Beyond the Black Disk
On August 21st, 2017, the United States will be treated to an event that hasn’t been seen in 99 years: a coast to coast total solar eclipse. By that night, photographs of the blackened sun and its extraordinary corona will fill the Internet, but for those looking for something a little different, there are more eclipse day wonders to look out for ‘beyond the black disk.’
Enter our exclusive, original 4-part series, Eclipse Across America. In anticipation of the once-in-a-lifetime event, our film crew teamed up with leading eclipse chasers, astronomers, and NASA scientists to travel and explore the path of the August eclipse. What they returned with is a preview of the different eclipse phenomena that will be on display that day and an inside look at how scientists are using this event to help us understand not only our home star, but the countless others in our Universe.
Inside an approximately 70-mile wide track stretching from Oregon to South Carolina (known as the path of totality), millions of lucky people will have a chance to witness the fully-eclipsed sun and its corona glowing around its edge. This view of the sun’s outer atmosphere is truly one of a kind in our Solar System, making this August’s eclipse a “can’t miss” event for citizen scientists and astronomers alike. But in the seconds leading up to the corona coming out, there will be plenty more to see… if you know where to look.
The experience of a total solar eclipse is really the experience of being in the shadow of the moon. As serene as those moments of totality may appear, this shadow is actually traveling more than 1000 mph! That motion may be difficult to sense from ground-level, but from a high point within the path of totality–a mountaintop, a butte, or even a hill with a clear, wide view of its surroundings–you will have a chance to look down and witness that shadow racing across the surface…weather permitting, of course!
As that shadow speeds toward you on the ground, the so-called ‘diamond ring’ phenomenon will be revealed up in the sky. The moon’s cratered surface yields a bumpy, uneven silhouette so when it passes in front of the sun on August 21st there will be a moment when one final beam of light finds its way through one of these imperfections on the moon’s edge. From Earth, this beam will glow like a sparkling gem on the edge of a dimly lit ring. But even this tiny fraction of the sun’s light will be far too bright to observe with bare eyes. Make sure you’re still wearing your eclipse glasses for this one.
While the diamond ring will only be visible from inside the path of totality, Baily’s beads will be best experienced just along the edge of that path. One example–at the Gateway Arch, in St. Louis, Missouri, the alignment between the observer, the moon, and the sun will be ever so slightly shifted off center. Looking up from the base of the Arch, the moon will cover more than 99.95% of the sun’s surface, and similar to the diamond ring effect, trickles of light will find their way through the moon’s canyons and imperfections. But instead of a single gem of light, the result here will be the appearance of a luminous, beaded edge that you will be able to see through your eclipse glasses far longer than anyone stationed near the center of the path of totality.
And then, for those in the path of totality, comes the corona. It will be stunning, guaranteed. Even seasoned eclipse chasers don’t always have the words to describe the power of the experience. Will you?
Watch the Eclipse Across America series trailer here: