Thursday, June 19, 2014

About Solar Eclipses Part 2 - The Four Types of Solar Eclipses

We left off the last post talking about the "happy accident of nature" that calls a solar eclipse. While people of faith in God do not believe in "accidents" but in the purposeful planning of God, let's look at more of what the article said and see how God delicately planned our universe to create this "happy accident" (Tweet that!):

These are a happy accident of nature. The sun's 864,000-mile diameter is fully 400 times greater than that of our puny moon, which measures just 2,160 miles. But the moon also happens to be about 400 times closer to the sun than the Earth (the ratio varies as both orbits are elliptical), and as a result, when the orbital planes intersect and the distances align favorably, the new moon can appear to completely blot out the disk of the sun.

Fascinating, isn't it?

The article explains that the moon casts two types of shadows:

  • the umbra: "that part of the shadow where all sunlight is completely blocked out and takes the shape of a dark, slender cone." (Tweet that!)
  • the penumbra: surrounds the umbra and is "a lighter, funnel-shaped shadow from which sunlight is partially obscured." (Tweet that!)

Here are the four types of solar eclipses. These explanations and quotations come from the article, "Solar Eclipse: What is a Total Solar Eclipse & When is the Next One?" by Joe Rao, Skywatching Columnist.

Total solar eclipses

"During a total solar eclipse, the moon casts its umbra upon Earth's surface; that shadow can sweep a third of the way around the Earth in just a few hours.  Those who are fortunate enough to be positioned in the direct path of the umbra will see the sun's disk diminish into a crescent as the moon's dark shadow rushes toward them across the landscape.

"During the brief period of totality, when the sun is completely covered, the beautiful corona – the tenuous outer atmosphere of the sun – is revealed. Totality may last as long as 7 minutes 31 seconds, though most total eclipses are usually much shorter.  On the average a total eclipse occurs somewhere on Earth about every 18 months."

Partial solar eclipse

Occurs when only the penumbra passes by you. Part of the sun always remains in view. (Tweet that!) How much of the sun is obscured depends on how close you are to the path of a total eclipse.

Annular solar eclipse

Similar to a total eclipse, the moon appears to pass across the sun but it is too small to cover the disk of the sun, like a penny over a nickel. (Tweet that!) This is because the moon's orbit is elliptical and so sometimes it is closer and at other times it is farther away. In his article, Joe Rao tells us, "The sky will darken . . . somewhat; a sort of weird 'counterfeit twilight' since so much of the Sun still shows." (Tweet that!)

Hybrid solar eclipses

Also called annular-total, or "A-T" eclipses, hybrids account for only about 5% of all solar eclipses. They occur when the cone-shaped umbra shadow falls just short of reaching the Earth. (Tweet that!) Most hybrid solar eclipses start as annual, then become total as the earth rotates and its roundness "reaches upwards" to meet the tip of the cone – the umbra – near the middle of the eclipse, and then retreats again into an annular eclipse.

There is a lot of additional interesting information in the article if you'd like to learn more.

My next post is scheduled for Saturday, which is the "longest day of the year" (with the most daylight), the summer solstice. We'll talk about the prophetic and spiritual significance of the coming total solar eclipse on March 20th of next year.

Related article:

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