Daniel and Kelly’s Extraordinary Universe - Can we see the surface of exoplanets?

Episode Date: May 28, 2020

Could we build a telescope that let us see what planets around other stars look like? Learn more about your ad-choices at https://www.iheartpodcastnetwork.comSee omnystudio.com/listener for privacy information.

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so you can work, create, and boost productivity all on one device. My boyfriend's professor is way too friendly, and now I'm seriously suspicious. Wait a minute, Sam. Maybe her boyfriend's just looking for extra credit. Well, Dakota, luckily, it's back to school week on the OK Storytime podcast, so we'll find out soon. This person writes, my boyfriend's been hanging out with his young professor a lot. He doesn't think it's a problem, but I don't try. Now he's insisting we get to know each other, but I just want or gone. Hold up. Isn't that against school policy? That seems inappropriate.

Maybe. Find out how it ends by listening to the OK Storytime podcast on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. December 29th, 1975, LaGuardia Airport. The holiday rush. Parents hauling luggage. Kids gripping their new Christmas toys. Then everything changed. There's been a bombing at the TWA terminal, just a chaotic, chaotic scene. In its wake, a new kind of enemy emerged, terrorism. Listen to the new season of Law and Order Criminal Justice System on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Hey Daniel, you know those awesome and amazing pictures of Earth that you see from space?

I love those Earth as the blue marble pictures. They are gorgeous. Yeah, but I think they're also a little bit creepy. Creepy because it gives you a sense for like how tiny we are, how insignificant we are in this vast ocean of space. No, because it sort of makes me feel like. Like, what if there's something out there taking a picture of us, you know? Like if I step outside, am I on camera? Yeah, what if they're like aliens on other planets watching us on the surface of the Earth? Yeah.

Well, I guess that would really worry me, except that I don't think I'm that interesting. I don't know. I bet everything that we do would be hilarious to aliens. Live from Earth, it's every night. Earth, the live action comedy show. Hi, I'm Jorge, I'm a cartoonist and the creator of PhD comics. Hi, I'm Daniel. I'm a particle physicist, and I'm always wondering if the aliens are watching. Or hearing or listening, right? They could be, or feeling us. I don't know.

Or sending emails to our podcast. That's right. Any one of those emails you get every week, every day, could be from an alien. That's right. I have no idea who was actually behind those emails. It could be a person. It could be a clever dog. It could be our interstellar listeners.

I'm sorry. Bob from China could actually be Bob from Alpha Centauri. You never know. It could just be their handle. If he's from Alpha Centauri and he's managed to email us, I wish he would send us some answers and not just some questions. Wouldn't that be disappointing if you finally meet aliens? And all they have is just more questions.

Well, that really just depends on who meets who. I mean, if they make it here, they got to know more about physics than we do. Well, anyways, welcome to our podcast, Daniel and Jorge Explain the Universe, a production of I-Hard Radio. In which we talk about all the incredible, beautiful, amazing, weird, bonkers phenomena that make up the universe around us and share with you our wonder and try to touch on the wonder that's inside you, the curiosity to understand. the universe. That's right. We talk about all the amazing things to see from this little rock that we're sitting on called planet Earth. And we also like to talk about all the things we can quite see just yet, but that we may one day. That's right. The journey of humanity and science has been one of ever-reaching ability to see further and further into the universe. First, we just looked up with our eyeballs, then we built telescopes to reveal the moons of Jupiter and the farthest planets. Then we saw even further to discover that there were other galaxies. is out there in the universe. And now we have an incredible 3D vision of a huge, vast reach of space. But there are questions that remain.

What's out there? Who's out there? What are they doing? Are they listening to this podcast? Who or what is out there? Because who knows if aliens even go by who, right? What's their pronoun? Not sure.

Is that your first question? My first question is about physics. Your first question is what's your pronoun? Well, yeah, that's kind of the standard these days. That's true. Diplomacy will be important. if we don't want to get eaten before we even get to ask physics questions. I see.

Or if we want to choose how we get eaten, you know? You never know. But we do talk about aliens sometimes in this podcast, and it's something that we talked about having skepticism about, and we've talked about whether it's possible that there are aliens out there. But I guess one thing we've never really touched on is the fact that if there are aliens out there, they probably come from a planet. Yes, a planet or a moon or some rocky body.

But, you know, again, it depends on sort of how you define aliens. If you define it to be some kind of life that's similar at all to ours, then, yeah, you'll need some kind of environment that's similar hours. But, you know, you could imagine aliens living in energy streams inside suns or intergalactic media on very long timescales. The more science fiction you read, the more crazy ideas you need to think about. Oh, I see. Huh.

Well, I guess, yeah, I guess I'm thinking more of, like, aliens who live on planets. And so the question is, could we ever take a picture of these aliens and their planets and what's possible to see from other planets that are not in our solar system? And it's crazy that we even think about this kind of question because remember, it's only like 20, 25 years ago that we figured out that there are other planets out there and that we could detect them. We could like measure them and prove that they exist. That's like a very recent discovery. You know, in the 1980s, we had ideas. We were pretty sure there were planets in other solar systems, but we'd never actually seen one.

And so it's pretty recent that this is like something we can grapple with at all. And so now, of course, we're getting greedy and we're wondering like, well, you know, how well can we see them? Can we zoom in on these planets? Yeah. So to the end of the podcast, we'll be asking the question, can we see the surface of exoplanets? And right off the bat, I want to clarify something because I feel like a lot of the coverage of exoplanets when they discover a new one, it usually says, you know, new, earth-like planet discovered.

And then in the article, there's a picture of a nice ocean world with continents, whatever. And I think people get the impression that that's a picture of that planet. But for some reason, space journalism usually features artists baloney renditions instead of real data. So much to impact there, Daniel, in your statement. First of all, a space journalist, and man, what a fun title to have in your business card. I'm a space journalist. Yeah, exactly. I'm a space reporter.

Kudos to those people, but why do they keep featuring, you know, artist's imagination over data? I have nothing against artist's imagination, but it's not a stand-in for actual knowledge. I would just put in my business card, intrepid space reporter. Why not? But maybe this might not be a word that everyone who's listening has heard of before, exoplanet. Does that mean that it's like a ex-planet or a, you know, like a kitchen utensil type of planet? It just means a planet outside of our solar system, right? That's why we put the word exo in front of it. It's like outside planets. Yeah, XO just means in another solar

system. And so exoplanet just means a planet around another star. You know, we've seen in our solar system there are eight or nine planets depending on which side of that ridiculous argument you fall. but other solar systems are really far away, three, four, ten, a thousand light years away. And so the planets around those stars, remember planets are really small compared to stars. And so the planets around those stars are very difficult to even detect, not to mention actually image,

or like zoom in on to see what's going on in that neighborhood. Yeah, and like you said, up until about 20, 30 years ago, we only had an idea that there could be other planets out there, but we didn't really confirm or really have physical evidence that there existed other planets. Like, it could have been that every star we see in the night sky doesn't have any planets.

And we are the only planets in the universe. That's right. Just like we don't know whether we're alone in the universe, we didn't until recently know whether we were the only planets in the universe, which is kind of crazy. But, you know, the universe is crazy sometimes. And you don't know if you're one of a kind

and the reason you're asking this question is because you're the only one around to ask it, or if you're one in a trillion. So far, the trend seems to be the one in a trillion direction. There are lots of galaxies. There are lots of stars. Now we know there are lots of planets. But you can't make assumptions.

You can't just, you know, artist's imagination your way to answers. You have to actually figure them out. Yeah. And so now we know that there are a ton of planets out there. You know, not just like a few planets out there, but it's like almost every, we know for sure, almost every star out there has probably a handful of planets, right? Yeah. And every time we discover one.

of these planets. I wonder like, wow, what does it look like? What's going on over there? Yeah. And it's a fascinating question. And, you know, we only recently saw close-ups of the planets in our solar systems. We sent these missions just in the last 20, 30 years to take close-up images of Jupiter and Saturn and then in the last few years of Pluto. You know, Pluto, until we sent New Horizons to image it was just like a little fuzzy dot in even the most powerful telescopes. Now we know it has that cool heart shape on it. But, There's like a human need to visualize things, to see them close up. Yeah.

And so the question is, if we are ever going to, I don't know, study other exoplanets out there in the galaxy or in the universe or, you know, sort of get confirmation of what they look like, what will we need to do? Like, do we need to send the satellite to take a picture or could we take a picture from here? Yeah, it's a fascinating question. I would love to see these pictures of planets around other stars. and maybe we'll see like aliens

spelling out messages for us or something. SOS. Like with rocks at the beach. Yeah, exactly. Send more pizza. Maybe that's what the heart in Pluto is. Hmm. There's a message from plutonians right now

that we're totally like, oh, that's cute. It's a heart. And they're in distress. Oh, man. And here we are making jokes about it. Man, we are heartless. But anyways, as usual, we were curious to see how many people

knew sort of about exoplanets and also whether or not we can see the surface of exoplanets. And so Daniel went out there into the wilds of the internet to ask this question. Yes, so thank you to everybody who volunteered your time to answer speculative questions online

and to hear your wild speculations on the podcast. If you'd like to participate in future listener questions, please just shoot us a message to questions at danielanhorpe.com. So think about it for a second. do you think we can see the surface of other planets in the galaxy? Here's what people had to say.

I don't think we have any technology right now to see planets, exoplanets from space. That might depend what you mean by sea. I don't think we can see the surface of exoplanets. I'd imagine you'd need to get a spacecraft out there. I'm not sure. I think they might be too far away. I don't think we can actually physically see any surface. of exoplanets, as I don't think we've got a telescope that is anywhere near them?

Yes, definitely. I would say no. I don't think we can. As far as I understand, we can't really see exoplanets at all. We can just detect them. All right, not a lot of optimism here for taking a picture. Everyone's like, no, only a couple of yeses. Yeah, pretty much universally shot down because it seems ridiculous.

right? Like we said, the planets in our own solar system are so far away that it's hard to image. So how could you possibly imagine taking a picture of the surface of planets super far away around other stars? It sounds like ridiculous science fiction. Yeah, it's like trying to, I guess, take a picture of a marble that's across the world maybe. I don't know if the scale works out, but it sounds like that, it's that hard. Yeah, a marble across the world that's next to a really bright light. Yeah, next to a lighthouse, I've heard that. Yeah, exactly. And now you want to see like, yeah, but is it a blue marble?

Is it a green marble? Are there tiny little bugs walking on the surface of that marble? People want to know. What's the pattern of air molecules around that little marble? Yeah, we want to predict the weather on other planets, even though we can't even predict the weather here on Earth. All right, well, step us through this. I guess maybe let's start with the basics.

Like, how do we know where there are other planets out there and how many they are? Like, what do we know, how do we find other planets outside of our solar system? Right. Well, the first thing to understand is that seeing those other planets directly is really, really hard, which is why this whole, like, topic is so ambitious and maybe ridiculous. And the way that we know that those planets exist is not by seeing them, right? Those pictures you see in the science articles are not pictures of those planets. They're totally made up.

Instead, all we can do is see the effect of those planets on the stars that they are orbiting. Like, we don't see anything really directly about the planet. We see how it impacts the star and sort of in two different ways. Yeah, it's kind of like that listener who said it kind of depends on what you mean by seeing another planet, right? Like if we only see its effects on other things, is that really count as seeing or not? Yeah, and we got into that rabbit hole when we talked about the black hole. Like, are we seeing the black hole? Are we seeing the gas around the black hole, et cetera, et cetera.

Well, in this case, what we're seeing is two different effects. on the star. One is the wobble of the star. So when a planet orbits a star, it's orbiting because the star is pulling on it with its gravity. But there's a reverse effect also. The planet is pulling on the star with its gravity. So the two are sort of tugging on each other. And of course, the planet is much smaller. So it moves a lot more, but the star also moves. And if you take really careful pictures of the star, you can detect this wobble because it's periodic, right? As the planet goes around, it wobbles steadily. It's not like a random jiggle. So if you watch it over a period of time, you can see the star moving. And that tells you how massive the planet is, whether there's a

planet there and how massive it is. Right. You measure the wiggle in the star. And you do it through like the Doppler effect, right? When it wiggles towards us, then the light shifts a certain color. And when it's wiggling away from us, it shifts another color. And so physicists, astronomers can actually detect that, in a little bit of light that comes from that star, you can actually detect that wiggle, which is amazing. Which is amazing, right? Like, everything that the astronomers are doing here is sort of aspirational. Like, 20 years beforehand, people would have scoffed it.

Like, that's impossible. But now we're doing it. And that's the kind of thing that motivates you to think, like, well, what do we think now might be impossible that in 20 years we'll have figured out? And then we'll be thinking about the next thing, right? Science and technology moves exponentially. So it's good to think big. Anyway, so that's the first method.

The second one is the brightness method, and that's if the planet happens to pass between us and the star, then it partially blocks the light from that star. It's like a fly, you know, flying in front of a lighthouse. You can detect a very small dip in the amount of light that comes from the lighthouse. And again, it's periodic. You can see it regularly. So you build this up over many, many orbits,

and you can get evidence that it's there. Right. And it's kind of a very specific dip. the light, right? Like little fly flying in front of a lighthouse, you would see the light from the lighthouse, sort of like a fly eclipse almost, but only a little bit. You see the light sort of dip, stay even as the fly makes it across the lighthouse surface and then pop back up when the fly leaves the kind of the brightness of the lighthouse. And so you're looking for these very specific kind of dips in the light, right? That's right. Not every variation in a star's brightness

is due to a planet. You're exactly right. It has to be very consistent with the orbit of an object around the star and it would make that pattern. In fact, there was that star recently we saw where there was a very

inconsistent dip in the light around the star. And people thought, oh, maybe that's aliens building some huge megastructure and it's only half finished and they haven't finished the parking lot on that interstellar mall

and that's why the light is dipping in this weird way. They just went straight for the aliens. They're like, there's an unusual variation, aliens. Aliens. Yeah, and so we've seen this on lots and lots of planets now, but, you know, it requires the planet to be in the right plane, like the plane of these solar systems, the plane around which the planets are orbiting the star is randomly organized in the galaxy.

And so it has to be aligned just right, so the planet actually goes in front of its star. So not every big planet out there can we even see with this brightness method. Right. And this is sort of historical, right? because I think they started detecting planets with the wobble method, I think, and then they sort of switched to the brightness method of looking at the dips in the light, and that's where the explosion of exoplanets really, or the discovery of exoplanets happened because then we were able with the Hubble telescope

to just like survey a bunch of stars at the same time and look for these dips in brightness. Yeah, and now we have dedicated telescopes just to do this, just to find planets through the brightness method. So it's much more powerful now that we have the technology. And now we've seen thousands and thousands of planets. Like we haven't seen them in the sense we don't have an image of them. We have to resort to artists if we want to poof up our science journalism a little bit. But we have evidence that they exist.

We know their mass and we know their radius. And so we know something about them. But we don't have images of them. We don't know necessarily what they look like. I feel like we know they've seen their shadow kind of, right? We've seen how they block the light. And that tells us a lot about like the mass and the orbit. We don't have a picture of a surface yet.

Yeah, that's a great analogy because we know from the shadow that it exists. It must be there because it's blocking the light. It's having this impact on the light source. But it's not the same thing as seeing the object itself. All right. Well, let's get into the problem of taking a picture of the surface and whether or not it's even possible. But first, let's take a quick break. Ah, come on, why is this taking so long?

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Unlock AI experiences with the ThinkPad X1 Carbon, powered by Intel Core Ultra processors, so you can work, create, and boost productivity all on one device. December 29th, 1975, LaGuardia Airport. The holiday rush, parents hauling luggage, kids gripping their new Christmas toys. Then, at 6.33 p.m., everything changed. There's been a bombing at the TWA terminal. Apparently, the explosion actually impelled metal glass. The injured were being loaded into ambulances.

Just a chaotic, chaotic scene. In its wake, a new kind of enemy emerged, and it was here to stay. Terrorism. Law and order, criminal justice system is back. In season two, we're turning our focus to a threat that hides in place. sight that's harder to predict and even harder to stop listen to the new season of law and order criminal justice system on the iHeart radio app apple podcasts or wherever you get your podcasts my boyfriend's professor is way too friendly and now i'm seriously suspicious

oh wait a minute sam maybe her boyfriend's just looking for extra credit well dakota it's back to school week on the okay story time podcast so we'll find out soon this person writes my boyfriend has been hanging out with his young professor a lot. He doesn't think it's a problem, but I don't trust her. Now he's insisting we get to know each other, but I just want her gone. Now hold up, isn't that against school policy? That sounds totally inappropriate. Well, according to this person, this is her boyfriend's former professor and they're the same age.

And it's even more likely that they're cheating. He insists there's nothing between them. I mean, do you believe him? Well, he's certainly trying to get this person to believe him because he now wants them both to meet. So, do we find out if this person's boyfriend really cheated with his professor or not? To hear the explosive finale, listen to the OK Storytime podcast on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. But this is a really hard prompt to actually see the surface. But actually, I was just kind of thinking back.

Isn't there, don't we have a picture sort of of some exoplanets orbiting around a star? Like, I have a memory of some, of like an image of some blobs around a bigger blob, which is the sun. Well, the thing that's important to remember, though, is that it's theoretically possible. Like, what happens to a photon which comes off of some exoplanet, some planet really far away? the light from its star is hit it and then it's come out into space and we know obviously that happens you can see the earth from space right it doesn't glow on its own it's reflecting light from its sun but think about what happens to a photon that hits that exoplanet and flies off into space there's nothing that prevents it from getting to earth right it can fly from the surface of that planet

carrying information about the aliens lunch or whatever and come all the way to earth and hit your eyeball no theoretical problem to that just like it's theoretically possible to see a Marvel halfway across the world if you somehow had a good enough eye. Exactly. The problem is that you don't get very many of those photons, right?

You get one photon from that alien's lunch, but because the planet is so far away, most of the photons go in other directions, and those photons spread out. And as you get further and further away, the density of those photons drops like one over the distance square. Think about the

surface of a sphere that surrounds that The area of that surface of the sphere grows like the radius squared. And so by the time it gets here, you just have very few photons. So really it's a question of like gathering enough light. The light is getting here. You just need to gather enough of it and separate it out from any other light that might be overpowering it or confusing you. And as you were saying earlier,

there are a very small handful of these things where we have seen the planet directly. I mean, we have a few pictures where the planet is far enough from the star and big enough to reflect enough light that we can see that it's there. But that only works for a very few exoplanets when we've seen thousands of them the other ways. And for the ones where we can directly image them, it's not very satisfying. It's not seeing the surface of the exoplanet. It's just like one pixel.

It doesn't tell us if it's an ocean world or if there are forests or just dust. We really need a lot more magnification to see the features, to see the surface of the planet. Right, because I guess, you know, it's kind of like the picture of Earth from the Moon. You know, we can take a picture of the Earth from the Moon, but then you could even go further. And technically, you could still take a picture if you had kind of a big enough zoom lens. Yeah, exactly. And you can imagine, like, taking a picture of the Earth from Pluto, right?

Like, you've seen those pictures of satellites that are flying out into the outer reaches of the solar system. The Earth looks like a tiny dot. All the information is still there. When you went outside and you waved up at the sky, the information from those photons is still out there in space, but it's spread out really far. And so the photon's density is very low. So you would need to either gather information for a long time or a really big lens.

Like somebody did the calculation and discovered if you wanted to take the picture of another planet around another star, you'd need a telescope that's like 100 kilometers wide. And you'd need to gather light for like 10,000 years. Wow. That would not fit. my iPhone for sure or my lifespan. You know that pause

when you press the take the picture button and it actually collects the light and takes the picture and then you hear that click sound? Imagine if that pause is 10,000 years. All right, take the picture.

Don't move. Smile. Oh, man. And hold it. So that's how much it would take but, you know, I feel like we have telescopes that like gather one photon

at a time. You know, couldn't we make use of every photon that comes in and kind of reconstruct the hazy picture. Yeah, but you know, you could imagine building a telescope that's 100 kilometers wide, even if it's not actually physically 100 kilometers wide by assembling different telescopes that

are like around the earth, et cetera, et cetera. But you'd still have to gather light for a very, very long time because there just aren't that many photons. I mean, we're talking about a very small object that's not even that bright and it's really, really far away. So the numbers are really working against you, but in principle, those photons are there. if you develop a big enough telescope or run it for long enough, then, hey, maybe it's possible.

So that's the nexus of the idea. That's the technical challenge that this problem is facing. Right. It's just that it's really small and so it's really faint. Yeah. And it's super far away. Exactly. All right.

Well, then how could we possibly ever see the surface of these other planets, Daniel? Well, the idea is literally build as big a telescope as possible. And because that's the only way you can overcome these tiny numbers. is to have a massive telescope. And, you know, we can't build something that's like the size of the Earth. So the idea is to use things that are already there, to use the Earth or the Sun, especially as a lens. Because remember, the Sun is a big ball of stuff and stuff has gravity and gravity bends light.

And so a big ball of stuff can act as a huge lens. We've seen this in the sky already. If you Google gravitational lensing, you can see. these amazing pictures where we have some blob of dark matter. And in the background, way behind it is a galaxy. And the life from that galaxy is distorted by the dark matter acting as a gravitational lens. Right. Yeah. We could use the sun as our zoom lens. Yeah. Is that kind of the, except that it's on fire. Except that it's on fire, which, you know, causes some problems. Usually that's not what you want in your telescope, but in this case. Usually you don't want it to be too hot to

handle. Yeah. Yeah. And so we're thinking, if you're going to build a telescope using some big massive object, use the biggest thing nearby. And the sun by far is the biggest blob of mass. But you were saying you need about, I guess you need a hundred kilometer wide lens, but over 10,000 years. I was just wondering, like, if you could use the moon or something. Yeah, the moon just wouldn't be big enough. So the idea is to use the sun because it gathers a lot of light. Like, it's so strong gravitationally that it's pulling. photons nearby and focusing them. And so you get a factor of a hundred billion magnification if you use the sun as a lens, which is a pretty big number. Right. What was the number again?

A hundred billion. A hundred billion, ten to the eleven. Oh, wow. That's a lot of zeros. Yeah, it's a lot of zeros. Before the X in the label of your telescope. And so the idea is you have your planet, which you're on image, which is really, really far away. And then between the planet and you, you put the sun. So then the sun bends a bunch of the photons which are flying towards our solar system but which otherwise would not have hit Earth now get all bent together

to some focal point, some focal point on the other side of the sun where you can gather all these photons together. So it's like you're capturing a huge number of photons which otherwise would have just kept flying apart and you're bending them together into one place so you can gather them together.

That's essentially how the magnification works. Oh, you need to put your camera, your sensor pretty far away from the sun. You're saying way past Pluto. Way past Pluto. Yeah, this thing would be 60 billion miles from the sun. Yeah,

you have the exoplanet, which is like light years away, and then you have the sun. Then you have the focal point, which is on the other side of the sun from the exoplanet, but yeah, it's 16 times as far away from the sun as Pluto. Wow. Have we ever gone out that far? We have not. We have not. Oh, all right. No.

So Voyager 1 is a thing that's gone the furthest, the man-made object that's deepest in space. And it's only gone 13 billion miles. And so this thing would need to be out there 60 billion miles. And, you know, Voyager 1's been going for 40 years. So there are a lot of technical hurdles to making this work. Just to take a picture. Yeah. I say let the artists do it, Daniel.

Use your imagination. Sounds cheaper. They should draw more aliens then. If you're going to let an artist do it, then let him. run wild. But I just love the scale of this idea, the hubris the like, you know, let's use the sun to take a picture. I just love it.

But how would you, I guess, block the, you need to block the light from the sun and then gather the other the light coming from around the sun. Yeah, because you can't see the photons that actually hit the sun, right? The sun is not transparent. What you're seeing are the photons that sort of skim the sun. They go near

the sun and then get bent towards your camera. And your camera is some satellite that's like, super deep in space, right? But if you do this, there's a lot of information there. In principle, they've crunched the numbers. You can take a picture of that planet that's like megapixel quality. What? For real?

For real. Every pixel that you capture in your satellite would be equivalent to like 25 square kilometers on the surface of that planet. Which is not a small, which is nothing. It's pretty small. You could see, you know, oceans, you could see continents. You probably couldn't see aliens spelling out SOS on the beach. Unless they're big aliens.

Unless they're really, really, they've had a lot of pizza. But yeah, you could see the shape. You could see like, you know, even maybe megastructures, right? You could see stuff on the surface. Oh, cities, maybe. Yeah, if they have like a massive space infrastructure, you might even be able to see that. So that would be incredible. I mean, imagine seeing that picture.

Imagine being those scientists, building this technology, pressing the button. And then, you know, a few years later, you get the result and you get to actually see this. Like, wow, what a moment that would be for. humanic. Wow. So let's do it. Why don't we do it? It sounds like it doesn't it sounds like you just have to build a satellite. What's what's the technical or financial hurdle here? Well, number one is that it'll take a long time to get there, right? So we spent 40 years getting Voyager 1 out 13 billion miles. So we don't want this to happen in 160 years, right? We need to somehow get there faster. Right. But Voyager doesn't have like booster rockets or anything, does it? Can we have technology now to get there faster. Yeah, exactly. Voyager is not a race car, right? We have ways and ideas to make things go faster.

And the idea is, instead of sending one big satellite, which is sort of hard to power, sending a bunch of micro satellites, like streams of pearls of satellites, and each one powered by a solar sail. A solar sail is not actually like a jet engine of any kind. It just captures the energy of the sun's own light and sails on it. It captures those photons and it uses that to pull itself along. All right. Well, it sounds pretty cool.

And I say, let's do it, Daniel. Let's just, let me hop on the phone here with NASA and I'll let him know I approve this plan. That's what they've been waiting for. Absolutely. But let's talk about maybe what we would actually see in these other planets if we ever took a picture of them. But first, let's take a quick break. taking so long. This thing is ancient. Still using yesterday's tech, upgrade to the ThinkPad X1 Carbon, ultra-light, ultra-powerful, and built for serious productivity with Intel Core Ultra

Processors, Blazing Speed, and AI-powered performance. It keeps up with your business, not the other way around. Whoa, this thing moves. Stop hitting snooze on new tech. Win the tech search at Lenovo. Lenovo, Lenovo. Unlock AI experiences with the ThinkPad X1 Carbon, powered by Intel Core alter processors so you can work, create, and boost productivity all on one device. December 29th, 1975, LaGuardia Airport. The holiday rush, parents hauling luggage, kids gripping their new Christmas toys. Then, at 6.33 p.m., everything changed. There's been a bombing at the TWA terminal.

Apparently, the explosion actually impelled metal glass. The injured were being loaded into ambulances, just a chaotic, chaotic scene. In its wake, a new kind of enemy emerged, and it was here to stay. Terrorism. Law and order, criminal justice system is back. In season two, we're turning our focus to a threat that hides in plain sight. That's harder to predict and even harder to stop. Listen to the new season of Law and Order Criminal Justice System on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts.

My boyfriend's professor is way too friendly, and now I'm seriously suspicious. Wait a minute, Sam, maybe her boyfriend's just looking for extra credit. Well, Dakota, it's back to school week on the OK Storytime podcast, so we'll find out soon. This person writes, my boyfriend has been hanging out with his young professor a lot. He doesn't think it's a problem, but I don't trust. Now he's insisting we get to know each other But I just want her gone Now hold up, isn't that against school policy?

That sounds totally inappropriate Well according to this person This is her boyfriend's former professor And they're the same age And it's even more likely that they're cheating He insists there's nothing between them I mean, do you believe him? Well, he's certainly trying to get this person to believe him

Because he now wants them both to meet So do we find out if this person's boyfriend Really cheated with his professor or not? To hear the explosive finale Listen to the OK Storytime podcast on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. All right, Daniel, so you have a plan for taking pictures of planets outside of the galaxy,

and people have crunched the numbers, and it is kind of possible. If you put a satellite out past, way past Pluto, you could use our sun as the lens and actually take, like, high-risk. solution pictures of planets in other stars. Yeah, yeah, exactly. So what's the hurdle here? The hurdle is really just making it work and getting the money. We think we know how to do it.

There's just a lot of technical issues to overcome. And this is something that NASA is actually supportive of. This is not just like crazy bonkers idea out there on the internet. You know, in some Reddit thread, this is a proposal that's into NASA that's moving along the stages that could actually be approved. And they're taking these challenges seriously. And the challenges are basically like how to get out there quickly, how to point this thing accurately enough, how to build a big enough satellite because the image is going to be still really huge and you want to sample it enough, how to control this thing when it's really far away. Also, how to pick which planet to look at because one issue is you build this thing, you send it to one place in space, it can only look at one planet.

