SciShow Tangents - Exoplanets

Episode Date: March 9, 2021

The Tangents crew blasts off beyond the Sun’s familiar orbit to check out all the weird, wild, possibly-inhabited exoplanets circling distant stars! Who needs our boring old solar system anyway? Head to the link below to find out how you can help support SciShow Tangents, and see all the cool perks you’ll get in return, like bonus episodes and a monthly newsletter! https://www.patreon.com/SciShowTangentsFollow us on Twitter @SciShowTangents, where we’ll tweet out topics for upcoming episodes and you can ask the science couch questions! While you're at it, check out the Tangents crew on Twitter: Ceri: @ceriley Sam: @slamschultz Hank: @hankgreenIf you want to learn more about any of our main topics, check out these links:[Definition]https://www.iau.org/science/scientific_bodies/commissions/F2/info/documents/[Fact Off]Not-quite-sunscreen snow exoplanethttps://iopscience.iop.org/article/10.3847/1538-3881/aa899bhttps://www.eurekalert.org/pub_releases/2017-10/ps-ads102617.phphttps://pubchem.ncbi.nlm.nih.gov/compound/Titanium-dioxidehttps://pubchem.ncbi.nlm.nih.gov/compound/61685https://tdma.info/how-your-uv-protective-sunscreen-works/https://www.nationalgeographic.com/science/article/120529-global-warming-titanium-dioxide-balloons-earth-environment-scienceMessages to Gliese-581chttps://www.nasa.gov/topics/universe/features/gliese_581_feature.htmlhttps://phys.org/news/2012-07-potential-habitable-exoplanets.htmlhttps://arxiv.org/abs/1207.4515https://www.universetoday.com/19335/messages-from-earth-beamed-to-alien-world/http://news.bbc.co.uk/2/hi/science/nature/7660449.stmhttps://www.nature.com/news/2007/071102/full/news.2007.212.html[Ask the Science Couch]Exoplanets arthttps://www.nasa.gov/feature/jpl/the-art-of-exoplanetshttps://www.scientificamerican.com/article/how-artists-portray-exoplanets-never-seen/https://www.theatlantic.com/science/archive/2017/02/exoplanet-trappist-nasa/517590/https://www.wired.com/2014/05/artist-rendering-exoplanets/[Butt One More Thing]Space poop challengehttps://www.nasa.gov/feature/space-poop-challengehttps://www.nasa.gov/feature/winners-of-space-poop-challenge-receive-30000

Hello and welcome to SciShow Tangents, the lightly competitive knowledge showcase. I'm your host, Hank Green, and I'm joined this week as always by science expert, Sari Reilly. How comfortable are you with that title? Oh, not at all. I was just thinking about that. Every time you say it, I'm like, no, that's fake. Expert is not anywhere in the top 50 words I'd use to describe myself. We are also joined by our resident everyman, Sam Schultz. I'm very comfortable with that title. If you could go on a vacation to someplace that doesn't exist, what would it be like there? Tell me your ideal vacation spot.

Anything can be different. It can be purple. You can fly. It can be low gravity, high gravity. purple you can fly it could be low gravity high gravity i this is because i just watched a documentary about the the seas mission which is they spent a year on an island in hawaii as if they were on a mission to mars it was like a group of six people it would be cool to go to just somewhere like that where it's it's like rocky and weird and probably more weird things to discover. Like non-earthly tide pools in like green water.

And like there's lots of animals and all of them taste just like Welch's fruit snacks. No, I don't want to eat them. I'd be a gentle tourist. Isn't it like leave only footsteps, take only memories? And bites. Just a little nibble. Come on. You guys want to go on a vacation where you're working and doing science?

Is that what you're saying? No, it's not working. If I have to think hard about it, then it's working. But if I can just look at it and go, oh, I'm learning, then that's fun learning instead of work learning. I just go to Disneyland or something. But I've never been on a vacation that wasn't more work and exhausting than not being on vacation. So I'd like to just go somewhere else where I could sit in a chair and everybody would leave me alone.

