A total solar eclipse will be sweeping the US mainland on Monday, August 21. Here's our round-up of need to know details:
1. Where will it be?
A total solar eclipse occurs when the moon passes between the earth and sun, blocking its light temporarily. It's a pretty awesome opportunity to see our near Earth objects interacting and an opportunity to use one my favorite but little-used words: syzygy. (Syzygy is the aligment or confluence of objects, stemming from the Greek for yoked together. It's not always refering to celestial bodies but often does. It's also the best Scrabble word of all time.)
From Charleston, South Carolina to Portland, Oregon, millions of Americans will be in the path of the total eclipse. Here is the most comprehensive interactive map of its travel times we've seen -- just be sure to note that it's in Universal Time!
Not in the path of totality? Fear not! Cities as far away as Chicago, New York and elsewhere in the country will still see 70-80% totality -- meaning the sun will be mostly but not completely covered. (Which is still pretty cool.)
2. What will it be like?
Eclipses have been around since astronomical objects began orbiting. In human history, they've been recorded as far back as the Babylonians (and you can read more about the history of observations and the omens which attended them on The Conversation).
In the path of totality, the air temperature can drop, animals can become anxious or upset their usual rhythms, and the sudden darkness can sometimes trigger sensor-driven city lighting. Astromaven talks details. The writer Annie Dillard explains the human experience in a beautiful essay currently reprinted in The Atlantic:
It began with no ado. It was odd that such a well advertised public event should have no starting gun, no overture, no introductory speaker. I should have known right then that I was out of my depth. Without pause or preamble, silent as orbits, a piece of the sun went away. We looked at it through welders’ goggles. A piece of the sun was missing; in its place we saw empty sky.
3. How can I see it?
You know you should never stare directly at the sun. And it's still true during the eclipse.
You can either get special viewing glasses (make sure they are licensed and from a reputable source!) or create a pinhole camera. Our friends at CIERA -- Northwestern's Center for Interdisciplinary and Experimental Research in Astrophysics -- have created a handy how-to guide to do just that!
4. Can I be part of something?
Here in Chicago, lots of organizations are hosting viewing parties. The Adler Planetarium is hosting Eclipse Fest and will have satellite viewing sites across the city (and is giving away free viewing glasses with admission while supplies last!), but lots of other places from the Parks District to the Hancock are getting involved, too.
5. Yeah, but can I be a part of, you know, science?
Of course! NASA's done a lovely round up of eclipse-related citizen science projects where you can help collect data. Most (like air temperature data) can be done through an app on your smartphone, connected to your GPS. If you're looking for something a little more homegrown, you can even do some animal behavior observations when your cat (or friendly garden coyotes and bats) respond to the surprising nightfall for the California Academy of Sciences.
6. What if I miss it?
If you can't sneak out for a lunch time peek or are way too far from the flight path to see much, this isn't the only eclipse. Here's an interactive globe from Scientific American to help you plan the next one in your area or your next eclipse hunting excursion (bring on 2045!).