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Sun Series: How to Experience a Total Solar Eclipse

Season 7Episode 3Mar 26, 2024

On April 8, 2024, the Moon will pass in front of the Sun, casting a shadow across Mexico, the United States, and Canada. Total solar eclipses have fascinated human beings for thousands of years. Watching the Moon eclipse the Sun is a surreal, multi-sensory experience that you’re not likely to forget. But Eclipses also offer unique opportunities for NASA to study the relationship between our star and home planet. Join current and former NASA sun scientists Kelly Korreck, Fred “Mr. Eclipse” Espenak and Cherilynn Morrow on a journey through time and space to solve eclipse mysteries.

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About NASA’s Curious Universe Podcast

Come get curious with NASA. As an official NASA podcast, Curious Universe brings you mind-blowing science and space adventures you won’t find anywhere else. Explore the cosmos alongside astronauts, scientists, engineers, and other top NASA experts who are achieving remarkable feats in science, space exploration, and aeronautics. Learn something new about the wild and wonderful universe we share. All you need to get started is a little curiosity.

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Episode Description: 

On April 8, 2024, the Moon will pass in front of the Sun, casting a shadow across a long swath of Mexico, the United States, and Canada. Total solar eclipses have fascinated human beings for thousands of years. Watching the Moon eclipse the Sun is a surreal, multisensory experience that you’re not likely to forget. But Eclipses also offer unique opportunities for NASA to study the relationship between our star and home planet. Learn how to experience a Total Solar Eclipse. Join current and former NASA sun scientists Kelly Korreck, Fred “Mr. Eclipse” Espenak and Cherilynn Morrow on a journey through time and space to solve eclipse mysteries.

[MUSIC: Aeros by Arun Ganapathy]  

HOST PADI BOYD: Have you ever experienced a total solar eclipse? It’s this strange, magical, somewhat unsettling moment when… in the middle of the day… the world suddenly goes dark, as the Moon blocks out the Sun.   

[SFX: Children shouting, playing on a playground] 


The first eclipse I saw was back in the early 1960s. And I was only, let’s see, that would have made me 11 years old. 

[SFX: Waves lapping at a dock] 


My first total solar eclipse was in 2017. And I had the privilege of being on the USS Yorktown in Charleston Harbor in South Carolina. 

PADI: That’s Fred Espenak and Kelly Korreck. Kelly is a NASA Sun scientist who studies total solar eclipses, and Fred’s an eclipse addict. He’s earned his nickname, Mr. Eclipse, by experiencing 30 of them, all over the world.  

PADI: Now, the odds that you, listening to this episode, are currently experiencing a total solar eclipse are pretty low. They’re rare phenomena. In any given place, where you live, for example, you’ll only get one about every four centuries. So, I’m not going to get in the way here…. I’m going to let Kelly and Fred tell you what experiencing one firsthand is like. 


And leading up here this is actually a really, kind of eerie scene.  


You start to notice that the quality of light now is starting to look a little odd.  



The light seems weird, and your brain definitely starts thinking, something doesn’t seem right. So, there’s this feeling of kind of anxiety yet also excitement.  



The Sun is no longer a disk in the sky, it’s a thin crescent. And on the ground underneath a shade tree, you’ll see the ground covered with little crescent Suns, it’s an amazing thing.  


[SFX: Tinkling windchimes] 



And the first part that happens is Baily’s Beads. So, you see these bright little lights, they’re the Sun’s rays coming through the mountains and valleys on the Moon. 


[SFX: Heatbeat, whooshing wind] 



We forget that the Sun is what’s giving us warmth but in the last 10 minutes when you’ve got over 90% of the Sun covered, the temperature is going to start to drop. My reaction physiologically is that the hair on the back of my neck is standing up, my heart is racing, and you just get a visceral feeling in your gut that something is wrong. This just does not seem natural. It seems so far out of any kind of everyday experience. 


[SFX: Sheep bleating, crickets chirping] 



What does happen in general in eclipses is that animals think it’s nighttime. So, animals such as crickets, or roosters, who you know, think it’s nighttime, it’s time to roost. 



If you’ve got birds around, they might start singing their evening songs because they think it’s sunset, it’s getting dark out for them. 


[SFX: Owls hooting, tinkling windchimes] 



So, you’re seeing these light beads all along the side of the dark moon that’s covering the bright sun. And then you see one final one, which is called the diamond ring. And you see totality. 


[MUSIC: Advanced Technology by Thomas Gallicani] 


[SFX: Whooshing wind] 



And in the last few seconds, the moon’s shadow races over you and it’s traveling over a thousand miles an hour, you don’t see the edge of the edge of the shadow. It’s just either you’re in it or you’re out of it. It just sweeps over you so rapidly. You’re plunged into it and suddenly, daylight drops to an eerie twilight. About as dark as it gets maybe about a half hour after sunset. And when you look out in the direction of the horizon, you’re looking at the edge of the shadow into areas that are still in daylight. So, you look around the horizon and you’re surrounded by a sort of 360-degree sunrise in all directions, sunrise and sunset. And of course, then you look back up at the sky to where the sun had been. And there’s no brilliant sun in the sky anymore. What it’s been replaced by is a black disk surrounded by this eerie gossamer halo, which is the Sun’s corona. 



At this time, you don’t need your special glasses, you can look with your own eyes, at the protrusions from the Sun, which are filaments, they are millions of degrees of hot gas that are flowing off the Sun.  


[SFX: Explosive solar storm sonification] 



And it’s indescribable, it’s so beautiful. The shape of it is always different at each eclipse because it’s affected by the magnetic fields of the Sun, which are changing from day to day. 



And it was breathtaking. The things that I had studied my entire career were there right in front of my eyes, and they had been hidden by the brightness the Sun normally has. And so I was with friends, and there was much laughter and hugging and just overall an amazing experience. 


[2023 Ring of Fire Eclipse broadcast: Wow, it looks great]  



Even though most total eclipses last two or three minutes, all of them seem to last only a few seconds, subjectively, because this happens so quickly. Because now you’re outside the Moon’s shadow again, and you’re plunged right back into bright sunlight. The shadow races off across the Earth’s surface and leaves you. You got another hour or so of partial phases. But you’ve just experienced a total eclipse.  


PADI: Everyone who experiences a total solar eclipse seems to come away with the same question… 



For most people, the first question on their mind is… 



…when’s the next one, when do I get to do that again?  



Because I want to see it. 



Because it is just such an amazing experience. 


[THEME MUSIC: Curiosity by SYSTEM Sounds] 


PADI: This is NASA’s Curious Universe. Our universe is a wild and wonderful place. I’m your host Padi Boyd and in this podcast, NASA is your tour guide.  


PADI: Welcome to the second episode of our Sun series! It’s a big year for our nearest star… we’re near solar maximum, when the Sun is at its most active and explosive, and NASA’s Parker Solar Probe is going to make its closest approach to our star, flying through its atmosphere! So, in our star’s honor, we’re taking a deep, five-part dive into the plasma. If you missed our first episode, you might want to go back and check that one out too! 


PADI: At the time of this recording, there’s a total solar eclipse on the horizon in North America. On April 8, 2024, the Moon will pass directly between the Sun and Earth, totally blocking its light for several minutes along a path stretching from Mexico to Canada. And since our Sun’s atmosphere, the corona, is particularly active right now, scientists are expecting a pretty stellar show. 


[2023 Ring of Fire Eclipse broadcast: We’ve got about two minutes here folks. As you can hear, the crowd is chanting and counting down until our moment right now…] 


PADI: Roughly 32 million people living in the path of totality, locations where the Moon will completely cover the Sun, will get to experience a total solar eclipse. And 99% of Americans will experience at least a partial eclipse. 


[2023 Ring of Fire Eclipse broadcast: One more minute, folks…] 


PADI: But if you live elsewhere in the world, don’t tune out! Wherever you are on Earth, chances are there will be a total solar eclipse somewhere near you, at some point within your lifetime. And you won’t want to miss it. When the Sun and Moon, the two most important celestial objects in our sky, align perfectly to cast a shadow right on us, it’ll be a reminder like no other of our place in the solar system… on a little ball of rock in the vastness of space.  


[2023 Ring of Fire Eclipse broadcast: Five four three two one. Oh my God. I mean it doesn’t look real. I didn’t think I would cry, like what is going on! Gina, I thought I’d have goosebumps, but I’m literally shaking. I know, I agree…] 


[MUSIC: Repercussions by Elliot Greenway Ireland] 


PADI: So, in this second episode, we’ll learn all about eclipses… the science behind this cosmic coincidence, what drives umbraphiles, also known as eclipse chasers, to chase totality all over the world, how Indigenous Americans a thousand years ago studied and respected the Sun and Moon during eclipses, and the unique NASA research that can only happen during the few short minutes when everything aligns. Oh, and we might just solve a mystery… one that has to do with tree rings, bowls, spacecraft and ancient petroglyphs carved into a desert rock. 



An Eclipse is all about being at the right place at the right time. And things literally aligning, just with you.  


PADI: That’s Kelly’s again. She’s a NASA Sun scientist… a heliophysicist! And she’s also the program manager for the 2024 eclipse. 



So, what we’re talking about aligning here is the Moon, the Sun and the Earth. And depending on which order they’re in, you’re going to either block out the Sun or block out the Moon.  


PADI: When things align differently, so Earth casts its shadow on the Moon, that’s a Lunar eclipse. But what’s happening on April 8 is rarer… a solar eclipse. 



So that means the Sun is out front, the Moon is in the middle, and it’s blocking out the Sun to the Earth’s vantage point. And it doesn’t happen everywhere on Earth, it’s a very special path that you actually can see the moon completely blocking out the sun. 


PADI: On a map, that path looks like a long, curved stripe that the circular shadow of the Moon travels along as the eclipse swoops across Earth’s surface.   



The path of totality, or that path where you’re going to see that total eclipse, is really narrow, because actually the Moon’s shadow is very narrow, the Moon is very small compared to the Earth and compared to the Sun, it just happens to be just far enough away at the right size to actually block out the sun. 


PADI: That we have total solar eclipses at all is something of a cosmic coincidence. Not every planet with a moon has eclipses like ours! The Sun is way bigger, 400 times wider, than the Moon… but the Moon can fully block its light because it also happens to be 400 times closer to us than the Sun. So, to us here on Earth, they look exactly the same size. And of course, to experience an eclipse, not only do you have to be in exactly the right place, the “path of totality,” you also have to be there at just the right time. 



Eclipses only happen every so often, about every 18 months, somewhere on Earth.  


PADI: That’s because the Moon’s orbit is slightly tilted… so it doesn’t always perfectly line up with the Sun and the Earth. But while it takes centuries on average for an eclipse to repeat in a given place, they’re happening fairly often somewhere on Earth. So, if you miss the total solar eclipse in North America this April, not to worry!  


[MUSIC: Looking at Earth by Elliot Greenway Ireland] 


PADI: You can catch the next one in Europe in 2026, in Africa in 2027, in Australia in 2028 and so on for at least the next few million years. It’s an eclipse world tour! But that also means when there’s an eclipse in your neighborhood, and you don’t have to voyage halfway around the planet to see it, it’s pretty special. And experiencing it is even more special. 



As much as it’s a celestial event, and it’s a date, and it’s a time, it’s a full experience. It’s really a full body inspirational, almost spiritual experience to see this eclipse. 


PADI: Soaking up that cosmic dance firsthand can be transformative. So much so that some people get hooked! 



Eclipse chasers go all over the world in search of these eclipses, and actually we know very well where they’re going to be for the next about 5,000 years. So, we can plan our travel accordingly. 


PADI: Since they happen somewhere on Earth every 18 months or so, as an eclipse chaser you can experience quite a few eclipses in a lifetime… if you’re willing to do some serious travel, that is. And some folks are more than willing… those eclipse chasers, or as they’re sometimes called, umbraphiles, lovers of shadow.  


[MUSIC: Toy Soldiers by Adam Paul Courtenay Burns] 


PADI: Mr. Eclipse, Fred Espenak, is one of them. For him, part of the fun of eclipses is mathematical. He likes to make his own predictions about where they’ll happen next.  



But on a more visceral, gut-wrenching appeal. It is simply the most incredible celestial event you can see, and you don’t need a Hubble Space Telescope, all you gotta do is be able to get into the path of the eclipse and be there on the right day and the right time and have some luck with the weather to see this event. 


PADI: Fred is a retired NASA astronomer. Now, he lives out in the Arizona desert with his telescopes.  



I built one observatory. And it got so crowded, I had so many telescopes, I had to build a second one. So, I’ve got two now. The skies out here are absolutely beautiful. I lose a lot of sleep. 


PADI: He started working at NASA in 1976, the week the Viking spacecraft landed on Mars. It wasn’t Fred’s main job, but he quickly got into making eclipse predictions. Which isn’t an easy thing to do… 



The first component is you’ve got to have a good model for, it’s called an ephemeris, basically it’s a mathematical model that describes where the Earth, the Moon, and the Sun are in space with respect to each other. 


PADI: With that ephemeris, you know when an eclipse will happen. But to figure out where it’ll happen, you have to model how the Moon’s shadow moves. 



You’ve got a shadow moving over a curved surface that’s not perfectly circular either, you have to take into account the fact that the Earth’s shape is an oblate spheroid. It’s sort of a little squashed sphere a little bit. And you have to take that small effect into account and the speed of the shadow and how rapidly it moves across the Earth’s surface. A lot of mathematics, a lot of modeling on the computer. 


PADI: Fred is far from the first person to predict future eclipses. Humans have been doing that for at least the last 3,000 years, just by keeping track of the Moon and Sun’s positions in the sky. Then, they got a lot more accurate. 


[SFX: Birds chirping, horse hooves on cobblestones] 


[MUSIC: Playfully Curious by Adam Paul Courtenay Burns] 


PADI: In the 1700s, Edmund Halley, yes, the same guy the famous comet is named after) made the first models of how the Moon’s shadow moves across the Earth during eclipses. He asked regular people across England to time the eclipse, using the grandfather clocks in their homes.  


[SFX: Ticking grandfather clock] 


PADI: Suddenly, we could predict both when and where eclipses would happen with precision. Here at NASA, a couple of centuries later, Fred got so into predicting eclipses like Halley and generations of people before him, that he earned his nickname… 



I guess one time somebody introduced me as Mr. Eclipse because I was developing a reputation for lecturing on eclipses and photographing eclipses and talking about eclipses. So that name just sort of, sort of stuck. 


PADI: But Mr. Eclipse’s total obsession with totality started long before he joined NASA, back when he saw that first eclipse in the 1960s as an 11-year-old. 



And I had a small amateur telescope, a department store telescope, that my parents had gotten me a year or two earlier. And I was very excited about the upcoming eclipse. And I was visiting my grandparents in southern New York, at their summer home. And from where I was located, it was only a partial eclipse.   


PADI: Looking up through his little telescope, Fred was mesmerized. But the thing is, a partial eclipse isn’t anything like a total eclipse. The way Fred puts it… 



A partial eclipse is sort of like getting five out of the six numbers in the lottery, you almost won. But basically, you lost. If you don’t get all six numbers, six numbers is the total eclipse. Five numbers is a partial. There’s no comparison. One’s a loser and one’s a winner… 


PADI: He’s thought a lot about this.  



A partial eclipse is like having a tailgate party in the parking lot during the Super Bowl. 


PADI: So, after watching the partial eclipse from his grandparents’ house, Fred decided he had to see a total eclipse. But there was a problem. The next one on the continent was in 1970, almost a decade away. So as an 11-year-old, he put it on his calendar. After years of waiting, the day finally arrived. By then, Fred had a driver’s license, he was a senior in high school… 


[MUSIC: Magical Secret by Bertrand Allagnat] 


[SFX: Car engine starts, car drives away] 



I convinced my parents to let me borrow the family car unchaperoned and drive 600 miles south to get into the path of this total eclipse. And I’ve been planning this thing for seven years. I had read lots of books and magazine articles about it. I had my little telescope with me with a camera hooked up to it now. I was going to try to take pictures of this event. And I managed to get a couple of pictures. But I was absolutely dumbfounded by the event. It was so spectacular, so incredible. So far beyond anything I possibly could have imagined.  


PADI: As Fred drove to the eclipse, he had accepted that it was a once-in-a-lifetime opportunity. But after he saw it, he had to see the next one.  



So initially I thought this was my one chance. After this was over, I knew I had to see another eclipse. One was not enough, that three minutes went by so quickly. And there was so much to see. And it was so exquisitely beautiful.  


PADI: The next one in the U.S. wouldn’t happen for 21 years, in 1991. But there would be one in Canada in 1972. 



Well, that was only 1000 miles to drive to. I could get to that.   


PADI: After the eclipse in Canada that year,1991 still seemed like far too long to wait, so he looked for the next eclipse. 



The next one after ‘72 was in 1973. Now this was a little more challenging, because this one was in the Sahara Desert in northern Africa. 


[SFX: Play flies overhead, seatbelt chime rings] 


PADI: As you might have guessed, he made it there. And that was just the beginning. At some point, once you start chasing eclipses, it gets hard to stop. 



And that was the start of a, you might say a lifelong addiction of chasing total eclipses all over the world. So, by this point, over the past 50, 53, 54 years, I’ve been to 30 total eclipses of the Sun. And I’ve seen a total eclipse on every continent, including Antarctica. So, it’s taken me all over the world. Unusual places like the Altiplano of Bolivia, or the desert in Mongolia, or East Africa with wild animals and spectacular wildlife. 


[SFX: Frogs chirp, desert winds woosh, lions roar] 


PADI: Not every eclipse has been spectacular… some have been frustrating, ruined by cloudy skies, an eclipse chaser’s worst nightmare. 



You can predict exactly where and when a total eclipse is going to be, when it’s going to start, when the total phase will begin, exactly how many seconds of totality you’re going to get. All these things can be predicted years in advance, but you can’t predict the weather tomorrow.  


PADI: But Fred does get asked a lot… does he have a favorite? 


[MUSIC: Electro Strut by SACEM] 



The funny thing about that question is, occasionally, my wife Pat will go to some of my lectures with me. And she noticed that I was answering that question wrong. When I told people what my favorite eclipse was, she had to remind me that my favorite eclipse was the one where the two of us met. Because that was almost 30 years ago, halfway around the world in India, we were both on the same eclipse trip together. Sparks flew. And eventually, we got married, and she’s been a traveling companion to most of my eclipses since then. 


PADI: It’s hard to describe what’s so special about eclipses to someone who hasn’t experienced one before. But there’s just something about how it’s both predictable, routine and inevitable for Earth and humanity in general… and so profoundly affecting to actually witness in person. 



No matter what mankind does, there’s nothing we can do to change, or impede or affect in any way, the eclipse. It’s going to happen at a certain time. And at a certain place. It’s an inevitability of it. And it gives you a sense of perspective of how small and insignificant we are in the universe. And yet at the same time, we’re a piece of it, we’re an integral part of it. So, it’s, it’s an interesting effect, to experience a total eclipse, and it’s a humbling experience, I think. 


PADI: And for the April 2024 eclipse, Fred’s plans are made. He’s going down to Mexico, where he’s crossing his fingers for clear skies, and getting ready to add another eclipse to his collection. 


[MUSIC: Internal Logic by Elliot Greenway Ireland] 


PADI: Eclipses are incredible to experience, but for NASA, they’re also really important opportunities for science. For centuries we’ve looked up at the sky with big questions, and eclipses have repeatedly given us the answers, during experiments that are only possible during the few moments of totality. Here’s Kelly again. 



The eclipses are special for science, because they set up the right conditions in our laboratory of the Sun, the Earth and the Moon. So, for instance, Einstein’s theory of relativity was actually proven during an eclipse. 


PADI: After Einstein published his theory of general relativity in 1915,  scientists’ big question was whether he was right about gravity’s power to affect space and time, warping light around stars.  


[SFX: Warping whooshing sound] 


PADI: After four years of waiting for a solar eclipse to dim the Sun enough to look, they proved him right!  


[SFX: Solar hum sonification] 


PADI: Today, our big question is about the Sun itself… why its atmosphere, the corona is so much hotter, millions of degrees hotter, than its surface. Scientists are studying the Sun all the time using lots of tools and spacecraft, but they’re particularly excited about the upcoming eclipse. Without an eclipse, it’s pretty hard to see and study the corona from here on Earth, because the surface, the photosphere, is a million times brighter. 



It’s like trying to take a picture of a light bulb, it’s really hard to see anything else, you know, around it. Because it’s the brightest thing in a picture. So, when you block out the sun, that middle part that super bright, you’re able to look at, at the outside. 


PADI: We have spacecraft and telescopes that block out the Sun, creating an artificial eclipse so scientists can look at the corona through the instruments’ eyes, but they’re not nearly as good at the job as our own Moon is. So here at NASA, every eclipse is an opportunity … the Sun being blocked by our Moon offers scientists a few precious moments to study the faint corona of our star. And those moments of totality are so precious that heliophysicists have a trick up their sleeves to get the most out of that very limited time, using a fancy, high-flying plane called a WB-57. 


[SFX: WB-57 flies overhead] 



So, this eclipse is going to be around for four and a half minutes of time. So that sounds really, really short. But clever scientists have figured out how to extend that a little by using the WB-57 airplane and putting their instruments aboard that and flying along the path. So, they don’t get a lot more time. But they get a little bit more time to make observations and get that important data during the eclipse.  


PADI: By flying really fast and high up in the Earth’s atmosphere during the eclipse, they can get about 10-20 seconds more out of totality than you can on the ground. It’s not that long, because the shadow is moving much faster than an airplane can fly. But every moment counts! 


[MUSIC: Human Behavior by Jan Telegra] 


PADI: Eclipses have happened as long as humans have lived on Earth, and much longer than that. And beyond being unique opportunities for eclipse chasers to experience and scientists to study, the alignment of our Earth, Sun and Moon provides a unique opportunity to connect across time and space, with sungazers past and present. And even, maybe, make new discoveries in the process. 



All of our ancestors, not just in the Southwest, but you and I have Sun-watching ancestors, all of your listeners have people in their history, in their ancestry, who learned to live well, and in harmony with the cycles of the Sun. So, the seasonal cycles of the Sun they used to learn where the Sun rises and sets on a horizon to track time. And to, ah, it’s time for the winter, winter ceremony, time to prepare for harvesting, time to prepare for planting. You learn to live in harmony with the seasonal cycle of the Sun, we wouldn’t be here if our ancestors didn’t figure that out. 


PADI: That’s Cherilynn Morrow, astrophysicist and outreach director of NASA’s PUNCH mission.  



I like to introduce myself these days by saying I’m a solar physicist, by mind and training, and I’m an educator at heart. And I am a singer songwriter, by soul. 


PADI: Cherilynn grew up wanting to become an astronaut. She became a pilot, and then an astrophysicist. Then she realized her true calling was connecting other people of all backgrounds and cultures to space and science through our Sun. She never made it to the Moon, but now she spends her time in a place she says is nearly as otherworldly. It’s a place called Chaco Canyon, in northwestern New Mexico. The place where Sun watching on this continent began. 


[SFX: Crickets, desert wind, crackling campfire] 


[MUSIC: Human Behavior Jan Telegra] 


Cherilynn 30:09 

Chaco Canyon captured my heart and my spirit of adventure. Chaco was like my “Moon.” It’s a very austere high desert landscape… long horizons as far as you can see, which makes it very good for Sun-watching. And canyon walls, red rocks, low vegetation, juniper, saltbush, sage. Pungent desert-like smells, very dry climate, very cold in the winter and very hot in the summer. So, it’s a very remote and challenging natural environment for anyone to live in. And yet a thousand years ago, all roads in the region led to Chaco. 


PADI: There’s evidence of ancient, thousand-year-old sun-watching throughout the Southwest, at Chaco culture sites like Mesa Verde, Bears Ears and Chimney Rock. But Chaco Canyon drew people from across the region. It was especially important. It’s a world heritage site today, well-known for its monumental sandstone buildings, perfectly aligned to the cardinal directions. But the more scientists have studied Chaco, the more they’ve come to realize that the ancestral Puebloans who once lived here were watching the sky. If you look closely enough, you’ll find spiral petroglyphs, rock art carved into cliff faces, that act as little “stand here” signs. They indicate exactly the right spot to wait and look out at the horizon to see the Sun shine through certain rock formations on the equinox and solstice. So when it was time to pick a place to focus outreach efforts for NASA’s new PUNCH mission, Cherilynn picked Chaco.  


[MUSIC: Garden of Synapses by Jan Telegra] 



So, by focusing on Chaco, which is regionally important to the descendants of the people who lived and built Chaco, yet it also is a world heritage site, we actually are able to connect with the cultures there. So, we’re in collaboration, right, with the descendants of the ancestral Puebloan people who made Chaco come alive a thousand years ago. 


PADI: To Cherilynn, there’s a direct line from the past inhabitants of Chaco, who studied the sun here to learn how to live within the seasons it controls, and NASA’s own efforts to study the sun through missions like PUNCH. The PUNCH mission consists of four suitcase-sized satellites that will fly through the space between the Sun and Earth to form a three-dimensional image of the incoming solar wind, data that could improve space weather forecasts beyond what we can do today.  


[SFX: Whooshing spacecraft flies overhead, beeping] 



PUNCH is going to study the science of when does the sun’s corona, the Sun’s outer atmosphere, right, that we see during a total solar eclipse. When does that corona end and the solar wind to stream begin that region between the planets that interplanetary space? When does the corona end and the solar wind begin?  


PADI: So just like the petroglyphs and calendar-like rock formations the ancestors of today’s Puebloans built here at Chaco to understand and live within the earthly seasons our Sun controls… 



The PUNCH mission is going to play a role in learning to live well and in harmony with the Sun’s magnetic activity cycle.  


PADI: That activity cycle and its storms affect our technological world. 



Our theme portrays NASA’s exploration of the sun, NASA heliophysics, as a natural extension of humans long-lived inclination and dedication to studying the rhythms and mysteries of the Sun. Really, our ancestors got it started to learn how to live well with the Sun and NASA exploration is just an ongoing, contemporary way in which we do that. 


PADI: As Cherilynn dug in further at Chaco, she learned about a particularly interesting connection to NASA science at a site called Rock of the Sun.  


[MUSIC: Searching for Clues by Jean-François Berger] 


PADI: It was one of those rock carvings… a petroglyph… but one unlike any other she’d seen in Chaco Canyon. 


[SFX: Crickets, footsteps on gravel] 



So, this petroglyph is about hand size. If an adult person reaches their hand, spreads out their thumb to pinky, that’s about the size of the petroglyph, eight inches across. It’s a circle and it has curlicue lines emanating from all around the petroglyph. And then up to the left, there’s another pecking of a smaller circle. 


PADI: Those curlicue lines look suspiciously like a stormy solar corona visible during an eclipse that coincides with solar maximum… like our 2024 eclipse will today. Picture the scene: An ancestral Puebloan nearly 500 years before the first Europeans set foot in New Mexico, looking up at a darkening sky and an angry, flaming Sun, and creating a permanent record of what they saw.  


[SFX: Chipping at rock, carving sounds] 



They may have even collaborated on it, like multiple people saw it only for a few minutes during totality, and then collaborated… what did you see? What did you see? And they collaborated on what would be represented in the stone. This is not the same as taking a picture. Your eyes are actually better at seeing the structures of the corona. If you notice when you look and you perceive those structures raying out from the disk in the sky, you take a picture and you’ll get far less information. 


PADI: Those ancient Chaco inhabitants, looking up at a less polluted sky, would have been able to see the corona more clearly during their solar maximum eclipse than we’ll be able to in 2024. But does the Rock of the Sun petroglyph really depict a stormy solar corona during an eclipse? Well, just like we can predict eclipses thousands of years into the future, we can also accurately determine when they happened in the past. So we do know there was an eclipse in 1097. 



We know that the 1097 eclipse path of totality included Chaco, so that’s for sure. 


PADI: Through some wild science that involves tracking radiation from the sun recorded in tree rings, scientists determined the 1097 eclipse did happen during a period of high solar activity.  


[SFX: Buzzing radiation, whooshing solar storm sonification] 



And that means that it was more likely that there would be solar storms…where that stuff coming off the sun can be exploded off, out of the corona. These are the type of storms that PUNCH will monitor from the time they leave the corona all the way to Earth orbit. Well, of course, we don’t have PUNCH in 1097. But what we have are naked eye observations by the people who were resident in Chaco.  


[MUSIC: Onceness by Lorenzo Ferrara] 



This was a time of high solar activity but also high human activity in Chaco. This was a time when people were still building the monumental sandstone architecture that we can see the remains of when we go there today. 


PADI: So, the indigenous Chacoans really would have been looking up at a very active corona. But Cherilynn still has questions. 



We know that it was a stormy time of high maximum activity. Did the Chacoans witness some kind of kinks or curls or curves in the corona during totality? Just a few minutes of time, that’s all you get. Did they witness something that they then recorded an impression of in that rock art? We’re very excited about that question and about how modern NASA spacecraft like this, the Solar and Heliospheric Observatory, SOHO, who routinely measures the corona or makes images of the solar corona, Solar Dynamics Observatory, other missions who are observing the corona, we can compare with that data that we didn’t have before. And see, wow, those features do they line up? Do they match up with what we now routinely observe in the corona? 


PADI: She hopes that by bringing together the petroglyph carving, some old drawings of eclipses from the 1800s, Chacoan pottery she came across with similar curlicue motifs, and NASA imagery of the corona, she’ll be able to narrow down how humans depict the corona during solar maximum in art. There’s no way to know for sure. But one thing is certain… this petroglyph is pretty special. 



What we know from our cultural partners and the descendants with whom we’re working, what we know is that whatever they saw, it was important to them. Or they wouldn’t have taken the time and trouble to carve it rock so beautifully, and so meticulously. 


PADI: There’s no reason to think experiencing an eclipse in 1097 would be any less enchanting than it is today. 



The spectacle of the Moon blocking out all of the light of the Sun in the middle of the day is just transcending. Because of the eerie lighting, it’s just surreal, the earthly existence becomes a bit surreal, and the celestial reality becomes very real. It’s a lovely cosmic coincidence that we have this thing, a total solar eclipse from Earth.  


[MUSIC: Unraveling Minds by Jan Telegra] 


PADI: The most important point is that eclipses are this unique, cosmic coincidence that we can experience here on Earth. And when we experience them, we can take a moment to think about our place in the universe, and our place in human history. 



When we come into contact with viewing the sun’s corona, we can commune across time, with the Chacoans across time, space and culture, connecting the ancestral people who witnessed this eclipse in 1097, and may have recorded it in their rock art to now where we, you know, can see an eclipse at a time of high solar activity… 


[SFX: Rock carving, cheering] 


[2023 Ring of Fire Eclipse Broadcast: Wow, this is amazing, you can hear people screaming in the background. People are so excited…] 


CHERILYNN: …and connect it not only with them, but connected with the NASA missions that are exploring. 


[SFX: Whooshing spacecraft, beeping] 


PADI: As you look up at the Sun’s stormy corona this year, revealed by the solar eclipse, just like Chacoans did almost a thousand years before you, think about how many people have done the same throughout history. And think about NASA’s Parker Solar Probe, flying through that corona that you can see with your own eyes for just a few minutes during totality. 

[2023 Ring of Fire Eclipse Broadcast: Take off your eclipse glasses, safely of course, and make sure you look at the shadows around you, look at how the environment has changed, just make note of this entire event…] 


PADI: And in all that brief excitement, don’t forget to take a moment to reflect on how many millions of other people are doing just what you’re doing, across the country… looking out into the cosmos at a rare event that is beyond human existence, all together, all at once. 



And I feel like that’s a very unifying idea that something in the natural world is being offered that we can all, all of us, no matter where we are in the U.S. can connect to. This is a way in which we can feel the unity. Everybody in the 48 contiguous United States can see at least a partial. We’re all in this cosmos. We all belong to this cosmos and this universe. This is our star, all of us, one Sun. 


PADI: Wow, I’ve got goosebumps… I’m so, so excited to experience this eclipse myself, and I’m especially excited to share it with all of you! So, before we go… a quick word from the NASA astronauts of Expedition 69: Steven Bowen, Woody Hoburg, and United Arab Emirates astronaut Sultan Alneyadi. They just got back from the International Space Station, and they have a total solar eclipse safety message for us. Let’s take a listen. 


MUSIC: Awakenings by Elliot Greenway Ireland] 



Hello eclipse fans! Expedition 69 here, and we’re on a mission to get you all ready for the upcoming total eclipse. 


This is exciting and there’s a lot to cover. 


  … If you are in the path of totality, everything will get dark. And you’ll be in for this show of a lifetime. Expect lots of goosebumps. 

I’m sure everyone watching wants to know how to safely see it, right? Here’s the deal. The only time you can look at the total eclipse without eye protection is during a brief period of totality, when the Moon completely covers the Sun. Viewing any part of the Sun without protection, even for a short amount of time can cause serious eye damage. 


Never look directly at the Sun without proper eye protection. Sunglasses are not enough to shield your eyes from harmful solar rays. Use certified solar viewing glasses or handheld solar viewers to observe the eclipse. These specially designed glasses provide the necessary protection. 


If you want to use a telescope, binoculars or camera to view the Sun, you must place a safe solar filter on those too, except during totality. If you don’t have eclipse glasses, you can use an indirect viewing method like a pinhole projector. Make a small hole in a piece of cardboard or paper…  


…or use a colander.  


You can even use your hands.  


Basically, use any holy object and cast a shadow on a nearby surface and check out the crescent shapes. If you’re not lucky enough to be near the eclipse, maybe you’re outside the U.S., you can still experience it all though with NASA live coverage on NASA+ April 8 from one to 4 p.m. Eastern Daylight Time. 



That was a lot. Did we miss anything? 



I think that covers it. You can find all this information and more at 



Happy viewing! 




PADI: This is NASA’s Curious Universe. This episode was written and produced by Christian Elliott. Our executive producer is Katie Konans. The Curious Universe team includes Jacob Pinter, Maddie Olson and Micheala Sosby. Krystofer Kim is our show artist. 


PADI: Our theme song was composed by Matt Russo and Andrew Santaguida of SYSTEM Sounds. Special thanks to NASA’s heliophysics team, Marcellus Proctor, Julia Tilton and Scott Swofford. 


PADI:  If you enjoyed this episode of NASA’s Curious Universe, please let us know by leaving us a review and sharing the show with a friend. And remember, you can “follow” NASA’s Curious Universe in your favorite podcast app to get a notification each time we post a new episode.  


[STINGER: 3…2…1… This is an official NASA podcast]