Homeschool Resource Central: Astronomy on the Horizon: A Total Eclipse of the Moon Tomorrow Morning

Watching the heavens and their movements forms an ancient pasttime. The Babylonians did this with considerable interest, and became noted for their abilities -- sometimes better than others -- to make forecasts that would actually indicate where this or that celestial body would appear under some special condition in advance -- a star (often a planet like Venus since they could not tell the difference well) might appear brighter at this or that time of year, etc. Many other civilizations did likewise, from the early Egyptians to the Greeks. People have always been fascinated by the heavens. And well they should be.

The Babylonians (or "Chaldeans" later), the people from whom Abraham came originally -- for he lived in "Ur of the Chaldeans" -- conflated (mixed together) the biblically-forbidden are of astrology with the biblically-warranted science of astronomy. Christians -- buy a telescope and knock yourself out. Study the heavens all you want, for "the heavens declare the GLORY of God" (Psalm 19) -- The first of these, astrology, seeks to foretell the future by (falsely) assuming that the positions and relations of star clusters (constellations) set the course of human destinies. Stars do not, of course, do this. God does.

Galileo Galilei liked telescopes, and used them to study the moon, in order to gather evidence to show that the earth travels about the Sun in a day when this was not commonly known or accepted. This was astronomer, Nicolaus Copernicus,' "Heliocentrism" or "Heliocentric model," which contrasted sharply with the teachings of Rome at the time. He was placed under house arrest for a time by Cardinal Robert Bellarmine (later one of the "Pope Piuses"), for his "eccentric and subversive" views.

In any case, tomorrow, astronomers will have their telescopes out in force, as the earth's shadow ("penumbra") overtakes the moon completely. Surprisingly, when this happens, not one of the angels yells, "Down in Front!" This process -- a lunar eclipse -- can only occur during the cycle of a full moon, and it can be spectacular. Here is a brief post telling the short, but fairly inclusive, story of what happens when we get a lunar eclipse.

"A total eclipse of the Moon occurs during the early morning of Tuesday, August 28, 2007. The event is widely visible from the United States and Canada as well as South America, the Pacific Ocean, western Asia and Australia. During a total lunar eclipse, the Moon's disk can take on a dramatically colorful appearance from bright orange to blood red to dark brown and (rarely) very dark gray.

An eclipse of the Moon can only take place at Full Moon, and only if the Moon passes through some portion of Earth's shadow. The shadow is actually composed of two cone-shaped parts, one nested inside the other. The outer shadow or penumbra is a zone where Earth blocks some (but not all) of the Sun's rays. In contrast, the inner shadow or umbra is a region where Earth blocks all direct sunlight from reaching the Moon.

If only part of the Moon passes through the umbra, a partial eclipse is seen. However, if the entire Moon passes through the umbral shadow, then a total eclipse of the Moon occurs."

If you want to read more from this site, go here: http://sunearth.gsfc.nasa.gov/eclipse/LEmono/TLE2007Aug28/TLE2007Aug28.html

All students should learn what a "penumbra" is, and be able to use "penumbral" in a complete sentence. This can be used as a simple synonym for "shadowy," (poetically, most often) or in its more technical sense, as you see above. They should also try to come up with important ways to distinguish "astrology" from "astonomy."

Genesis tells us that God gave the stars (as well the other heavenly bodies) for "signs, seasons, months and years." The intended point is that the provide an objective (not earth bound) way to measure the passing of time, instead of doing things "old school," by merely using one king's list to compare against another -- which is helpful if -- and only if -- you already know some fixed point in time when this or this king in at least one of the lists actually reigned. Reported eclipses, solar or lunar, since they happen only at certain times, which can be known from reported observations by historians like Herdotus, help historians determine just when this or that king ruled. This helps historians fix times and places more accurately.

Of course, God knew we would have a problem keeping our times and season in order, so we have help by His kindness from the stars, sun and moon. Technically, the Sun is just a fairly ordinary yellowish star. But it happens to be just in the right place -- if it were 1% closer to Earth we would be -- in scientific terms -- "toast," and if it were 1% further -- we would be "Iceberg city." The goodness of God then shows up in the least details of astronomy and the other sciences as well.

So man the telescopes, and have fun at tomorrow's lunar party. But it happens "not so bright" and very early -- 2:52 AM (PST) to 4:22 AM. So bring the coffee.

A few other good astronomy terms to know are (I have included a few wikipedia links for help):

precession

constellations

solar eclispe

asteroid http://en.wikipedia.org/wiki/Asteroid

meteor (meteoroid)

solar flare (this can be a bit spectacular too) http://en.wikipedia.org/wiki/Solar_flare

equator

prime meridian

galaxy (galactic)

Milky Way http://en.wikipedia.org/wiki/Milky_way

comets (see Halley's comet) http://en.wikipedia.org/wiki/Halley%27s_comet