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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.
IN THIS UPDATE:
- Anouncements
- Signs & Seasons Sale Continues!
- Jay Ryan on Jesus Geek podcast
- Support the Boy Scouts!
- 2011 Old Farmer's Almanac
- Signs of the Seasons
- The Astronomy of the Jewish High Holy Days
- Dance of the Planets
And the LORD spake unto Moses, saying, Speak unto the children of Israel,
and say unto them, Concerning the feasts of the LORD, which ye
shall proclaim to be holy convocations, even these
are my feasts. - Leviticus 23: 1, 2
Welcome to the Classical Astronomy Update!
Hello Friends,
Our family is always amazed at how quickly the days grow short this time of year. Lately, the Sun is already down and night is falling at 8:00 PM, while only a couple weeks ago, it was still daylight at that hour. The days will be equal with the night on Wednesday, September 22, the autumnal equinox, and after that, the days will rapidly grow shorter. Now is a unique time of year to notice these seasonal changes, so pay attention!
All this is explained on pages 106-109 of our Signs & Seasons homeschool astronomy curriculum. Also, check out the articles on the autumnal equinox at The Sky This Month at our website.
From time to time, we receive a question asking whether we teach "Biblical Astronomy." Usually, this means that people want to know whether we promote one of the various theories of "The Star of Bethelehem" or the so-called "Gospel in the Stars" and such. I've not yet written a newsletter explaining my views on the latter topic, and maybe someday I will. But let me just emphasize that the topics of astronomy discussed in our Signs & Seasons curriculum and our Classical Astronomy Update newsletter are certainly within the definition of "Biblical Astronomy."
Our foundational Scripture for the Classical Astronomy site is:
And God said, Let there be lights in the firmament of the heaven to divide the day from the night; and let them be for signs, and for seasons, and for days, and years: - Genesis 1:14 (KJV)
Using this verse, we explain that there are many "signs" that an experienced skywatcher can observe in the sky to practice traditional methods of timekeeping and navigation. The modern translations clearly emphasize this aspect of the purpose of the Sun, Moon and stars:
And God said, "Let there be lights in the expanse of the sky to separate the day from the night, and let them serve as signs to mark seasons and days and years, - Genesis 1:14 (NIV)
I've heard from critics that have lectured me that the Hebrew word for "signs" can also mean various other things, such as "signs and wonders" and so forth. I'm not a Hebrew expert, and am not prepared to engage in a hairsplitting match over such topics. However, I am aware that traditional historical, astronomical timekeeping is nearly forgotten in our high-tech era, and I simply seek to teach about those lost aspects of learning the sky, which are strongly emphasized in the Biblical text. Of everyone out there discussing "Bibical Astronomy," I'm not aware of anyone else that teaches the scope of the subject matter taught here at Classical Astronomy.
I would therefore encourage everyone to learn the traditional, Biblical methods of marking time by the Sun, Moon and stars, and and appreciate that this is the definition of "Biblical Astronomy" clearly defined in the text of Scripture.
Announcements
Signs & Seasons Sale Continues!
As reported in the last newsletter, our Signs & Seasons homeschool astronomy curriculum is in its second printing! We still have about a dozen copies remaining of the first printing at a special, reduced closeout price of $32.00! That's $7.00 off the regular list price of $39.00!
If your family has been considering Signs & Seasons, now is the time to order! Quantities are limited and this sale ends when the last copy is sold! Visit our Online Ordering page today!
(NOTE! - Be sure to order through the special "sale" link, otherwise you'll end up ordering a copy of the new printing at regular price!)
Also, don't forget to order the companion workbook, the Field Journal and Test Manual, to enable your student to earn high school credit. For a limited time, any book/workbook combination orders will receive a free pair of Eclipse Shades, for observing the Sun!
Jay Ryan on the Jesus Geek Podcast!
I was recently interviewed by my friend John Wilkerson for his Jesus Geek podcast. Unlike the last time when we discussed astronomy, this time John and I talked about patents, which has been my "day job" since 1987. Check out Part I of our interview:
John is a Christian homeschool dad in New York state, and a very smart and savvy computer techie. John has mentioned that some people have had a problem with the name of his show, Jesus Geek. I think this is a very clever play on the term "Jesus Freak," which Christians have been called by the world since at least the 60s. The term "geek" has been a synonym for "computer nerd" for at least 20 years. I think this name could be construed as a modern synonym for "fool for Christ" and shouldn't be construed as demeaning the LORD Jesus. Anyway, John's show is great, and if you are a Christian involved in computers or technology, you'll like what John has to say.
Support the Boy Scouts!
Our family has had a wonderful experience in Christian-based scouting programs. Our sons have been involved in Cub Scouts and Boy Scouts, and our daughter is involved with American Heritage Girls. I'm very happy to report that my oldest son, Dave Ryan, has recently become an Eagle scout!
Scouting has many goals and benefits, such as helping young men develop leadership, service, life skills, and good character qualities. Many other Christian homeschool families have also had a wonderful experience. It has also been a safe and wholesome for our family to shine for Jesus among people who do not necessarily share our faith. We decided to get involved with scouting after the Boy Scouts of America went all the way to the Supreme Court to defend Duty to God against the ACLU. There is a saying that "the enemy of my enemy is my friend," and we like that the BSA has that enemy!
Our sons' troop is now having its annual popcorn sale fundraiser. If you would be willing to support our sons and scouting, please consider ordering some Boy Scout popcorn online. If you don't like popcorn for yourself, please note the "military donation" option where the BSA sends scout popcorn to American military servicemen and women. Please visit:
Many thanks for your support of scouting!
2011 Old Farmer's Almanac
Another sure sign of fall is that the 2011 Old Farmer's Almanac is finally out! I grabbed my copy yesterday! Published every year since 1792, the OFA is the oldest continuous publication of any kind in the USA. It is also the most readily available resource for astronomy information, with 2 million copies in print, available at every supermarket and drugstore. Read it to find out IN ADVANCE the upcoming sky events for the coming year!
The 2011 Old Farmer's Almanac has an excellent article about the cycle of the Moon, with nifty illustrations. It also includes highlights of planetary events for the coming year. The calendar pages will help you keep track of the celestial bodies from day-to-day and week-to-week. There is also a ton of recipes, gardening tips, and other useful and entertaining information.
One thing -- the OFA does include a couple pages in each issue dealing with aspects of astrology. This reflects certain old almanac traditions, from back in the days before astrology was debunked by modern science. I always encourage everyone to treat the OFA like your local newspaper, and disregard this silly and useless portion of this otherwise informative and entertaining piece of Americana.
Signs of the Seasons
The Astronomy of the Jewish High Holy Days
Most Christians are aware that the Jewish calendar is a lunar calendar. However, most people are not clear on what exactly this entails. Scripture does not specifically give any details for keeping a calendar. However, the Old Testament is replete with references to certain "days of the month." It's generally understood from historical tradition that the changing phases of the Moon were used in Biblical times "for signs and for seasons, and for days and years" according to Genesis 1:14. Therefore, we can infer the times of the Hebrew holy days from the "days of the month" mentioned in Scripture.
The timing of the principal Hebrew holy days is given in several places, including Leviticus 23. As we've seen in previous Updates
, the Passover is kept in the springtime according to Lev. 23:5, following similar astronomical rules for determining the Christian feast of Pascha or "Easter." We've also seen how the Christian feast of Pentecost follows similar calendar rules to the Hebrew Shavuot.
Rosh Hashana
The Jewish High Holy Days also follow the astronomical rules of the Hebrew lunar calendar. These holidays begin with Rosh Hashana, which means "head of the year" in Hebrew. This holiday is defined in this verse:
Speak unto the children of Israel, saying, In the seventh month, in the first day of the month, shall ye have a sabbath, a memorial of blowing of trumpets, an holy convocation. - Lev. 23:24
"The first day of the seventh month" indicates the New Moon of the Hebrew month of Tishrei, corresponding roughly to September. This is not the "astronomical" New Moon meaning the "conjunction of the Moon with the Sun," as seen on wall calendars. The Hebrew New Moon is the Rosh Chodesh, or "the head of the month," meaning the first sighting of the waxing crescent Moon in the western sky, after sunset. This sighting was accompanied by the blowing of the shofar (i.e. "trumpet"):
Also in the day of your gladness, and in your solemn days, and in the beginnings of your months, ye shall blow with the trumpets over your burnt offerings, and over the sacrifices of your peace offerings; that they may be to you for a memorial before your God: I am the LORD your God. - Numbers 10:10
Each month in the Hebrew calendar traditionally would begin with the sighting of the Rosh Chodesh. In ancient Israel, this sighting would be made by the Levites, and the new month would not begin until the priests confirmed the sighting. In modern mainstream Judaism, these dates are calculated and tablulated in advance, and may not line up with any actual observations. Rosh Hashana is a very special Rosh Chodesh, with the first sighting of the waxing crescent Moon mark the beginning of the Hebrew civil year
Yom Kippur
On the tenth day after the first sighting of the waxing crescent Moon is Yom Kippur, or "the Day of Atonement," the holiest day of the Hebrew calendar:
Also on the tenth day of this seventh month there shall be a day of atonement: it shall be an holy convocation unto you; and ye shall afflict your souls, and offer an offering made by fire unto the LORD. And ye shall do no work in that same day: for it is a day of atonement, to make an atonement for you before the LORD your God. - Leviticus 23:27, 28
The "tenth day" of Tishrei corresponds to the waxing gibbous Moon, which is seen rising in the east in the early evening of Yom Kippur.