You can't like turn this thing to look at a totally new planet. We can't turn it? We can't turn it because the location of an image for an exoplanet is in a specific spot in space. And then if you want to image another exoplanet, you have to go to where that image is, right? The image is always on the other side of the sun. You can't move the sun, so you have to move where your camera is. And those locations are really, really far apart. And so basically you have to pick before you go.

You just send your camera out there, and you have a telescope dedicated to one planet. Oh, really? I would think that there are so many stars out there that we would have our thousands of exoplanets that we know about and could focus on. Wouldn't the space be littered with images of these planets? Yeah, but you have to be really precise about where you're imaging.

And so in order to change the target that you're looking at, you need to be able to move laterally. And most of these spacecraft that we're sending are only going to be able to move radially. Like we're sending them out there. And they're actually going to be traveling outwards as they take an image. They're not going to stop.

It's not like they get out there to the focal point and then they just stop. They get out there, they start taking images when they get to the focal point but it's more actually of a focal line. And as you move along that line, you get further from the sun. You take pictures of different parts

of the planet. So you have to integrate over many years as you move further and further away. So it's like a one shot deal. Couldn't we build a spacecraft that stands still and takes the picture? Yeah, that would be much more complicated. You'd have to be able to stop. These things are going to be moving really

really fast by the time they get out there. To get out there at a reasonable amount of time, you need to accelerate to a very high speed. And then to stop requires as much energy. But you no longer have access to, you know, the solar energy in order to slow down. And we only know how to build solar sails to sort of speed up. Slowing down is a whole different problem.

You need a solar parachute or something. Solar break, yeah. All right. Yeah, you were telling me that these things would need to be, would take 25 years to get there. And they would need to be 300 times more accurate than Hubble, which is pretty, kind of our state of the art, kind of. Yeah, exactly, because you have to point very precisely. Like, the light is going to be coming from that planet bending around the sun, making this Einstein ring.

It gets distributed all the way around the sun. Then you have to point at exactly the right spot in the Einstein ring. And even still, even though you have all this magnification from the sun, you still have to spend a lot of time building up the image. So you want to keep your camera pointed at exactly essentially the same target pixel for weeks and weeks and weeks or months in order to gather enough photon to actually see what's there. Does it sound less appealing by the minute here, Daniel? I'm like, hmm, how much do I want to see a picture of another planet? What do you mean? It's just engineering trouble.

You want to, you want to. I mean, I want to enough for both of us, trust me. What if we pick one planet and we send a satellite and it's a boring planet? That's a real concern, you know, if we have 4,000 plans to pick from, it could be like 100 of them, have amazing superstructures and alien life on them, and we just pick one that's like dust and rubble. And it's like yawn and that was $100 billion and 30 years of work. Oh my goodness. Let's send 4,000 satellites then. That's obviously the solution. That is a great idea. I'm loving that idea. It's kind of how people take pictures these days with their phone. You know, they don't just take one picture. They go like tap, tap, tap, tap, tap, tap, tap. And then later. You picked the one where nobody's blinking.

Yeah, I'm pretty sure they do that because those pictures are free. And if each one costs $100 billion, people might press that button with a little more thought. Yeah, they might think about it a little bit more for sure. Yeah, and, you know, we think we know how to solve this problem, but there are still a lot of technical issues. Like, we are seeing faint photons coming through the corona of the sun, essentially. And you have to pick out these photons from that corona. It's not an easy job to increase the signal to noise.

ratio to the point, but this is actually going to be doable. You need a pretty good set of sunglasses or pretty solid thumb to put in front of the sun. Yeah, absolutely you do. In addition, this thing has to basically control itself. It's going to be so far away from the earth that we can't like send messages. You can't drive this thing with a joystick. It's going to take four days for messages from Earth to get to our camera that's out there in the solar focal point. And so it basically has to organize itself.

It has to be basically a. AI power. Oh, my goodness. The first AI photographer. That's right. How do we know it's not just doing deep fakes and sending us images that's made up on the internet? That's right. The alien could gain sentience and then it'd be like, this is too much work.

If I send them a born planet, they're going to fire me. I'll just deep fake a fun, cool planet with aliens in it. Yep. And then we'll get all excited. We'll send an interstellar ship towards the direction of that planet. and then only in a thousand years where we discover that we relied to. That sounds like an awesome plot

for a science fiction novel. A little bit of a letdown at the end, but sounds interesting. But you're right. We could take a picture of this planet and we could discover nothing. Or it could be fascinating. Or it could be like confusing and fuzzy, right?

We're going to see a picture of this planet. We're not going to necessarily be able to tell what we want. We're not going to see literal aliens walking around on the surface at 25 square kilometers per pixel. we might just be able to make out fuzzy details. I mean, remember what it was like when we first got pictures of the surface of Mars from Earth? People thought they saw faces and canals and there was lots of excitement, of course, all of which was Bubkis. Why, they did see a face, didn't they?

