Once you’ve got that nailed down, all that’s left to do before Aug. 21 is learn how to watch the eclipse safely and purchase safe-viewing accessories.
Solar eclipse safety
The term “solar eclipse” is often used to describe both total solar eclipses and partial solar eclipses, which can cause confusion about viewing safety.
Technically, a total solar eclipse occurs when the moon completely covers the sun, when viewed from Earth. A partial solar eclipse is when the moon covers part of the sun.
Both a total and partial eclipse will be visible from the U.S. on Aug. 21, during a rare eclipse route across the breadth of the country: What you will see depends on where you are located at the time.
Folks in certain parts of 14 states will be able to witness a total eclipse — which will last no more than a minute or two. See “13 Best Spots to Watch the Upcoming Total Solar Eclipse” to learn more about where and when the total eclipse will be visible.
It’s safe to look only during when the sun is totally eclipsed by the moon, according to NASA. So if you are in those states during the moments of the total eclipse, when only the sun’s corona is visible, you can watch briefly without safety glasses. But as the moon moves into and out of place, you will see just a partial eclipse, so common sense cautions against damaging your eyes by looking at the sun remain in effect.
A partial eclipse is what will be seen in most of the U.S. on Aug. 21, NASA said in a recent announcement. So you must use protective eyewear if you want to watch the phenomenon.
As NASA summarizes on its “Eclipse Eyeglass Safety” webpage:
“A total solar eclipse is about as bright as the full Moon — and just as safe to look at. But the Sun at any other time is dangerously bright; view it only through special-purpose safe solar filters.”
To be clear: You can permanently damage your vision by looking at the sun with your naked eye at any time outside of the brief moment of a total eclipse.
Safe eyewear for solar eclipses
NASA advises using only protective eyewear that meets all of these criteria:
- Has certification information with a designated ISO 12312-2 international standard
- Has the manufacturer’s name and address printed somewhere on the product
- Does not have scratched or wrinkled lenses
- Is not older than three years
- Is not a homemade filter
- Is not an ordinary pair of sunglasses — not even very dark ones
Check out NASA’s flyer that shows you how to tell if eyewear meets these criteria.
Five manufacturers produce eclipse viewing accessories that meet the ISO 12312-2 international standard, as verified by the American Astronomical Society. Those with bases in the U.S. include:
You may find some products have already sold out, though. Before you buy anything, make sure that the shipping you choose will get your purchase to you before Aug. 21.
You may be able to score a free pair of eclipse glasses from a local library. Several thousand libraries nationwide are providing some 2 million pairs for free. NASA describes them as “safety-certified glasses.” To find a participating library, visit the STAR Net website.
Failing all of those options — or if you just want to be extra protective of your vision — you can enjoy the eclipse from the comfort of your air-conditioned living room or computer desk by simply visiting NASA.gov/EclipseLive on Aug. 21. NASA Television will cover the eclipse in real time as it moves from coast to coast for a special program called “Eclipse Across America: Through the Eyes of NASA.”
Do you have big plans for the solar eclipse? Share them by commenting below or on our Facebook page.