronomical basis for the Hebrew feasts of Passover and Sukkoth.  In general, the Hebrew calendar is based on a lunar calendar, where the phases of the Moon are used to count days and otherwise measure time.  As can be read in those articles, Passover is timed to land on "the fourteenth day of the first month" (Lev. 23:5) and Sukkoth is timed to "the fifteenth day of the seventh month" (Lev. 23:34).  Both of these dates happen to be on or very near the Full Moon of their respective months.
 
Our generation is unaccustomed to observing the simple cycle of the Moon's phases, even though it is before our eyes every night of our lives.  The Moon's phases are very easy to understand for anyone who will consistently make observations at sundown and sunrise over the span of a month.  The Moon's phases are so simple to understand that even little kids can learn the cycle, as is the subject of our children's storybook, Moonfinder.  The lunar cycle is explained in greater detail in our Signs & Seasons curriculum.  Anyone wishing to better understand the Moon's cycle should consult these books.
 

 
Essentially, after the first sighting of the crescent Moon in the evening sky, fourteen (or maybe fifteen) nights pass before the Full Moon is seen, rising in the east as the Sun sets in the west.   At this time, the position of the Full Moon in the sky is opposite the position of the Sun in the sky.
 
(From Moonfinder
 
If one could have a "God's-eye view" of the solar system, one would see the Full Moon on the opposite side of the Earth, compared to the Sun.  The Sun, Earth and Moon would roughly line up during the time of the Full Moon. 
 
(From Signs & Seasons
 
So anyway, since Passover and Sukkoth always occur at the time of the Full Moon, the Moon is always aligned on the opposite side of the Earth from the Sun during the time of these feasts.  
 
Scripture also indicates that Passover occurs in "the first month," which, in the Hebrew lunar calendar, is the month of Abib or Nisan, which falls around March and April of our civil calendar.  At this time, the Sun is very near to the point in the sky of the vernal equinox.  In the present century, the place of the vernal equinox is located in the constellation Pisces.  (That is to say, the Earth is at a place in its orbit where the Sun lies along the same line of sight as the constellation Pisces).   During the Hebrew month of Abib, the Full Moon appears in the opposite side of the sky from the Sun, near the place of the autumnal equinox, in the constellation Virgo
 
(The equinoxes and their placements among the constellations are also explained in detail in Signs & Seasons).
 
 
Note that the Scriptures also indicate that Sukkoth occurs in "the seventh month," which, in the Hebrew lunar calendar, is the month of Tishrei, which falls around September and October of our civil calendar, on the opposite side of the year from Passover.  At this time, the Sun is very near to the point in the sky of the autumnal equinox, in Virgo.  During the Hebrew month of Tishrei, the Full Moon appears opposite from the Sun near the place of the vernal equinox, in the constellation Pisces.  So the circumstances of the Sun and Moon among the constellations are opposite during Sukkoth compared to Passover.
 

The Reasons for Eclipses
 
Just as the Hebrew feasts always occur at or near the Full Moon, an eclipse of the Moon also occurs during the Full Moon.  There are twelve Full Moons during each year (sometimes thirteen) so it is not unusual for lunar eclipses to coincide with the Hebrew feasts.
 
A lunar eclipse occurs when the Full Moon passes through the shadow of the Earth.  This shadow crossing causes the Moon to change color, from anywhere between a pale orange color, a deep red, or a charcoal grey color, barely visible.  The reddish-orange color is due to red light being filtered through the Earth's atmosphere, that shines on the Moon.
 
Before I began learning about Classical Astronomy, I always wondered why we do not have a lunar eclipse every month.  I basically understood that during the Full Moon, the Moon was "behind" the Earth, compared to the Sun.   It seemed like the Moon should pass through the Earth's shadow every time the Moon was full.
 
The reason why this does NOT happen is that the orbit of the Moon is inclined to the plane of the Earth's orbit around the Sun.  The plane of the Moon's orbit  is tilted 5.2 degrees to the plane of the ecliptic, which is the plane of the Earth's orbit around the Sun.  Each month, as the Moon circles the Earth, it passes from a northern extreme point, above the plane of the ecliptic, and a southern extreme point, below the plane of the ecliptic. 
 

 
As the Moon circles through its orbit, there are two points where the Moon crosses the ecliptic.  These are the nodes of the Moon's orbit.  The Moon has an ascending node, shown symbolically as ☊ , where the Moon crosses the ecliptic heading north, and a descending node, shown symbolically as ☋ , where the Moon crosses the ecliptic heading south.  The ascending node is also depicted as a Greek letter omega ( Ω),  and that letter shown upside down to designate the descending node.  In old literature, the ascending node was commonly referred to as "the dragon's head" and the descending node as "the dragon's tail."
 
Since the nodes are the points where the Moon crosses the ecliptic, an eclipse can only occur at the times when the line connecting the nodes is lined up with the Sun (hence the name "ecliptic.")  If the New Moon is near a node when it is near the Sun, a solar eclipse can occur.  If the Full Moon is near a node that is behind the Earth, inside the Earth's shadow, a lunar eclipse can occur.  


 
Just like everything else in astronomy, the nodes have a cycle of their own.  At certain months of each year, the nodes line up with the Sun, and eclipses can occur. During other months each year, the nodes are not aligned with the Sun, and there are no eclipses. 
 
During the months when the nodes are aligned, the New Moon and Full Moon are in a straight line with the Sun and Earth.  Thus, the shadow of the New Moon passes over the Earth, and a solar eclipse can occur.  Similarly, the Full Moon passes through the Earth's shadow, causing a lunar eclipse in which the Moon turns red.  During the other months, when the nodes are not aligned with the Sun, the New Moon's shadow does not touch the Earth, and the Full Moon does not pass through the Earth's shadow.  In these months, there are no eclipses.  
 

 
At any given time, the line connecting the Moon's nodes is pointed in a particular general direction, so that each node appears to lie on a given point along the ecliptic.  The position of the nodes shifts slowly through the constellations, due to a complicated gravitational interaction between the Earth and the Moon.
 
The motion of the nodes is slow enough so that when there is a solar eclipse in a given month, there is also usually a lunar eclipse in the same month.  Depending on all the various cycles of the Sun and Moon, sometimes you can have two partial solar eclipses in consecutive months, with a lunar eclipse in between.  There are various "rules of eclipses" that determine when eclipses might occur.
 
The rules of eclipses dictate that, when a set of eclipses occurs in a particular month, when the line of the nodes is aligned with the Sun, you will get another set of eclipses six months later, when the line of the nodes is again aligned on the opposite side of the Sun.  But the eclipses themselves are opposite.  In a month where a solar eclipse happens when the Moon is at the ascending node, the lunar eclipse during the same month will be at the descending node.  But six months later, on the opposite side of the Sun, the solar eclipse happens when the Moon is at the descending node, and the accompanying lunar eclipse is at the ascending node.   
 

 
Anyway, since the Hebrew feasts of Passover and Sukkoth also occur at the Full Moon, and since they are also separated by six months, it's not all that usual to have lunar eclipses to occur during both these feasts in the same year.  Actually, since there are twelve months in the year and twelve constellations in which the Sun and Moon can seen, lunar eclipses occur during the Hebrew feasts about every six years, on average.

In the months in between these eclipses, the Moon still passes the ascending and descending nodes every month, as it orbits the Earth.  However, the Moon is in different phases in those months as it passes the nodes, besides New Moon and Full Moon.  During those months, the Sun and the Earth's shadow are nowhere near the Moon when it passes the nodes. 
 
For example, on April 15, 2014, during the first so-called "Blood Moon" of the current eclipse triad, the Sun was aligned with Pisces, just past the vernal equinox, and the Full Moon was passing the ascending node in Virgo, near the point of the autumnal equinox. 
 
During June, 2014, when the Moon passed the ascending node in Virgo, the Sun was no longer opposite the Moon, and the Moon was in a phase close to First Quarter.  Similarly, in August, two months after that, the Moon was a waxing crescent while passing the ascending node in Virgo, as the Sun was aligned with Leo.
 

During October, 2014, the Sun itself is aligned with the stars of Virgo.  Thus, the Full Moon is opposite the Sun, at the descending node in Pisces, on October 8, for the second eclipse in the "Blood Moon" tetrad.  But when the Moon reaches the ascending node in Virgo during October, while the Sun is passing through that constellation, this results in the partial eclipse of the Sun, to be seen on October 23.    
 
As mentioned above, the nodes do appear to move slowly to the west along the ecliptic, a phenomenon called "regression of the nodes."  In this way, solar and lunar eclipses occur at different places along the ecliptic, in different months, over a span of years.  Otherwise, eclipses would always occur on the same dates every year, and there would be no variation. 
 
The months in which the eclipses occur are different from year to year, and vary in an 18 year cycle, called a saros. But the nodes slip about 20 degrees per year, of the full 360 degrees of the circle of the ecliptic.  Since a zodiac constellation represents about 1/12 of the ecliptic circle, or 30 degrees, therefore similar eclipses occur in the same constellations for about two consecutive years.
 
For this reason, in 2014 and 2015, the Moon's nodes happen to be lined up with the equinoxes, in Pisces and Virgo, and therefore coincide with Passover and Sukkoth.  However, due to the regression of the nodes, the "Blood Moon" eclipses occur at different points along the ecliptic, and therefore, on different dates from 2014 to 2015. 
 
 On April 15, 2014, during the first so-called "Blood Moon" eclipse, the Moon's ascending node ☊ was at a celestial longitude (position on the ecliptic) of 208 degrees away from the point of the vernal equinox.  By April 4, 2014, the following Passover, the ascending node regressed to ☊ = 190 degrees, causing the eclipse to shift to the other side of Virgo, compared to the previous year.
 
 
Similarly, on October 8, 2014, the second "Blood Moon," the descending node ☋ is at 20 degrees.  By the final "Blood Moon" in the tetrad, September 28, 2015, the descending node is at zero degrees celestial longitude, lined up with the point of the vernal equinox. 
 
So really, there is nothing all that significant about lunar eclipses coinciding with the Jewish feasts, and certainly nothing we should regard as sufficiently momentous and apocalyptic that they should be construed as prophetic signs. Rather, these eclipses just happened to align in this manner due to a fortuitous convergence of celestial cycles, the Earth and Moon simply following their paths ordained by their Creator, which can be determined beforehand with the modern understanding of celestial mechanics.
 
The only reason that this convergence of eclipses with Hebrew feasts seems significant is just that few people have paid attention to this commonplace type of event prior to the "Blood Moon" hype, and the devotees of this pop doctrine are simply naive to the celestial realities that the Creator has established. I encourage everyone to learn more and google the terms and concepts discussed in this newsletter.
 
I realize that a lot of that was probably a lot to swallow for some readers!  Hope it helped paint a picture of what's going on in the sky with the Sun and Moon.  Again, please feel free to ask questions.  I'll try to give you my best answers, and will share more detailed explanations in this newsletter when the third "Blood Moon" rolls around, in another six months. 
 
Til next time, God bless and clear skies,
- jay
 
The Ryan Family
Cleveland, Ohio, USA
 
 
When I consider thy heavens, the work of thy fingers, the moon and
the stars, which thou hast ordained, what is man that thou art
mindful of him? and the son of man, that thou visitest him?
- Psalm 8:3-4, a Psalm of David