While partial solar eclipses often occur up to two times per year, Monday’s event offers a once-in-a-lifetime experience for viewers in the United States because a large swath of the country will experience a complete blotting out of the sun by the moon.
Jason Smolinski, assistant professor in the Department of Physics and Astronomy at Calvin College, explained the reason Monday’s eclipse is so unique.
“Monday’s solar eclipse is unique for the United States because it is the first time the path of totality has reached the mainland since 1979 – but that was just through a few states and then up into Canada.
“The last time totality passed through the United States on a coast-to-coast trip was in 1918. For many people, this will be a once-in-a-lifetime opportunity to see the glow of the solar corona as the moon obscures the sun’s disk.”
Smolinski said based on the path of the moon, sun and Earth, the best location for viewing Monday’s eclipse is southern Illinois.
“Anywhere along the path of totality is a good place to watch the eclipse, but not all places are equal,” he said. “Duration of totality, for one, varies along this path because the apparent speed of the moon’s shadow changes as it passes along the curved surface of the Earth. The point on the Earth closest to the moon should experience the slowest-moving shadow. However, the rotation of the Earth affects this as well. Earth rotates in the same direction the moon orbits, so the Earth’s rotating surface is effectively trying to ‘keep up’ with the moving shadow.
“There will be some point where these two effects add up optimally to create a longest duration of totality, and for this eclipse that point is in southern Illinois. Moving away east or west of this point along the path of totality reduces the experienced duration of totality by a few tens of seconds, and moving north or south away from the mid-line of this path reduces the duration of totality much more dramatically.”
Unfortunately, Grand Rapids’ location means viewers will only experience 84 percent coverage of the sun.
“This is because Grand Rapids lies too far away from the points where there is perfect alignment between the Sun and Moon,” Smolinski said. “Being north of the path, viewers in Grand Rapids will see the Moon appear ‘below’ the Sun in the sky, obscuring the bottom portion and leaving a downward-facing solar crescent at the time of maximum eclipse.”
For viewers in Grand Rapids, the partial solar eclipse begins at 12:58 p.m. and ends at 3:43 p.m. Maximum eclipse occurs at 2:22 p.m.
Smolinski said while watching the eclipse viewers should not at any time stare directly into the sun.
“To safely view the eclipse from Grand Rapids, it is necessary to either wear certified eclipse glasses, which cut down the sunlight’s intensity to a safe level, or use some indirect means of viewing the eclipse by using something like a pinhole camera.”
He said even just glancing into the sun can be dangerous to eye health and increased staring exacerbates the potential for permanent eye damage. “This cannot be understated,” he emphasized. He also warned that sunglasses do not serve as adequate eye protection.
And before you think about recording the solar eclipse, Smolinski said put your camera down.
“Just as it is not safe to view the eclipse without protective eyewear or an indirect viewing method, using one’s cell phone camera to view and/or record the eclipse should also be avoided,” he said. “The electronics and camera chip in a digital camera are sensitive, and a camera is ultimately a lens that focuses light onto those electronics.
“When pointing a camera at the sun, a quick point-and-shoot is pretty harmless but sustained pointing can damage the camera chip and may even damage your phone screen. This is to say that using a cell phone camera as an alternative to eclipse glasses is a very effective way to ruin your phone. While this might be better than ruining one’s vision, it’s still not desirable. Don’t use your phone to view the eclipse.”
Smolinski said instead of spending the solar eclipse glued to your phone, take a break from technology.
“When you view the eclipse, put down your phone and participate in an activity that goes back as long as there have been humans to look up and notice such an event,” he said. “This connects you with the human race in a unique way. People in centuries past feared these events, but even while we now know exactly what is happening and why there is still a primal response within us that says ‘this feels weird!’ Experience that sense, put yourself in the shoes of the ancients, and know that future generations will do the same thing.”
*Photo by Giorgio Galeotti, partial Eclipse of the Sun – Montericco, Albinea, Reggio Emilia, Italy