Yeah, vacation is definitely work. And in fact, I am almost certain that the majority of the enjoyment I get out of a vacation is thinking about it beforehand. I don't know who you are. I love vacation. I love not doing anything. Well, it's just that I never not do anything. I always end up doing stuff. I'm like, oh, I'm in this place.

I need to do the things. You got to figure out where to sleep. Yeah. What to do. I hate figuring out what to do. I just wander. I just pick a direction and walk and then figure out something to do. And then I'm like, I'm so satisfied what to do. I just wander. I just pick a direction and walk and then figure out something to do.

And then I'm like, I'm so satisfied with this vacation. Well, my goal is to someday go visit some other planet. That sounds very stressful and hard. And also impossible. So it's good to have dreams that you're definitely not going to achieve. So you're listening to SciShow Tansy right now. And every week on this show,

we get together to try to one-up, amaze, and delight each other with science facts and science games. And we try to stay on topic, but we aren't always great at that. Our panelists are playing for Hank Bucks and for Glory. And I'll be awarding those Hank Bucks as we play. And at the end of the episode, one of you two will be crowned the winner.

Now, as always, we're going to introduce this week's topic with the traditional science poem from Sari. When humans of yore first gazed up at the sky, they marveled at objects, but then wondered why. Some stars stayed static, but others did fly across the horizon as weeks passed them by. These stars weren't stars at all, it turns out. These wandering orbs of astronomical doubt, they were planets like Earth on an elliptical route, round the sun which our system could not exist without. Scientific advancements like telescopes and such led to ideas about planet formation so much that we dreamt of other stars with planets in a clutch, and astronomers went seeking with a careful touch.

Through the method of Doppler and patience we found one exoplanet, then another was crowned, That was like a tearjerker. Yeah, I got inspired. I remember being a kid and, you know, being taught that, like, we don't know if there are any other planets in the whole galaxy, in the whole universe. And then now it's like, you know, one thing I learned from that is that I'm pretty sure everybody was pretty sure there were, but, like, we didn't have any evidence for it. And so scientists don't say things that they don't have evidence for. And after all, there are a lot of freaking stars, so it'd be really unusual if

there were not planets. But I remember very specifically being told, we don't know if there are other planets out there. And now it's just like the idea that during my life, for a pretty big hunk of it, we just had no idea that there were planets outside our solar system. And now it is like knowledge as true as knowledge gets. It's really cool. So our topic for the day is exoplanets. That's a pretty easy thing to define. Planet is hard to define, but once you've defined planet, then exoplanet gets easy. Yeah. Yes. Once you have list of things that make up a planet, then exoplanet is just a planet that orbits around another star that is not our sun. Very easy to distinguish them from other kinds of planets because there are like rogue planets that don't have a star.

Those aren't exoplanets. They specifically have to be orbiting a star that is not our sun for it to fall under. I didn't know that. I would have assumed that rogue planets would count as exoplanets because they are, after all, exo. And planets. They are, in fact, both exo and planet, but they are also rogue, which trumps both of those. Oh, okay. Where does the word planet come from? I think it comes from, oh, it comes from wandering stars. So from a word of uncertain etymology, planasthai, P-L-A-N-A-S-T-H-A-I. And so like my poem, that's how I got inspired. I looked up the etymology first and I was like, oh, old humans were just staring up at the sky and they were like, oh, some of the stars, they wander.

And then no one called them. So they were like wandering stars. And then we were like, hmm, a planet is a different thing, actually. I mean, I imagine the exact same thing would happen on any planet where there was somebody looking up at the sky being like, look at those, look at those special stars that are just like, I don't care. I don't care about the rest of y'all.

I'll be in a different place every night. Yeah, very slowly. So not so much like, but more like, I mean, time passed faster back then. It does seem like there should be a way to define what a planet is because it seems pretty clear

that like Jupiter and Earth are different from like an asteroid. But turns out there's like, there's a bit of a sliding scale where it's like, well, what is Ceres? It's in the asteroid belt. It's really big. It's spherical, but it's not really a planet.

And we knew about it for a long time. We never called it a planet. And then if you say that, then like, okay, well, what about Pluto then? And it's like, that's, it's a slippery slope because if Pluto's a planet, then we're going to have to start thinking there might be tons of them.

