Is there life on other planets?

NARRATOR: You're listening to Brains On, where we get curious about the science of everything.

SANDEN TOTTEN: Hey, team, it's Sanden. I'm sure you've looked up at the night sky and wondered, are we alone? Are there other life forms out there? Could there be some alien on some other distant planet staring up at its sky, wondering about me, asking if I exist?

If so, you and that alien should check out our episode on the search for life on other planets. It's one of our favorites from early on in Brains On's history, And we're bringing it back from the vaults to share with you right now.

I'll be back in a little bit for the latest Brains Honor Roll. In the meantime, let's have Molly take it away.

MOLLY BLOOM: Hi, I'm Molly Bloom. And here with me today is 12-year-old, Gwen Alexander. Hi, Gwen.

GWEN ALEXANDER: Hi.

MOLLY BLOOM: Gwen helped us figure out the topic for today's show. Gwen wants to be an astrophysicist when she grows up, someone who studies the physics of the universe. So she's the perfect match to help us talk about space.

Think about how many stars you can see when you stare into space. Remember, that's just a tiny fraction of what's out there. There's so much to talk about when it comes to space, we couldn't come up with the question, so we asked Gwen to.

GWEN ALEXANDER: Is there life on other planets? This question has captured the imagination of many writers over time. They've imagined what these lifeforms would look like, where they would come from, would they come in peace or in violence.

MOLLY BLOOM: I spoke with an 11-year-old science fiction writer named Jasper Nordin. We asked him to write a piece inspired by this very question.

NARRATOR: I Am the Universe by Jasper Nordin.

JASPER NORDIN: Aliens are awesome. Some are so huge, 50,000 beings could fit on their pinkie fingertips. Some are so tiny that several trillion of them could live on a head of a pin.

There is a theory, however, that the universe itself is a massive alien. The stars and planets are really pores on its skin. In fact, every species there is might be a separate universe.

NARRATOR: Near Pluto, 2082.

JASPER NORDIN: The space shuttle landed on the newly discovered moon of the moon of the moon of Pluto. It was a barren place, mostly just rock and mountains and a few cacti and other plants. I kept walking forward.

The rest of the exploration squad ahead of me, the notification on my space helmets interactive CPU read that my oxygen supply was slowly dwindling, meaning the moon had no atmosphere unlike the other two moons of Pluto. There were four other members of the squad, all under 30. The ground shook, creating a crack that swallowed up a crew member at the front.

We dashed forward hoping to outrun it. I turned around and saw another member with a claw protruding from his forehead. I kept running near a huge cliff. I saw a giant asteroid overhead that crashed into the ground.

[BOOM]

I awoke under a pile of rock. I pushed the top off and fell down a small hill of rock on the surface. A few meters away, I saw the last remaining member of the squad, or at least his arm sticking out of a rock pile. I reached up to my face. The glass on my helmet was shattered. I gave a small gasp of surprise and fell over, unconscious.

I awoke again in a small tube of glass. It rose higher and higher into the stars. All the stars coalesced into a single circle of light in an empty black ocean. To my surprise, billions and billions of other circles of light appeared around me.

I rose even higher as a blackness slowly became more of an apricot color. I got a very huge shock. The entire universe was a giant alien.

[MUSIC PLAYING]

MOLLY BLOOM: That was just the beginning of I Am the Universe by Jasper Nordin. You can read the rest of his story at our website, brainson.org.

I sat down with Jasper to talk about the first time he wrote a story.

JASPER NORDIN: I remember when I was seven or eight, I wrote a book about this family of secret agents.

MOLLY BLOOM: What was it called?

JASPER NORDIN: The Secret Agent Family.

MOLLY BLOOM: Nice. And when you write stories, do you plan them out ahead of time or do you just kind of start writing and see what happens?

JASPER NORDIN: I think of the beginning, a few characters, and ending. I just squeeze in the middle as I go along.

MOLLY BLOOM: So you come up with the ending before you really start writing it?

JASPER NORDIN: Yeah. I try to make them as epic as possible. So I put it in a few explosions if I can. And, yeah, I try not to make them too emotional because I don't like emotional stuff that much.

MOLLY BLOOM: So how many hours a week do you spend writing?

JASPER NORDIN: I remember one time on a snow day, my mom left around 10:00 o'clock and I was working on a story. She got back around 5:00 o'clock and I was still working non-stop. So that's about the longest I've ever done. Usually I spend about two hours, if I can.

MOLLY BLOOM: And so these days, what are you most interested in writing about?

JASPER NORDIN: Mostly science fiction.

MOLLY BLOOM: So what is it about science fiction that attracts you?

JASPER NORDIN: I just find it interesting what some people think the future might be like or what they think the universe itself might be like.

MOLLY BLOOM: Do you think there is life out there beyond Earth?

JASPER NORDIN: I think there definitely is. They're probably searching for us too.

MOLLY BLOOM: And then are there things about the universe itself that sort of inspire the aliens that you create?

JASPER NORDIN: Kind of like how a lot of planets have no oxygen, like, some lifeforms might have adapted to grow without oxygen, which makes them extremely hard to fight or whatever.

MOLLY BLOOM: So these lifeforms are living on planets that are not like ours?

JASPER NORDIN: Yeah, completely different. Some could be a lot like ours, some could be volcanic or mostly aquatic, like, there was no water on it all or no atmosphere.

MOLLY BLOOM: So since the planets are different, then the beings on these planets would be different as well.

JASPER NORDIN: Since they had to adapt to find a way to survive.

MOLLY BLOOM: Very interesting.

JASPER NORDIN: If they didn't, they would end up dying. Survival of the fittest.

MOLLY BLOOM: If you want to see the aliens Jasper invented for his story, you can see his drawings at our website. And while you're there, you can send us your pictures of your own alien creations. Head on to the website brainson.org.

AUTOMATED: Ba, ba, ba, ba, ba, ba, ba, ba, ba, ba, ba, Brains On.

MOLLY BLOOM: So Gwen, do you think there's life out there?

GWEN ALEXANDER: It's very possible. It might not be intelligent life, but there could be bacteria on other planets.

MOLLY BLOOM: When you imagine life forms out there, do you ever imagine them as aliens who might come visit us or try to contact us?

GWEN ALEXANDER: Yes, but that's not very-- it's hard to imagine that there could be those. And it's hard to know what they would look like.

MOLLY BLOOM: So you're more focused on the facts that we actually know right now.

GWEN ALEXANDER: Yeah.

MOLLY BLOOM: Do you think that if there is life out there, that it would look like humans or would it look totally different?

GWEN ALEXANDER: It depends on the planet they come from. Like Jasper said, if they come from a volcanic planet, they might be different because they have to adapt to their surroundings. Most of the ones, I imagine at least, are green. I don't know, and they have one eye.

MOLLY BLOOM: Green, one-eyed aliens.

GWEN ALEXANDER: Yes.

MOLLY BLOOM: So we all have our ideas about what life might be out there. But what ideas do scientists have about this?

GWEN ALEXANDER: I interviewed Laura Danly. She's an astronomer and the curator of Griffith Observatory in Los Angeles, California. I asked her, what makes a life-bearing planet?

LAURA DANLY: Well, first of all, you need to have the gravity of a planet to pull together all the ingredients so that the chemical reactions of life can take place. And the second thing that we think is really essential is that you need to have liquid water. We think that liquid water is the best fluid medium for life.

But a lot of the reasons are, first of all, water is made up of an oxygen atom with two hydrogens on one end. So it's like a mini magnet. It has a positive end and a negative end because just the way the atom is arranged.

GWEN ALEXANDER: Cool.

LAURA DANLY: And so it can act as a catalyst. It can make chemical reactions happen. And it can act as a solvent. It can break apart atoms. And so a planet with liquid water is important.

You need a power source, some sort of energy source. We have the sun. You can also get life around volcanic vents in the ocean, so even volcano energy is good enough.

GWEN ALEXANDER: Oh, yeah.

LAURA DANLY: And then lastly, you just need the right molecules. You need the right atoms. Life on Earth needs carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur.

So you need the right ingredients. You need a liquid medium, and you need a source of energy all contained on a planet. And you need that planet to be stable for a long enough period of time that the chemistry can cook up life and make it happen.

GWEN ALEXANDER: Yeah, that's really cool. What are scientists currently doing to search for life in the universe? What have they found that proves or hints at the possibility of life?

LAURA DANLY: Scientists have gotten really enthusiastic about searching, not directly for life, but for evidence of environments where life could happen. As a scientist, you like to make hypotheses and you like to do experiments to test those hypotheses. So the more we learn about life on Earth and what makes it possible for life to survive on Earth, the more it tells us about what kinds of environments on other planets might be suitable for life.

Particularly on Mars because it's close enough for us to go there and send lots of missions, we're looking to see whether or not those conditions ever existed in the past or maybe exist in the present. We're pretty sure now that liquid water existed on Mars in the past in abundance, and enough abundance that life might have formed because the conditions were right.

GWEN ALEXANDER: Cool.

