By Sarah Caughron

First thing is first – what is actually happening on August 21, 2017?

{You can find lots of great online resources – many that I’ve linked in the body of this post – that go into great detail, but for the purposes of not writing a textbook, I will keep my explanation simple and easy to translate.}

Dubbed “the Great American Solar Eclipse,” this extraterrestrial event will darken the skies from Oregon to South Carolina moving west to east across about a 70 mile width of land.  This path of totality allows viewers to see a truly special sight – the moon (totally) covering the sun.  If you are outside of the path of totality (like here in Atlanta), you can still witness a partial eclipse, which will look like the moon taking a bite of the sun. Not sure where you are in the path? Check out this link.  Type in your zip code, and it will generate a cool animation.

The sun is enormous, and it’s important to communicate this enormous size to your kids.  In fact, about 1.3 million earths can fit inside the sun, and the sun makes up about 99% of the total mass of our solar system!  Many individual sunspots (dark regions of magnetic activity on the sun) are bigger than the Earth. The sun is the ONLY star in our solar system, and it’s vitally important to our planet, as we receive energy from the sun.  It’s the star of the show! (ha! See what I did there?)

The sun is 400x larger than the Moon and 400x more distant.   It’s really a matter of cool space geometry that the, in comparison, tiny moon can even appear to cover the sun.  Our moon orbits about  239,000 miles away from earth, traveling at about 2000 mph!  This is the right distance for the moon to appear the same size as the sun as we observe it from land. It takes about 27 days for the Moon to make one trip around Earth. This refers to the sidereal period of moving 360 degrees of revolution when compared to the full cycle of moon phases – the synodic period – which takes around 29.5 days because the Moon has to make up for the orbital motion of the Earth.

In sum, the moon and the sun are not actually the same size – it’s just a glorious geometric happenstance.

Fun fact from the astronomy professor friend: ”Due to Tidal interactions with the Earth, the Moon is slowly retreating away from the Earth (and the Earth’s rotation is slowing down, i.e., the days are getting longer). Every year, on average, the Moon is about 4cm farther away. This speed of retreat is about the same as the speed your fingernails grow. (How cool is that?!?)

Because the Moon is getting further away from the Earth, the time when we Earthlings can experience a total eclipse is slowly coming to an end. In roughly half a billion years, the Moon will be too far away from the Earth for a total eclipse to ever occur again.”

Just how rare is a solar eclipse? 

You might be surprised to learn that this phenomenon isn’t that rare. Interestingly, the sun and moon line up about every 18 months, and there are even people who spend their lives and careers as “eclipse chasers,” traveling all over the world to witness this amazing phenomenon. So, yes, this does happen “all the time,” but it doesn’t happen all the time when a significant portion of the US population has access to experience this event.

What happens during a solar eclipse?

When the moon covers the sun, that’s when the magic happens!  Not only does the sky darken, but the sun’s outer atmosphere, the corona (not the beer!) becomes visible.  You can see this giant ball of gas in action, and people have reported seeing twisting and curling light emitted from the corona. Most of the sun, and all of the corona (“crown” in Spanish and Latin) is made of plasma, the 4th state of matter!

During the solar eclipse, stars and planets will become visible, too, in the middle of the day. Though, it’s important to note that they are always present, but the light from the sun prevents us from seeing them. Keep an eye on the sky for Venus, Mars, Mercury, and Jupiter (see illustration below)!  Other features of the solar eclipse include the diamond ring effect and Bailey’s beads, which I’ve labeled below, so be on the lookout for these characteristics as you watch the eclipse. Depending on where you are along the path of totality, some viewers will be able to experience totality for as long as about 2 minutes, 40 seconds to only a few brief seconds in other locations.

Fun fact from the astronomy professor about the corona: “The shape of the corona depends on the magnetic field of the Sun, which is constantly changing and has an activity cycle that lasts 11 years. Since the magnetic field of the Sun is so complex, the view of the corona during every eclipse is unique and offers valuable, new scientific data that is only available during eclipses.”

What to expect when you’re eclipsing: How much time is this thing going to take?

This is perhaps the most important piece of this post! While it is a matter of just walking outside and looking at the sky, it isn’t quite that simplified.  It’s true that the main event is up to 2 minutes and 40 seconds of totality (depending on your geography), but it’s important to allot enough time to view the eclipse. Keep in mind that traffic will be a beast.  I am leaving on Saturday for the Monday afternoon eclipse viewing (that might be a touch ambitious, but I have the option to leave on the weekend, so why not!?). If you endeavor to leave Monday morning and head into the path to totality, I’d prepare for a Plan B, which might include pulling over and watching from the interstate!

When planning your day, plan for about 180 minutes of eclipse viewing time! I know… 180 minutes?!?  I, too, am struggling with the reality of keeping the solar glasses on my kids – and intact –  for that long! The meat-and-potatoes of the event is about a 20-30 minute segment, so if you have to choose your time wisely, choose the latter part of the ingress.

The ingress, when the moon starts covering the Sun and progresses toward totality, takes about 90 minutes. You’ll need your eclipse glasses for this because it is the only way to directly and safely observe this phenomenon. For about the first 70 minutes or so, it is cool to look up at the sky about every 5 minutes. Around the last 20 minutes of the ingress, you will notice that is when things start getting noticeably darker. The egress, after totality towards the Moon and Sun separating, takes the same amount of time as the ingress, and works mostly in reverse the aforementioned process.