What was our problem with Pluto? It was too small? They decided like, what's a definition that's going to work for us and where there will be a clear line that we can draw? And that was, has to be a sphere and it has to have sort of cleaned up the area

around its orbit. So it's not like sharing its orbit with a bunch of other things. So it's big enough that it's collected all of the rocks for the most part in its orbit. So it's not like sharing its orbit with a bunch of other things. So it's big enough that it's collected all of the rocks for the most part in its orbit. And Pluto very much hasn't done that. It's got a lot of other stuff around it. I'm not sure about Pluto, but definitions of planets also have to do with mass. And that's where when the International Astronomical Union defines these things, they put equations in their definition bullet points.

Because, like, for example, the working definition of an exoplanet includes, I'm reading this from their website, objects with true masses below the limiting mass for thermonuclear fusion of deuterium that orbit stars. Ground dwarfs are stellar remnants that have a mass ratio with the central object below the L4 slash L5 instability equation are planets. Right. No matter how they are formed.

Right. I always forget. In our solar system, we don't have to worry about this because we don't have any brown dwarfs or it's not like a binary star system. We don't have to worry. But most star systems have more than one star. So that matters to them, but it does not matter to us. Yeah. Yeah. So you get more complicated the more objects you try to fit under the same definition. You have to really, really draw those boundaries carefully

to be like, this little, this size of thing is planet. Everything else, something else. With all that being said, I think it is now time

for us to start our first game because we have been going on for a while. And I would like to introduce you to our game for the week, Exoplanet or Earth, socially distanced vacation destinations. We've all been cooped up. We've been scrolling through Airbnb listings

and we've been writing little stories in our heads about our preferred vacations in a cozy cabin on the other side of the world. But one day we will be free to plan vacations and trips again. And when that time comes, wouldn't it be nice to go on a trip to an exoplanet? It may sound unlikely with the uninhabitable conditions and distant travel. But if we could travel to those planets, we could see all sorts of amazing things. And the following are descriptions to tell you what to expect on your potential exoplanet visit.

Some of which are exoplanets and some of which are just very weird places here on planet Earth. It's up to you to decide, exoplanet or Earth, are you ready? Uh-huh. So I'm going to give you four destinations. You both get to each vote on whether you think it's planet Earth or planet Exo. Vacation destination number one. Are you finding yourself at odds with your travel partners? Maybe even yourself? Over whether you want to visit somewhere hot or cold? Never fear.

The days of having to choose are long behind us. This destination pulls a double duty. For those of you who want extreme cold, there's plenty of that to test even your toughest parkas. And for those of you who want a little bit of warmth out of your vacation, or just a little sit by the fire after a long, cold, nice hike, take a nice, relaxing nap next to our lava lake. There's got to be lava lakes on Earth. Sounds like Greenland or something to me. This is interesting because I think this is one situation where my knowledge of Earth will mess

me up. There's like a sulfurous volcano, but that's somewhere tropical, I think. It's like a lake, but it's very caustic. I think there's a lava lake in, I want to say Antarctica, but I'm not positive. There aren't just lava lakes everywhere? That seems like something that would be everywhere. Okay. I'm going to say Antarctica then, which is on Earth. I might have misled you. I'm going to guess exoplanet, Sam, because I don't trust myself.

Oh, man. It's on Ross Island in Antarctica. Sari not only knew it, but knew it exactly and still got it wrong. I feel terrible. It's Mount Erebus. Mount Erebus in Antarctica. And it is very, very cold there, as you might expect. Because not only is it in Antarctica, but it's also a mountain.

So it's high up in the atmosphere and has a lava lake at it. Freaking heck. I need to stop. This is my problem throughout my entire 16 years of school, too. If I thought more than, like, 10 seconds about a question, I was going to get it wrong and overthink it. I just need to say the first thing

that comes out of my mouth. That's what I always do. That works for me. Or just say the first thing that comes out of Sari's mouth. Yeah. That works even better. Vacation destination number two. Are you looking for a nice romantic spot to take your favorite person?