LAURA DANLY: What we don't know is whether there's any liquid water there today. We know there's no liquid water on the surface. But there's some evidence that there could be liquid water under the surface. And maybe there's a whole subsurface ecosystem with life in it. We just don't know.

GWEN ALEXANDER: That would be cool.

LAURA DANLY: That would be very cool. So that's why we go to study it. And that's why this has been kind of a long program of a couple of decades, we've been sending spacecraft. And it will be when you get to be in college at grad school and start going to work perhaps, that'll be the time when we're really drilling under Mars and looking for water and seeing if there aren't little creatures under the surface.

GWEN ALEXANDER: So you mentioned this earlier that a planet could be different than Earth and still have life. So a planet containing life wouldn't have to be exactly like Earth?

LAURA DANLY: No, it wouldn't. In fact, there is a moon in our solar system that circles the planet Jupiter called Europa.

GWEN ALEXANDER: Yeah, I've heard of it.

LAURA DANLY: Yeah, Europa is a great moon. It's one of the four major moons that was seen by Galileo when he looked at Jupiter with his little telescope. And you can see it through-- well, if you have really good binoculars and good eyes, but you can certainly see it through a small telescope.

There are four moons around Jupiter. And I'll just tell this to you because someone told this to me when I was about your age, and I've always remembered it. The way to remember them are the initials, I Eat Green Cats, IEGC, and that's for Io, Europa, Ganymede, and Callisto. So that's the order of the moons around Jupiter, the big ones.

The second moon, Europa, we think has a huge liquid water ocean underneath of it. There's a lot of evidence for that. We think that as it circles around Jupiter, tidal forces from the planet, just like the moon has tidal forces on Earth, that tidal forces, gravitational tug from Jupiter to Europa stretches and pulls the moon and melts the ice inside.

GWEN ALEXANDER: Oh, cool.

LAURA DANLY: So here we have this completely icy moon-- it isn't even a planet. It's a moon.

GWEN ALEXANDER: Yeah.

LAURA DANLY: And it's got a totally cracked, but solid ice surface crust. But underneath, there's probably a really big liquid ocean. And it may have all the right ingredients and conditions for life.

GWEN ALEXANDER: That would be cool.

LAURA DANLY: It would be very cool. And it's nothing like Earth. I mean, we couldn't go there and survive.

GWEN ALEXANDER: Yeah.

LAURA DANLY: But the creatures, if there are creatures that came to life there, are perfectly adapted to it and think it's just a beautiful day there on Europa where they are, even if it's not anything like Earth.

GWEN ALEXANDER: Yeah. Thank you.

LAURA DANLY: Oh, you're more than welcome. I really enjoyed talking to you.

GWEN ALEXANDER: I liked talking to you too. It was fun.

[FANFARE PLAYING]

[THE YOUNG PLUS, "E-U-R-O-P-A"]

MARK SANCHEZ: (SINGING) E-U-R-O-P-A. E-U-R-O-P-A. Hey! Europa with the secrets locked away. Will you be a place that we can visit someday?

E-U-R-O-P-A. E-U-R-O-P-A. Hey! Maybe we should scan this icy room for signs of life. I hope we'll get to soon.

390,400,000 mile. Europa so far and still you manage to beguile. What lies beneath your ice? We sit around, hypothesize.

Someone call the scientists. Hey, scientists! E-U-R-O-P-A. E-U-R-O-P-A. Hey!

Europa with your secrets locked away. Will you be a place that we can visit someday? E-U-R-O-P-A. E-U-R-O-P-A. Hey!

Maybe we should scan this icy room for the signs of life. I hope we get to soon.

If there's water, then there's life, at least that's what we think is right. If your oceans do exist, we'd be greeted with far out fish. For something on a smaller scale, more granul microbes, get real.

Someone call the scientists. Hey, scientists! E-U-R-O-P-A. E-U-R-O-P-A. Hey! Europa with the secrets locked away. Will you be a place we can visit someday?

E-U-R-O-P-A. E-U-R-O-P-A. Hey! Maybe we should scan this icy room for signs of life. I hope we get to soon.

[MUSIC PLAYING]

Hey, astronomers. Hey, astronomers. Hey, astrobiologists. Someone call the scientists. Hey, scientists!

SANDEN TOTTEN: Woo, that song. Man, so good. OK, that was E-U-R-O-P-A by the Young Plus. And there's some deep insidery info. Our very own Mark Sanchez wrote and performed that song. Very cool stuff, Mark.

Speaking of cool stuff, time to give a shout out to all the fans who sent us cool stuff like drawings, letters, questions, high fives, and mystery sounds. That's right. It's time for the honor roll. Let's do this.

[LISTING HONOR ROLL]

Do you have questions for us or a drawing or a mystery sound? Send them to brainson@mpr.org. That's M as in Minnesota, by the way.

Oh, and we've been having a lot of fun on Twitter and Instagram lately. So feel free to follow us there. We're @brains_on. on Thanks. Now back to Molly and Kate and the search for life on other planets.

GWEN ALEXANDER: You're listening to Brains On. Today we're talking about the search for life in the universe.

MOLLY BLOOM: Now that your ears are warmed up, it's time for the mystery sound.

GIRL: Mystery sound.

MOLLY BLOOM: Here it is.

[STRANGE SOUND]

I'm sure you have a guess about what the mystery sound is. And we will get back to it in a little bit. First, another question.

GWEN ALEXANDER: What does the search for life have in common with a fairy tale? Turns out, a lot.

SANDEN TOTTEN: We all know the story of Goldilocks, right? She sneaks into this house and she finds some food.

[SLURPS]

GOLDILOCKS: Oh, this porridge is too cold. This porch is too hot. This porridge is just right.

SANDEN TOTTEN: She apparently really likes porridge. Anyway, of course, after eating all the porridge, Goldilocks gets tired and she wants to take a nap.

GOLDILOCKS: This bed is too hard. Oh, this bed is too soft. This bed is just right.

SANDEN TOTTEN: So the thing about Goldilocks is she was a bit of a picky diva. But more importantly, she also went from one extreme to another until she found a happy medium.

Well, scientists believe life is a bit like Goldilocks. It needs the right conditions to exist.

GOLDILOCKS: Well, duh, life has refined tastes, obviously, like moi.

SANDEN TOTTEN: Sure. So when scientists search for life on other planets, they're looking for planets in something called the Goldilocks Zone.

GOLDILOCKS: Love the name. Good job picking that one, scientists.

SANDEN TOTTEN: So planets are thought to be in this Goldilocks Zone if they are not too close or not too far from their home star. Here in our solar system, planets like Mercury and Venus are close to the sun, making them super hot and not good for life.

GOLDILOCKS: Seriously, turn up the air conditioning, Venus, I'm baking here. Anyone got an iced tea?

SANDEN TOTTEN: But planets like Neptune are so far away from our sun, they're freezing all the time, which is also bad for life.

GOLDILOCKS: Where is my parka?

SANDEN TOTTEN: You see, scientists think that in order for life to form on a planet, you need liquid water. So planets that are too hot are bad because all the water will evaporate into gas. Planets that are too cold are no good because all the water will freeze. But planets in the Goldilocks zone are just right. Water can stay water because the temperatures are mostly above freezing and below boiling.

GOLDILOCKS: That's why I only love Earth. Water is liquid here, perfect for a swim in the pool.

SANDEN TOTTEN: The list of planets with potential for life gets even bigger if you consider that some may have liquid water under the surface. That's why scientists are interested in Jupiter's moon, Europa. It's frozen on top, but seems to be liquid underneath.

GOLDILOCKS: Hey, so this house I'm in is pretty boring. I mean, I ate all the porridge and already took a nap. I'm thinking of taking a vacation someplace new. How many habitable planets besides this one are out there anyway?

SANDEN TOTTEN: Well, scientists think there are lots of other planets around distant stars that are also in this so-called Goldilocks Zone. In fact, some scientists estimate there could be billions of planets in our galaxy alone that fit the bill. And they've already identified dozens of them.

GOLDILOCKS: Like, oh my God, brilliant. I'll start packing my bags. Just think, eating all the porridge I want on some exotic, tropical, distant planet, drinks by the lake.

Oh, I can't wait. Should I bring my sun hat?

SANDEN TOTTEN: I hate to burst your bubble, Goldilocks, but the nearest planet in a habitable zone is still trillions of miles away. We don't have spaceships capable of taking us there.

GOLDILOCKS: Seriously? So you just build up my hopes to shoot them down. Scientists are the worst.

Oh, we don't have spaceships that can fly trillions of miles, Goldilocks, because we don't want you to take any vacation. Blah, blah, blah. I should make some calls and get your research funding revoked.

SANDEN TOTTEN: Whoa. Whoa, come on. It's not my fault they haven't invented those spaceships. By the way, Goldilocks, that house you snuck into, wasn't it the home of some bears?

GOLDILOCKS: What?

SANDEN TOTTEN: Your story, it's called Goldilocks and the Three Bears, right? I'm pretty sure it is. And if I remember correctly, you just ate all their porridge. Man, they're going to be really hungry when they get home.

