Fact Check

Answering Your Questions About the 2017 Total Solar Eclipse

The 21 August 2017 celestial event will be viewable to millions in North America, but taking the proper precautions is important.

Published Aug. 19, 2017

 (Igor Zh. / Shutterstock.com)
Image Via Igor Zh. / Shutterstock.com
We check an assortment of claims about the 2017 total solar eclipse over North America.

A total solar eclipse will be visible across swaths of North America on 21 August 2017, the first of its kind since 1974:

The celestial event has stirred excitement and mass travel to the regions from which totality will be visible (the rest of the continent will still see a partial eclipse). Naturally, it has also sparked a whole cornucopia of misinformation and hoaxes. While NASA has published its own list of misconceptions about eclipses, we want to address some rumors about the event ourselves:

Was the eclipse calculated for the wrong year?

One extremely bogus claim is that the date was miscalculated by one year because NASA failed to "carry the one".  NASA astrophysicist C. Alex Young says that is a popular hoax:

I know people have checked their numbers more than once. I've heard that one — that's a good one.

Young, an associate director at the agency's Goddard Space Flight Center in Maryland, will host a live online broadcast tracking the eclipse across the U.S. (We should note that watching the livestream on a laptop or desktop computer will not cause eye damage.)

Around 10 million people, he said, reside along "path to totality," with more traveling to areas where it will be visible. According to NASA:

The path of totality is a relatively thin ribbon, around 70 miles wide, that will cross the U.S. from West to East. The first point of contact will be at Lincoln Beach, Oregon at 9:05 a.m. PDT. Totality begins there at 10:16 a.m. PDT. Over the next hour and a half, it will cross through Oregon, Idaho, Wyoming, Montana, Nebraska, Iowa, Kansas, Missouri, Illinois, Kentucky, Tennessee, Georgia, and North and South Carolina. The total eclipse will end near Charleston, South Carolina at 2:48 p.m. EDT. From there the lunar shadow leaves the United States at 4:09 EDT. Its longest duration will be near Carbondale, Illinois, where the sun will be completely covered for two minutes and 40 seconds.

The number of people who will be able to witness the eclipse, Young said, has fueled the interest in this particular event, as well as the connectivity and access that will allow more to follow it:

So many people have access to what's happening but also, everyone in the United States — all of North America — are gonna experience at least a partial eclipse. So many people have access to this online but will get to experience this in some sort or another. There hasn't been anything that broad-reaching ever in terms of astronomical events like this. It really is unprecedented.

Are eclipses harmful to your health?

Only if you look directly at the sun before or after totality without the appropriate protective glasses. An eclipse is nothing more or less than the moon passing between the sun and the earth, casting a large shadow over the earth as the moon blocks the sun's light. This allows the solar corona, which is luminous electromagnetic radiation that is always present but normally too faint to see, to be briefly visible in the form of a ghostly (sometimes green) light. It does not bring any new radiation into the planet's atmosphere, and thus cannot spoil or poison food, affect a developing fetus, or accurately foretell any impending disaster. And no, eclipses don't send expectant mothers into labor.

Are eclipse glasses worthless?

The National Aeronautics and Space Administration partnered with the American Astronomical Society to release a list of vendors and retail chains who are selling glasses that meet the 12312-2 international safety standard. Young told us that welder glasses can also be used, so long as they meet the same standard.

Both groups have also released guides for watching the eclipse with either a pinhole camera or through optical projection (which can be done by using binoculars or a telescope, though at risk of damaging each device). Using regular sunglasses, however, would be worthless for the occasion — and even potentially harmful, said the agencies:

While you're enjoying a "comfortable" view of the "dim" Sun, solar infrared radiation could be cooking your retinas. And you wouldn't know till later, because your retinas don't have pain receptors. Only after the eclipse, when you notice blind spots or other vision problems, would you realize you'd made a catastrophic mistake.

The same is true of ordinary camera filters, old X-rays, mobile phone camera lenses, and smoked glass; viewing the eclipse through them will offer no protection to your eyes, although you can take photographs of the eclipse with a camera or a cell phone — with a proper filter attached.