You could just go to your local sunset lookout or you could step things up and give your beloved the gift of a very strange sunset. Come visit us and you'll be able to witness an unusual sight in the evening. A sunset that sets not with our beautiful but familiar shades of orange and pink, but rather goes from blue to green. This unique sight is

the result of gaseous chemicals around you that absorb red light, resulting in a display that is sure to delight and amaze. I think there's a beach in LA where the sunset is green and that has chemicals everywhere because it's LA. I've never heard of that beach in LA, so you're teaching me something. I know there are like northern lights, so the aurora borealis on earth, which is like those blue green atmospheric phenomena that's not a sunset thing but it's not a sunset yeah but there are like gases being energized in earth's atmosphere but i don't think it makes me think that those gases only appear for a very short time and like not concentrated enough regularly for it to be like a for sure green blue sunset i'm gonna go i'm gonna

go with earth again i'm gonna go exoplanet again all right swapped it on its head as sam was wrong and sari was right this was about hd 209458b also known as osiris it's a gas giant that has an atmosphere of carbon monoxide and sodium. The sodium particles absorb the red light, which would likely give you a blue-green sunset. Much of its atmosphere is currently escaping, and also carbon monoxide and sodium, in general, two of the worst things to breathe in. Vacation, destination number three for the rock climbers among you. This is going to be the destination of your ascension dreams. When you arrive, you'll be surrounded by basalt, that

volcanic rock that makes for exciting climbs. With a landscape that's been compared to the moon, even the non-climbers in your group will have plenty of sights to take in and appreciate. And with cloudy weather, rarely a problem here, you should be able to make the most of your trip. Maybe you'll even want to extend it. I don't know. There's basalt on Earth. I know that. There are basalt columns like in Washington.

I think this is somewhere in like Utah or something. I also think this feels like on Earth where you'd train rovers or something like that. So I'm going to guess Earth. Sam, Earth? Oh, yeah, Earth. I'm sorry. That was the exoplanet LHS 3844B. It's a rocky planet.

Our biggest clue here was that it is unlikely to rain because it does not seem to have an atmosphere. They think that it's covered in basalt and that the cooled rocky parts of it would resemble the darkest parts of the moon called the mare, I think. LHS 3844B is tidally locked, meaning one side of it is permanently facing the star at orbits, and the star-facing side is around 1400 degrees Fahrenheit. So while you would not get rained on, you probably would be praying and hoping for a little bit, a couple drops, please. Thank you very much. And finally, vacation destination number four. For a relaxing retreat, a visit to our baths is sure to inspire you. You may be surprised to

find it among the rocky scenery, but when you arrive, it is hard to miss the dazzling pools of neon green that fill in depressions left by ancient volcanoes. The impressive hue is a product of sulfur that fills the depths. Though, of course, given that sulfur is neither gentle on the skin nor the nose, it may be best to enjoy these baths from a distance. Well, you go first this time. I'm going to give you the right answer. You're going to give me the right answer? I already talked about this.

This is the volcano in Indonesia, I think. I think it's, and I'm going to screw myself over if this is wrong, but I think it's called Kawaii Gen, and I think it's like a sulfury blue-green lake. It's very cool and weird. So Earth. I'm very confident Earth. I think Hank's having a little fun with us.

And he's talking about Yellowstone National Park, which is right in our backyard. So I'm going to go with Earth as well. You are both right. It is Earth, though the specific neon green pool of water that i was talking about was neither of the ones though you are both right that those places have sulfury water but the devil's bath in new zealand wayotapu as like it looks like the simpsons green radioactive color it is amazing oh this is super green yeah it's like looks like surge oh god this is where they poured it all in the when that yeah when they ran out no one wanted surgery more so they just took it to new

zealand so that means that you uh tied it up here you both each got two points next up we're going the fact off. Did you know SciShow Tangents has a Patreon? Help us! Head on over to patreon.com slash scishowtangents to learn more about

how you can help support the show and get great rewards. We've got stuff for you. We've got bonus episodes. There's access to a Tangents patron-only Discord. Sam, what Patreon perk are you most excited about? Well, I gotta say, it's pretty

hard to beat a bonus episode, but I worked all day today on the Tangents newsletter, which I think is turning out really fun. It's going to have pictures. It's going to have art. It's going to have bonus science couch questions. It's going to have bonus butt facts. It's going to have whatever I want to put in it because it's all mine. Ha ha ha. But the thing that really makes me radiate with true joy is that once we reach 500 subscribers, we have a goal where we will record an audio commentary for Cars 2 and Time Travel Mater so we can figure out once and for all if and how cars drink water. And I want to do it so bad.

