You may have fond memories of the spectacular view on March 7, 1970, when the last total solar eclipse was visible in Georgia and South Carolina.
The rest of us might be wondering what we can look forward to seeing Aug. 21.
During this eclipse, if you were to look down from an airplane or orbiting satellite, you would see the round shadow of the moon, about 70 miles in diameter, moving from the Pacific to the Atlantic, racing at over 1,000 miles per hour.
With apologies to astronauts, most of us will be viewing this eclipse from the ground looking up. The best viewing locations will be in the path of this round shadow – the path of totality. During the hour prior to totality, excitement will build as you observe the partial phases of the eclipse.
These partial phases begin after “first contact” when the edge of the moon begins to block out the sun. Over this hour between first contact and the beginning of totality (second contact) the moon will cover up more and more of the sun, like sliding a dark, round cookie pan over top of a large, bright yellow cheese pizza.
The round edge of the moon will give the sun a crescent appearance. Outside of the path of totality, this is the extent of the show. So a trip to the totality path is well worth the effort.
During the partial phases it is essential to use a solar filter meeting ISO standards – both for your eyes and for any cameras aimed at the sun. Your surroundings will mimic twilight as you notice increasing darkness and a drop in temperature as a greater percentage of the sun is blocked by the moon.
While you certainly planned ahead to locate a spot with a clear view of the sky, you may wish to take a few moments to look into the shade of a nearby tree. Countless images of the partially eclipsed sun will be projected onto the ground from the pinhole effect of the leaves.
As totality is imminent, you will no doubt be looking skyward through your filter, but a video camera aimed along the ground will capture the drama of the moon’s shadow racing over you. I suspect you will enjoy reviewing the audio of everyone’s reaction to this shared experience should you videorecord the crowd from a few minutes before until a few minutes after totality.
During the last few seconds before totality and the first few seconds afterward, the surface of the sun gleams brightly as a spot on the edge of moon. Because the sun’s glowing atmosphere completes a circle around this spot, these fleeting moments are known as the diamond ring effect.
For the two minutes of totality, the moon will completely block the sun’s disk, revealing the corona that is the outer atmosphere surrounding the sun – invisible until totality. You can take off your filter now, as the corona is only as bright as the full moon, fading as it extends from the sun. Look for spots of the sun’s disk peeking between the mountains on the moon’s limb known as Bailey’s Beads.
As the moon gradually moves across the sun, beads disappear a few at a time as others appear elsewhere. While the eclipsed sun is the center of attention, take a moment to scan the sky. The sky will be as dark as night and, barring cloudiness, you will be able to see the brighter stars and the planets Mars and Venus.
Upon completion of totality you can look forward to an hour of the re-emergence of the sun through a reverse repeat the partial phases.
When you are converted to a true eclipse enthusiast, you can begin to consider travel plans to see future eclipses elsewhere around the world every few years.
To learn more about the science and history of eclipses and viewing them safely, attend the free Solar Eclipse Symposium on Friday, Aug. 18, at Augusta University’s Maxwell Theatre. Solar telescopes will be set up for viewing the sun from 5:30-6:30, followed by three 20-minute presentations in the theater.
Thomas Crute, Ph.D., is the chairman of the Department of Chemistry and Physics at Augusta University. He has been looking forward to this eclipse for nearly as long as he can remember.