We're still trying to learn the nature of just how the sun tumbles around and what causes sunspots and how these things affect other things. And better predicting when solar storms will be a threat to the earth and how we can mitigate that radiation when it does come. The sun in a sense, oh yeah, we can look at it and know stuff about it. But there are so many just crazy things about how those particles in that plasma and the magnetism moves and works together. And a lot of it we say is unpredictable, but some of it may be predictable if we're observing the right things over the right period of time.
From the very beginning of human history, people have looked to the sun. It rules how we live, who regulates our days, months and years. Yet it is the celestial body that provides lots of information, but still holds some mysteries. This is random acts of knowledge presented by Heartland Community College. The Challenger Learning Center at Heartland Community College is dedicated to educating people of all ages about the vital STEM skills that help us unlock the mysteries of the universe. Today, we'll talk about what we have learned and what we can still learn about the sun. With our expert from the Challenger Learning Center.
My name is Libby Tormek. And I'm a flight director at the Challenger Learning Center at Heartland Community College.
So I'd like to talk about something today that literally our lives revolve around. And that is the sun for something that has such a profound impact on everything that we know. And do. We have a lot of mysteries in our lives about the sun, things we still don't know things that scientists are studying. But also just things that we don't necessarily think about. Even though we may have heard of some of the terms. I guess the first one is something that happens twice a year, and it's the equinox.
Lots of people mostly just know the word Equinox from seeing it on their calendars a couple times a year, and some people will confuse Equinox with the solstice is there are two solstices and two equinoxes, and they appear on your calendar. And that's kind of how I originally knew them. These are the four days each year that mark the official changing of the seasons. And it has to do with Earth and its orbit around the sun. So Earth has seasons because of its axis being tilted. So that causes different parts of the earth to be exposed to the sun's rays a little more intensely at different times in its orbit. So that gives us our seasons. So the solstice is marked the beginning of winter and summer. So we often have the longest day of the year and the shortest day of the year. But the equinoxes they marked the beginning of spring and fall in the name Equinox comes from Latin roots for equal a night. So the equinoxes are the days where the day and the night is basically exactly the same. It's almost the opposite of the solstice is and so those are pretty cool days to watch out for. And they just mark the change of seasons.
Well, those are the normal activities that we see of the Sun as it relates to us on Earth and our rotation around it, rotation of the Earth. But there are events that happen periodically with the sun that are very mysterious to me, probably less so to people that know more about it. But we always hear about sunspots, what actually are sunspots.
Great question. So the study of the Sun is called Helio physics, and so Helio physicists observe this mysterious burning, pulsating ball of electromagnetically charged gas and radiation and ions and particles. And so one of my first weeks working with the Challenger center, I actually got to hear from a NASA Helio physicist, his name was Lou mayo. And Lou Mayo told us all about how the sun is this moving, rotating, tangling mass of electricity. And he said, it's kind of like if you take a ball of yarn and you throw it in a closet with a bunch of junk and then you pull it out, you know, a few years later it's gonna be ratty and tangled and messed up and that is happening to the magnetic field lines on the sun. And so sunspots are when certain areas of the sun get kind of cooler and darker as this energy tangles and so I can still see it in my mind, you know, from nine plus years ago, Lou Mayo this tall guy long ponytail puts on his sunglasses gives a thumbs up and says sunspots are cool, because they are these cool Dark Spots on the Sun. But the tangling of radiation and magnetism that comes along with sunspots, causes all different other kinds of solar phenomena that do affect us even all the way here on the earth
knows that what causes solar flares? Yeah, exactly the
magnetic radiation around the sunspots, twists and tangles, it can start to arc and form these really cool loops called solar flares. And sometimes that radiation is even strong enough that it gets released explosively from the sun out into space and that's called coronal mass ejection or a CME. In fact, all of that radiation streaming off of the Sun in many directions is what we call the solar wind. Sometimes that heads towards the earth or towards other planets and causes some interesting effects.
Yeah, when it does head towards the earth, there are things that can happen, I guess if they're particularly large, then it can affect communications, it can affect other things on Earth and has at different points in our recent history.
Yeah, so CMEs and solar flares, they fall into different size categories, the X class is the largest and most dangerous. And when that radiation heads towards the Earth, our earth is actually protected by this invisible magnetic field that's caused kind of by the Earth's core and things that are happening there. And so when the radiation hits the Earth's magnetic field, sometimes that radiation does interfere with satellites with radio communication. But other times that radiation gets channeled along the magnetic field lines of the earth to the north and south poles, and it creates these dazzling light displays that we call the northern or southern lights, the auroras. So when that radiation hits the gases in Earth's atmosphere, those gases get excited, and they release these colors of light. So for example, we get blue and purple when the nitrogen gets excited. We have red and green from the oxygen getting excited. So that basic chemistry playing with the sun's radiation causes some gorgeous effects.
Now, I know that there are some times that they say the Northern Lights are more active on a more reliable basis, certain seasons, does that mean that the storms are somewhat reliable?
I mean, as reliable as a giant tangled ball of electromagnetic forces can be the sun does have more active and less active cycles as years go by. And astronomers have been able to observe the sun over time to kind of track and realize that these cycles happen. So all of
these terms, sometimes you hear them talk about solar wind, but it's not wind, obviously, there's no atmosphere in the vacuum of space, but they mean things that move like or at least in the broadest sense, it seems to travel. Yeah, that might we might think of something be moved by the wind.
Yeah, the solar particles and the radiation that's being ejected as being pushed explosively outwards towards things. And yeah, so it is kind of like wind and has that effect.
Well, I've also heard the term coronal rain, which again, isn't rain, it's something else. It's super
hot plasma. So when we think about a sunspot, sunspots are cool, those cool Dark Spots on the Sun, and then the tangled lines of radiation and magnetism around them that sometimes warp and loop over the cool areas. When that explodes, it releases that radiation of a CME and then sometimes that plasma and these arcs can kind of cool and start to fall back down towards the sun's atmosphere. It's Corona, net plasmas channeled back on those magnetic loops. So sometimes it looks like a surreal source list 3d waterfall coming back down to the sun. And what was cool when I looked a little more into this, NASA has some recent footage of One such instance of coronal rain, and it looked like it was happening pretty quickly. But that coronal rain event actually happened over a span of 10 hours. And smaller solar flares can have coronal rain that takes 30 hours to fall back towards the surface of the Sun, which is pretty crazy.
So you mentioned earlier talking to a NASA scientist that studies sunspots and other things. How does NASA study the sun, I imagined that the old fashioned way is you've got your telescopes, and you look at the activity and you measure maybe some of these, these elements of radiation changing. But what is NASA doing? And what have they learned from the sun studies?
Well, first, I gotta take my required moment to say never point a telescope at the sun.
Don't do that today
and don't look directly in. That's right. There are special solar filters you can put on the end of a telescope that then do allow you to look at the sun. So if you have a solar filter, you're approved to look at the sun. One of the ways NASA studies the sun is to look through telescopes on the earth with solar filters. But NASA also has a suite of over 20 missions orbiting the Earth and the Sun that study the sun and almost more importantly for us, its interactions with things on earth. So we have satellites that are studying the radiation when it hits Earth's magnetic field and things like that. But we also have a suite of missions that are orbiting the Sun itself. One of the most well known missions is SDO, the Solar Dynamics Observatory. And this little mission has a bunch of tools that let it observe the sun in different wavelengths of light. And so those let us see different layers of the sun as that solar activity is happening and sto is really neat. They update the page online for sto frequently so you can go on and see near live photos of the Sun at any given moment. So a number of years ago a friend of mine gave me a card with my birthday son on it because she had gone to the sto gallery and found the picture of the sun from when I I was, you know, that day, the time I had been born and stuff, which was really, really neat. NASA's most recent mission to the sun actually just launched last year in August on August 12. It was the mission called the Parker Solar Probe. And over a span of seven years, it's going to use successive flybys of Venus to close its orbit closer and closer on the sun, and get closer to the Sun's surface than any other mission before. So being there in that Corona, it's going to be able to make measurements take pictures
that was going to be my next question is when they're sending these probes? How close can they get to the sun? I imagine that there's a point where you could be too close. And first of all, you know, you'd have the Icarus effect or something, maybe damage your vehicle, but also, there's probably all that radiation that causes transmission problems as well.
Yeah, so when we say close to the sun, you're right, it's still relatively far away. The Parker Solar Probe is going to have to deal with such hazardous radiation and extreme heat, that it's covered in a four and a half inch thick carbon steel plated shield, and it has tools and arrays that can retract and come in and out, you know, as needed, depending on where it is in its orbit. In fact, it's supposed to reach its second perihelion, which means its closest point in its orbit to the sun on September 1.
It's not just the sun that NASA scientists are studying our Sun, it's other suns as well, other stars. Well, how does our Sun match up with the majority of the stars that we know about and study? Is ours unique? Is it big, small medium for us to just write, but for using the three bears measuring stick, but how does it fit and what are the other suns that NASA is most interested in studying.
As far as our Sun in comparison to other stars, there are many different size categories for stars and heat categories, and our Sun is an average one kind of right in the middle. So if you're going with the Goldilocks analogy, it is literally just right for us. As far as studying other planets and other suns. There are some pretty remarkable ways that we can find other planets. And depending on their sizes, we may look at if the planets distance is too close or too far if the size is too big or too small. And there's actually a category that we play some of these planets into called the potentially habitable planets and we call the zone the Goldilocks zone that they're in. These planets that are found orbiting other stars, other suns are called extrasolar planets or exoplanets. And I looked actually this morning, and NASA has confirmed over 4000 exoplanets found so far.
4000, that's amazing. On Star Trek or something, they seem to find planets that could support human like life every five minutes. So I don't know if they've gotten to 4000 different planets on Star Trek, but it seems I guess, a little bit more believable than that there are other things out there like that. How do they go through the process of identifying these exoplanets?
I'm so glad you asked this question, I actually find it really, really fascinating. So we use ground based telescopes and a couple of missions, most notably NASA's Kepler and test missions that train themselves on patches of the night sky and observe the light wavelengths of the stars. And they're kind of two major ways that I know of that we search out and find exoplanets. One of them is using what we call the Doppler effect. And for us here on the earth, the Doppler effect, we experience it when say, a fire truck drives by on the street I live close to a fire station. So I hear that sound all the time. When the fire truck is far away, it seems to have a low pitch, and then when it gets closer to you, that pitch seems to go up. And then it goes down when the truck gets further away. So the Doppler effect speaks to how the frequency of waves seems to change as the source changes its position relative to the observer. So turns out this happens with light waves, and not just with sound waves. So if we're observing a light source far away, and it moves, the frequency of those waves seems to change. So now you may be thinking that's cool. But what is firetruck have to do with finding a planet? Well, if a star has another body in its system, whether it's another star or it's an exoplanet, that body is going to have its own gravitational pull that's going to affect the star, it's going to cause it to kind of wobble a little bit just like if you held the kid by two hands and started spinning him around in a circle. That pole is going to cause you to wobble to stay stable so stars wobble when they have something else orbiting them. So we can measure the frequency of the light coming from that star. And if it ends up having a predictably circuit a wobble, then we can guess that there may be something like a planet orbiting it. We can also look at the light that That star is giving off if planet transits in front of that star, it's gonna block a tiny bit of light. So again, we observe over a long period of time. And if there's predictable dips in the light given off from a star, then we think that might mean that there's a planet orbiting it too. And so if we look at several of these methods and kind of put them together, we can build a really compelling case that there's probably a planet orbiting that star,
and the characteristics of that planet probably can be extrapolated from what you think the distance is, from that sun, with the size of that shadow, for lack of a better word that yeah, Disgust might be, is that how they figure out what they think those planets might be? Like?
Exactly, that's, they use observations and a lot of math. And that's how they can guess that a planet may be, you know, three Earth sizes or this far away, and it's in its Goldilocks zone, because its star is large, or it might have this kind of atmosphere. And so we're you know, as humans, we've always been obsessed with seeing if there's other life in our solar system, NASA has some really cute vintage travel poster style graphics of exoplanets and what they might be like, and what always cracks me up thinking about this is to imagine that there may be aliens on one of those planets using these methods to surmise if Earth is potentially a habitable planet traveling around its star, you know, be pretty cool.
So when they will send these probes to our sun? What do they still hope to know? What are the mysteries of the sun that we haven't cracked quite yet?
I think part of it is we don't even know some of the mysteries till we get there and find them out. We're still trying to learn the nature of just how the sun tumbles around and what causes sunspots and how these things affect other things. And better predicting when solar storms will be a threat to the earth and how we can mitigate that radiation when it does come learning about the sun's corona its atmosphere about its insides, the sun in a sense, oh, yeah, we can look at it and know stuff about it. But there are so many just crazy things about how about those particles in that plasma and the magnetism moves and works together. And a lot of it we say is unpredictable, but some of it may be predictable if we're observing the right things over the right period of time. So you teach
people of all ages at the Challenger Learning Center, when you try to teach younger kids about the sun. Maybe some of the things that we've talked about today are the things that you get into but what are some of the things, some of the activities, some of the messages that you want to get people to grasp but when they come to learn at the Challenger Learning Center about the sun,
a lot of people just see the sun is that's cool. It gives us heat, man, the summer is hot. We go around at the end. But all of these things about the solar cycle, cool sunspots and flares, radiation, auroras, the mysteries of the sun. These are interesting, and they impact our life. And so we want to educate people about those things. So everything from fun 3d Pen crafts about the sun to activities that actually helped demonstrate maybe auroras or solar winds, and we'll go in our spaceship and fly to some of the planets because the solar radiation hits other planets magnetic fields and cause auroras on other planets too. And so we'll get to kind of take a big picture solar system, look at the sun and its effect in our little neighborhood.
Well, let me thanks so much for coming in and talking to us about the sun today,
you bet.
Libby torbreck as a flight director at the Challenger Learning Center located at Heartland Community College, she teaches kids from kindergarten age through high school about science and space. She also has a fair amount of knowledge about what NASA is doing with various projects, including solar science. If you'd like to hear more interviews about science and space, as well as discussions about art, history, wellness and more, check out our other random acts of knowledge episodes on iTunes, Spotify or audio moon. Thanks for listening