Yeah, they saw a face, but it was just a mountain shape where they happened to have a shadow that looked like a face, right? No, I mean, isn't there a big smiley face on the surface of Mars? Or did I read that in a comic book? Yeah, I'm not sure if that was an artist impression or actual data. All right. Well, it sounds like it's going to be pretty difficult to get a picture. Can we send a satellite to another planet, Daniel, and take a picture closer? We certainly could, and that would be awesome, but it would take a zillion years to get there. A zillion. I guess what's the closest exoplanet that we know about?

Yeah, the closest exoplanets are, you know, in the five to ten light year distance. And that's pretty far away. You know, if you built Hubble, for example, and sent it that far away, you couldn't send it really. high speeds very easily. You can't tolerate a lot of acceleration. So it would take a long time to get there and then take those pictures and send them back. I mean, hey, that also sounds like a good idea. Let's do both. Let's do it all. Let's do it all. I mean, we're spending trillions on everything these days. So why not 100 billion to see pictures of aliens? Yeah. Well, it would take maybe like a couple of dozen years, you think, or hundreds of years to go and take a picture of another planet.

How long it takes to get out there depends a lot on the propulsion you use. And for your very expensive, important telescope, you probably want gentle acceleration, but you also wanted to get going pretty fast. So I think the best option is to build like a solar sail the size of Texas. And that might be able to get your telescope up to like 10% of the speed of light. And it would still take like, you know, 50 to 100 years to get there. But hey, yeah, that sounds like a great idea. You're like, this one is Daniel approved. Call NASA. And you start a Reddit thread here to tell me we approve. I only have enthusiasm. I have no responsibility.

And that's why I have no authority also to make these decisions. Somehow the two are linked, but you're not quite sure why. Exactly. Exactly. No, but I think it's a fascinating question. I think it's sort of the next generation, you know, the next frontier and understanding what's out there in the universe is to get these close-up pictures of what's going on.

And so I'm looking forward to it. I'm hoping that this kind of thing happens and that we press the button and we see the picture and that I get to see the picture, a literal picture, not an artist's impression of what's happening on these planes. Right. Because, you know, it feels like a basic human curiosity, you know, to see pictures, to see, like, actual photographs of something, not just like the blip in the light or, you know, the gravitational effects or something.

You know, there's something about our human brain that we just, we need to see it. Yeah. And, you know, it makes you wonder if there are alien civilizations out there that already have this technology. If we're on the verge of it and we've only been around for a few tens of thousands of years as a civilization,

certainly somebody else has figured this out and somebody else may have even put a picture of Earth up on their wall somewhere out there in the universe. And then tragically, they'll swipe left. They're like, oh, look at this blue planet. It looks kind of boring.

Let's keep going. Yeah, or maybe that's good, right? Yeah. Oh, look, this blue planet. It doesn't look delicious. Let's keep on. What do you want for lunch today? You guys feeling like Earth or some other planet.

That's right. Everybody look as unappealing as possible. I think we're on our way there, Daniel. That's right. I do my best not to look delicious every day. All right. Well, we hope you enjoyed that and hope you look at the night sky or look at the sky out there and wonder what do other planets look like?

Do they look like Earth or Mars or Venus or Jupiter or maybe something completely different? That's right. And remember that the technology is the capability. that we are scoffing at today are things that scientists and engineers are imagining and working on to make possible for tomorrow. And humanity's ability to see

what's out there in the universe to understand what's in this crazy bonkers cosmos and to peel back layers of reality to penetrate what's really happening seems unlimited. And so hopefully our children and our children's children will know so much more about the way the universe actually looks.

Yeah. Yeah. And they won't have to use their imagination. That's right. And maybe it'll even be cheap by then. There'll be an app for that in 500 years, right? That's right. You can swipe left, right, up and down. See any planet you like.

Well, thanks for joining us. See you next time. Thanks for listening. And remember that Daniel and Jorge Explain the Universe is a production of I-Heart Radio. For more podcasts, from iHeartRadio, visit the iHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows. Ah, come on, why is this taking so long?

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on new tech. Win the tech search at Lenovo.com. Lenovo, Lenovo. Unlock AI experiences with the ThinkPad X1 carbon powered by Intel Core Ultra processors so you can work, create, and boost productivity all on

one device. My boyfriend's professor is way too friendly, and now I'm seriously suspicious. Wait a minute, Sam. Maybe her boyfriend's just looking for extra credit. Well, Dakota, luckily, it's back to school week on the OK Storytime podcast, so we'll find out soon. This person writes, my boyfriend's been hanging out with his young professor a lot. He doesn't think it's a problem, but I don't trust her. Now he's insisting we get to know each other, but I just want her gone. Hold up. Isn't that against school policy? That seems inappropriate.

Maybe find out how it ends by listening to the OK Storytime podcast on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. December 29th, 1975, LaGuardia Airport. The holiday rush, parents hauling luggage, kids gripping their new Christmas toys. Then everything changed. There's been a bombing at the TWA terminal, just a chaotic, chaotic scene. In its wake, a new kind of enemy emerged, terrorism. Listen to the new season of Law and Order Criminal Justice System on the

IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. This is an IHeart podcast.