This is the Classical Astronomy Update, an email newsletter especially
for Christian homeschool
families (though everyone is welcome!)
Please feel free to share this with any interested friends.
He stretcheth out the north over the empty place, and hangeth the earth upon nothing. He bindeth up the waters in his thick clouds;
and the cloud is not rent under them. He holdeth back the
face of his throne, and spreadeth his cloud upon it. He
hath compassed the waters with bounds, until the
day and night come to an end. - Job 26:7-10
IN THIS UPDATE
Southern Extreme of Venus
Lunar Eclipse -- Friday Morning Before Sunrise
The seasonsal wheel has turned again. We had an unseasonably warm spring and summer here in Cleveland, with sunny and warm days extending well into the fall. But the inevitable cycles of nature have prevailed and the temps have cooled and the perpetual cloud layer has arrived over the Great Lakes. Which is great weather to stay inside and write! I'm happy to report that I'm nearly halfway through the
script portion of Measuring the Heavens, the mathematical sequel to our Signs & Seasons curriculum. Hoping to make good progress over the winter, but there are still "miles to go before I sleep."
Speaking of Signs & Seasons, we have not raised prices on this curriculum since it was first introduced in 2007. However, with "Bidenflation" rising in earnest, it seems inevitable that a price increase will happen in '22. So if you've been considering ordering this book, now might be a good time. It makes a
great Christmas present. Order from Christianbook.com and save 17%!
My adult son and I recently attended a Walking Stick Retreat in West Virginia. It was a neat experience. These retreats are hosted by the friends and family of the late Christian musician Rich Mullins. I met Ann, a homeschool mom and newsletter reader who was also
attending. The next retreat is next spring in Indiana. It's a cool bunch of folks and I'd suggest that everyone check it out, especially if you'd like some encouragement in your life.
I wrote a couple blogs recently. I highly recommend that everyone check out the new Christian movie, The Most Reluctant Convert, a biographical film about the great C.S. Lewis, the first film by Max McLean and his Fellowship for the Performing Arts. It's a truly wonderful
film, follow the link for details. But hurry, the limited engagement only runs through next weekend.
With all the recent news stories about the changes in Superman comics, I also recently blogged about My Old Friend Superman. You might be interested in reading my reflections on this character, and how reading Superman comics as a kid in the 1970s directly led to my creating Classical Astronomy in
adulthood. If you're a homeschooler, you can get a FREE blog of your own at Homeschoolblogger.com.
For more information about topics from Classical Astronomy
discussed in this newsletter, please check out
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.
The Southern Extreme of Venus
I hope everyone is enjoying the beautiful sight of Venus, the blazing Evening Star, glittering in the western sky after sunset. If you participate in the Classical Astronomy group at MeWe, you would have seen the recent infographic of the waxing Moon passing Venus and also the
other evening planets, Saturn and Jupiter.
In the present season, Venus is at an 8-year southern extreme in its position in the evening sky. As long time readers of this newsletter might recall, Venus follows a recurring cycle where 5 synodic periods repeat every 8 years. A synodic period is a complete cycle of Venus' evening and morning apparitions, which entails the time between two consecutive inferior conjunctions (i.e., alignments with the Sun),
or other geocentric phenomena, such superior conjunctions or maximum eastern and western elongations. (These conjunctions and elongations are explained in detail in Signs & Seasons.)
So anyway, one of these 5 synodic periods includes a maximum eastern elongation that occurs in late October, when the ecliptic forms a shallow angle to the horizon. As a result, Venus appears very low to the horizon and very far to the south from the place of the sunset during the evenings when it appears at its maximum distance from the Sun.
Here's the takeaway -- in the current season, Venus appears at its farthest extreme to the south of anytime in the last 8 years, or for the next 8 years to come. In the early evening after sunset, Venus can be seen at an azimuth of about 210 degrees, only about 30 degrees to the west of due south. This might be a cool difference to notice if you're a regular observer of Venus and are accustomed to seeing it much
farther to the north.
Be sure to look on the next clear evening since Venus won't be there for long. After passing maximum eastern elongation on October 29, Venus is now overtaking the Earth in its orbit, and will thus approach alignment with the Sun, and will appear to move closer to the place of the sunset with each passing evening. By year's end, Venus will disappear into the sunset glow, and will emerge from the sunrise in January,
beginning a new apparition as the Morning Star. Venus will then be visible in the morning sky for most of 2022.
As an additional feature, you can look up in fall evenings and see Venus lined up with the bright planets Saturn and Jupiter. These planets are currently lined up with each other along the ecliptic, the circle in the sky that corresponds to the plane of the Earth's orbit around the Sun. So when you're looking up at these planets, imagine that you're gazing out into space and seeing these planets in
their places in the solar system.
Check out Signs & Seasons for a complete explanation of the ecliptic and how it relates to observing the Sun, Moon and planets in the sky. It's always amazing to me that Classical Astronomy and the concept of the ecliptic are
omitted from standard education today, yet textbooks and pop media is filled with "wow" astro-topics such as black holes and exoplanets. The latter are exotic, invisible objects only inferred from theory. Yet the ecliptic is the basis for many things we see in the sky, including the passing seasons, which has fundamental relevance to every human life.
This is mystifying hole in American education, since there are many scientists with advanced degrees who are unaware that planets like Venus, Saturn and Jupiter are readily visible on any clear night, and are in fact among the brightest "stars" that can be seen in the sky. I've made a career for over 30 years telling people for the first time that these planets can be easily seen every night of our lives. Yet
there are some who would rather believe that these brilliant planets, which had been famous in every culture down through pre-industrial history, are instead airplanes or even UFOs! There's still much work to be done to restore our lost legacy of Classical Astronomy.
Lunar Eclipse - This Friday Morning Before Sunrise
There will be a deep partial eclipse of the Moon before sunrise on the morning of this coming Friday, November 19. This eclipse will just fall short of being a total lunar eclipse.
In a regular total lunar eclipse, the Moon is fully immersed in the Earth's umbra, which is the full shadow of the Earth. In a total lunar eclipse, the entire disc of the Full Moon is darkened since the direct rays of the Sun are blocked by the mass of the Earth.
In this Friday's eclipse, most of the Moon passes into the Earth's umbra, but there is a tiny bright rim along the bottom edge that misses the Earth's umbra and still has some solar rays shining upon it. (The below image is from Eclipses Illustrated -Book 1.)
As shown in the image above, the sublunar point on the Earth at mid-eclipse will be in the Pacific to the west of Mexico. The sublunar point is the place on the globe where the Moon appears directly overhead at the zenith. So this eclipse will favor the west coast of the United States and other locations along those longitudes.
While there are always peunumbral phases at the beginning and end of each eclipse, there is not much to see at these times. The partial phase of the eclipse begins at U1, the first contact of the Moon with the umbra, which occurs at 7:18 UT on November 19. This translates into the following local times:
Partial phase begins:
2:18 AM Eastern Standard Time
1:18 AM Central Standard Time
12:18 AM Mountain Standard Time
11:18 PM Pacific Standard Time (Thursday, November 18).
The maximum eclipse (or mid-eclipse) will be 9:02 UT, which is:
4:02 AM Eastern Standard Time
3:02 AM Central Standard Time
2:02 AM Mountain Standard Time
1:02 PM Pacific Standard Time.
The partial phase ends at 10:47 UT, which is:
5:47 AM Eastern Standard Time
4:47 AM Central Standard Time
3:47 AM Mountain Standard Time
2:47 PM Pacific Standard Time
These times might be rude hours of the night for many people, but these celestial events happen when they happen, and there is always somewhere in the world where an eclipse can be viewed in the comfortable evening hours. But it's worthwhile for sleepyheads to set an alarm and at least take a quick peek at one of God's wonderful phenomena.
If that's still too much to ask for some prospective eclipse watchers, take comfort in the fact that there will be a total lunar eclipse visible at more sensible hours over the USA in May, 2022!
Can't say beforehand how Friday's eclipse might appear. If the Earth's atmosphere is clear, the eclipsed Moon might be a pale orange color, not much darker than the illuminated edge. But if the atmosphere is dirty, the eclipsed portion of the Moon might appear very dark, so the illuminated edge might appear very bright in contrast. This is explained by the Danjon scale of eclipse darkeness in Eclipses Illustrated -Book 1.
For more details about eclipses and various phenomena, check out both our ebooks:
Til next time, God bless and clear skies,
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