The Great American Solar Eclipse of Monday, August 21, 2017 is now 29 days away. The eclipse is total, and the path of totality sweeps across the entire country from Oregon to South Carolina. If you’ve not seen a total solar eclipse, and you’re considering getting into the path of totality, do so. I cannot stress enough how incredible the experience is. A total solar eclipse is, perhaps, the most fantastic sight in nature. I’ve seen two totalities (1979 and 1991), and I’ve literally been waiting for this event for decades. I’m positioning myself near Madras, Oregon, where I will get about 100 seconds of totality.
For most of the lower 48 states, the eclipse will be partial, and will still be an enjoyable experience. Some school districts will already be in session on August 21, including my own (yes, I’ll be taking two days off from work). Here are a few tips on how to safely view the eclipse, and to get your students excited about the event.
In southern California where my school is located, the moon will cover about 62% of the Sun at maximum eclipse, which occurs at about 10:20 am PDT. The Sun will be too bright to directly look at, even at maximum eclipse, so safety is paramount. First of all, I highly recommend purchasing a pair of so called “eclipse glasses”. Go to My Science Shop (a subsidiary of Astronomy Magazine) to find these excellent wraparound glasses.
These wraparound glasses (I’ve bought six pairs for family and friends for our trip to Oregon) safely allow you to look directly at the Sun. They’re $20 apiece, and well worth it (you can also use these glasses to look at the Sun at any time, for that matter). You can also buy a 5-pack of these cheaper versions for $10. I prefer the wraparounds, though, for the extra safety and durability.
You can also observe the eclipse with some simple pinhole projections. Prepare your students ahead of time. Take some cardboard and punch some holes in it with a hole punch. Tape tinfoil over those holes and poke a hole in the tinfoil with a pin. Hold the cardboard perpendicular to the Sun’s direction. Cast the Sun’s image onto a piece of white foam board held behind the cardboard. I’ve attached a few photos from the partial eclipse of May 20, 2012, as an example. That eclipse, by the way, was an annular eclipse and, from my location, I observed about an 80% partial.
Another means of projecting is to tape cardboard (with the tinfoil pinhole) over the objective lens of binoculars, but with a wider pinhole. Cast the magnified image onto foam board. If you have a tripod, mount the binoculars to steady the image.
Tree leaves can act as a natural source of pinhole images. Especially at maximum eclipse, look for pinhole images of the near crescent Sun on the ground from sunlight filtering through the leaves. An example of when I observed such images projected onto a white wall is attached.
I’ll prepare my students and my substitute for the event the week prior. I’ll be doing these simple things in Oregon, as well as observing the eclipse, both partial and total, through a Dobsonian telescope with a solar filter.
Lastly, if you’re thinking about getting into the path of totality, take a look at this interactive Google map as an aid.
I wish you all the best in your endeavor to observe the eclipse, with or without students! As part of your preparation, a lesson plan and activity about lunar phases is helpful. You can find a version of my own lesson here.