On April 8, a total solar eclipse will be visible on a path that crosses North America, from the west coast of Mexico to the east coast of Canada. In this episode, Molly and co-host Aminah cover all your eclipse essentials: What causes an eclipse? What’s it like to experience one? How do you watch one safely? (Spoiler alert: Don’t stare at the sun without special eyewear. Really. Please. Don’t do it.) Plus, indigenous science educator Nancy Maryboy tells us about Navajo and Cherokee traditions during an eclipse and we’ll meet Dr. Ralph Chou, a scientist who has seen 29 total solar eclipses. And, of course, a stellar new mystery sound!


Want to teach your students about the eclipse? Check out our Brains On 2024 Eclipse Lesson Plan and Brains On 2024 Eclipse Activity Sheet for fresh ideas about how to bring the science of eclipses to your classroom!

Prefer video to audio? Watch an animated version of this episode on YouTube:

Wondering how much of the eclipse you’ll be able to see? Check out NASA’s interactive 2024 Eclipse Explorer. Enter your zip code for the exact percent coverage and timing of the eclipse in your area.

Reminder: it is REALLY important to view the eclipse safely! As cool as a solar eclipse is, you cannot just go out and stare at the sky.

The sun is really, really, really bright, even when it’s partially covered. That much light at once can damage your eyes. That means regular sunglasses won’t cut it if you’re staring right at it. To safely watch the solar eclipse, you’ll need special eclipse viewing glasses. You can order them online or see if your local public library will be giving them out. Starting April 1st, Warby Parker will also be giving away free pairs of eclipse glasses in all stores.

Don’t have special eclipse glasses? Don’t worry! You can make a pinhole projector out of cardboard or a piece of paper. You can find instructions and pinhole projector templates from NASA here.

Even if you don’t have eye protection that will allow you to look directly at the sun, you can just go outside and look at the world around you. There’s some cool stuff that will happen.

Observation checklist:

  • What’s happening with the weather? A breeze might pick up during totality because the air cools down significantly.

  • What’s happening with plants and animals? You might see flowers close up, or birds start to roost as if they’re getting ready to go to sleep.

  • What does the light feel like? The quality of shadows and light will change as the sun gets obscured.

We hope you get out there and observe what’s happening. We’d love to hear what you see! You can tell us on Facebook or Instagram. Tag us @brains_on, or send us a picture, video, audio, or note at brainson.org/contact.

And if you won’t be in the US for this solar eclipse, don’t worry! There are plenty more coming up. In 2026, Greenland, Iceland, and Spain will have one. In 2027, it’ll be Morocco, Spain, Libya, Saudi Arabia, Algeria, Egypt, Yemen, and Somalia’s turn. And in 2028, Australia and New Zealand will get the treat. 

Wherever you’ll be, we hope you enjoy learning about this astounding natural phenomenon!

Audio Transcript

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ANNOUNCER 1: You're listening to Brains On where we're serious about being curious.

ANNOUNCER 2: Brains On is supported in part by a grant from the National Science Foundation.

MARC SANCHEZ: Is this thing on? Testing. Testing . Check one, two.


Oh, [CHUCKLES] perfect.


AMINA: You excited to watch the eclipse?

MARC SANCHEZ: Hey, Molly and Amina. I'm almost ready. I just need to give one of my famous speeches first.

MOLLY BLOOM: The one about how you should always carry a bag of salsa in your jeans?

AMINA: Or the one about how back hair should have its own styling products?

MARC SANCHEZ: No, not the pocket salsa or body hair gel speeches. My other famous speech, the patented Marc J Sanchez pep talk. This one's for the moon.

AMINA: A pep talk for the moon?

MARC SANCHEZ: Yeah, you know, an eclipse is a big moment for the moon. It's the star of the show. Not the literal star. That's the sun. But an eclipse is like the moon's big performance. And I don't want it to get stage fright and run away at the last minute.

MOLLY BLOOM: Marc, I'm pretty sure the moon has never run away from the sun during an eclipse.

MARC SANCHEZ: And that, Molly, is proof my speeches work. Now, if you'll excuse me-- [CLEAR THROAT] hey, Moon, it's your old pal Marc again. I know it's a lot of pressure to have all eyes on you. I once played tree number three in an off, off, off, off, off, off Broadway production of The Wizard of Oz. So believe me, I get it. But I know you can do this. You are the moon for Pete's sake.

You light the night. You make the tides. You're the reason we believe in werewolves. Did a cow jump over the sun? No, it did not. It jumped over you, my friend, because you're the star of the show. Again, not literally. You're just a giant space rock, but you're the best darn giant space rock out there. Now, go block that sun. Show 'em what you're made of, which isn't cheese, despite what I was told as a kid. Go, moon!