However, even if you ordered the proper glasses, it's important to keep in mind that not all eclipse viewing glasses are equal. On 12 August 2017, less than two weeks before the eclipse, retail giant Amazon issued a recall for certain counterfeit viewing glasses. They offered full refunds, but left people scrambling for eye safety. The move created a secondary panic when legitimate and verified eclipse viewing glasses were caught up in the recall as well:

"Safety is among our highest priorities. Out of an abundance of caution, we have proactively reached out to customers and provided refunds for eclipse glasses that may not comply with industry standards. We want customers to buy with confidence anytime they make a purchase on Amazon.com and eclipse glasses sold on Amazon.com are required to comply with the relevant ISO standard," the company said in a statement.

Amazon said customers who did not receive an email purchased glasses that were safe to use. The company did not reveal how many glasses were recalled or how much money was refunded. Anyone who is concerned about their eclipse glasses but did not receive an email about the recall can reach out to Amazon customer service.

Viewers don't need to have one black side and one reflective side in order to be effective, despite what you may have heard, but special solar filters are essential to look at the event directly (until full totality) without frying your eyes. In their absence, or in the absence of an appropriately darkened welding filter (Shade 12 or above) optical projection or a homemade pinhole camera is the safest choice.

Do eclipse glasses expire?

NASA said that anyone who bought one of the recommended sets of glasses can use them indefinitely as long as they are not damaged:

If your eclipse glasses or viewers are compliant with the ISO 12312-2 safety standard, you may look at the uneclipsed or partially eclipsed Sun through them for as long as you wish. Furthermore, if the filters aren't scratched, punctured, or torn, you may reuse them indefinitely. Some glasses/viewers are printed with warnings stating that you shouldn't look through them for more than 3 minutes at a time and that you should discard them if they are more than 3 years old. Such warnings are outdated and do not apply to eclipse viewers compliant with the ISO 12312-2 standard adopted in 2015.

Can you watch the eclipse through your phone's "selfie" mode?

You can view the eclipse through your phone's "selfie" mode so that you can watch it on your screen. That will spare your eyes, but be sure to make certain it won't burn your phone's photoreceptors; for example, Apple says iPhones and iPads are safe to point at the sun because the lens is so wide, meaning that the full force of the light the sun emits is relatively dim, but if you use a telephoto clip-on lens or something else to magnify the sun and its light, a filter is probably a good idea.

Are pets in danger of eye damage if they are outside during the eclipse?

While humans need to take precautions to guard their eyes, the consensus among experts is that pets are in no immediate danger. Author and veterinarian Dr. Jessica Vogelsang explained to us:

It's hard for me to criticize such a well-meaning warning, because there's really no harm in following the advice to keep pets inside during the eclipse. It's better to be too cautious than not cautious enough. But in the interest of offering a realistic risk assessment, the likelihood of a pet ruining their eyes the same way a human would during an eclipse is much lower- not because the damage would be any less were they to stare at the sun, but because from a behavior standpoint dogs and cats just don't have any interest in doing so. We tend to extrapolate a lot of things from people to pets that just doesn't bear out, and this is one of them.

I've seen lots of warnings from the astronomy community and the human medical community about the theoretical dangers of pets and eclipses, but I'm not sure if any of them really know animal behavior all that well. It's not like there's a big outcry from the wildlife community to go chase down coyotes and hawks and bears and give them goggles either. While we in the veterinary community absolutely appreciate people being concerned about their pets' well-being, this is a non-issue for us.

Pet owners unsure of how their pet would react to the eclipse, she said, should keep them inside since "if nothing else they'll avoid the chaos outside from all the partygoers."

Angela Speck, a co-chair of the AAS National Solar Eclipse Task Force, had the same advice for pet owners in a video NASA released on 21 June 2017:

It's no different than any other day. On a normal day, your pets don't try to look at the sun and therefore don't damage their eyes, so on this day they're not gonna do it either. It is not a concern, letting them outside. All that's happened is we've blocked out the sun, it's not more dangerous. So I think that people who have pets want to think about that. I'm not going to worry about my cat.