This interactive map from NASA will give you the exact times you can view the eclipse based on your geography.

Use Protection! 

You’ve probably perused articles floating around social media and news reports about proper eyewear? It’s true! People are selling fraudulent eyewear.  If you want to make sure you have the right eyewear, you can follow this link to confirm you’ve got the Right Stuff (yes, another pop culture space reference), but as a rule of thumb, you can’t see through eclipse glasses UNLESS you are staring at the sun. You also want to ensure the lenses are US made with the code ISO 12312-2 printing on them, but THIS IS NOT ENOUGH!  Companies have been caught fraudulently printing this number on glasses.  So, again, please cross-check your viewers with this list to be extra-sure.

Once the eclipse goes into totality, you can remove your protective eyewear and observe it. A total solar eclipse is about as bright as a full moon and safe to view without eye protection. But, as soon as the moon moves out of the path, you MUST resume your protective eyewear.  This is NOT a drill.  Your eyes can get irreversibly damaged from staring at the sun.

The astronomer on eye protection: “Proper eclipse protection only lets in 1/100,000th of the ambient light. Any more, and you are on the train towards the permanent eye damage stop.

People ask this all the time, and I’ll just give the answer: “NO, sunglasses are not good enough… and more NO, you can’t stack a bunch of sunglasses together to get the same effect.”

Do I have eclipse glasses? Oh yes! I am actually leaving Atlanta, taking the kids out of school, and traveling to Nashville for 2 minutes of totality!  Since we will be in Music City, I selected a multi-pack of certified eclipse glasses because 1 pair had a cowboy hat for my space cowboy (cue Steve Miller Band’s “The Joker”). Plus, I thought that having fun glasses would increase my chances of not having to fight and struggle with my kids, pleading with them to keep them on!

I ordered my glasses by searching Amazon for, I kid you not, “wacky eclipse glasses.” I checked that these were made by American Paper Optics, and they arrived as advertised!

Want more info? Here are some reputable links with more detailed explanations as well as cool videos and animations:

• Great American Solar Eclipse: https://www.greatamericaneclipse.com/
• Royalty-free Images, Videos, and Links: (make sure to give credit to the owner/author) https://eclipse.aas.org/resources/images-videos#sequences
• Interactive Solar Eclipse Map: Look up anywhere and get the following details –
  • For Total: Duration; onset; start of totality; end of totality; end of eclipse
  • For Partial: Start time, maximum, and end time. Percent partial
  • http://xjubier.free.fr/en/site_pages/solar_eclipses/TSE_2017_GoogleMapFull.html
• Good Eclipse Animations: http://space.rice.edu/eclipse/eclipse_animations.html
• Like the cover photo? Here’s the blog post link to that eclipse experience!

Summary & FAQ from my astronomer friend Sean Lindsay, PhD, University of Tennessee (Dr. Lindsay is also featured in this short video about the eclipse!):

• When was the last US Total eclipse? 1979, but only observable near the Canadian border of the Pacific Northwest
• When is the next US Total eclipse? April 8, 2024. It sweeps from the Southwest in Texas, to the Northeast through upstate NY and out through Maine.
• Will I see anything if I’m outside totality? Yes, all of the US will experience a partial eclipse (part of the Sun will be blocked by the Moon)
• What if there are clouds? This is very unfortunate, but it will still get dark during Totality. In fact, if the streetlights don’t come on, it will be pitch dark.
• What to look for during totality: The Sun’s corona (the white, soft glowing light around the Sun; it’s the outermost atmosphere of the Sun). You will also be able to see Jupiter and Venus during totality as well as some of the brighter stars
• Why is this one so special? It is a coast-to-coast eclipse, which hasn’t occurred in the US since 1918.  It will be the most photographed even in human history. It’s a total eclipse… all of them are amazing.
• How often do total eclipses occur?  Quite frequently with the geometry of the Sun, Moon, and Earth being favorable for an eclipse twice per year, but a total eclipse for any given geographic location can be quite rare. For example, places in the southwest US haven’t had the opportunity to see a total eclipse for about 1,000 years.
• Can I see the shadow (the umbra) approaching? Without a lot of planning and proper set up, most likely not. The shadow of the Moon will be moving from west to east at nearly 2,000 mph! That’s pretty fast to catch it coming toward you.

Whew! I know this was a lot of technical information, but I hope you have found this post useful and a meaningful way to enhance your 2017 eclipse viewing experience.

This post was originally published on Sisterhood of the Training Pants

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About the Author

Sarah is an archaeologist and former museum minion giving it hell as a stay-at-home-mom in Atlanta, Georgia.  She loves coffee, bad TV, and gin, but not necessarily in that order.  When she isn’t battling a never-ending pile of laundry or wrangling two spirited children, she’s writing about life’s insights and indignities at her website The Sisterhood of the Training Pants.  For something to read, check out the blog.  For something to do, check out Camp Mom. Follow Sarah on Facebook, Twitter, Pinterest, and Instagram.