MOLLY BLOOM: Bravo, Marc.

AMINA: Yeah, the moon must feel so pumped up right now.

MARC SANCHEZ: Thank you. Thank you. Just doing my part. But phew, that really took it out of me. I could use a snack. Chips and pocket salsa anyone?




MOLLY BLOOM: You're listening to Brains On from APM Studios. I'm Molly Bloom, and I'm here with my co-host, Amina from Orlando, Florida. Hi, Amina.

AMINA: Hi, Molly.

MOLLY BLOOM: Today we're talking about one of the most sensational celestial events to our skies, a total solar eclipse. Here in North America, we have eclipse fever. That's because on April 8, a total solar eclipse will be visible on a path all the way from Mexico across the central United States to the East Coast of Canada.

AMINA: The rest of North America will get a glimpse of a partial eclipse.

MOLLY BLOOM: And just in case you don't listen to the end of this episode, we need to say right now, do not look at the solar eclipse without special eye protection. And no, your regular sunglasses won't cut it. More on that later. Just remember--

MAN (SINGING): Do not stare at the sun. Don't do it.

MOLLY BLOOM: So Amina, what are your plans for April 8? What are you going to do?

AMINA: So the thing is I have a dance competition the weekend right before the eclipse and the competition is here in Florida. So if we do decide to go to the solar eclipse, we'll have to leave on Sunday to go to somewhere where we can view it.

MOLLY BLOOM: Like, the total solar eclipse?


MOLLY BLOOM: Would you watch the partial one from potentially?

AMINA: Yeah, probably.

MOLLY BLOOM: You know, the last time there was a solar eclipse was 2017, and I was in Minnesota. And I saw a partial solar eclipse but it was still super cool. So I would say, even if you're not in the path of totality, it is still worth it to get a pinhole or some eclipse glasses and check it out. It's very cool. Amina, have you ever seen a solar eclipse before?

AMINA: I saw a partial one. It was really cool because I got to see it both through the pinhole viewer and the eclipse glasses.

MOLLY BLOOM: Very cool. So just in case people don't know, like, what is it like to look at it through the pinhole?

AMINA: Basically, it's like a little crescent of light on the ground. It kind of looks a little bit like a crescent moon.

MOLLY BLOOM: Very cool. And then when you look at it through the eclipse glasses, how is it different?

AMINA: Well, through the eclipse glasses, everything, except for the sun, is pitch black. It's really cool. Also, the sun, it's orangish through the eclipse glasses that we used.

MOLLY BLOOM: Cool. So I know two of your family often likes to look up at cool celestial events that have happened. Like sometimes you guys go camping, right, so you can see them?

AMINA: Yes. Pretty recently, we went on a camping trip to Sarasota so that we could view, a total lunar eclipse. It was very fun. It lasted, like-- it lasted a few hours. We were out there until, like, 11:00 to maybe 3:00.


AMINA: Yeah.


AMINA: Oh, and we saw a turtle laying her eggs.

MOLLY BLOOM: A sea turtle?


MOLLY BLOOM: Oh, that's so cool. During the lunar eclipse?


MOLLY BLOOM: Whoa, that's very magical. That's amazing,

ROBOTIC VOICE 1: Ba ba ba ba ba ba ba ba ba ba Brains On.

MOLLY BLOOM: So what causes an eclipse? Spoiler alert. This awe-inspiring astronomical phenomenon actually happens because of the moon.

AMINA: The Earth is always spinning, like someone spinning a basketball on their finger.


MOLLY BLOOM: And as the Earth spins, the moon is slowly circling around it. It takes about a month for the moon to make one lap around our planet.

AMINA: During a total solar eclipse, the moon passes right between the sun and the Earth.

MOLLY BLOOM: For a few minutes, the Earth, Moon, and Sun are perfectly aligned. There's actually a cool astronomy word for this, syzygy, spelled S-Y-Z-Y-G-Y. Syzygy, such a great word.

AMINA: When this happens, the moon completely blocks the light from the sun and casts a shadow on the Earth.

MOLLY BLOOM: A total solar eclipse happens about once every year and a half. But lots of them are only visible from very remote places on Earth like the middle of the ocean.

AMINA: A lot of our planet is covered by oceans, so that makes sense.

MOLLY BLOOM: So being able to see a total solar eclipse where we live is a pretty special event.

AMINA: OK, so maybe you're thinking, the eclipse is just a shadow. Boring. Yawn. Who cares?

MOLLY BLOOM: Well, I would argue that all shadows are super cool.

AMINA: You mean like how the shifting sizes and angles of these diaphanous forms remind us of our own physical heft and the inexorable march of time?

MOLLY BLOOM: Yes, and shadow puppets. I learned how to make a pretty convincing swan the other day.

AMINA: That too. And the eclipse is the most spectacular shadow of them all.


MOLLY BLOOM: A solar eclipse starts out slow, hopefully, on a clear, sunny day where there are no clouds to get in the way. And I will say again that you definitely should not be looking at the eclipse without special eye protection. More on that in a bit. The sun starts as a nice big circle. Then as the moon starts to move in front of the sun, a small bite is taken out of it. After this first nibble, the moon starts to cover more and more of the sun until all that's left is a thin, little crescent.

It can take more than an hour to reach this point. By now the sky is pretty dark and then things start to happen faster. As the moon slips in front of the sun, a few spots of sunlight peek around its moony edges. These are called Baily's beads basically. We're catching a glimpse of sunlight shining through the moon's mountains, valleys, and craters. Then there's a bright flash of light along the edge of the moon.

Astronomers call this the diamond ring effect. And a few seconds later, totality begins. Totality is the special name for when the sun has been completely covered by the moon. The sky gets dark like it's twilight. When that happens, you can see the outer layer of the Sun's atmosphere. It looks like glowing wisps of light coming off the dark circle where the sun used to be.

Once darkness falls during the eclipse, you might notice animals acting like it's nighttime. Crickets sometimes start chirping. Birds return to their nests. And even honeybees might fly back to their hives.


AMINA: But the darkness won't last long.

MOLLY BLOOM: The total solar eclipse only lasts a couple of minutes before the sun starts to peek out again. First, a sliver of the sun will be visible.

AMINA: Then, as the moon moves out of the sun's way, the sky gets lighter.

MOLLY BLOOM: Until, eventually, the sun is revealed again. If you won't be in North America on April 8 for the solar eclipse, there are plenty more coming up. In 2026, Greenland, Iceland, and Spain will get the treat. 2027 brings the phenomenon to Morocco, Spain, Libya, Saudi Arabia, Algeria, Egypt, Yemen, and Somalia. And in 2028, it'll be Australia and New Zealand's turn.

AMINA: And if you happen to be in any of these places during an eclipse, remember--

MAN (SINGING): Do not stare at the sun. Don't do it.

ROBOTIC VOICE 2: Brains, Brains, Brains On.

MOLLY BLOOM: Humans have been fascinated by solar eclipses for thousands of years.

AMINA: And also a little bit afraid of them.

MOLLY BLOOM: Which makes sense if you think about it. Before we understood the science behind solar eclipses, it felt like the sun was randomly going dark in the middle of the day. One way humans master their fear of the unknown is by studying things. And that's just what Chinese and Greek astronomers did, starting as early as 4,000 years ago.

AMINA: They recorded the movements of the sun, moon, planets, and stars, and tracked when solar eclipses happened.

MOLLY BLOOM: By about 2,000 years ago, these astronomers had recorded enough information to start predicting when future solar eclipses would occur.

AMINA: Another way humans handle fear of the unknown is by creating and telling stories.

MOLLY BLOOM: And for a very, very, very long time, humans have shared stories that explain why solar eclipses happen. For example, people in ancient China thought an eclipse was caused by a dragon eating the sun.


AMINA: Vikings in Scandinavia believed it was two wolves that swallowed the sun.


And some communities in South America said it was a puma.


MOLLY BLOOM: Indigenous tribes in the United States have a long tradition of studying the sun, moon, and stars. And I had the chance to chat with Nancy Maryboy about eclipses. She's Navajo and Cherokee and also an indigenous science expert.


NANCY MARYBOY: Every community and every tribe has their own perceptions of the eclipse. Navajos feel that an eclipse is a bad omen. And not all tribes do, but Cherokee does and so does Navajo. There's a very traditional protocol you follow. So you'd go in your house and everything would stop. And you'd go in there and you'd sit there for the whole time of the eclipse and you wouldn't-- you'd be very quiet, very reverent. You wouldn't eat anything. You wouldn't drink anything.

You'd sing certain songs that traditionally-- about the eclipse. You'd just talking very quiet voices and you'd wait it out. A lot of tribes think of the universe, the Earth, and the sky worlds as needing to be in balance. And when something out of the traditional order, the process of the universe happens, like in eclipse, that eclipse is disrupting the order of nature. And so that's why a lot of tribes want to make sure the eclipse is corrected and the sun is out again.

