On August 21, 2017, the moon will cast its shadow across most of North America, with a narrow path of totality tracing from Oregon to South Carolina. Tens of millions of people will have a chance to see something that the continental US hasn’t seen in ages — a total eclipse of the sun. Will you be ready?
The last time a total solar eclipse visited a significantly populated section of the US was in March of 1970. I remember it well as a four-year-old standing on the sidewalk in front of my house, all worked up about space already in those heady days of the Apollo program, gazing through smoked glass as the moon blotted out the sun for a few minutes. Just watching it was exhilarating, and being able to see it again and capitalize on a lifetime of geekiness to heighten the experience, and to be able to share it with my wife and kids, is exciting beyond words. But I’ve only got eight months to lay my plans!
Where and When
First, the basics. Totality will cross the Pacific coast at 17:15 UTC just north of Depoe Bay, Oregon. It will proceed across southern Idaho into Wyoming – Grand Teton and Yellowstone visitors will have quite a treat – then Nebraska, a tiny corner of Kansas, Missouri, small slivers of Illinois and Kentucky, across Tennessee and a fraction of North Carolina, finally heading out to sea between Charleston and Myrtle Beach, South Carolina at 18:49 UTC. Need to see how close you are to totality and when you can expect the eclipse to start? NASA has put together a handy interactive Google Map for just that purpose.
Your first task is to decide where you’re going to watch events unfold. Assuming you want to witness totality, quite a few major cities are in or very near the path – Salem, Oregon; Boise, Idaho; Lincoln, Nebraska; Kansas City and St. Louis; and Nashville, Tennessee. Viewing opportunities will abound in and around these cities, so it won’t be much of a chore to step outside at the appointed hour. However, I’ve heard that the sight of the moon’s shadow racing across the land is especially exciting if you can get somewhere elevated. So on the 21st you’ll find me sitting on the top of Menan Butte outside of Rexburg, Idaho, watching the shadow approach across the plains to the west.
It’s worth noting that the path of totality east of the Mississippi is within a reasonable day’s drive of about half the population of the United States. If you need to travel to get to totality, you’ll need to think ahead, because you’re going to be competing with a lot of other eclipse watchers in addition to the usual summer travelers. Destination locations, like national parks and major resort areas, are likely to be booked. In fact, it may be too late already — I can’t find a hotel room in Idaho Falls for that weekend to save my life. Looks like we’ll be camping by the side of the road.
How to Observe
Once you decide where to be and make the appropriate sacrifices to the weather deity of your choice for clear skies, what are you going to do? Most people will be content with just watching, but no matter where you go there are likely to be a ton of people and a party atmosphere, so be prepared to be sociable.
For direct viewing before totality, you’ll want to think about eye safety. At more populated viewing sites, vendors will no doubt be doing a brisk business selling eclipse glasses at incredible markups, so you might want to order yours ahead, and maybe have a few extras to share with unprepared watchers. A shade 14 welding helmet filter will also do the trick, as will fully exposed and developed black and white photo film, as long as it’s a silver-based film. Pinhole cameras are a good choice too, but you’ll need at least a meter focal length to project a decent image. If you don’t feel like toting a refrigerator box around, projecting the image from a telescope or binoculars onto a screen is a good way to go too.
And don’t forget to bring a flashlight – it’ll be as dark as night for the few minutes that it takes for the moon’s shadow to pass.
Eclipses Aren’t Just for Watching
Hackers and space geeks might not be content to just watch, of course. Personally, I’ll be tending an array of cameras to capture the event, as I suspect many others will. Many ham radio operators will be trying to use daytime ionospheric skip to work long-distance contacts during the eclipse, and there are some coordinated efforts to conduct experiments during the eclipse. Others with a scientific bent and the right resources might choose to replicate Sir Arthur Eddington’s confirmation of Einstein’s General Relativity during a 1919 solar eclipse; the bright star Regulus in the constellation Leo will be close enough to the sun to allow measurement of the gravitational lensing Einstein predicted. And you might even be able to get funding for public outreach efforts to enhance the viewing experience.
No matter how you choose to spend Eclipse Day 2017, enjoy it. If you do happen to miss it, don’t worry — the US gets treated to another total eclipse in 2024.
And if you happen to find yourself on Menan Butte outside of Rexburg, Idaho, come on over and say hi.