By: Rhiannon Cook

     This year, on Monday, April 8, most of North America got to witness a near once-in-a-lifetime event: a total solar eclipse. For a brief and incredible four minutes, the moon covered the sun completely, an occurrence known as totality, and made the world go dark – right in the middle of the day.

     A solar eclipse is quite a rare circumstance, and it’s even less often that you have the opportunity to see totality. The last eclipse visible in the U.S. was in August of 2017, and before that, it was in 1979. 38 years separated these astronomical crossovers, and it may be a decade or two before we see another. While we wait for the next one, The Squire was inspired to find out more about solar eclipses, and we took the time to interview Eisenhower’s physics teacher, Mrs. Vanatta, for some fun facts and other information regarding the celestial bodies.

     We already mentioned that solar eclipses don’t happen very often- sometimes 50 or more years apart! But why is that the case? Well, we know that the moon orbits the Earth, and the Earth orbits the sun, so the paths of the moon and the sun are bound to cross. But they don’t do so often because the moon’s orbit around us is not perfectly circular. According to NASA, the moon’s orbit around us is tilted about five degrees differently compared to our orbit around the sun, so they miss each other most of the time, and leave us without an eclipse. “The motion of the sun, moon and our planet is not on the same plane; the orbits are not perfectly circular, their timing is not the same, and the eclipse may appear in different locations,” mentions Vannatta. “A partial eclipse occurs roughly every 1-3 years somewhere on the planet.” With the Earth and moon moving simultaneously, at different rates and in different paths, it is rare that they line up with the sun, and it takes years for them to do so perfectly again. But like Vannatta mentioned, there’s still a chance for a partial eclipse to appear, as their paths draw closer together. Some years will have to pass before we get to see another total solar eclipse.

     Everyone has a fairly general understanding of what a solar eclipse is, but there’s more to how it happens than meets the eye. A solar eclipse is when the Earth, the moon, and the sun, all align perfectly so that it looks like the moon fully covers the sun, from the distance we see it, at least. This alignment of the three planetary bodies is known as a ‘syzygy.’ Though it makes it look like the moon is big enough to cover the sun, we know that the sun and the moon are very different in size. NASA’s research states that the sun’s diameter is about 400 times larger than the moon’s.  The answer to why an eclipse still looks the way it does is perspective. The distance between the moon and us as we see it cross paths with the sun creates the illusion that the circumference of the moon is as big as the sun’s. It’s like using your finger to block the sun from your eyes on a regular sunny day; of course, your finger is millions of times smaller than the sun, but, due to the perspective at which you see your finger and the sun, you can totally block the light out. Now, one might wonder why we can still see a little bit of light from around the moon during the eclipse. The light we see peeking out is the sun’s “corona,” or crown of light – it’s the sun’s outer atmosphere. “The sun’s outer atmosphere, called the corona, is still visible as a faint halo surrounding the darkened disk of the moon. The corona is much dimmer than the sun’s surface, so it’s normally overwhelmed by the sun’s brightness,” explains Vannatta. “But during a total solar eclipse, it becomes visible due to the moon blocking out the sun’s glare.” Usually, the intense light of the sun’s body outshines the corona, and we can’t see it during the day. An eclipse gives us the chance to see this light and creates the infinitely cool appearance of a total solar eclipse.

     Although there is more to it than meets the eye, don’t let the eclipse literally meet your eyes! It is still the sun and its rays shining through, and you need to protect your eyes. That’s why there are special eclipse glasses. These eclipse glasses, unlike regular sunglasses, have special film to filter out the dangerous ultraviolet rays that the sun emits. Vanatta uses the example, “…like our welders wear special glasses to protect their eyes when welding, solar eclipse glasses block out a percentage of the UV light.” And actually, you can look at the eclipse ONLY when it reaches totality. Enough of the sun is covered at that point so that your eyes are safe to take a peek. However, be sure to keep the glasses on for every other moment you watch the eclipse.

     We just saw a solar eclipse and learned plenty about it, but there’s still more to learn about its counterpart, a lunar eclipse. With a solar eclipse, the moon comes between the Earth and the sun, and blocks out the sunlight. A lunar eclipse, however, works in almost the opposite way. The Earth comes between the moon and the sun. “Moonlight” is actually just the moon reflecting sunlight and shining it on us. So when the Earth comes in between that, we get a different effect. “When Earth blocks the sunlight from reaching the moon, it’s like the moon is hiding in Earth’s shadow,” says Vannatta. That shadow the Earth casts keeps most of the sunlight from reaching the moon, but the little that does still reach it makes it look a brilliant red, at least during a total lunar eclipse. There are partial ones too, but they’re harder to notice as the moon is more so just dimmed. Although, it generally happens when the moon is full, so sometimes during a partial lunar eclipse, you can see part of the shadow we cast. Vannatta mused, “Maybe someday you can fly to the moon, grab a lawn chair, grab your glasses and watch.”

     Hopefully you now feel even more blessed to have seen such a rare and exciting phenomenon and have learned something new about our sun and moon and their beautiful exchanges. The Squire thanks Mrs. Vanatta for educating us on such a fascinating experience, and we look forward to the next eclipse!