So they have their different ways of behaving to ensure that will happen. All over the world, there are many different people, different societies, different tribes, and everybody sees the sky in a different way. And it depends on where you are on the Earth and the society, the community you live in. But there's not just one size fits all.

There's many different stories that are told. And the more you know, the more it enriches your understanding of the sky.

MOLLY BLOOM: There's so much to learn from indigenous knowledge about the night sky and we have lots of links in the show notes and on our website. That's brainson.org. All right, Amina, before we learn more about the solar eclipse, it's time for the--


CHILD 1 (WHISPERING): Mystery sound.

MOLLY BLOOM: Amina, are you ready to hear the mystery sound?


MOLLY BLOOM: OK, here it is.


What do you think?

AMINA: Um, it kind of sounds like-- I am not 100% sure if this is correct, but I listen to a lot of ASMR videos and it kind of sounds like wax cracking.

MOLLY BLOOM: Oh, interesting. Now can you tell us what ASMR videos are, just in case people don't know?

AMINA: ASMR is this thing where people will take an object, put it really close to a microphone and make some kind of satisfying sound with it.

MOLLY BLOOM: Yeah, and it's called ASMR because sometimes it sort of triggers this thing in your ear where it feels good to listen to it. And we actually have an episode about slime where we talked about what ASMR is. So if people are interested, you can go find that slime episode. OK, so your guess is wax cracking?


MOLLY BLOOM: All right, well, we're going to hear it again after the credits, get another chance to guess, and hear the answer. So stick around. [MUSIC PLAYING] Hi, friends. Are you planning on watching the eclipse? We would love to see your photos showing how you safely watched this awesome phenomenon. Send them to us at brainson.org/contact. While you're there, you can send us mystery sounds, drawings, and questions.

AMINA: Like this one.

CHILD 2: How do parrots mimic other sounds or creatures?

MOLLY BLOOM: Again, that's brainson.org/contact.

AMINA: And keep listening.



AMINA: You're listening to Brains On. I'm Amina.

MOLLY BLOOM: And I'm Molly. Today we're talking about one of the most astonishing, jaw-dropping, astronomical events in our skies, the total solar eclipse. This phenomenon happens when the Earth, Moon, and Sun are perfectly aligned.

AMINA: As the moon passes between the sun and the Earth, it blocks our view of the sun.

MOLLY BLOOM: Depending on where you live, you might see a partial eclipse. That's when the moon blocks part of the sun.

AMINA: Or you could see a total eclipse where it completely covers the sun. For a short time, the sky darkens and day turns to night.

MOLLY BLOOM: But no matter what, you cannot stare at the sky during an eclipse. Nope, no way. Please don't, really don't do it.

MAN (SINGING): Do not stare at the sun. Don't do it.

MOLLY BLOOM: Here to explain is Dr. Ralph Chu. He's an eye doctor and astronomer from the University of Waterloo in Canada. And he says bright light like the light from the sun can seriously damage our eyes.

DR. RALPH CHU: The problem with looking at the sun is that it's just too much light entering the eye. It just overwhelms the photoreceptors at the back of the eye.

AMINA: Photoreceptors are a special kind of cell in our eyes that help us see. Cells are the building blocks of all living things.

MOLLY BLOOM: And when these photoreceptor cells in your eyes get overwhelmed with too much light, they start to break down.

AMINA: That can damage your eyes and even affect your vision.

MOLLY BLOOM: If you burn your finger, you'll know it's burned because it'll hurt. But Ralph says if you look at a solar eclipse without special eye protection, you can damage your eyes without even knowing it.

DR. RALPH CHU: The problem is there are no pain receptors at the back of the eye. You don't feel it. And you go to sleep, everything's fine. Wake up the next morning and all of a sudden, you realize you can't see the face in the mirror, you can't see the face of the person across the table at breakfast, and you've got this big blur spot instead.

AMINA: You might be thinking, OK, I'll just wear my sunglasses to protect my eyes. Problem solved, wrong,

DR. RALPH CHU: Unfortunately, regular sunglasses don't block enough light to make it safe to look at the sun.

MOLLY BLOOM: Normal sunglasses block 75% to 90% of visible light. That might sound like a lot but there's so much light coming from the sun, that you need to block out 99.9996% of it to keep your eyes safe. That's practically all of it.

AMINA: So wearing sunglasses isn't safe during an eclipse. To watch a solar eclipse safely, you'll need to wear special eclipse viewing glasses that can block out that much light.

MOLLY BLOOM: You can order them online or maybe get them from your local science museum. Since these glasses block out so much light, remember, you can't really do anything in them besides look at the solar eclipse. Don't try to walk while wearing them. You won't get very far.

AMINA: Ralph says to remember to put your eclipse glasses on first and then look at the sun, not the other way around.

MOLLY BLOOM: And once you have your eclipse glasses on, you'll be able to safely watch one of the coolest events in our solar system. Ralph says it's a very special thing to be able to see a solar eclipse. He's seen 29 of them in his life.

DR. RALPH CHU: I was 12 years old when I first saw my first eclipse back in the 1960s. It was totally unexpected but it was a life-altering event for me.

MOLLY BLOOM: He says you could also look at the eclipse through a telescope fitted with a special solar lens or you could make a pinhole projector that lets you look at it indirectly. We have instructions on how to do that on our website brainson.org.

AMINA: But even if you don't have eye protection that will let you look directly at the eclipse, you can just go outside and look at the rest of the world around you. Ralph says there are some cool stuff that will happen,

DR. RALPH CHU: When it's close to totality, there tends to be a little bit of a breeze that sets up because the shadow of the moon causes the air to cool down. Just watch what happens to the birds and the flowers around you during the eclipse as it gets dark. There are some plants where the flowers will close up at night. And you'll see this happening as the eclipse proceeds and it gets darker.

The other thing is that, the crescent being so narrow, all of a sudden, you start getting effects on how you see things around your world because in that zone of totality, you've got this very, very thin light source illuminating the world. You get different appearances to the sharpness of edges and, you know, what shadows there are look really weird.

MOLLY BLOOM: So get out there and observe what's happening. But remember--

MAN (SINGING): Do not stare at the sun. Don't do it.


AMINA: A solar eclipse happens when the moon passes between the sun and the Earth, blocking our view of the sun.

MOLLY BLOOM: If you're in North America, you'll have a chance to see a total or partial solar eclipse on April 8.

AMINA: There are more coming up that will be visible in other parts of the world.

MOLLY BLOOM: But no matter what, you cannot stare at the sky during a solar eclipse.

AMINA: Do not stare at the sun. Don't do it.

MOLLY BLOOM: That's it for this episode of Brains On.

AMINA: This episode was written by Molly Bloom and Shahla Farzan. We had production help from Rosie DuPont, Anna Goldfield, Aron Woldeslassie, Nico Gonzalez Wisler, Ruby Guthrie, and Marc Sanchez.

MOLLY BLOOM: We had editing help from Sanden Totten. This episode was sound designed by Rachel Breeze. And we had engineering help from Alex Simpson and Lawrence Vexler. Beth Perlman is our executive producer. The executives in charge of APM Studios are Chandra Kavati and Joanne Griffith. Special thanks to Rebecca Benjamin.

AMINA: Brains On is a non-profit public radio program.

MOLLY BLOOM: There are lots of ways to support the show. You can subscribe to Brains On Universe on YouTube where you can watch animated versions of some of your favorite episodes or head to brainson.org where you can send us questions, mystery sounds, and drawings.

AMINA: And don't forget to send us pictures of your solar eclipse viewing parties.

MOLLY BLOOM: OK, Amina, are you ready to hear that mystery sound again?



MOLLY BLOOM: OK, new thoughts. What do you think?

AMINA: I mean, it sounds like the thing that I said before but also, it kind of sounds like somebody crumpling a plastic water bottle.

MOLLY BLOOM: Ooh, very nice guess. Are you ready for the answer?


MOLLY BLOOM: OK, here it is.

JOE: Hello. My name is Joe, and this is the sound of me turning the Rubik's cube.

MOLLY BLOOM: A Rubik's cube. Do you know what that is?

AMINA: I should have known that.

MOLLY BLOOM: Oh, do you play with them?

AMINA: Yeah, I know how to solve them. I watched a YouTube video about it.


MOLLY BLOOM: So cool. I don't know how to solve them. That is very cool. Yeah, I mean, I think you were not that far off. Like, the plastic crinkling of the water bottle sounds a lot like mixing up a Rubik's cube.

AMINA: Yeah.

MOLLY BLOOM: So how fast can you solve it?

AMINA: My fastest time is, like, 48 seconds, I think. In the high 40s.

MOLLY BLOOM: What? Amina, that is incredible. Holy cow. So impressed.


Now it's time for the Brains Honor Roll. These are the incredible kids who keep the show going with their questions, ideas, mystery sounds, drawings, and high fives.



We'll be back next week with an episode all about how medicine knows where to go in our bodies to stop the pain.

AMINA: Thanks for listening.

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