Kids' science podcasts with educator lesson plans to learn all about the solar system, answering questions about gravity, orbits, the stardust that made the Earth, the sun, and planets like Mercury, Venus, Mars, Jupiter, and Neptune, plus other celestial bodies like Pluto, comets, asteroids, and Jupiter’s moons Io and Europa; also exploring questions about life on other planets, eclipses, stargazing, and the inventions scientists use to understand and explore space, the earth, and the solar system such as spacesuits, spaceships, satellites, the international space station, Quindar tones, space photography, and astronaut experiments with tardigrades and dropping a feather on the moon, plus episodes looking beyond our solar system at time travel, the expansion of the universe, x-rays, the multiverse, black holes and wormholes.


Volcanoes in space!

The biggest volcano in our solar system is not on Earth -- and its footprint is as big as the entire state of Arizona.


Brains On! - Volcanoes in space! - Lesson Plan

The biggest volcano in our solar system is not on Earth -- and its footprint is as big as the entire state of Arizona.

[MUSIC PLAYING] Brains On. 

MOLLY BLOOM: You're listening to Brains On, where we're serious about being curious. And sometimes, we get curious about little offhanded remarks we hear from scientists. Like recently, when our co-host, Destiny Rodriguez, asked NASA volcano expert Carolyn Parcheta this simple question. 

DESTINY RODRIGUEZ: Where is the biggest volcano? Mauna Loa is our planet's biggest volcano. It's not the biggest in the solar system, but Mauna Loa is the biggest on Earth. 

MOLLY BLOOM: Not the biggest in the solar system? It turns out there are much bigger volcanoes out there. Earth doesn't even have the most volcanoes in the solar system. So today, we're going to explore this further. Get ready for [CLEARS THROAT] volcanoes in space. Stay tuned. 

[MUSIC PLAYING] 

This is Brains On from Minnesota Public Radio and Southern California Public Radio. I'm Molly Bloom. With me to talk about volcanoes on other planets and moons is our pal, Sanden Totten. 

SANDEN TOTTEN: Hey, Molly. Maybe we should call them spacecanoes? 

MOLLY BLOOM: Or lunar lava flows? Either way, there are a lot of them. So let's start with Destiny's original question. 

DESTINY RODRIGUEZ: Where is the biggest volcano? 

SANDEN TOTTEN: That would be on Mars. The biggest one we know of is called Olympus Mons. And it is ginormous, almost three times the height of Mount Everest, which is Earth's tallest mountain. And keep in mind, Molly, Mars is only about half the size of Earth. Here's how Carolyn Parcheta explained Olympus Mons to Destiny. 

CAROLYN PARCHETA: You can google a picture of this if you don't believe me, but the base where it touches the ground, the circular footprint of the volcano, is as big as the state of Arizona. And it reaches several miles high into the air. 

DESTINY RODRIGUEZ: That's huge. 

MOLLY BLOOM: The size of Arizona? How did it get so big? 

SANDEN TOTTEN: Lots and lots of eruptions over many, many, many, many years. But Mars actually has an unfair advantage when it comes to growing really big volcanoes. 

MOLLY BLOOM: What's that? 

SANDEN TOTTEN: Well, this is going to take some explaining. But, you know how in the volcano episode, we talked about how Earth is made up of all these different layers? 

MOLLY BLOOM: Yep, I remember. If you haven't heard that episode, you might want to go back and check it out. 

SANDEN TOTTEN: Right. Now, the top layer of the Earth sits on something called a tectonic plate. These aren't like dinner plates, they're actually massive plates of rock, the size of entire continents. So these huge plates, they're are actually moving all the time, just really, really, really slowly, about the same speed your toenails grow. 

MOLLY BLOOM: That is slow. 

SANDEN TOTTEN: Yeah. So, we don't notice them moving most of the time. OK, so on to volcanoes. Volcanoes form when magma, hot magmas bubbling up from deep inside the Earth, it'll build pressure and crack a hole in one of these plates. 

[RUMBLING SOUND] 

And the hotspot will then start pumping out lava onto the surface. Then, more lava comes out. It'll pile on and on, up and up, until it forms a giant mountain. 

[MUSIC PLAYING] 

MOLLY BLOOM: That's how volcanoes grow. 

SANDEN TOTTEN: Exactly. But, remember how I told you these giant tectonic plates are always moving? 

MOLLY BLOOM: Yes. So how does that affect it? 

SANDEN TOTTEN: So, the hole that was cracked open where the volcano formed, over time, as the plate slides, that hole will just move away from the hotspot where the magma is bubbling. When that happens, the magma is covered up again. Now eventually, the pressure will build again. It'll crack a new hole in the ground. The lava piles back up. And a new volcano is built. But then, that hole moves away too. A new crack forms, more lava builds up, another big mountain. And the cycle repeats over and over again. A new crack forms. 

MOLLY BLOOM: More lava builds up. 

SANDEN TOTTEN: Another big mountain. A new crack forms. 

MOLLY BLOOM: More lava builds up. 

SANDEN TOTTEN: Another big mountain. A new crack forms. 

MOLLY BLOOM: More lava builds up. 

SANDEN TOTTEN: Another big mountain. A new crack forms. 

MOLLY BLOOM: More lava builds up. 

SANDEN TOTTEN: Another big mountain. OK, wait. Sorry, I'm getting carried away. Where were we? 

MOLLY BLOOM: A new crack forms, more lava builds up, another big mountain. 

SANDEN TOTTEN: Right, right. OK, so that's why on Earth, volcanoes can only get so big before they lose their steam. 

MOLLY BLOOM: Very cool, but what does this have to do with volcanoes on Mars? 

SANDEN TOTTEN: OK, well on Mars, the surface of the planet doesn't slide around like it does on Earth. So that one magma hot spot can keep growing and growing its volcano until it gets bigger and bigger and bigger. And that's why Mars can make such mighty volcanoes like Olympus Mons. 

MOLLY BLOOM: I wonder what it would be like to see something that big erupt. 

SANDEN TOTTEN: Well, to find out, you'd need a spaceship to get to Mars and probably a time machine, since the last time Olympus Mons had a major eruption was probably 20 million years ago. But I spoke with Bruce Betts, who studies space for the planetary society. And he told me, when Olympus Mons would majorly erupt, most of Mars would notice. 

BRUCE BETTS: Large, large scale eruptions, like out of the center, would have definitely sent out Mars quakes and affected things all over the place. But you also would have had thousands of smaller eruptions over time that wouldn't have been nearly as noticeable if you weren't nearby. 

SANDEN TOTTEN: Another cool thing Bruce Betts told me, volcanoes are everywhere in our solar system, on planets like Mercury and Venus. Even our own moon once had volcanoes. In fact, the most volcanically active spot we know of is one of Jupiter's moons named Io. 

MOLLY BLOOM: Io, spelled just like it sounds, the letter I and the letter O. 

SANDEN TOTTEN: Yeah. Io has so many volcanoes erupting all the time, its surface kind of looks like melty, gooey cheese. Bruce Betts called it a space pizza. 

BRUCE BETTS: The volcanoes look vaguely like pepperoni. And it has a range of types of volcanoes too. It's got silicate volcanoes that are like volcanoes on Earth. But it also has sulfur volcanoes that spew out sulfur and stuff that's called sulfur dioxide. And there's very little atmosphere, so the material goes flying up tens of kilometers into space, and then falls back down. 

MOLLY BLOOM: Wow. That is not a place I would like to visit, sounds very hot and very noisy. But it's cool that volcanoes really are all over the place. 

SANDEN TOTTEN: Yeah, probably all across the universe. Anywhere there's a solid planet, near or super far away, there could be a volcano. 

MOLLY BLOOM: Why do you think that is? Why are volcanoes so common? 

SANDEN TOTTEN: I asked Bruce Betts the same thing. And he told me volcanoes are just nature's way of releasing heat stored up inside planets and moons. 

BRUCE BETTS: Just like if you heat up a pot of water, then you start getting bubbles, and you start getting the hot waters moving up. Well, when the interior of a planet is hot, either from its original formation or the radioactive materials making heat, that heat has to go somewhere. And the hot stuff likes to go up. Just like hot air rises, hot rock rises. And it keeps going until it hits the surface where it can come out and cool off. 

MOLLY BLOOM: Very interesting. Thanks, Sanden, for sharing all of this. 

SANDEN TOTTEN: Any time, Molly. 

[MUSIC PLAYING] 

MOLLY BLOOM: Right now, we're working to find an answer to this question from one of our youngest listeners. 

GIRL: Hi, my name is Casey. And I'm 4 3/4. My question is, how does the car GPS know where the car is going? 

MOLLY BLOOM: Thanks, Casey. That is an excellent question. We will have an answer for you very soon. 

[JINGLE] Ba ba ba ba ba ba ba ba ba ba ba ba Brains On. 

One of the coolest parts about making brains on is hearing from you. We love it when you send in questions like Casey, or draw us pictures, or record your own mystery sound. And as a way to say thank you, we started the Brains honor roll. I present to you the next crop of Brains honor rollees. They are. 

[LISTING HONOR ROLL] 

I'm Molly Bloom, and thanks for-- wait, what did you say? I forgot who now? Oh, that's right, the mystery sound. We can't end this episode without putting your brain to work. Let's go. 

[MUSIC PLAYING] Mystery sound. 

Here it is. 

[POPPING SOUNDS] 

That sound is making me strangely hungry. Let's get 10-year-old Max to tell us the answer. He is the one who sent it to us after all. 

BOY: That was the sound of popcorn popping. We popped it in the microwave. 

MOLLY BLOOM: Thanks, Max. That mystery sound goes great with some butter and salt. 

[MUSIC PLAYING] 

Can you think of another sound that might come from a kitchen, the basement, the park, maybe right out your front door? Mystery sounds are everywhere. If you think you have a good one, email it to us, brainson@m-- as in Minnesota-- pr.org. And you can always send questions, drawings, and high fives to that address too. If you're looking for more episodes of Brains On, head to our website brainson.org, or you can subscribe in your favorite podcast app. That's all for this episode. We'll be back soon with more answers to your questions. Thanks for listening. 

[MUSIC PLAYING] 



The mystery of gravity

Gravity is a very familiar force to us here on Earth. We know how it behaves and how it affects us. But where does it come from? We’ll also talk to a NASA astronaut about what it’s like to experience micro-gravity.


Brains On! - The mystery of gravity - Lesson Plan

Gravity is a very familiar force to us here on Earth. We know how it behaves and how it affects us. But where does it come from? We'll also talk to a NASA astronaut about what it's like to experience micro-gravity.

[RECORD SCRATCHING] CHILDREN: Brains On! 

RICHARD R. ARNOLD: You want my full name? My full name is Richard R. Arnold, but I go by Ricky. Well, it depends how long you know me, but-- and I'm a NASA astronaut. 

MOLLY BLOOM: You're listening to Brains On, where we're serious about being curious. I'm Molly Bloom, and I just want to make sure you heard what he just said. 

RICHARD R. ARNOLD: I'm a NASA astronaut. 

MOLLY BLOOM: OK, one more time, a little slower. 

RICHARD R. ARNOLD: I'm a NASA astronaut. 

MOLLY BLOOM: You guys, an astronaut. 

[UPBEAT MUSIC] 

Richard is going to tell us a little bit about what it's like to float in space while we try to wrap our heads around the G word, Gravity. Our episode about roller coasters got us pretty curious about gravity. We know what gravity feels like on Earth. It's the force that keeps your feet planted on the ground. When you throw a ball up in the air, it comes back down. That's gravity. 

To get out of some of Earth's gravitational pull, you've got to get yourself a rocket. That's how astronaut Richard Arnold did it. 

GROUND CONTROL: 5, 4, 3, 2, 1, 0, and liftoff. 

[ENGINE BOOMING] 

RICHARD R. ARNOLD: When you are on a rocket and you ride take that 8 and 1/2 minute ride to space, it's constant acceleration, constant acceleration. You're just going faster and faster. And then all of a sudden, the main engine cuts off. And you kind of float up out of your seat. Once it stops, you're free-floating until you decide to turn around and come back home. For my first mission it was 13 days, but for the last few years, the missions have been six months long. 

MOLLY BLOOM: Six months without needing to put your feet on the ground. Whoa. 

RICHARD R. ARNOLD: By and large, it's a lot of fun because you're just able to do things that you always dreamed about doing. You can fly from one module to the next in the International Space Station. You can sleep on the walls. You can sleep on the ceilings. It doesn't matter how you're oriented. 

You get used to managing your personal life and your personal effects. But you misplace something for a second, and you could spend days looking for it because it's all floating. In whatever direction it started moving, that's the way it's heading. And unless it happens to be picked up by a fan and you can find it against the filter, you could spend days looking for something as simple as a fork or a toothbrush. Whereas in your house, if you drop something, you've got a pretty good idea of where it's going to be. 

MOLLY BLOOM: You might think that everything Richard is talking about is happening with zero gravity, but that's not the case at all. When astronauts go into space, they're still in the Earth's gravitational field. They call it microgravity. 

RICHARD R. ARNOLD: We're only 200 miles up, so what's really happening is you're not really experiencing much difference in gravity. What you're experiencing is being in freefall around a planet for an extended period of time. It's kind of like taking a baseball and throwing it so far over the horizon that it's going to eventually curve to the ground, make a parabola to the ground, but you throw it so far and so fast that it's falling around the horizon all the time. And that's kind of what we do when we launch rockets. 

[UPBEAT MUSIC] 

MOLLY BLOOM: Mass is the measure of how much matter is in a thing. And matter means stuff, atoms, molecules, the tiny building blocks of everything. One of the things we know about gravity is that it's created by mass. Earth is really large, has a lot of mass, and therefore has gravity. So do other planets and stars. But why? Why does gravity exist? To find out, I called my friend Chris. 

CHRIS MENDILLO: So my name is Chris Mendillo. I'm an astronomer at the University of Massachusetts in Lowell, Massachusetts. 

MOLLY BLOOM: I asked him what seems like a pretty basic question. Do we know where gravity comes from? 

CHRIS MENDILLO: We don't, really. It's strange because it's sort of the most familiar of the forces in the universe to us. I mean, we deal with it every day. It's something we kind of take for granted. We know that it has a lot to do with mass and that mass-- for 300 years, we've known that mass creates gravity. But we don't really know where it comes from. And we don't know where it comes from as well as we know, or we think we know, where the other forces in the universe come from. 

MOLLY BLOOM: Chris said there are a couple of different avenues through which scientists are trying to figure it out, string theory and quantum gravity. Explaining those is definitely a task for a future episode, but the very basic premise is this. 

CHRIS MENDILLO: I mean, in science, everything is about, if you have a theory, it has to produce a prediction that you can test. And if you test it and it works, then it might be true. And if you test it and it doesn't work, then it's definitely not true. And that's how all science works. No one's been able to come up with an origin theory of gravity that if you could test it, you could show it's possible or that it's true. 

MOLLY BLOOM: So if we already know so much about how gravity behaves, does it matter if we know where it comes from? 

CHRIS MENDILLO: Understanding the origin of gravity would certainly help figure out how black holes work. 

MOLLY BLOOM: I had always had this idea in my head that a black hole was literally a hole in space that sucked things into it. I think I got it from cartoons. But Chris set me straight. 

CHRIS MENDILLO: There's nothing magic about it. It's normal matter. It's just confined to a very small space. We know really well how they form. They form when giant, massive stars collapse. 

One of the basic things about black holes is they don't-- it's not like they produce more gravity than what you started with. If the Sun just turned into a black hole right now, the Earth's orbit wouldn't change. Everything would be fine. We wouldn't have a sun, so that would be bad. But the gravity wouldn't increase. It's the same matter. It's the same amount of mass. It's just, it would be compressed down into the size of a baseball instead of the size of the Sun. 

MOLLY BLOOM: And the reason they're called black holes? We can't see into them. 

CHRIS MENDILLO: We can't see into them because gravity distorts and bends light. Well, in a black hole, the gravity is so strong that light can't escape. That's why they're black. There's nothing we can measure. 

MOLLY BLOOM: And knowing more about gravity and black holes would help us learn a lot about our universe. 

CHRIS MENDILLO: Black holes are the reason we're here. The only reason we have a galaxy that looks like our galaxy is because there's a giant, supermassive black hole at the center of it that holds the whole thing together. So understanding the origin of gravity, yeah, is certainly important for knowing why we're here, why anything is here. [LAUGHS] 

[SERENE MUSIC] 

MOLLY BLOOM: Do you have any questions about gravity or space or anything else? Send them to us at BrainsOn at M, as in Minnesota, PR dot org. Your question could be rocket fuel for an upcoming episode. 

Speaking of mysteries, we have another mystery for you. It's the mystery sound. 

MAN: Shh. 

CHILD: (WHISPERING) Mystery sound. 

MOLLY BLOOM: Here it is. 

[WHOOSHING] 

That mystery sound was actually sent to us by nine-year-old Sophia Chu. Have an idea what it is? Let's hear it again. 

[WHOOSHING] 

Any other guesses? We're about to reveal the answer, so if you want a little more time to think about it, just hit pause. We'll be here when you get back. All right. Here's Sophia with the answer. 

SOPHIA CHU: Hello. I am Sophia Chu. And I'm nine years old. That was the sound of kicking the snow down the storm sewer. I think it's a really interesting sound. 

[UPBEAT MUSIC] 

MOLLY BLOOM: Is there a sound in your life that you think would make a good mystery sound? We'd love for you to send it to us, just like Sophia did. You can record it using a smartphone's recording device and send it in an email to Brains On at M, as in Minnesota, PR dot org. If we choose your sound, we'll call and ask you about it. 

That's it for now. You can listen to all of our episodes any time at our website, BrainsOn.org, or you can find them in your favorite podcast app. You can also follow us on Twitter and Instagram at Brains_On. If you like the show, do us a favor and leave a review in the iTunes store. It really helps other kids and parents know about the show. Thanks for listening. 

MAN: Ba, ba, ba, ba, ba, ba, ba, ba, ba, ba, ba, ba, Brains On. 

Secrets!

If you look a little closer, listen a little harder, you’ll notice the secret life of things all around you. Want to know about the secret lives of bees, crickets, coral — and your own backyard? Give a listen!


Solar System

Solar System

Volcanoes in space!

The mystery of gravity

Secrets!