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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 Special!
- New Creation Astronomy DVD
- Signs of the Seasons
- Observing the Shadows of the Solstice
- Dance of the Planets
The day is thine, the night also is thine: thou hast prepared the light and
the sun. Thou hast set all the borders of the earth: thou hast made
summer and winter. Remember this, that the enemy hath
reproached, O LORD, and that the foolish people
have blasphemed thy name. - Psalm 74:16-18
Welcome to the Classical Astronomy Update!
Hello Friends,
The days are now at their longest of the year for those of us in the northern hemisphere. Though the Summer Solstice -- June 21 -- is technically the longest day, the length of daylight is actually nearly as long by a matter of minutes from about late May through mid July. So enjoy the long days while they last! To our friends in the southern hemisphere, currently enduring the shortest days, don't worry, your days will start getting longer very soon!
For more information about the solstice and the constellations visible during this month, check out our page, The Sky This Month, at the Classical Astronomy website.
Announcements
Signs & Seasons Special -- Ends June 25!
This week, we are running a promotional for our Signs & Seasons homeschool astronomy curriculum. For any orders of the curriculum and/or the workbook, we'll throw in a FREE pair of Eclipse Shades solar viewers. These Shades are not only for use during a solar eclipse, but you can look at the Sun anytime with perfect safety to your eyes. Eclipse Shades filter 99.9% of the Sun's bright light, and ALL the harmful UV and infrared.
Signs & Seasons can make an excellent summer course for your homeschool. Take advantage of the warm weather and mostly clear skies. Your hardworking homescholar can pick up a whole high school credit over the summer! Our Eclipse Shades promotional ends July 25, so place your order now! For more information, please visit Classical Astronomy Online Ordering.
New Creation Astronomy DVD
Our family recently had an opportunity to review an excellent Creation Astronomy DVD entitled, What You Aren't Being Told About Astronomy by Spike Psarris. This fascinating and visually appealling video provides much important information describing the contradictions and complications with the evolutionary theories of modern astronomy.
In this video, the first of a coming series, Mr. Psarris focuses on the solar system. Moving planet by planet, Mr. Psarris describes the theories of the formation and development of the planets and their moons, and points out the problems with the secular creation myths. I like Mr. Psarris's approach -- straight and simple, he exposes the deficiencies and contrivances of the mainstream explanations, and gives a short summary at the end of each segment listing the evidentiary problems with the timeframes of evolutionary models as compared to a young creation.
For example, he shows in several instances how the moons and planets of the solar system have too much heat to be billions of years old. He also describes how the magnetic fields of these bodies are too strong to be billions of years old, given their observed rates of decay. Generally, the solar system appears to be a young place!
In particular, Mr. Psarris shows how modern astronomers repeatedly shore up the weaknesses of their theories by supposing asteroid collisions with the solar system bodies. This is done to great humorous effect throughout the video.
What You Aren't Being Told About Astronomy is a great addition to the body of creation literature. Spike's delivery is crisp and professional, but he interjects a great amount of humor, with a straight-up, dry delivery. Our kids laughed heartily throughout the video and enjoyed it immensely. Well conceived and executed, our family is looking forward to further volumes in this series. Please support this Christian entreprenuer by ordering this DVD from www.CreationAstronomy.com.
Signs of the Seasons
Observing the Shadows of the Solstice
In this newsletter and in our Signs & Seasons curriculum, we simply try to point out the easily-observable aspects of Classical Astronomy that are usually overlooked in our modern generation. One of those aspects is the varying length of shadows over the span of the year.
As the Sun moves through the zodiac constellations over the annual cycle of the seasons, the Sun moves to its highest point overhead in the sky on the summer solstice. On this day, the noon shadows are the shortest. Because of the orientation of the sky, the height of the Sun corresponds to the length of daylight, so the Sun is highest in the sky on the longest day of the year.
Here's a picture of our son Dave, taken a couple years ago and first reported in the Classical Astronomy blog. Dave is standing in our backyard compass on June 17, near the summer solstice, a little while before "high noon," when the Sun crosses the meridian (not the same as "clock noon.") Note how short his noon solstice shadow is, as seen from the latitude of Cleveland, Ohio (about 41 degrees north).
(Instructions for making your own backyard compass are included in Signs & Seasons and the companion workbook.)
After the summer solstice, the Sun begins to move south through the constellations. The Sun's noon height decreases over the summer, and the days grow correspondingly shorter. Here's a pic showing Dave's shadow around noon on the autumnal equinox, September 23, when the daylight is the same length as the period of nighttime.
Note how much longer Dave's shadow is, nearly as long as he is tall. See how long the shadows are of the trees and other objects in the backyard, and how our kid's playset is in the shade, though it was in daylight at noon on the solstice. Also observe how different the noon sunlight looks when the Sun is at a slanting angle and not directly overhead.