I didn't know about this idea. I mean, I still have never, I've not seen this. I've still not seen it. Fresh for you? Fresh for me? I've never seen it either. I'm not a baby. I've never seen Cars 2.

After you asked me if I would watch Cars 2 for the Patreon, I was like, now I can never see it in my normal life. No, we can't. We can't watch it or time travel major if you want to join the scishow tangents patreon community get lots of good perks and help us reach this very lofty and important goal check out patreon.com slash scishow tangents or just search scishow tangents patreon on google Welcome back, everybody. It's time for the Fact Off. Our panelists have brought in science facts

to present to me in an attempt to blow my mind. And after they have presented all their facts, I will judge them and award Hank Bucks any way I see fit. And to decide who goes first, I have a trivia question for you. The Milky Way galaxy is thought to have trillions of planets. To date, we've confirmed over 4,000, and we have another 5,000-plus candidates waiting to be confirmed.

Out of trillions, that doesn't seem like much, but we haven't been able to seriously search for very long. The first exoplanets discovered and confirmed were two rocky planets orbiting a pulsar in the Virgo constellation. They were found in January of what year? Okay. How old's Hank? So it can't be older than that.

How old is Hank, Sam? He gotta be 40, right? 40, I think. 40 is the correct answer. Was the 80s 40 years ago? Yeah, 81. Okay, okay. Now we're getting somewhere.

I will say 1985. Now we're getting somewhere. I will say 1985. I'm going to say 1992. Because that is the correct answer and you knew that. You knew it, didn't you? I'm pretty sure that you just knew that. Yeah, I did.

You made it look like you didn't know but I knew you knew it. You did the math on your fingers with me. She knew the whole time. It was a bonding experience, Sam. We had to like bring the listeners along with our learning journey. It was a bonding experience, Sam. We had to bring the listeners along with our learning journey.

That's science expert Sari Reilly right there. Coming in for the kill. I'll go first. Sam has time to recollect himself. In October 2017, there were a bunch of spacey articles with titles like Hubble Observes Exoplanet That Snows Sunscreen about the exoplanet Kepler-13ab.

And I guess I'm going to well actually NASA and Popular Mechanics and the Eureka Alert press release because it's not that chemically simple. It's a much weirder story. So Kepler-13ab is called a hot Jupiter because it's a gas giant exoplanet, and it's actually one of the hottest known exoplanets, partially because it orbits so close to its parent star. And it's tidally locked, so there's one light side and one dark side, and this will be important. Astronomers think there's a compound in the atmosphere of hot Jupiters called titanium two oxide, or TIO, which is one atom of titanium

bonded to one atom of oxygen. As a gas, it absorbs light from the star and radiates it as heat, making the atmosphere warm and toasty. And Kepler-13ab is quite weird because strong winds push this titanium oxide gas around, and on the dark side, it condenses into clouds and crystal flakes like titanium oxide snow instead of water snow. And on the dark side, it condenses into clouds and crystal flakes like titanium oxide snow instead of water snow. And then the exceptionally strong surface gravity of the exoplanet makes the snow fall towards the surface. And because of this titanium oxide snow falling, there's less gas absorbing light and radiating heat in the upper atmosphere. So it's cooler in higher altitudes, which is the opposite from other exoplanets like this. And this is what the 2017 paper was studying, a weird atmospheric pattern. Now, titanium 2 oxide sounds a whole

lot like the chemical titanium 4 oxide, also called titanium dioxide, or TiO2, which is one atom of titanium bonded to two atoms of oxygen. And that's found a lot on Earth. It's everywhere from white paint called titanium white to sunscreen because titanium dioxide's chemical structure makes it really good at scattering UVA and UVB rays, so it's reflective and bright and protects our DNA. And as far as I can tell, it does not radiate heat. So mixing up those two chemical names is the source of confusion in those headlines saying, wow, sunscreen is falling like snow. And unlike titanium dioxide, which is in sunscreen, titanium oxide on exoplanets that warms their atmospheres is rarely found or made on Earth.

