Wednesday, October 22, 2014

Partial solar eclipse visible to Mid-Southerners on Thursday

In an event that won't be seen again for nearly 3 years, a partial solar eclipse will grace the sky over North America on Thursday, October 23. Partial solar eclipses happen when a new moon comes between the sun and the Earth, but they don't align in a perfectly straight line. Therefore, the moon only partially covers the sun's disc. 

Diagram of how a solar eclipse occurs, as a new moon passes between viewers on Earth and the sun.
Graphic credit:
In the Memphis metro, the partial eclipse will begin at 4:52pm Thursday afternoon as a small shadow on the right side of the sun. As the shadow moves across the top of the sun, a maximum eclipse (shown below) will occur at 5:53pm low on the western horizon. The sun will slip below the horizon at 6:14pm, thus ending the viewing opportunity prior to the end of the eclipse.

How the sun will appear at maximum eclipse (5:53pm Thursday) just prior to setting. For an animation of the complete eclipse cycle, see

The next solar eclipse opportunity won't be until August 21, 2017 when a total eclipse takes place. While we look forward to that opportunity, don't miss the chance to see this partial eclipse or you'll have to wait another 3 years to see it again!

As to viewing an eclipse, remember the #1 rule is to NEVER look directly at the sun, eclipsed or otherwise, without protective eyewear! The sun’s UV radiation can burn the retinas in the eyes leading to permanent damage or even blindness. The only way to safely see a solar eclipse is to wear protective eclipse glasses, look through welder's goggles with a rating of 14 or higher, or to project an image of the eclipsed sun using a pinhole camera. Here's info on making a simple camera from Mr
One safe way of enjoying the Sun during a partial eclipse--or anytime--is a "pinhole camera," which allows you to view a projected image of the Sun. There are fancy pinhole cameras you can make out of cardboard boxes, but a perfectly adequate (and portable) version can be made out of two thin but stiff pieces of white cardboard. Punch a small clean pinhole in one piece of cardboard and let the sunlight fall through that hole onto the second piece of cardboard, which serves as a screen, held below it. An inverted image of the Sun is formed. To make the image larger, move the screen farther from the pinhole. To make the image brighter, move the screen closer to the pinhole. Do not make the pinhole wide or you will only have a shaft of sunlight rather than an image of the crescent Sun. Remember, this instrument is used with your back to the Sun. The sunlight passes over your shoulder, through the pinhole, and forms an image on the cardboard screen beneath it. Do not look through the pinhole at the Sun.
Be safe and have fun watching the eclipse on Thursday!

Erik Proseus
MWN Meteorologist

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