Young added, "The reality is that animals are smart enough not to look at the sun, even the partially eclipsed sun." He did note, however, evidence that other animals such as whales and dolphins have observed eclipses once they begin, before avoiding the sun once they concluded.

Will the eclipse cause earthquakes and damage infrastructure?

Young refuted the notion that the eclipse would be responsible for any tremors or infrastructure damage, though he anticipated traffic increases for people coming or going from eclipse-centered gatherings, as well as a possible shortage of other necessities:

I've been hearing reports that pretty much all the suppliers of porta potties have been completely tapped out and everything's rented. I suspect there will a lot of people buying water and food so that's gonna bring up the numbers quite a lot. There's even a concern that it might become difficult to get gasoline. I don't have any hard numbers, but it's very possible that it could be an issue.

For those outside the path of totality or who wish to spare their retinas, the eclipse can be viewed online at multiple web sites.

Do revised maps show inexplicable deviations from the eclipse's totality path?

There have been no revisions to NASA's map of where the solar eclipse can be viewed, nor are there any reported irregularities or strange deviations from the path of the shadow:

Map of eclipse totality across North America

An interactive map can be viewed here. (As you can see, there are no strange jogs or veers.)

Conspiracy theorists have also claimed that the eclipse would foreshadow the end of the world, or the appearance of Nibiru a fabricated "renegade planet" people have also said would destroy the Earth.

Will NASA launch bacteria-filled balloons during the eclipse?

Yes, kind of. More than fifty high-altitude balloons will be released across the United States for the Eclipse Ballooning Project, which is led by Montana State University's Angela Des Jardins. The balloons will live-stream the event from high altitudes:

Students will conduct high altitude balloon (HAB) flights from around 25 locations across the 8/21/2017 total eclipse path, from Oregon to South Carolina, sending live video and images from near space to the NASA website. While the cost of conducting HAB flights is low, there are  interesting challenges presented by this highly collaborative effort. These challenges are broad – technical, political, administrative – and present an amazing hands-on learning opportunity for the students who participate. Several potentially long lasting partnerships with other federal agencies and with industry will develop. Several partnerships, including with ATA Aerospace, which conducted the Red Bull Stratos flight, are already in progress.

In addition to the primary camera payloads that students will build to provide footage of the moon’s shadow on Earth and the darkened sun, each team will fly a secondary payload of their choice. Links to information and pictures about each team’s secondary payload will be included online. In a second effort in collaboration with NOAA, dozens radiosonde balloons will be flown to gather important science data on eclipse stratospheric temperature and ozone fluctuations.

Some of the balloons will carry metal tags coated with a type of bacteria called Paenibacillus xerothermodurans, which is an especially hardy life form found in the soil outside the Kennedy Space Center in 1973 and isolated in NASA clean rooms, so that their resilience in the upper layers of the atmosphere can be tested when the balloons return to the ground. Because of the specific conditions in the stratosphere that are affected by the eclipse — low temperatures, lower oxygen levels, and high levels of ultraviolet radiation — the experiment will potentially offer inside into how bacteria might behave on Mars.

Students will track the balloons using GPS tags, then and mail the tags back to NASA once they find them. (Despite rumors and speculation, the bacteria is not harmful to humans or the environment.)

Are people selling tickets to view the eclipse?

Yes. In some areas, observatories and event planners are offering tickets to specific viewing areas and festivals, particularly along the "totality path". However, the eclipse will be above most of North America, so there is no need to buy a ticket unless you feel like paying to share the experience with like-minded strangers. Even if you do, though, most of the events appear to have sold out fairly quickly.

Will a group of coal industry people be protesting the eclipse?

A group of people purporting to be associated with the coal industry have put out a press release on 11 August 2017, saying that they plan to hold a protest in the western Kentucky town of Hopkinsville (which has temporarily rebranded itself as Eclipseville, or the "point of greatest eclipse") in order to bring attention to how important their industry is, and how it has been mistreated by the "fake news" media:

Kentuckians for Coal is an ad-hoc coalition of miners, union officials, family members and coal users created to defend the Kentucky coal industry against encroachment from renewable energy industries and from economic development initiatives aimed at lessening America's dependence on coal. Kentuckians for Coal stands against the eclipse and those who worship it.