GOLDILOCKS: Wait, bears?

SANDEN TOTTEN: Yeah, bears. So hey, good luck with that.

GOLDILOCKS: I didn't sign up for bears. I'm terrible with animals. Besides, I was just about to leave. Yeah, they'll never even know I was--

[BEAR GROWLING]

--here.

SANDEN TOTTEN: So remember, kids, the Goldilocks Zone is the area around a sun that's not too hot and not too cold, perfect for liquid water and life. And also, kids, remember, don't eat a bear's porridge. They don't like that.

[BEAR GROWLING]

GOLDILOCKS: Help.

MOLLY BLOOM: So what do you think?

GWEN ALEXANDER: I think it's cool that there could be life underneath the surface of a planet. That'd be cool, like, if on Mars, there's whole cities of life forms underneath the surface.

MOLLY BLOOM: Yeah, it sort of opens up a whole other load of possibilities there.

GWEN ALEXANDER: Yeah.

MOLLY BLOOM: So now back to that mystery sound.

GIRL: Mystery sound.

[STRANGE SOUND]

MOLLY BLOOM: To me, that sounds like a space can opener. Do you have any guesses?

GWEN ALEXANDER: It sounds like popcorn.

MOLLY BLOOM: Oh, yeah. Space popcorn.

GWEN ALEXANDER: Space popcorn.

MOLLY BLOOM: Should we find out what it is?

GWEN ALEXANDER: Sure.

MOLLY BLOOM: OK.

COLLETTE LOR: I'm Collette [? Lor, ?] and I drive robots on Mars. You just heard the sound of a Martian Rover driving over rocks.

MOLLY BLOOM: So do you know what a rover is?

GWEN ALEXANDER: Yeah, isn't a rover something that explores other planets?

MOLLY BLOOM: Exactly. So it's a robotic vehicle that's sent to a distant place to study it and send information back to scientists on Earth. It's kind of like a really high tech remote control car for other planets.

Collette, who you just heard from, works with rovers for NASA in Pasadena, California. And that sound wasn't recorded on Mars. It was actually recorded right here on Earth when NASA was testing a model of a rover that was later sent to Mars.

Collette helps drive that rover on Mars by sending it commands from here on Earth. Let's hear a little bit more about that.

COLLETTE LOR: The rover is named Curiosity. It has six wheels, a drill, it has a scoop. We have the arm that is in the front of the vehicle. And we can reach out and touch rocks.

And then it also has a mast that holds the cameras. And that basically acts as our eyes on the surface of Mars. We've got cameras that help us with our navigation, cameras that are closer to the ground so that we can see what's directly in front of us. So if there's a particular rock we want to touch, we can get sort of a dog's eye view of the rock.

And we also have a camera that's at the end of the arm, so you can actually do a Martian selfie. So basically, we spend our time picking scientifically interesting targets. So we identify what the target is, and then we'll send the rover to it through driving.

And then once we get to the science target of interest, then we will put the arm out, we'll touch the rock. And we'll do various chemistry experiments to see what the rock is made of. We're on a Martian road trip.

In a lot of ways, it feels like a trip that you might take with your family. You stop along the way. You decide which sights you want to see as you're going along. And that way, it's a lot of fun.

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

GWEN ALEXANDER: This episode was produced by Mark Sanchez, Sanden Totten, and Molly Bloom.

MOLLY BLOOM: Many thanks to--

GWEN ALEXANDER: Jennifer Miller.

MOLLY BLOOM: Cheryl Alexander.

GWEN ALEXANDER: Jessie Alexander.

MOLLY BLOOM: Lisa Berg.

GWEN ALEXANDER: Andrew Nordin.

MOLLY BLOOM: Jeff Jones.

GWEN ALEXANDER: Laura Danly.

MOLLY BLOOM: Eric Ringham.

GWEN ALEXANDER: And Johnny Vince Evans. Brains On is a co-production of MPR News and KPCC.

MOLLY BLOOM: You can find more episodes and fun stuff at our website, brainson.org or on iTunes. We have a Facebook page. Like us there and follow us on Twitter. We're @brains_on. Phew.

GWEN ALEXANDER: Thanks for listening to this episode of Brains On. I'm Gwen Alexander.

MOLLY BLOOM: And I'm Molly Bloom.

GWEN ALEXANDER: All right, now go fire up your neurons.

[MUSIC PLAYING]

KIDS: Brains On! Brains On! Brains On! Brains On! Whoo-hoo. Woo!