Sukkot
Five days after Yom Kippur is Sukkot, or the "Feast of Tabernacles," a seven day feast where Israel recalls 40 years of wandering in the wilderness:
Speak unto the children of Israel, saying, The fifteenth day of this seventh month shall be the feast of tabernacles for seven days unto the LORD. - Leviticus 23:34
Most years, the fifteenth day of Tishrei corresponds roughly to the Harvest Moon, or the first full Moon of autumn. This is interesting in that, due to the orientation of the sky during this season, the Moon rises shortly after sunset for each night of the seven day observance. Thus, there would be considerable moonlight for the entirety of this feast, another example of the LORD's provision for His chosen people. (For more information on the Harvest Moon effect, check out this archive article.)
In my experience, not many people today understand or appreciate the astronomical aspects of the Hebrew lunar calendar, including Jewish people. However, observing the phases of the Moon for keeping time can enhance our appreciation of Scripture and the astronomical foundation for these holidays.
Dance of the Planets
Jupiter and the Equinox
If you've been outside lately in the early evening after dark, you've no doubt noticed the bright planet Jupiter. You can't miss Jupiter coming up in the east in the hours after sunset. Jupiter is a blazing blowtorch, shining much more brightly than other stars in the sky. In fact, Jupiter is the fourth brightest object in the sky, coming after the Sun, the Moon, and Venus.
Venus is currently on the decline, laying low in the southwest at evening twilight. Jupiter, on the other hand, is rising in the east shortly after sunset, and dominating the night sky, and reaching its highest point at the meridian sometime after 1:00 AM.
On September 21, 2010, Jupiter reaches opposition, when it is opposite the Sun in the sky. At opposition, Jupiter rises in the east as the Sun sets in the west. As seen from a "God's eye view" out in space, at opposition, the Earth is ata point in its orbit where it passes between Jupiter and the Sun. At this time, these three celestial bodies fall in a line. Our Signs & Seasons homeschool astronomy curriculum has a more complete explanation of
opposition and other aspects of the motions of the planets.
This is no big deal, and it happens every year, though few people notice it or mark the event in any way. After opposition, Jupiter is visible in the evening sky at sunset, and will creep across the sky toward the west for many months, following the seasonal advance of the constellations, amd finally disappearing into the sunset sometime by the end of the winter. We'll keep an eye on Jupiter in future Updates throughout the coming seasons.
The astro-media is currently hyping this opposition of Jupiter as "the best in nearly 50 years," that Jupiter is brighter now than it has been in years past. While this is true, it is only brighter by a tiny amount. In 2010, Jupiter is at opposition while it is very near perihelion, which is the closest point in its orbit to the Sun.
However, Jupiter has a fairly circular orbit, unlike other planets such as Mars. Plus, Jupiter is about five times the distance from the Sun as the Earth, unlike Mars, which is only one-and-a-half times that distance. The brightness of Mars at opposition can vary dramatically, but the brightness of Jupiter only varies by small amounts from year to year, and is pretty consistently bright all the time.
Jupiter is at its closest to Earth (and therefore brightest) at oppositions that occur on October 8. This would be an opposition that occurs while Jupiter was at perihelion. This last occurred on October 8, 1963. A better opposition that this year will occur on October 2, 2034, and an even better one on October 7, 2046. It's not too early to start holding those dates!
What I find more interesting for 2010 is that Jupiter is currently very close to the point of the vernal equinox in the night sky. As is appreciated by readers of Signs & Seasons
, the vernal equinox is the place in the sky where the ecliptic crosses the celestial equator. The Sun reaches this place each year on about March 21, which is the first day of spring for the northern hemisphere, and this day is more familiar to most people than the point in the sky.
In the current season, Jupiter is passing through the stars of the constellation Pisces. Though this constellation is very faint, not visible from under the city lights, you can easily see Jupiter to the south of the Great Square of Pegasus, a prominent constellation of autumn. In the current season, Jupiter can easily help new observers to learn this constellation, and from there, all the fall constellations.
In another very interesting development for 2010, the Full Moon will pass Jupiter only two days past opposition, on the evening of Wednesday, September 22, which is the autumnal equinox, the first day of fall. This is bound to be some sort of rare occurrence, though I don't know how often this might happen.
The significance of this conjunction of the Moon and Jupiter is that this is also the Harvest Moon. Jupiter and the Moon will be seen closest on the first evening of fall, and the Moon will rise early each night for several days thereafter. This means that you can see the Moon pull away from Jupiter for each following night, and you can easily observe the Moon's daily motion through the stars. This promises to be a very interesting sight for those who will trouble themselves to make it a point to look.
As if all that is not enough excitement, in 2010, the conjunction of Jupiter and the Harvest Moon falls along the Hebrew feast of Sukkot. The widening separation between these celestial bodies can be visible from night to night, by anyone sleeping outside in tents. Be sure to point this out to your Jewish friends!
Coming in future Classical Astronomy Updates:
- We'll continue to follow the motions of Jupiter the remainder of throughout 2010.
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
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