The protest is scheduled for high noon on Monday, August 21, 2017, in front of the offices of the Kentucky New Era newspaper at 1618 E. 9th Street, Hopkinsville, just as the eclipse begins. The "totality"--the complete blocking of the Sun by the Moon--will start at 1:24:39 and will last 2 minutes and 40 seconds.

The protesters chose the New Era office location because the newspaper and other fake-news media have been over-hyping the eclipse because of its potential to boost local economic development, while ignoring the importance of the coal industry.

The story has been picked up by news organizations and blogs as legitimate, but we have found several reasons to be tremendously skeptical. For example, the press release appears to have been written with tongue lodged firmly in cheek:

Hopkinsville, with a population of 33,000, has two other great claims to fame. One is as the birthplace of the world-renowned psychic Edgar Cayce. He made his home in Hopkinsville, and died there in 1945, after predicting the date of his own death. The other is the notoriously pagan annual celebration of extra-terrestrials, which commemorates a terrifying landing by space aliens in 1955, 62 years ago to the day, known as the Little Green Men Festival.

When more than 250,000 people descend on the town for four days in August, including busloads of Amish from Pennsylvania and rumored Arab royalty, hucksters will peddle overpriced souvenirs as area hotels jack up their room rates by 400%; gas stations run out of gas; and cell phone service crashes due to demand. Traffic jams, a run on available food, an invasion of prostitutes, and rowdy crowds will test the patience of both local residents and the extra law enforcement brought in to maintain order. In addition, there is the serious threat to spectators' eyesight if they look at the sun without special eclipse-viewing glasses.

Secondly, there appears to be no Joseph Calvin (no matter his rank) living in Hopkinsville, and no one has responded to a voice mail message we left at the number supplied in the release. Finally, as of 2015, there are no more union coal miners working anywhere in the state of Kentucky.

Do personal electronics such as cellphones present a danger due to "cosmic rays," "gamma rays," or "cosmic gamma rays"?

Among rumors spreading on social media about the solar eclipse were ones that involved the putative danger posed by cell phones on the day of the event:

I heard something about comic rays and about not being able to use our phones during 12:30 p.m to 3:30 a.m

However, the claim circulated for years prior to the eclipse and still made "no scientific sense whatsoever."

Does an eclipse happen only during the full moon, new moon, or doesn't it matter?

According to NASA, eclipses can take place during a new moon, under certain circumstances:

Eclipses only occur if the Moon is located within 0.5 degrees of the plane of the ecliptic, on a line that passes through the center of the Sun and the Earth. The Moon travels along an orbit that is inclined by 5 degrees to the ecliptic plane, so there are only two opportunities each month when it passes through the plane of the ecliptic. These points are called the ascending and descending nodes. Eclipses of the Sun only occur if new moon occurs when the Moon is near of one of these nodes. A similar argument explains why lunar eclipses do not occur every full moon at the node opposite the Sun from the Earth.


NASA.    "Eclipse 101."

International Organization for Standardization.     "ISO 12312-2:2015."

American Astronomical Society.      "Reputable Vendors of Solar Filters & Viewers."

American Astronomical Society.     "Projection: Pinhole & Optical."

NASA Jet Propulsion Laboratory.     "How to Make a Pinhole Camera."

NASA.     "Eclipse Live."

"2017 Total Solar Eclipse Science Briefing."     YouTube, uploaded by NASA.    21 June 2017.  

Netburn, Deborah.    "Will the Great American Eclipse Make Animals Act Strangely? Science Says Yes."     Los Angeles Times.    9 August 2017.

NASA. "Why Don't Eclipses Occur Every New Moon?"

Austin, Jon. "'Black Moon' eclipse to signal 'end of the world' in just FIVE DAYS." Express. 16 August 2017.

Arturo Garcia is a former writer for Snopes.

Brooke Binkowski is a former editor for Snopes.