As millions of Americans prepare for next week's total solar eclipse, scammers are lying in wait to take advantage of people looking for last minute eclipse glasses.
The glasses are key to safely viewing the eclipse on April 8. Experts warn that watching it without proper protection or with glasses that haven't met certain qualifications could cause eye damage.
Eclipse glasses are not regular sunglasses; they're thousands of times darker and must comply with the ISO 12312-2 international standard. In addition to reducing the sun's visible light to a comfortable brightness level, the glasses also block potentially harmful ultraviolet and infrared radiation.
As the eclipse nears and retailers run out of real eclipse glasses, scammers may be out with counterfeit and fake eclipse glasses that won't protect your eyes, the American Astronomical Society warned.
"There's no way to tell just by looking at them whether eclipse glasses are genuinely safe, but it's easy to tell if they are not safe," Rick Fienberg, Project Manager of the AAS Solar Eclipse Task Force, said in a statement.
First, put your glasses on indoors and look around. You shouldn't be able to see anything, except very bright lights, which should appear very faint, according to the AAS. If you can see anything else, such as household furnishings or pictures on the wall, your glasses aren't dark enough for solar viewing.
If your glasses pass the indoor test, take them outside on a sunny day and look around again. According to the AAS, you still shouldn't see anything through them, except perhaps the sun's faint reflection off a shiny surface or a puddle.
If your glasses pass that test too, glance at the sun. The AAS says you should see a sharp-edged, round disk that's comfortably bright.
If your glasses pass all three tests, they are probably safe, according to the AAS.
To see if your glasses are legitimate, you can also check the AAS website, which has published a list of reputable manufacturers and authorized dealers.
"If we don't list a supplier, that doesn't mean their products are unsafe — there are just too many brick-and-mortar and online sources of solar viewers and filters for us to vet them all. But they all get their products from a relatively small number of manufacturers," the AAS said.
"As long as you can trace your filters to a reputable vendor or other reliable source, you should have nothing to worry about," the society added. "What you absolutely should not do is search for eclipse glasses on the internet and buy whatever pops up in the ads or search results."
Also note that NASA doesn't approve or endorse commercial products, so any claim to the contrary is a warning sign that you're not dealing with a trustworthy seller.
If you don't have eclipse glasses or a handheld solar viewer, you can use a pinhole projector, which has a small opening (for example, a hole punched in an index card) and projects an image of the sun onto a nearby surface.
The path of totality -- where the moon's shadow completely covers the sun -- will slice right through the country, passing over many densely populated cities. The eclipse is expected to be breathtaking, with a totality duration of 4 minutes and 27 seconds -- nearly twice as long as the last total eclipse in 2017.
The eclipse's path of totality will move through the country beginning in Texas around 12:23 p.m. CT and ending in Maine around 4:40 p.m. ET.
An estimated 31.6 million people live in the path of totality, according to NASA. It will be able to be seen in parts of Texas, Oklahoma, Arkansas, Missouri, Illinois, Kentucky, Indiana, Ohio, Pennsylvania, New York, Vermont, New Hampshire and Maine. Small parts of Tennessee and Michigan will also experience the total solar eclipse.
You don't need to live within the path of totality to see the eclipse. NASA says 99% of people who reside in the U.S. will be able to see the partial or total eclipse from where they live. Every state, plus parts of Alaska and Hawaii, will experience at least a partial eclipse, where the moon covers most but not all of the sun. Here's what the total eclipse will look like in each U.S. state.
What you can see during a total solar eclipse depends on the weather and the location from which you view it. You need clear skies to have the full eclipse experience, with a clear view of the sun and moon. You may be able to see a 360 degree sunset, some particularly bright stars or even planets in the darkened sky. The air temperature will drop and often an eerie silence will settle around you, NASA says.
The next total solar eclipse visible from the U.S. won't happen again until 2044.