There’s a solar eclipse coming up on Monday, August 21st, which will be visible to all of North America. The “path of totality” where the total solar eclipse is visible will stretch through 13 states from Oregon to South Carolina. In the centre of that 112-km wide path, the total eclipse will last from 2 minutes to 2 minutes and 40 seconds. Outside of this path, observers will see a partial eclipse.
Here are some tips for safe viewing:
Regular sunglasses, even very dark sunglasses, are not enough.
Warn children of the danger in viewing the eclipse without protective eyewear.
Do not look at the uneclipsed or partially eclipsed sun through an unfiltered camera, telescope, binoculars, or other optical device.
Do not look at the sun through a camera, a telescope, binoculars, or any other optical device while using your eclipse glasses or hand-held solar viewer – the concentrated solar rays will damage the filter and enter your eye(s), causing serious injury.
If the filters on your eclipse glasses are torn, scratched, punctured or coming loose from their cardboard or plastic frames, discard them.
If you are unable to get glasses, one way of indirectly observing the eclipse is by using a pinhole projector. NASA has instructions on how to do this, as well as files to print out and use, here.
Big events also mean big opportunities for scammers and unscrupulous businesses. With a rare event like this, it is important to plan carefully and to trust your instincts. Here are some things to be wary of while you get ready for the eclipse.
Counterfeit Eclipse Glasses
To view the solar eclipse directly without damage to your eyes, you need special solar filter glasses. These are much more powerful than sunglasses. While sunglasses only block about 50% of the sun’s rays, solar filter glasses block more than 99.99%. Unfortunately, many of the solar glasses available online may be counterfeit or do not meet safety specifications. Your best bet is to stick with a brand whose glasses are certified by NASA and the American Astronomical Society (AAS). Here is a list of reputable vendors from AAS.