So Kepler-13ab, in my opinion, doesn't really have sunscreen snow. It's more like little hot rocks falling out of the sky, leaving atmospheric cold spots in their wake, which in some way seems cooler, no pun intended, to me. Could we do this, and would it be useful to us there is a there is a hypothesized experiment saying we should shoot titanium dioxide nanoparticles into earth's atmosphere to counteract global warming and the greenhouse effect why not i mean is there that much titanium dioxide around there's a lot of it naturally. Huh. Because I usually like you hear titanium

and you're like, ah, titanium. That's expensive. Yeah, but titanium dioxide, it's in like everything. It's like a food additive. It's in paint. It's in whatever else I said.

Sunscreen. Titanium is the ninth most common element in the Earth's crust. Huh. It's got a great marketing department because it does.

Yeah, I mean, it's just a good name. Titanium. So you, did you identify this inconsistency on your own, Sari? You're just like, why do you keep saying that? That's a different thing. Yes, yeah. It was weird because in the press release

and within all the articles, they said it was like titanium dioxide was found in the atmosphere. And then I went to the paper and there was no dioxide anywhere. It was all TIO. And then I looked at the PubMed or whatever, the PubChem articles about the two compounds. And I was like, no, these are different things. They don't overlap in any way.

And so it was very weird because at first I was like, oh, I'll talk about sunscreen snow. And then as I was researching, I was like, I'm going to talk about how everyone was wrong about sunscreen snow. Perfect. Well, actually, Sam, it's time for you to take it on. So one of the first questions that jumps into people's minds when a new exoplanet is discovered is, could there be life on it? And since we know that life exists on earth, we came up with the earth similarity index by which we measure how similar to earth an exoplanet is and by extension, how likely it is to have life as we know on it. So the ESI is an equation that looks at a planet's radius and density. I think because if a planet is too big, it would squish us. Is that why?

Like, its gravity would squish us? Yeah. Okay. It's escape velocity. So we know that it won't just go flying off away from its sun, I suppose, at some point. I think that that's probably the escape velocity of the planet, which would just be a metric for, like, gravity at surface level. Okay.

So they're not worried that they're going to land somewhere and then it'll get flung off into the universe? No, probably not. Okay. Well, probably not. Okay. Well, that makes more sense. And temperature, because humans are sensitive and they need a nice place to live if we're going to go take over this planet. So the equation spits out a number from zero to one of a planet's earthness. And the closer to one it is, the more earth-like a planet is. So Mars' ESI is 0.55, for example, right now. I guess because there are a lot of good things going on for it, like size is okay, but it's a barren hellscape otherwise.

So it's only half as good as earth. So for planets not in our solar system, pretty much all we can figure out by looking at them is how long it takes to orbit their star and possibly how big they are because of how much they move the star they're orbiting or how much light they block when it passes in front of the star. So most other measurements from what I could tell were purely speculative, especially temperature, which I think scientists are just sort of like, could be like this based on how far away and what kind of star it's around. Nevertheless, there are plenty of lists of hypothetically habitable planets floating around on the internet that humans could either escape to

or find life on. Unfortunately, many of them are thousands of light years away. But in April 2007, scientists at an observatory in Chile found Glyse 581c, a mere 20.4 light years away from Earth. And on top of that, it seems to check off all of the right Earth similarity index boxes. It appeared to be the perfect distance from its star, it wasn't too much bigger than Earth, and its average temperature, if it had an Earth-like climate, was estimated to be around 104 degrees. Fahrenheit?

Well, yeah, 104 degrees Fahrenheit. A little steamy, but it's okay. That's fine. Yeah, and that's within the realm of possible. It's not 104 degrees Celsius. No, no, just Fahrenheit. I don't know Celsius, so I won't say that one. It's not 104 degrees Celsius. No, no, just Fahrenheit. I don't know Celsius, so I won't say that one.

It was calculated at the time to have an ESI of 0.92, which was, if not the highest number ever reported, among the highest ever reported. Another exciting thing happening in 2007 was social media. So Twitter was founded just the year before, and there were lots of social media sites popping up that don't exist anymore, like Bebo, which was a blogging platform owned by AOL, the name of which was an acronym for blog early, blog often.

So social media was really new and exciting and the market was super crowded. So sites were always finding opportunities to get their names out. And news about a potentially habitable planet not too far from Earth was just the right kind of opportunity for our marketing scheme. So in the interest of fostering interstellar friendship and brand awareness, Bebo ran a competition called A Message from Earth,

where users could vote on image and text submissions to Bebo, and the top 500 would be beamed from a radar telescope in the ukraine to gliese 581c so i couldn't find a complete list of the submissions that we sent but some of them were pictures of someone getting their first kiss messages from various politicians and a shout out from the british boy band mcfly which i've never heard of but we're a big deal in 2007 i guess the winning messages were shot into space in october of 2008 and are expected to arrive in mid-2029. So it's possible that in 2049, a bunch of aliens will show up and they'll be ready to see McFly live in concert. Except that's not very likely because by November of 2007, which was just months after Gliese 581 was discovered, its livability had already

been basically disproven. The main strike against it was that there was a new model that showed that its temperature was more like 800 degrees than 104 degrees, but that didn't stop Bebo. So they sent the message anyway. But since then, we found other planets in the same system, two other planets specifically, that could be habitable and they're much more likely to be habitable. And luckily for us, the Australian government already shot a bunch of tweets at one of them in 2009.

So when those aliens show up in 2050, they will want to meet Balloon Boy and David After Dentist. Oh, God. And they'll be like, how's Bebo doing? I just love the concept that all aliens will have this, like, totally outdated idea of what we are into. And they'll seem so lame when they get to us. Well, and they're not going to, like, Zoom here at the speed of light, probably. They'll just send us a little message and be like, oh, here's our newfangled social media platform that's going to be bankrupt in two years.

Santa McFly albums, please. We love it. If we got a song, just one song from another solar system. That would kick ass. It'd be such a banger. God, I hope it would be good.

What if it sucked? What if we got the one song that sucked and then we went to that planet and we were like, this song kicks ass. And they were like, that song?

Come on. That's how it would go down. Oh man, that's cool and it's it's the german is glisa i don't know oh gosh how we say it i'll go back through and it'll be after a german guy glisa i'll just put that in gosh i was so ready to give sari the points but then weird marketing got involved. I'm still getting, that's still a Sari point. I'm going to give five points to Sam and six points to Sari. Yes.

So that means Sari is coming out on top with eight points to Sam's seven. And it's time to ask the science couch. We've got a listener question for our couch, virtual couch of finely honed scientific minds. It's from at Emily Janetet6 and at AndrewTops. They ask, how do people create those artist renderings of what we think exoplanets look like? What information are those things

based on? So Sam went over a little bit of it. You know if it's rocky. You know its density. You can figure out its density. You can figure out how big it is. You can figure out some things about its atmosphere, depending on how you're, it's density. You can figure out its density. You can figure out how big it is. You can figure out some things about its atmosphere, depending on how you're detecting it. And like,

you're going to get, make guesses at how, how hot or cold it is. And so by, with that information, you can know a little bit about what the surface looks like. Do you get atmosphere stuff by looking at how the light is going through? Like the atmosphere of it,

if there is one. Yeah. So if it passes through, if it passes like in front of a star, that's how we detect a lot of ex Yeah, so if it passes in front of a star, that's how we detect a lot of exoplanets. They pass in front of their star and the brightness from the star dips. But you can see dips not just in overall brightness, but in different wavelengths.