Here's a pic showing Dave's noon shadow near the winter solstice. Note how long his shadow is, especially compared to the previous summer and autumn shots. On the winter solstice, the Sun is very low in the noon sky, and noon shadows around the shortest day of the year are nealy twice as long as the height of the persons or objects casting them, twice as long as on the equinox only three months before.
The shadows in our backyard were so long that Dave needed to stand next to the actual standing stone to find the Sun's rays, since the shadow of the pine tree in our backyard covered the compass. The standing stone and the "North" marker stone are indicated with red circles to make them more clear, since we had a big snow storm the day before. However, our neighbor's oak tree had lost its leaves, and didn't cast much of a shadow now as it did in the summer and fall.
Throughout history, it was common for farmers and sailors to use such obvious signs in the sky to measure the passage of time, as the LORD provided in making the Sun, Moon and stars (Gen. 1:14). However, in our generation, we have become reliant on technology such as clocks and wall calendars, and we no longer consult such simple signs, not even to simply appreciate the LORD's handiwork.
The seasonal changes in the shadows are among the many things your homescholar can learn from Signs & Seasons, our Christian homeschool astronomy curriculum. We hope that you all will learn to take some time from your busy lives to observe these common, everyday wonders.
Dance of the Planets
Saturn's Rings Edge-On
As reported in previous Updates, the classical planet Saturn has been shining in the evening sky after sunset since early March. Since last year, Saturn has been passing slowly through the stars of the constellation Leo. Saturn is the outermost planet of the solar system visible to the unaided eye, and has been seen by skywatchers on every clear night since ancient times.
Since Saturn is so far away, it moves very slowly through the constellations, taking nearly 30 years for a complete circuit of the zodiac, corresponding to a single orbit around the Sun. Saturn takes over two years to pass through one of the 12 zodiac constellations, compared to Jupiter, which passes through one constellation a year, and completing its orbit around the Sun in 12 years.
In the current season, Leo is seen moving west in the early evenings, toward the sunset, following the Sun's apparent annual advance through the constellations. By August, Leo will vanish into the sunset, and Saturn will disappear with it. The current season is a good time to learn to find Saturn in the night sky. The waxing crescent Moon will be seen passing near Saturn on the evening of Saturday, June 27. This will be an excellent opportunity to learn to identify Saturn.
Ring Plane Crossing
2009 is an uncommon year in the cycle of Saturn. Every 15 years, or twice in each 30 year cycle of Saturn's orbit, the Earth crosses the plane of Saturn's rings. Like the Earth, the poles of Saturn are inclined to the plane of it's orbit. As Saturn move through its orbit, the tilt of Saturn remains constant. Saturn's north pole points very closely to the North Star, Polaris, so the orientation of the sky as seen from Saturn would be very similar to how we see the sky here on Earth.
Like the Earth, Saturn has solstices, corresponding to the times when the poles of the ringed planet are inclined at their maximums toward and away from the Sun. Similarly, Saturn also has equinoxes representing the "in between" times between solstices.
These events can be observed through a telescope. When Saturn is at its solstices, the rings are turned to their maximum angle to the plane of the solar system, and appear their largest and most open as seen from the Earth. Saturn last had a solstice in 2001, when the south pole was turned toward the Sun, and the rings were at their widest as seen through telescopes here at home. The next solstice of slow-moving Saturn will be in 2017, when its north pole will be pointed at the Sun.
In between the solstices, near the times of Saturn's equinoxes, the rings appear very thin, because the plane of Saturn's rings is seen from nearly edge-on. Saturn will reach its equinox on August 10, 2009, when the plane of Saturn's rings crosses the Sun. In the meantime, throughout the summer of 2009, Saturn's rings will appear very thin.
In most cycles of Saturn's orbit, it is possible to see Saturn's rings actually vanish! As the Earth crosses Saturn's ring plane, the rings are viewed perfectly edge-on, and since they are so thin, they become completely invisible! Unfortunately, this time around, the crossing of Saturn's ring plane falls on September 4. At this time, Saturn will be very close to the Sun, and only visible grazing the horizon in very strong twilight. It's not likely that many people will be able to see a ringless Saturn at this time.
The next ring crossing of Saturn will be in 2025, but unfortunately, Saturn will again be too close to the Sun. Saturn's rings disappeared in 1995, but if you didn't see it then, you missed your best chance for quite a while! Our next best chance to observe a ring crossing will be 2038! Maybe by that time, our homeschool kids can show it to their own kids!
Coming in future Classical Astronomy Updates:
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In 2009, we will (try to) celebrate the Quadricentennials of Galileo and Kepler.
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In July, 2009 we will commemorate the 40th anniversary of the Apollo 11 moon landing.
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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