On August 21, 2017, a solar eclipse will be visible across a section the continental United States, coast to coast, for the first time since 1918.
A solar eclipse occurs when the Moon passes between the viewer on Earth and the sun, completely—and perfectly—blocking out the full diameter of the sun. During this event, if you are within the path of totality (the shadow of the eclipse), the sky darkens and you will be able to see the solar corona, the extended atmosphere of the sun made up of plasma and reaching millions of miles beyond the part of the sun that is normally invisible to us. This is, by all accounts, a spectacular and life-changing event. Anywhere else in the country, outside the path of this shadow, you will see partial phases of the eclipse. And while I’ve not yet personally seen one, I have nearly blinded myself observing the sun, so using precautions when viewing the eclipse is critical.
WHERE TO GO
If you plan on viewing the total eclipse, you will need to head to a part of the country where the 70-mile wide shadow will cross the continent. It will enter the US on the Oregon coast, then sweep across the country, exiting in South Carolina. A complete map of the eclipse path can be found here. NASA also has a website up for this event.
TIMING AND EXPERIENCE
If you are in the path of totality, the eclipse begins in Oregon at 10:15 Pacific Daylight
Time, and ends on the shores of South Carolina 94 minutes later. As the shadow approaches your location, you will see an increasingly large portion of the sun darkened by the mass of the Moon. A few moments before totality, you may see the shadow moving towards you across the landscape from the west as it rapidly approaches at a speed of between 2400 mph in Oregon to 1500 mph in South Carolina. As totality begins, just before the sun is completely covered by the Moon, you will see bright points of light along the edge of the disk called “Baily’s Beads.” These are bits of sunlight skimming through valleys and crevices in the lunar surface, and last for just a few seconds. Then—totality. At the centerline of the Moon’s shadow, this phase will last for about two minutes, to two minutes, forty seconds, depending on your location. At this time, the sky will be dark as late twilight—animals will react to what they perceive as sunset, temperatures will drop, and wind may blow as the air mass around you becomes colder. The solar corona will be visible and brighter stars will appear. Steve Fentress, director of the Strasenburgh Planetarium in Rochester, New York, and author of the new astronomy book “Sky to Space,” says that there will be other things to look at during this time: “During totality in this eclipse, the sky should become dark enough for Jupiter to be seen off to the Sun's lower left and Venus to the upper right.” Both will add to the spectacle.
Then, just as it began, the Baily’s Beads will appear on the opposite side of the lunar disk, and the sun will gradually emerge, moving into partial phases again. Then the large crowds will begin their long journey home, through massive traffic jams and throngs of exhausted but overjoyed eclipse-watchers.
A clever wag in Bend, Oregon appears to have coined the term “apocaclypse” for what is expected to be a massive short-term migration of people to the path of totality a day or so before the 21st. Most of the regions within the path are rural and served by two-lane highways at best, so traffic will snarl on the morning of the event, and local services will be strained. Emergency responders will likely not be able to get to people in need, food will be hard to come by, and even budget motels are already charging upwards of ten times their normal prices—hence the “apocaclypse.” Be sure to bring food, water, and any medical supplies you may need, and be prepared to spend many hours getting in and especially out of the area—it will be like a Beatles reunion (or ten Comic-Cons, depending on your generation) regarding traffic flow. Be prepared.
VIEWING THE ECLIPSE
This cannot be stressed enough: be smart and view the eclipse safely! Even short glances at the sun can cause permanent eye damage. Remember how kids used to burn ants under a magnifying glass? That’s exactly what the lenses in your eye will do to your retina if you get a shaft of direct sunlight shining into your unprotected eye for more then a moment.
PARTIAL PHASE VIEWING CAUTIONS
To observe any phase of the eclipse before or after totality—and even right on the verge of it—you need certified eye protection. There are hundreds of vendors all over the country and online selling “eclipse glasses” and “eclipse viewers”… but be wary. You must be sure that the viewing device you buy is rated for safety by the International Standards Organization, also known as ISO. Their rating, which must be printed on the viewing device, should read “ISO 12312-2.” This means that the viewing medium is properly made to block all harmful solar radiation and can be used to safely view the sun anytime. But there are many unscrupulous parties out there making fake knockoffs with cheaper materials, and some even have the ISO certification falsely printed on them. How can you make sure you are getting the real deal?
The only way to be sure that you are protecting your eyes, and those of your family, is to buy your viewing device from a reputable source. Some of the safe manufacturers are:
Ideally, you will have time to buy yours directly from the manufacturer from their website, if available. But most of us will go to a store or website to purchase. Retail outlets said to be reliable by the American Astronomical Society include:
Some reputable online outlets suggested by the same organization are: