Earthrise, a photo captured by the crew of Apollo 8, the first crewed mission to the moon in 1968.
Courtesy of NASA
December 25, 2018
Earthrise: The picture of our planet that changed the world
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50 years ago NASA astronauts took a picture that changed the world. It was a full color photo of planet Earth as seen from space. This image inspired many to think differently about our home.
In this episode we'll tell the tale of that epic snapshot. Plus we'll explain how Earth and our solar system formed in the first place. We'll talk to astrophysicist Lindy Elkins-Tanton about whether there are other planets like Earth in the universe. Plus we have an all new Mystery Sound and a Moment of Um that answers the question “Why do dreams seem longer than they are?”
So say cheese and enjoy!
Audio Transcript
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INTERVIEWER: You're listening to Brains On, where we're serious about being curious.
INTERVIEWER: Brains On is supported in part by a grant from the National Science Foundation.
SANDEN TOTTEN: How about now, Marc?
MARC SANCHEZ: Let me see.
[GRUNTS]
Well, it's really long. But it's still not long enough.
SANDEN TOTTEN: OK, let me try adding some more broomsticks. Hold on.
MOLLY BLOOM: Hey, Marc.
MIRA: That's a really long stick you're taping together.
MAYA: Yeah. What exactly are you and Sanden building?
MARC SANCHEZ: Oh, hey, Molly and Maya and Mira We're making the world's longest selfie stick.
SANDEN TOTTEN: So we can take the world's most epic selfie.
BOB: Can I be in it, too?
MARC SANCHEZ: Oh, hey, Bob. I didn't see you there.
BOB: I get that a lot.
MARC SANCHEZ: Sure.
BOB: All right.
MARC SANCHEZ: But technically, everyone's going to be in it.
SANDEN TOTTEN: I'm going to attach this flagpole, too. And maybe even a fire pole. We have a fire pole, right?
MOLLY BLOOM: Wait what kind of selfie is this exactly?
MARC SANCHEZ: A selfie of the entire world.
MIRA: Like, all of it?
SANDEN TOTTEN: From top to bottom.
BOB: Wait. So everyone will be in it, too? Oh, snap. I thought I was special.
MIRA: You'll need to be in space to take that picture, won't you?
MARC SANCHEZ: Not if you have a really long selfie stick.
SANDEN TOTTEN: OK, try again.
MARC SANCHEZ: Hold on.
[GRUNTS]
OK, OK. Let's see.
MAYA: Wow. It's clearing the clouds. I can't even see where it ends anymore.
MOLLY BLOOM: That is impressive.
BOB: Are you getting my good side?
MARC SANCHEZ: Yeah. Hold on. I think we might have done it. I just need to snap a pic to see if the whole world is in this photo. Oh.
MAYA: What?
MARC SANCHEZ: Who's going to press the button to actually take the picture?
BOB: I'm pretty sure I can't reach it.
SANDEN TOTTEN: Maybe we could build a second pole and hoist that up to press the camera button?
MOLLY BLOOM: Good luck figuring this out. We got to go tape the show.
MAYA: Yeah. If you get the shot, tag us in it.
MIRA: Later, guys.
BOB: Do I have time to change into a better shirt? This one has mustard on it. I don't want to be forever remembered as the guy with mustard on his shirt.
[MUSIC PLAYING]
MOLLY BLOOM: This is Brains On from American Public Media. I'm Molly Bloom, and my co-host today are super sister duo Maya and Mira from Charlottesville, Virginia. Hey, there.
MOLLY AND MIRA: Hi.
[LAUGHS]
MOLLY BLOOM: So you are interested in space. So what fascinates you most about space?
MAYA: That there are other planets like Earth.
MOLLY BLOOM: What about you, Mira?
MIRA: Everything
[LAUGHS]
MOLLY BLOOM: Well, there's a very particular reason we wanted to do this episode in this month of this year.
MIRA: It's the 50th anniversary of a very special moment for planet Earth.
MAYA: A moment that really captured the attention of the people on it.
MOLLY BLOOM: We'll let producer Ned Leebrick-Stryker tell this tale.
NED LEEBRICK-STRYKER: It's winter vacation, and your family is heading out on a road trip.
MOM: Come on, kids.
DAD: We're leaving.
MOM: Did you remember your swimsuit, your toothbrush, and your vitamins. Oh, and your boots, and your fleece sweater Grandma bought you, and your Shrek pajamas, and your Spider-Man socks, and your hockey stick, and your ice skates, and--
[CAR SCREECHING]
NED LEEBRICK-STRYKER: Now, imagine that this road trip is 240,000 miles away from home.
KID 1: Dad?
DAD: What's up?
KID 1: I have to go to the bathroom.
KID 2: Me, too.
DAD: Well, jeez. Why didn't you say anything when we passed that rest area 10,000 miles back.
NED LEEBRICK-STRYKER: And what if this destination was somewhere no one else had ever been?
MOM: Hello? Hello? Why didn't we book a hotel room?
NED LEEBRICK-STRYKER: Well, 50 years ago, three astronauts did just that. On December 21st, 1968, Bill Anders, Frank Borman, and James Lovell became the first human beings to ever leave Earth's orbit. They were a part of Apollo 8, the second manned spaceflight mission in NASA's Apollo Space Travel Program. But they weren't landing on the Moon. That would come a few months later.
Their only goal was to circle it to see if it was even possible for other spacecrafts to one day land there.
[MUSIC PLAYING]
So on December 24th, these three astro travelers were road tripping through space, about to fly around the Moon for the first time. As their rocket soared over the lunar surface, they saw something that totally surprised them.
EMMANUEL VAUGHAN-LEE: They looked up and saw the Earth rise before them, climbing over the lunar surface. And they scrambled to take a picture to capture that.
NED LEEBRICK-STRYKER: That's Emmanuel Vaughan-Lee, director of the documentary Earthrise, named after the very picture the astronauts took. The sight of our small planet far away above the surface of the Moon was something no one had ever seen before. The Earth was just this bright dot floating above the Moon's horizon, and astronaut Bill Anders had to capture it.
EMMANUEL VAUGHAN-LEE: It was the first selfie that was ever taken of the Earth. It was a photograph that was not planned. And if you listen to the audio recording, you hear the crew quickly scrambling and expressing their emotions and feelings about the incredible, beautiful sight that they're seeing. Quick, grab some color film. That's the most beautiful sight. We got to get a picture of that.
BILL ANDERS: Oh my god, look at that picture over there. There's the Earth coming up. Wow, that's pretty.
FRANK BORMAN: Hey, don't take that. That's not scheduled.
BILL ANDERS: Got a color film, Jim? Hand me a roll of color film.
JAMES LOVELL: Oh, man.
BILL ANDERS: Quick.
EMMANUEL VAUGHAN-LEE: It's this beautiful blue marble in the blackness of space set against this gray, lifeless body that is the Moon. It was the first color photograph taken of the Earth from another planet.
NED LEEBRICK-STRYKER: Today, it's so easy to find images of the Earth that you can livestream video of the planet from the International Space Station. But back in 1968, all people had were drawings, maps, and globes. Nobody had a real sense of what our planet truly looked like. When Apollo 8 returned, the Earthrise picture was printed in newspapers around the world, and it blew everyone's minds.
INTERVIEWER: That's the Earth? We're so tiny.
INTERVIEWER: It's beautiful. I wish I could live there. Wait a minute, I already do. Woo-hoo!
NED LEEBRICK-STRYKER: Seeing the Earth from this new perspective gave people a chance to think about our planet in a new way, and, as a result, influenced creative people the world over.
INTERVIEWER: This picture should be a postage stamp.
INTERVIEWER: This picture makes me want to paint.
INTERVIEWER: This picture makes me want to sing.
NED LEEBRICK-STRYKER: One guy named Archibald MacLeish saw the picture and started writing a poem. It was soon published in newspapers.
RICHARD NIXON: To see the Earth as it truly is, small and blue and beautiful, in that eternal silence where it floats, is to see ourselves as riders on the Earth together.
NED LEEBRICK-STRYKER: That's then President Richard Nixon reading from the poem at his first inauguration in 1969.
RICHARD NIXON: Brothers in that bright loveliness and the eternal cold. Brothers who know now, they are truly brothers.
NED LEEBRICK-STRYKER: Nixon would soon help create organizations to help the planet, like the National Oceanic and Atmospheric Administration and the Environmental Protection Agency. Plus, the Earthrise photo is also thought to have inspired the founders of Earth Day, which started the very next year in 1970.
Filmmaker Emmanuel Vaughan-Lee says it was a picture of the world that truly changed the world.
EMMANUEL VAUGHAN-LEE: There could be other photographs that are very powerful, but I don't think any other photograph will capture what that photograph did. And it really stands not just for that moment, but for what is a shift in consciousness, a shift in perspective that, again, can't be replicated. Because once that shift has happened, you can't go back. This photograph represented a much more unified view of what was possible. And I think it broke a lot of people's perception about who we are, where we are, and what it means to be part of one shared planet.
It's one of those photographs that's going to stand the test of time. In hundreds of years to come, I think it'll still be as emblematic as it is today.
NED LEEBRICK-STRYKER: It's been said that a picture is worth a words. But the Earthrise photograph went far beyond that. It gave the people of Earth a new perspective. That we are an incredibly small part of a vast universe. It's a perspective that is challenging, humbling, and even for a brief second, unifying. We may be separated by schools, cities, and countries. But this picture reminds us we all live on the same beautiful blue orb called Earth.
MOLLY BLOOM: It's hard to imagine what it was like for everyone to see a picture of the Earth for the first time. So if you could write a short message to planet Earth, like a planetary postcard, what would you say? Maya, do you want to go first?
MAYA: Sure. Dear Planet Earth, I've explored the world. And I hope this postcard will give you some memory of your happy moments.
MOLLY BLOOM: So Mira, what would you want to say to planet Earth in a postcard?
MIRA: Dear Planet Earth, I hope you stay strong and stay here for a long time so our ancestors will remember us.
MOLLY BLOOM: Very nice letters, you two. Now here's some cosmic correspondence from some of our listeners.
[MUSIC PLAYING]
RACHEL: If I could write a letter to planet Earth, I would say, Dear Planet Earth, thank you for giving us fresh air. It is really helpful. Love, Rachel.
SUBJECT 1: Dear Earth, I love you, and people should stop throwing food and waste food.
SUBJECT 2: Dear Planet Earth, Earth is good. We must be kind to you. Thank you for keeping us safe. Thank you for the pretty things we get to look at.
JACK: Dear Earth, I like your history. You have amphibians, dinosaurs, reptiles, and mammals. Love, Jack.
MOLLY BLOOM: A big thanks to Jack, Evan, Oliver, Caroline, and Rachel for sending in those heartfelt letters to Earth. And we agree, Earth is a pretty neat place in a pretty neat solar system. So it's no wonder so many of you are curious about our little neck of the cosmic woods, too.
NORI: Hi, my name is Nori, and I live in Mumbai, India. What was there before the Big Bang?
SUBJECT 3: What was the Big Bang, and how was all the planets made up?
SUBJECT 4: How are planets made?
SUBJECT 5: How did the Earth form?
SUBJECT 6: How did the solar system form?
MOLLY BLOOM: Thanks to Bridget, Kylie, Nora, Saru, and Nori for those excellent questions. Earth has a history. So does the solar system. In fact, there's a story behind the whole universe.
EARTH: Hey, Jupiter. What's this book?
JUPITER: What's that, Earth? Oh, that's our cosmic family photo album.
EARTH: What's that picture?
JUPITER: That's when our older brother Mars started sporting that crazy volcano, Olympus Mons. He thought he was so cool. This will never go out of style.
EARTH: What about this?
JUPITER: Oh, that's our great aunt twice removed, I think. Her name was Betty Black Hole. We stopped inviting her to family reunions because one time she ate all the potato salad and also all the light and matter in the surrounding area. Kind of rude, if you ask me.
EARTH: What about--
JUPITER: Here, why don't we start at the first page, Earth? This is where it all began.
EARTH: That picture is so grainy and old, I can barely tell what it is.
JUPITER: Yeah, it's from 14 billion years ago. That's our great-great-great-great-great-great-great-great-great-great-great--
EARTH: OK, I get it. It's very, very, very old.
JUPITER: OK, well, that's the Big Bang. That's the moment when the universe just popped into existence.
EARTH: Why?
JUPITER: We don't really know, Earth.
EARTH: Why?
JUPITER: Because we weren't around to see it.
EARTH: Why?
JUPITER: Hey, you see that button in the book? Why don't you just try pressing that?
EARTH: OK.
LAURA DANLY: Once upon a time, there was nothing, and then there was everything. We call that moment the Big Bang. But it really wasn't a bang like an explosion like we're familiar with. It really was just a big transition when the universe went from not existing to existing.
EARTH: Whoa, who's that?
JUPITER: That's Laura Danly. She's an astrophysicist. She helped us put together this album. She's super into cosmic genealogy. Check it out. Flip to the next page.
EARTH: What's this picture? It looks like space clouds.
JUPITER: Well, press the button to find out.
LAURA DANLY: Well, after the Big Bang, all the universe was just filled with matter and energy, like a big soup. But then, slowly and surely, gravity started pulling little islands of material together into galaxies.
EARTH: Like our galaxy, the Milk Away.
JUPITER: You mean Milky Way.
EARTH: Yeah, Milky Way.
JUPITER: Well, we come much later in the book. So that spacey soup stuff turned into galaxies and stars. Stars died off and released all kinds of materials, like carbon, oxygen, gold. A lot of the stuff in planets like you. Ah, here we are.
EARTH: That's us?
JUPITER: Yeah, that's our home. It formed about 4.6 billion years ago.
EARTH: Why?
JUPITER: I can actually answer that one. It formed because--
EARTH: I know, I know. It formed because our Sun formed and created a solar system around it.
JUPITER: Wait, if you knew, then why did you ask why?
EARTH: I like asking why. It's my favorite question.
LAURA DANLY: Before our Sun was here, there was just a cloud of gas. But then gravity pulled that cloud of gas together and the cloud got denser and denser and denser until finally, it was pulled together into a star, into our Sun. Well, at the same time that the Sun is collapsing, it's also spinning. So as it collapses further and further, it spins more and more.
And so surrounding the forming star is a disk of gas that falls into a spinning disk. And that's the disk out of which the planets in the solar system were made.
JUPITER: Oh, jeez.
EARTH: Who's that?
JUPITER: That's me in my younger years. So awkward.
EARTH: That's not you, Jupiter. That thing is small. You're ginormous.
JUPITER: Yeah, but I wasn't always a gas giant. I started out small, like you. I was a protoplanet first, but I just kept growing. Check it out.
LAURA DANLY: In the spinning disk of gas and dust, clumps start to form in protoplanets, little planetesimals, they call them. And those are just chunks of dust and material and ice that are also floating around, circling the newly forming star. So those smash into each other and get bigger chunks, which smash into each other and make bigger chunks. And eventually, you build up to the planets.
EARTH: Cool. I want to smash into things, too.
JUPITER: You did. See?
EARTH: That's me as a baby?
JUPITER: Yeah. Saturn and I were already very big by the time all the space dust and ice junk started crashing into each other in orbit, making baby you. See? There you are, orbiting the Sun as it forms. Flying into space rocks and getting bigger and bigger.
EARTH: But then why am I so much smaller than you still? Will I got to be your size?
JUPITER: Sadly, little sis, you're done growing.
EARTH: No fair.
JUPITER: Well, you know how we were all orbiting in this disk of ice chunks and dust and stuff while the Sun was forming? Once the Sun finally formed, it turned down like a mega giant furnace, making sunlight and letting out a huge gust of solar wind. Whoosh.
LAURA DANLY: And it blew away most of the remaining material that was inside the inner part of the disk. So we just flat ran out of material. The turning on Sun blew it all away, and there was nothing left to make the planets grow any larger.
EARTH: Aw man, I hate being so small.
JUPITER: Yeah, but look at it this way. You're the only planet in our family covered in oceans and plants and animals. That's pretty awesome, dude.
EARTH: I guess.
JUPITER: No, think about it. Your brother Mars, he was warm and wet at one point. But now he's all cold and lonely. No atmosphere. Oh, and there's Venus. She's a hot mess. So close to the Sun that all the water pretty much boiled off. She has runaway greenhouse gases, super overheated. Not much could survive there.
But you, you were just the right size and in just the right spot. When you formed, you were hot, and all this water evaporated into the air. But you had enough gravity to keep it from flying away.
EARTH: That's how I made my atmosphere.
JUPITER: Exactly. Plus, you have a molten core that creates a magnetic field.
EARTH: Yeah. That protects me from solo radio nations.
JUPITER: You mean solar radiation. And yeah, that radiation would wipe out life on you if you didn't have that magnetic field as a shield.
EARTH: I guess that I am pretty special.
JUPITER: See? I might be the biggest planet in our family, but you've got a pretty cool backstory. So what's it like being covered in life?
EARTH: Kind of itchy, actually.
[VOCALIZING]
AUDIO TRACK: Brains On.
MOLLY BLOOM: You know what goes well with the mysteries of Earth, space, and the universe?
MAYA: A mystery sound?
MOLLY BLOOM: You read my mind.
[MYSTERY SOUND CUE]
AUDIO TRACK: Mystery sound.
MOLLY BLOOM: Here it is.
[CREAKING]
[FIZZING]
OK. Before you even guess, I'm going to give you a little clue, because sometimes our mystery sounds are directly related to our episode topic, and sometimes they're not. And this is one of those times where it's not. So what do you think that sound was?
MAYA: It sounds like one of those instruments that has all of these little beads and sand droplets. And when you turn it around, it makes like a--
MOLLY BLOOM: Oh yeah, yeah, yeah, a rain stick.
MAYA: Uh-huh, yeah, that.
MOLLY BLOOM: Good guess. Mira, what do you think it is?
MIRA: I agree. It also sounds like something-- like many little things dropping down at the same time.
MOLLY BLOOM: Someone dropping coins or something?
MIRA: Yeah.
MOLLY BLOOM: Excellent guesses. OK, we're going to have the answer later in the show.
[MUSIC PLAYING]
Do you have a mystery sound to share?
MAYA: Or a burning question you just have to ask.
MIRA: Or maybe you want to tell us what you'd like to say to Earth.
MOLLY BLOOM: Do all those things at brainson.org/contact. That's how we heard from this listener.
ELI: Hi. My name is Eli. I live in Haddonfield, New Jersey. My question is, why do dreams seem longer than they are?
MIRA: We also love, love, love your drawings.
MAYA: Yeah, keep them coming.
MOLLY BLOOM: They totally brighten our day, and we love sharing them on social media.
MAYA: Maybe draw Marc and Sanden's epic selfie.
MIRA: You could even squeeze our buddy Bob in there.
MOLLY BLOOM: We'll have the answer to that question about dreams during our Moment of Um and give the newest rundown of friends to join the Brains Honor Roll at the end of the show. And speaking of friends, here's our pal, Joy Dolo.
JOY DOLO: Hey, Molly.
MOLLY BLOOM: Hi, Joy. Joy is the host of our new history show, Forever Ago, which we've been sharing a little bit of every week.
JOY DOLO: Yep. Every episode, we dig deep into the history of one cool thing. Like, have you ever wondered where shoes came from?
MOLLY BLOOM: I never really have thought about that before. I guess I take shoes for granted. But they really-- yeah, they had to get started somewhere.
JOY DOLO: Or some when. This week's episode is all about the backstory of shoes. Here's a little preview.
INTERVIEWER: The oldest pair that have been unearthed are called the Fort Rock Sandals, which were found in Oregon in 1938 by an anthropologist named Luther Cressman.
[COUGHS]
LUTHER CRESSMAN: Wow. There sure is a lot of ash in this cave.
INTERVIEWER: Cressman was exploring Fort Rock Cave. And inside, there was a layer of ash from a volcano eruption that happened thousands of years ago.
LUTHER CRESSMAN: Just got to keep digging. That's my motto. When you're in a hole, keep digging, and all your problems will be solved.
[COUGHS]
INTERVIEWER: And then he found something he had never seen before.
LUTHER CRESSMAN: Wait a minute, what's this?
INTERVIEWER: At first glance, Cressman's discovery might have just looked like a bundle of ropes. But on closer inspection--
LUTHER CRESSMAN: This looks like a-- pair of shoes?
MOLLY BLOOM: You can hear the full episode and the season finale of Forever Ago this Thursday. Find it on Apple Podcasts, Stitcher, or wherever you listen.
JOY DOLO: And if you like the show, leave us a review. All right, thanks for having me Molly. For the last time.
MOLLY BLOOM: I'll miss you. We'll see you soon.
JOY DOLO: I miss you already. Bye.
MOLLY BLOOM: Bye.
MAYA AND MIRA: Keep listening.
MOLLY BLOOM: This is Brains On. I'm Molly.
MAYA: I'm Maya.
MIRA: And I'm Mira.
MOLLY BLOOM: Earth is very clearly special. But is it totally unique?
MAYA: Are there other planets like Earth in the universe?
MIRA: To answer that question, we have a special guest.
MOLLY BLOOM: Lindy Elkins-Tanton is the director of the School of Earth and Space Exploration at Arizona State University, co-chair of the Interplanetary Initiative, and she's the principal investigator of NASA's Psyche mission.
MAYA: Welcome, Lindy.
LINDY ELKINS-TANTON: Hi. It's great to meet you all.
MIRA: Why are planets round?
LINDY ELKINS-TANTON: Planets around mainly because of the force of gravity. As the planet gets bigger and bigger, the very material that it's made of creates gravity that pulls the material closer together. And the lowest energy state, as a physicist would say, the easiest way for all the material to be as close together as possible is in a sphere. And so that's why planets are round. And that's why some really small asteroids are not round, because they just don't have enough gravity to pull them into roundness.
MAYA: That's really cool.
MIRA: I did not know that. Are there any other planets like Earth?
LINDY ELKINS-TANTON: We think that there must be. Just because it turns out there are so many planets out in the universe. It was only about 30 years ago that people didn't even know there were any planets outside of our solar system. And now we've discovered that virtually every star you see in the sky has got planets around it.
MOLLY BLOOM: How do they do that from so far away?
LINDY ELKINS-TANTON: It's been so fast, the rate at which scientists have figured out how to spot planets around other stars. You can't actually take a picture of the planet, because they're too small. But you can see if the planet blocks a little of the light from its star as that light comes toward the Earth. And sometimes you can see the star itself wobble a little bit as the planet goes around it.
We're just getting to the point some of our colleagues can take actual pictures of the planets. And they're not in great detail yet, but you can see a disk. And then the question comes, how do you know what that planet is like? You can know something about its temperature by how close it is to its star. And then other scientists look at the light that shines off the planet to the Earth, and then they can learn something about the composition of its atmosphere. And so bit by bit, you put together little pieces of evidence of what life on that planet might be like.
MAYA: Do other planets have auroras?
LINDY ELKINS-TANTON: I really love auroras. They're so beautiful, and I've been thinking about trying to make a trip to see more auroras. They're caused by little charged particles in space getting trapped in the Earth's magnetic field. So the two things you would need to make an aurora around any planet are a magnetic field, which not every planet has, and charged particles flying through space near that planet. And those are generally supplied by the star. So they would be around.
Now we've discovered that Jupiter has auroras. We can actually see the auroras on Jupiter. And in fact, you can see them on the internet. So we know already that there are at least a few other planets that do have auroras.
MAYA: Wow.
LINDY ELKINS-TANTON: Yeah.
MOLLY BLOOM: Can you tell us a little bit about NASA's Psyche mission?
LINDY ELKINS-TANTON: Yes. We just were selected by NASA to create a robotic mission with no people going into space, just a machine. We'll launch it in 2022. And it's going to fly out past Mars into the outer asteroid belt. And it's going to visit a metal asteroid named Psyche. We have sent space probes out and they visited rocky planets like Venus and Mercury and the Moon and Mars. And icy moons and gas giants, like Saturn and Jupiter.
But humankind has never visited a metal object before. And so we don't really know what a metal object looks like. We can't even get a good image of it from Earth. We don't know what craters look like in metal, if there are spires and peaks. If the surface is shiny or rubbly. We really have no idea. So it's truly exploration.
But the bigger goal even is to inspire everybody here on Earth to feel bolder in their own lives and to take a more courageous step out into the unknown. Think about this little Psyche mission going off into space to discover something new.
MOLLY BLOOM: That is so exciting. I cannot wait to see what you guys learn.
LINDY ELKINS-TANTON: Yay.
MIRA: Thank you, Lindy.
LINDY ELKINS-TANTON: Thank you all so much for inviting me on. I've really enjoyed this.
[MUSIC PLAYING]
MOLLY BLOOM: Now, before we go any further, let's figure out that mystery sound. Here it is one more time.
[CREAKING]
[FIZZING]
OK, any new thoughts about what that sound might be?
MAYA: It also sounds like one of those videos with a waterfall falling and all these birds tweeting.
MOLLY BLOOM: Oh. Yeah, there's definitely a bird kind of sound there. What do you think, Mira? And the other new thoughts?
MIRA: Like a high pitch-- like a bird with a high pitch.
MOLLY BLOOM: Really good guesses. You ready for the answer?
MAYA: Yeah.
MOLLY BLOOM: OK. This is a sound sent to us by another set of sisters, Abigail and Emma from San Antonio, Texas.
ABIGAIL: That was the sound of cut up potatoes baking in the oven.
MAYA: Oh.
MOLLY BLOOM: Have you ever heard a sound like that from potatoes?
MAYA: No.
MOLLY BLOOM: Yeah. I think they have to get very crispy to make that sound.
ABIGAIL: This sound reminds me of chirping birds. And I like it because I don't expect to hear this sound from my food. We make these potatoes every other week, because it is my daddy's favorite meal, called chicken baked potato rich casserole.
EMMA: I've eaten it about 40 times, and I think it's yummy.
MOLLY BLOOM: Well, that's it for this-- is that a launch?
MAYA: I guess Marc and Sanden are on their way to take the selfie. I wonder how it's going.
MARC SANCHEZ: Just a little further out. And perfect. Stop the ship. Stop the ship.
SANDEN TOTTEN: OK, OK. Can you see the whole thing through the window now?
MARC SANCHEZ: There it is. Earth. Ever seen anything more beautiful?
SANDEN TOTTEN: Wow. It's really pretty, dude.
MARC SANCHEZ: OK, let's finally take this whole Earth selfie. Are you ready?
SANDEN TOTTEN: Yeah, yeah, yeah. Hold on, let me just get my hair. OK, cool. On the count of three. One, two-- wait, wait. Three. Ah, something zipped across the window just when you snapped the picture.
MARC SANCHEZ: Really? Let me check the photo. Hold on. Wait, it's a guy in a spacesuit blocking the Earth. Is that--
BOB: Ha! I did it. I'm in your picture.
MARC AND SANDEN: Bob.
BOB: You got photobombed. Or should I say photobobbed?
[SNICKERS]
SANDEN TOTTEN: Oh, man. He's blocking the entire planet.
MARC SANCHEZ: Yeah. And wait, is that a mustard stain on his spacesuit?
BOB: A stain? Again? No!
[MUSIC PLAYING]
MIRA: The first color picture of Earth is a photo called Earthrise.
MAYA: It inspired a lot of people and captured the public's imagination.
MOLLY BLOOM: Our solar system started out as gas and dust floating in space.
MAYA: But after many years--
MIRA: And lots of cosmic collisions--
MAYA: The Sun and planets were formed.
MOLLY BLOOM: That's it for this episode of Brains On.
MAYA: Brains On is made by Molly Bloom, Marc Sanchez, and Sanden Totten.
MIRA: And it's produced by American Public Media.
MOLLY BLOOM: We had production help from Ned Leebrick-Stryker and Reen Barger, and engineering help from Michael Demark, Johnny Vince Evans, Sandy Houseman, and Corey Schreppel. Many thanks to Margarita Figueroa, Eric Ringham, Jimmy Lejoiner, Paul Tosto, Juliet and Hattie Davis, Meg Martin, Ewen Care, Valerie Kayler, Anna Weigel, and Coco Sanchez.
MAYA: Brains On is a nonprofit public radio podcast.
MIRA: And we rely on donations from our listeners to keep making new episodes.
MOLLY BLOOM: You can donate and check out our cool thank you gifts at brainson.org/donate.
MAYA: Now, before we go it's time for a Moment of Um.
AUDIO TRACK: Uh. Um. Um. Um.
ELI: My question is, why do dreams seem longer than they are?
[MUSIC PLAYING]
DEIRDRE BARRETT: Deirdre Barrett. I'm an assistant professor at Harvard Medical School. Research finds most dreams seem pretty much their real length. We walk through a setting or have a conversation and maybe wander one other place. And it feels like it's been about five or 10 minutes, and that's how long we've actually been dreaming.
But some dreams do feel like they've just gone on for days at a time. Our brain is in a really different state when we're dreaming. There's an area called the prefrontal cortex that's right behind our foreheads. And that area is much less active. Most of our logic comes out of there. That also is where we'll find points of time-keeping and estimating time and noticing what comes before something else. So because that's much less active, we're not as good a judge of how much time has passed.
And I think also some dreams are a little bit like movies. If you really think back over that dream epic that seemed to cover weeks of dream life, it's a little bit like a movie, where you saw the high points. Something happened and then something that was supposed to be three days later happened, and then something that was supposed to be once the person was older happened. And yet just like a movie, you could depict 20 years passing by in five minutes of film if you edited it right.
AUDIO TRACK: Um. Um. Um.
MOLLY BLOOM: This is not a dream, and I'm ready to groove through this list of names. It's the Brains Honor Roll. The rad kids who make this show what it is by sharing their questions, mystery sounds, and drawings with us.
[MUSIC PLAYING]
[LISTING HONOR ROLL]
AUDIO TRACK: Brains Honor Roll. High fives.
MOLLY BLOOM: See you next time, when we'll answer more of your questions.
MAYA AND MIRA: Thanks for listening.
INTERVIEWER: Brains On is supported in part by a grant from the National Science Foundation.
SANDEN TOTTEN: How about now, Marc?
MARC SANCHEZ: Let me see.
[GRUNTS]
Well, it's really long. But it's still not long enough.
SANDEN TOTTEN: OK, let me try adding some more broomsticks. Hold on.
MOLLY BLOOM: Hey, Marc.
MIRA: That's a really long stick you're taping together.
MAYA: Yeah. What exactly are you and Sanden building?
MARC SANCHEZ: Oh, hey, Molly and Maya and Mira We're making the world's longest selfie stick.
SANDEN TOTTEN: So we can take the world's most epic selfie.
BOB: Can I be in it, too?
MARC SANCHEZ: Oh, hey, Bob. I didn't see you there.
BOB: I get that a lot.
MARC SANCHEZ: Sure.
BOB: All right.
MARC SANCHEZ: But technically, everyone's going to be in it.
SANDEN TOTTEN: I'm going to attach this flagpole, too. And maybe even a fire pole. We have a fire pole, right?
MOLLY BLOOM: Wait what kind of selfie is this exactly?
MARC SANCHEZ: A selfie of the entire world.
MIRA: Like, all of it?
SANDEN TOTTEN: From top to bottom.
BOB: Wait. So everyone will be in it, too? Oh, snap. I thought I was special.
MIRA: You'll need to be in space to take that picture, won't you?
MARC SANCHEZ: Not if you have a really long selfie stick.
SANDEN TOTTEN: OK, try again.
MARC SANCHEZ: Hold on.
[GRUNTS]
OK, OK. Let's see.
MAYA: Wow. It's clearing the clouds. I can't even see where it ends anymore.
MOLLY BLOOM: That is impressive.
BOB: Are you getting my good side?
MARC SANCHEZ: Yeah. Hold on. I think we might have done it. I just need to snap a pic to see if the whole world is in this photo. Oh.
MAYA: What?
MARC SANCHEZ: Who's going to press the button to actually take the picture?
BOB: I'm pretty sure I can't reach it.
SANDEN TOTTEN: Maybe we could build a second pole and hoist that up to press the camera button?
MOLLY BLOOM: Good luck figuring this out. We got to go tape the show.
MAYA: Yeah. If you get the shot, tag us in it.
MIRA: Later, guys.
BOB: Do I have time to change into a better shirt? This one has mustard on it. I don't want to be forever remembered as the guy with mustard on his shirt.
[MUSIC PLAYING]
MOLLY BLOOM: This is Brains On from American Public Media. I'm Molly Bloom, and my co-host today are super sister duo Maya and Mira from Charlottesville, Virginia. Hey, there.
MOLLY AND MIRA: Hi.
[LAUGHS]
MOLLY BLOOM: So you are interested in space. So what fascinates you most about space?
MAYA: That there are other planets like Earth.
MOLLY BLOOM: What about you, Mira?
MIRA: Everything
[LAUGHS]
MOLLY BLOOM: Well, there's a very particular reason we wanted to do this episode in this month of this year.
MIRA: It's the 50th anniversary of a very special moment for planet Earth.
MAYA: A moment that really captured the attention of the people on it.
MOLLY BLOOM: We'll let producer Ned Leebrick-Stryker tell this tale.
NED LEEBRICK-STRYKER: It's winter vacation, and your family is heading out on a road trip.
MOM: Come on, kids.
DAD: We're leaving.
MOM: Did you remember your swimsuit, your toothbrush, and your vitamins. Oh, and your boots, and your fleece sweater Grandma bought you, and your Shrek pajamas, and your Spider-Man socks, and your hockey stick, and your ice skates, and--
[CAR SCREECHING]
NED LEEBRICK-STRYKER: Now, imagine that this road trip is 240,000 miles away from home.
KID 1: Dad?
DAD: What's up?
KID 1: I have to go to the bathroom.
KID 2: Me, too.
DAD: Well, jeez. Why didn't you say anything when we passed that rest area 10,000 miles back.
NED LEEBRICK-STRYKER: And what if this destination was somewhere no one else had ever been?
MOM: Hello? Hello? Why didn't we book a hotel room?
NED LEEBRICK-STRYKER: Well, 50 years ago, three astronauts did just that. On December 21st, 1968, Bill Anders, Frank Borman, and James Lovell became the first human beings to ever leave Earth's orbit. They were a part of Apollo 8, the second manned spaceflight mission in NASA's Apollo Space Travel Program. But they weren't landing on the Moon. That would come a few months later.
Their only goal was to circle it to see if it was even possible for other spacecrafts to one day land there.
[MUSIC PLAYING]
So on December 24th, these three astro travelers were road tripping through space, about to fly around the Moon for the first time. As their rocket soared over the lunar surface, they saw something that totally surprised them.
EMMANUEL VAUGHAN-LEE: They looked up and saw the Earth rise before them, climbing over the lunar surface. And they scrambled to take a picture to capture that.
NED LEEBRICK-STRYKER: That's Emmanuel Vaughan-Lee, director of the documentary Earthrise, named after the very picture the astronauts took. The sight of our small planet far away above the surface of the Moon was something no one had ever seen before. The Earth was just this bright dot floating above the Moon's horizon, and astronaut Bill Anders had to capture it.
EMMANUEL VAUGHAN-LEE: It was the first selfie that was ever taken of the Earth. It was a photograph that was not planned. And if you listen to the audio recording, you hear the crew quickly scrambling and expressing their emotions and feelings about the incredible, beautiful sight that they're seeing. Quick, grab some color film. That's the most beautiful sight. We got to get a picture of that.
BILL ANDERS: Oh my god, look at that picture over there. There's the Earth coming up. Wow, that's pretty.
FRANK BORMAN: Hey, don't take that. That's not scheduled.
BILL ANDERS: Got a color film, Jim? Hand me a roll of color film.
JAMES LOVELL: Oh, man.
BILL ANDERS: Quick.
EMMANUEL VAUGHAN-LEE: It's this beautiful blue marble in the blackness of space set against this gray, lifeless body that is the Moon. It was the first color photograph taken of the Earth from another planet.
NED LEEBRICK-STRYKER: Today, it's so easy to find images of the Earth that you can livestream video of the planet from the International Space Station. But back in 1968, all people had were drawings, maps, and globes. Nobody had a real sense of what our planet truly looked like. When Apollo 8 returned, the Earthrise picture was printed in newspapers around the world, and it blew everyone's minds.
INTERVIEWER: That's the Earth? We're so tiny.
INTERVIEWER: It's beautiful. I wish I could live there. Wait a minute, I already do. Woo-hoo!
NED LEEBRICK-STRYKER: Seeing the Earth from this new perspective gave people a chance to think about our planet in a new way, and, as a result, influenced creative people the world over.
INTERVIEWER: This picture should be a postage stamp.
INTERVIEWER: This picture makes me want to paint.
INTERVIEWER: This picture makes me want to sing.
NED LEEBRICK-STRYKER: One guy named Archibald MacLeish saw the picture and started writing a poem. It was soon published in newspapers.
RICHARD NIXON: To see the Earth as it truly is, small and blue and beautiful, in that eternal silence where it floats, is to see ourselves as riders on the Earth together.
NED LEEBRICK-STRYKER: That's then President Richard Nixon reading from the poem at his first inauguration in 1969.
RICHARD NIXON: Brothers in that bright loveliness and the eternal cold. Brothers who know now, they are truly brothers.
NED LEEBRICK-STRYKER: Nixon would soon help create organizations to help the planet, like the National Oceanic and Atmospheric Administration and the Environmental Protection Agency. Plus, the Earthrise photo is also thought to have inspired the founders of Earth Day, which started the very next year in 1970.
Filmmaker Emmanuel Vaughan-Lee says it was a picture of the world that truly changed the world.
EMMANUEL VAUGHAN-LEE: There could be other photographs that are very powerful, but I don't think any other photograph will capture what that photograph did. And it really stands not just for that moment, but for what is a shift in consciousness, a shift in perspective that, again, can't be replicated. Because once that shift has happened, you can't go back. This photograph represented a much more unified view of what was possible. And I think it broke a lot of people's perception about who we are, where we are, and what it means to be part of one shared planet.
It's one of those photographs that's going to stand the test of time. In hundreds of years to come, I think it'll still be as emblematic as it is today.
NED LEEBRICK-STRYKER: It's been said that a picture is worth a words. But the Earthrise photograph went far beyond that. It gave the people of Earth a new perspective. That we are an incredibly small part of a vast universe. It's a perspective that is challenging, humbling, and even for a brief second, unifying. We may be separated by schools, cities, and countries. But this picture reminds us we all live on the same beautiful blue orb called Earth.
MOLLY BLOOM: It's hard to imagine what it was like for everyone to see a picture of the Earth for the first time. So if you could write a short message to planet Earth, like a planetary postcard, what would you say? Maya, do you want to go first?
MAYA: Sure. Dear Planet Earth, I've explored the world. And I hope this postcard will give you some memory of your happy moments.
MOLLY BLOOM: So Mira, what would you want to say to planet Earth in a postcard?
MIRA: Dear Planet Earth, I hope you stay strong and stay here for a long time so our ancestors will remember us.
MOLLY BLOOM: Very nice letters, you two. Now here's some cosmic correspondence from some of our listeners.
[MUSIC PLAYING]
RACHEL: If I could write a letter to planet Earth, I would say, Dear Planet Earth, thank you for giving us fresh air. It is really helpful. Love, Rachel.
SUBJECT 1: Dear Earth, I love you, and people should stop throwing food and waste food.
SUBJECT 2: Dear Planet Earth, Earth is good. We must be kind to you. Thank you for keeping us safe. Thank you for the pretty things we get to look at.
JACK: Dear Earth, I like your history. You have amphibians, dinosaurs, reptiles, and mammals. Love, Jack.
MOLLY BLOOM: A big thanks to Jack, Evan, Oliver, Caroline, and Rachel for sending in those heartfelt letters to Earth. And we agree, Earth is a pretty neat place in a pretty neat solar system. So it's no wonder so many of you are curious about our little neck of the cosmic woods, too.
NORI: Hi, my name is Nori, and I live in Mumbai, India. What was there before the Big Bang?
SUBJECT 3: What was the Big Bang, and how was all the planets made up?
SUBJECT 4: How are planets made?
SUBJECT 5: How did the Earth form?
SUBJECT 6: How did the solar system form?
MOLLY BLOOM: Thanks to Bridget, Kylie, Nora, Saru, and Nori for those excellent questions. Earth has a history. So does the solar system. In fact, there's a story behind the whole universe.
EARTH: Hey, Jupiter. What's this book?
JUPITER: What's that, Earth? Oh, that's our cosmic family photo album.
EARTH: What's that picture?
JUPITER: That's when our older brother Mars started sporting that crazy volcano, Olympus Mons. He thought he was so cool. This will never go out of style.
EARTH: What about this?
JUPITER: Oh, that's our great aunt twice removed, I think. Her name was Betty Black Hole. We stopped inviting her to family reunions because one time she ate all the potato salad and also all the light and matter in the surrounding area. Kind of rude, if you ask me.
EARTH: What about--
JUPITER: Here, why don't we start at the first page, Earth? This is where it all began.
EARTH: That picture is so grainy and old, I can barely tell what it is.
JUPITER: Yeah, it's from 14 billion years ago. That's our great-great-great-great-great-great-great-great-great-great-great--
EARTH: OK, I get it. It's very, very, very old.
JUPITER: OK, well, that's the Big Bang. That's the moment when the universe just popped into existence.
EARTH: Why?
JUPITER: We don't really know, Earth.
EARTH: Why?
JUPITER: Because we weren't around to see it.
EARTH: Why?
JUPITER: Hey, you see that button in the book? Why don't you just try pressing that?
EARTH: OK.
LAURA DANLY: Once upon a time, there was nothing, and then there was everything. We call that moment the Big Bang. But it really wasn't a bang like an explosion like we're familiar with. It really was just a big transition when the universe went from not existing to existing.
EARTH: Whoa, who's that?
JUPITER: That's Laura Danly. She's an astrophysicist. She helped us put together this album. She's super into cosmic genealogy. Check it out. Flip to the next page.
EARTH: What's this picture? It looks like space clouds.
JUPITER: Well, press the button to find out.
LAURA DANLY: Well, after the Big Bang, all the universe was just filled with matter and energy, like a big soup. But then, slowly and surely, gravity started pulling little islands of material together into galaxies.
EARTH: Like our galaxy, the Milk Away.
JUPITER: You mean Milky Way.
EARTH: Yeah, Milky Way.
JUPITER: Well, we come much later in the book. So that spacey soup stuff turned into galaxies and stars. Stars died off and released all kinds of materials, like carbon, oxygen, gold. A lot of the stuff in planets like you. Ah, here we are.
EARTH: That's us?
JUPITER: Yeah, that's our home. It formed about 4.6 billion years ago.
EARTH: Why?
JUPITER: I can actually answer that one. It formed because--
EARTH: I know, I know. It formed because our Sun formed and created a solar system around it.
JUPITER: Wait, if you knew, then why did you ask why?
EARTH: I like asking why. It's my favorite question.
LAURA DANLY: Before our Sun was here, there was just a cloud of gas. But then gravity pulled that cloud of gas together and the cloud got denser and denser and denser until finally, it was pulled together into a star, into our Sun. Well, at the same time that the Sun is collapsing, it's also spinning. So as it collapses further and further, it spins more and more.
And so surrounding the forming star is a disk of gas that falls into a spinning disk. And that's the disk out of which the planets in the solar system were made.
JUPITER: Oh, jeez.
EARTH: Who's that?
JUPITER: That's me in my younger years. So awkward.
EARTH: That's not you, Jupiter. That thing is small. You're ginormous.
JUPITER: Yeah, but I wasn't always a gas giant. I started out small, like you. I was a protoplanet first, but I just kept growing. Check it out.
LAURA DANLY: In the spinning disk of gas and dust, clumps start to form in protoplanets, little planetesimals, they call them. And those are just chunks of dust and material and ice that are also floating around, circling the newly forming star. So those smash into each other and get bigger chunks, which smash into each other and make bigger chunks. And eventually, you build up to the planets.
EARTH: Cool. I want to smash into things, too.
JUPITER: You did. See?
EARTH: That's me as a baby?
JUPITER: Yeah. Saturn and I were already very big by the time all the space dust and ice junk started crashing into each other in orbit, making baby you. See? There you are, orbiting the Sun as it forms. Flying into space rocks and getting bigger and bigger.
EARTH: But then why am I so much smaller than you still? Will I got to be your size?
JUPITER: Sadly, little sis, you're done growing.
EARTH: No fair.
JUPITER: Well, you know how we were all orbiting in this disk of ice chunks and dust and stuff while the Sun was forming? Once the Sun finally formed, it turned down like a mega giant furnace, making sunlight and letting out a huge gust of solar wind. Whoosh.
LAURA DANLY: And it blew away most of the remaining material that was inside the inner part of the disk. So we just flat ran out of material. The turning on Sun blew it all away, and there was nothing left to make the planets grow any larger.
EARTH: Aw man, I hate being so small.
JUPITER: Yeah, but look at it this way. You're the only planet in our family covered in oceans and plants and animals. That's pretty awesome, dude.
EARTH: I guess.
JUPITER: No, think about it. Your brother Mars, he was warm and wet at one point. But now he's all cold and lonely. No atmosphere. Oh, and there's Venus. She's a hot mess. So close to the Sun that all the water pretty much boiled off. She has runaway greenhouse gases, super overheated. Not much could survive there.
But you, you were just the right size and in just the right spot. When you formed, you were hot, and all this water evaporated into the air. But you had enough gravity to keep it from flying away.
EARTH: That's how I made my atmosphere.
JUPITER: Exactly. Plus, you have a molten core that creates a magnetic field.
EARTH: Yeah. That protects me from solo radio nations.
JUPITER: You mean solar radiation. And yeah, that radiation would wipe out life on you if you didn't have that magnetic field as a shield.
EARTH: I guess that I am pretty special.
JUPITER: See? I might be the biggest planet in our family, but you've got a pretty cool backstory. So what's it like being covered in life?
EARTH: Kind of itchy, actually.
[VOCALIZING]
AUDIO TRACK: Brains On.
MOLLY BLOOM: You know what goes well with the mysteries of Earth, space, and the universe?
MAYA: A mystery sound?
MOLLY BLOOM: You read my mind.
[MYSTERY SOUND CUE]
AUDIO TRACK: Mystery sound.
MOLLY BLOOM: Here it is.
[CREAKING]
[FIZZING]
OK. Before you even guess, I'm going to give you a little clue, because sometimes our mystery sounds are directly related to our episode topic, and sometimes they're not. And this is one of those times where it's not. So what do you think that sound was?
MAYA: It sounds like one of those instruments that has all of these little beads and sand droplets. And when you turn it around, it makes like a--
MOLLY BLOOM: Oh yeah, yeah, yeah, a rain stick.
MAYA: Uh-huh, yeah, that.
MOLLY BLOOM: Good guess. Mira, what do you think it is?
MIRA: I agree. It also sounds like something-- like many little things dropping down at the same time.
MOLLY BLOOM: Someone dropping coins or something?
MIRA: Yeah.
MOLLY BLOOM: Excellent guesses. OK, we're going to have the answer later in the show.
[MUSIC PLAYING]
Do you have a mystery sound to share?
MAYA: Or a burning question you just have to ask.
MIRA: Or maybe you want to tell us what you'd like to say to Earth.
MOLLY BLOOM: Do all those things at brainson.org/contact. That's how we heard from this listener.
ELI: Hi. My name is Eli. I live in Haddonfield, New Jersey. My question is, why do dreams seem longer than they are?
MIRA: We also love, love, love your drawings.
MAYA: Yeah, keep them coming.
MOLLY BLOOM: They totally brighten our day, and we love sharing them on social media.
MAYA: Maybe draw Marc and Sanden's epic selfie.
MIRA: You could even squeeze our buddy Bob in there.
MOLLY BLOOM: We'll have the answer to that question about dreams during our Moment of Um and give the newest rundown of friends to join the Brains Honor Roll at the end of the show. And speaking of friends, here's our pal, Joy Dolo.
JOY DOLO: Hey, Molly.
MOLLY BLOOM: Hi, Joy. Joy is the host of our new history show, Forever Ago, which we've been sharing a little bit of every week.
JOY DOLO: Yep. Every episode, we dig deep into the history of one cool thing. Like, have you ever wondered where shoes came from?
MOLLY BLOOM: I never really have thought about that before. I guess I take shoes for granted. But they really-- yeah, they had to get started somewhere.
JOY DOLO: Or some when. This week's episode is all about the backstory of shoes. Here's a little preview.
INTERVIEWER: The oldest pair that have been unearthed are called the Fort Rock Sandals, which were found in Oregon in 1938 by an anthropologist named Luther Cressman.
[COUGHS]
LUTHER CRESSMAN: Wow. There sure is a lot of ash in this cave.
INTERVIEWER: Cressman was exploring Fort Rock Cave. And inside, there was a layer of ash from a volcano eruption that happened thousands of years ago.
LUTHER CRESSMAN: Just got to keep digging. That's my motto. When you're in a hole, keep digging, and all your problems will be solved.
[COUGHS]
INTERVIEWER: And then he found something he had never seen before.
LUTHER CRESSMAN: Wait a minute, what's this?
INTERVIEWER: At first glance, Cressman's discovery might have just looked like a bundle of ropes. But on closer inspection--
LUTHER CRESSMAN: This looks like a-- pair of shoes?
MOLLY BLOOM: You can hear the full episode and the season finale of Forever Ago this Thursday. Find it on Apple Podcasts, Stitcher, or wherever you listen.
JOY DOLO: And if you like the show, leave us a review. All right, thanks for having me Molly. For the last time.
MOLLY BLOOM: I'll miss you. We'll see you soon.
JOY DOLO: I miss you already. Bye.
MOLLY BLOOM: Bye.
MAYA AND MIRA: Keep listening.
MOLLY BLOOM: This is Brains On. I'm Molly.
MAYA: I'm Maya.
MIRA: And I'm Mira.
MOLLY BLOOM: Earth is very clearly special. But is it totally unique?
MAYA: Are there other planets like Earth in the universe?
MIRA: To answer that question, we have a special guest.
MOLLY BLOOM: Lindy Elkins-Tanton is the director of the School of Earth and Space Exploration at Arizona State University, co-chair of the Interplanetary Initiative, and she's the principal investigator of NASA's Psyche mission.
MAYA: Welcome, Lindy.
LINDY ELKINS-TANTON: Hi. It's great to meet you all.
MIRA: Why are planets round?
LINDY ELKINS-TANTON: Planets around mainly because of the force of gravity. As the planet gets bigger and bigger, the very material that it's made of creates gravity that pulls the material closer together. And the lowest energy state, as a physicist would say, the easiest way for all the material to be as close together as possible is in a sphere. And so that's why planets are round. And that's why some really small asteroids are not round, because they just don't have enough gravity to pull them into roundness.
MAYA: That's really cool.
MIRA: I did not know that. Are there any other planets like Earth?
LINDY ELKINS-TANTON: We think that there must be. Just because it turns out there are so many planets out in the universe. It was only about 30 years ago that people didn't even know there were any planets outside of our solar system. And now we've discovered that virtually every star you see in the sky has got planets around it.
MOLLY BLOOM: How do they do that from so far away?
LINDY ELKINS-TANTON: It's been so fast, the rate at which scientists have figured out how to spot planets around other stars. You can't actually take a picture of the planet, because they're too small. But you can see if the planet blocks a little of the light from its star as that light comes toward the Earth. And sometimes you can see the star itself wobble a little bit as the planet goes around it.
We're just getting to the point some of our colleagues can take actual pictures of the planets. And they're not in great detail yet, but you can see a disk. And then the question comes, how do you know what that planet is like? You can know something about its temperature by how close it is to its star. And then other scientists look at the light that shines off the planet to the Earth, and then they can learn something about the composition of its atmosphere. And so bit by bit, you put together little pieces of evidence of what life on that planet might be like.
MAYA: Do other planets have auroras?
LINDY ELKINS-TANTON: I really love auroras. They're so beautiful, and I've been thinking about trying to make a trip to see more auroras. They're caused by little charged particles in space getting trapped in the Earth's magnetic field. So the two things you would need to make an aurora around any planet are a magnetic field, which not every planet has, and charged particles flying through space near that planet. And those are generally supplied by the star. So they would be around.
Now we've discovered that Jupiter has auroras. We can actually see the auroras on Jupiter. And in fact, you can see them on the internet. So we know already that there are at least a few other planets that do have auroras.
MAYA: Wow.
LINDY ELKINS-TANTON: Yeah.
MOLLY BLOOM: Can you tell us a little bit about NASA's Psyche mission?
LINDY ELKINS-TANTON: Yes. We just were selected by NASA to create a robotic mission with no people going into space, just a machine. We'll launch it in 2022. And it's going to fly out past Mars into the outer asteroid belt. And it's going to visit a metal asteroid named Psyche. We have sent space probes out and they visited rocky planets like Venus and Mercury and the Moon and Mars. And icy moons and gas giants, like Saturn and Jupiter.
But humankind has never visited a metal object before. And so we don't really know what a metal object looks like. We can't even get a good image of it from Earth. We don't know what craters look like in metal, if there are spires and peaks. If the surface is shiny or rubbly. We really have no idea. So it's truly exploration.
But the bigger goal even is to inspire everybody here on Earth to feel bolder in their own lives and to take a more courageous step out into the unknown. Think about this little Psyche mission going off into space to discover something new.
MOLLY BLOOM: That is so exciting. I cannot wait to see what you guys learn.
LINDY ELKINS-TANTON: Yay.
MIRA: Thank you, Lindy.
LINDY ELKINS-TANTON: Thank you all so much for inviting me on. I've really enjoyed this.
[MUSIC PLAYING]
MOLLY BLOOM: Now, before we go any further, let's figure out that mystery sound. Here it is one more time.
[CREAKING]
[FIZZING]
OK, any new thoughts about what that sound might be?
MAYA: It also sounds like one of those videos with a waterfall falling and all these birds tweeting.
MOLLY BLOOM: Oh. Yeah, there's definitely a bird kind of sound there. What do you think, Mira? And the other new thoughts?
MIRA: Like a high pitch-- like a bird with a high pitch.
MOLLY BLOOM: Really good guesses. You ready for the answer?
MAYA: Yeah.
MOLLY BLOOM: OK. This is a sound sent to us by another set of sisters, Abigail and Emma from San Antonio, Texas.
ABIGAIL: That was the sound of cut up potatoes baking in the oven.
MAYA: Oh.
MOLLY BLOOM: Have you ever heard a sound like that from potatoes?
MAYA: No.
MOLLY BLOOM: Yeah. I think they have to get very crispy to make that sound.
ABIGAIL: This sound reminds me of chirping birds. And I like it because I don't expect to hear this sound from my food. We make these potatoes every other week, because it is my daddy's favorite meal, called chicken baked potato rich casserole.
EMMA: I've eaten it about 40 times, and I think it's yummy.
MOLLY BLOOM: Well, that's it for this-- is that a launch?
MAYA: I guess Marc and Sanden are on their way to take the selfie. I wonder how it's going.
MARC SANCHEZ: Just a little further out. And perfect. Stop the ship. Stop the ship.
SANDEN TOTTEN: OK, OK. Can you see the whole thing through the window now?
MARC SANCHEZ: There it is. Earth. Ever seen anything more beautiful?
SANDEN TOTTEN: Wow. It's really pretty, dude.
MARC SANCHEZ: OK, let's finally take this whole Earth selfie. Are you ready?
SANDEN TOTTEN: Yeah, yeah, yeah. Hold on, let me just get my hair. OK, cool. On the count of three. One, two-- wait, wait. Three. Ah, something zipped across the window just when you snapped the picture.
MARC SANCHEZ: Really? Let me check the photo. Hold on. Wait, it's a guy in a spacesuit blocking the Earth. Is that--
BOB: Ha! I did it. I'm in your picture.
MARC AND SANDEN: Bob.
BOB: You got photobombed. Or should I say photobobbed?
[SNICKERS]
SANDEN TOTTEN: Oh, man. He's blocking the entire planet.
MARC SANCHEZ: Yeah. And wait, is that a mustard stain on his spacesuit?
BOB: A stain? Again? No!
[MUSIC PLAYING]
MIRA: The first color picture of Earth is a photo called Earthrise.
MAYA: It inspired a lot of people and captured the public's imagination.
MOLLY BLOOM: Our solar system started out as gas and dust floating in space.
MAYA: But after many years--
MIRA: And lots of cosmic collisions--
MAYA: The Sun and planets were formed.
MOLLY BLOOM: That's it for this episode of Brains On.
MAYA: Brains On is made by Molly Bloom, Marc Sanchez, and Sanden Totten.
MIRA: And it's produced by American Public Media.
MOLLY BLOOM: We had production help from Ned Leebrick-Stryker and Reen Barger, and engineering help from Michael Demark, Johnny Vince Evans, Sandy Houseman, and Corey Schreppel. Many thanks to Margarita Figueroa, Eric Ringham, Jimmy Lejoiner, Paul Tosto, Juliet and Hattie Davis, Meg Martin, Ewen Care, Valerie Kayler, Anna Weigel, and Coco Sanchez.
MAYA: Brains On is a nonprofit public radio podcast.
MIRA: And we rely on donations from our listeners to keep making new episodes.
MOLLY BLOOM: You can donate and check out our cool thank you gifts at brainson.org/donate.
MAYA: Now, before we go it's time for a Moment of Um.
AUDIO TRACK: Uh. Um. Um. Um.
ELI: My question is, why do dreams seem longer than they are?
[MUSIC PLAYING]
DEIRDRE BARRETT: Deirdre Barrett. I'm an assistant professor at Harvard Medical School. Research finds most dreams seem pretty much their real length. We walk through a setting or have a conversation and maybe wander one other place. And it feels like it's been about five or 10 minutes, and that's how long we've actually been dreaming.
But some dreams do feel like they've just gone on for days at a time. Our brain is in a really different state when we're dreaming. There's an area called the prefrontal cortex that's right behind our foreheads. And that area is much less active. Most of our logic comes out of there. That also is where we'll find points of time-keeping and estimating time and noticing what comes before something else. So because that's much less active, we're not as good a judge of how much time has passed.
And I think also some dreams are a little bit like movies. If you really think back over that dream epic that seemed to cover weeks of dream life, it's a little bit like a movie, where you saw the high points. Something happened and then something that was supposed to be three days later happened, and then something that was supposed to be once the person was older happened. And yet just like a movie, you could depict 20 years passing by in five minutes of film if you edited it right.
AUDIO TRACK: Um. Um. Um.
MOLLY BLOOM: This is not a dream, and I'm ready to groove through this list of names. It's the Brains Honor Roll. The rad kids who make this show what it is by sharing their questions, mystery sounds, and drawings with us.
[MUSIC PLAYING]
[LISTING HONOR ROLL]
AUDIO TRACK: Brains Honor Roll. High fives.
MOLLY BLOOM: See you next time, when we'll answer more of your questions.
MAYA AND MIRA: Thanks for listening.
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