On August 21, 2017 a total solar eclipse will sweep across the United States. For two minutes the moon will completely occlude the sun, leaving only the solar corona. This rare event can be seen by 12 million Americans in a 70 mile wide path from Salem, Oregon to Charleston, South Carolina. Another 500 million Americans will be able to see at least a partial eclipse.
Here in Canton, Michigan, we will only experience an 80% eclipse, but be sure not to miss it. The beginning of the eclipse will start at 1:02 PM, peak at 2:26 PM, and end at 3:47 PM. Although this is a not to miss event, precautions must be taken to view the partial eclipse.
Staring directly at the sun, even partially blocked by the moon, can still cause permanent damage to the retina. The intensity of the sun’s light is so great, it only takes moments to cause damage. A burn to the retinal tissue, solar retinopathy, can cause permanent loss of vision. The retina does not sense pain. To prevent solar retinopathy never look directly at the sun, even while wearing sunglasses.
The only safe way to look directly at sun, partially eclipsed or not, is to wear special eclipse glasses. Eclipse glasses may look like regular 3D glasses, but they have a special filter for direct observation of the sun and comply with the requirements of ISO 12312-2.
An alternate way is by indirect viewing. A popular way to view the eclipse indirectly is to project the eclipse through a pinhole. Learn how to make your own pinhole camera here. Remember, you are not looking through the pinhole at the sun, but using it to cast a shadow of the eclipse on another surface.
Whichever way you choose to experience the eclipse, make sure you do it safely. Also, don’t miss it, because your next chance is April 8, 2024.