And based on the dips and those wavelengths, you can be like, ah, it's not just blocking light. At the edges, it's blocking certain wavelengths of light. And those are wavelengths that are blocked by carbon monoxide or carbon dioxide or methane or whatever. And then you can link those pieces of information together to find other things. So like if you know what's in the atmosphere and you know what temperature is on the surface, you can guess whether that's going to be in gaseous phase or liquid phase or solid phase,

kind of like I was describing with like the titanium oxide snow. It was like the dark side is cold enough that it will condense. And so you hypothesize what the weather is like based on what you know about weather on planets and moons and other things that we can observe. And that's a big part of it too, is like taking a look at objects we do know about and can see or can image pretty directly and then applying those characteristics to exoplanets because it's kind of like I don't want to reduce paleo art but my understanding of it is like we know what reptiles and birds look like nowadays and so you can take those characteristics and extrapolate them to dinosaurs. So you can look at Jupiter's moon Io, which is its volcanic moon. And it's like lava and volcanic terrain.

And they found that Trappist-1b, the exoplanet, was also kind of like reddish and lava-y. And so they were like, well, let's just make it look a little bit like Io. Let's render some surface characteristics that look similar. What's interesting is it seems to be like this is two guys' niche in science and art, which is quite fun. There's a visualization scientist named Robert Hurt and a producer named Tim Pyle who has a background in Hollywood special effects and they've been working together for at least 12 years now and and so like have been putting their their skills together I guess like with 1992 being the first exoplanet net as we're finding more systems they

are like the go-to guys to to help draw them and then they kind of bounce off each other of like using visualization software and then checking scientific knowledge. What is interesting, I read a few articles that interviewed them about various things like the TRAPPIST system or a Kepler planet, Kepler-186f. And they seem very concerned about making things seem less Earth-like.

So they like learn that a planet may have liquid oceans and land masses and things like that. And then they have a conversation of like, well, this is probably going to show up in a scientific article with like NASA found another Earth. And so they don't want to mislead people and they like want to make it enticing, but not too enticing. Like that just looks like earth. And so then they do it in a scientifically accurate way, but look at like the light spectrum or something and say, well, if there was vegetative life, it would be orange instead of green. So we're going to tint the land masses orange so that when people look at this, it's going to be like a weird proportion of land and water and kind of orangey. So people don't look at it and are like, why be like a weird proportion of land and water and kind of orangey

so people don't look at it and are like, why don't we just go there to Earth 2? If you want to ask the Science Couch your questions, follow us on Twitter

at SciShow Tangents where we'll tweet out topics for upcoming episodes every week. Thank you to at Sungamer101 and at JimJamJames and everybody else

who tweeted us your questions this episode. You can go to patreon.com slash SciShow Tangents to learn more. That's right, we have a Patreon.

Patreon.com slash scishowtangents. We would really love your support. We want to keep making this podcast. We also will make extra podcasts for our Patreon patrons. So if you like this show and you want to help us out, the biggest thing you can do is become a supporter of ours on Patreon. Of course, you can also

tweet about your favorite moments from the episode. You can leave us a review wherever you listen. And also, of course, if you like SciShow Tangents, just tell people about us. Thank you for joining us. I've been Hank Green. I've been Sari Reilly. And I've been Sam Schultz. SciShow Tangents is created by all of us and produced by Caitlin Hoffmeister and Sam Schultz, who also edits a lot of these episodes, along with Hiroko Matsushima. Our social media organizer is Paola Garcia Prieto. Our editorial assistant is Deboki Chakravarti. Our sound design is by Joseph Tuna-Medish, and we couldn't make any of this without

our patrons on Patreon. Thank you, and remember, the mind is not a vessel to be filled, but a fire to be lighted. But one more thing. In 2016, NASA proposed a contest called the Space Poop Challenge, asking for proposals for an in-suit design that could collect human waste for up to six days in case your spaceship explodes and you're just floating around out there. You don't have to hold in your poop. The first place winner was Dr. Thatcher Cardin, who designed what is basically a poop airlock that you can open and close when you're ready to release your stored up dookie.

It's like a little plug on the crotch of your suit and you pull it off and then the poop like sucks itself out, I think. How does the poop get in there? You poop it in there. So you just poop whenever you want, kind of like a diaper? You poop and it sucks it up into this airlock is what I'm pretty sure is happening. Then you open the airlock and then it sucks out into space from there. I just hold it in. Pooping in space seems like the ultimate nightmare.

There's a lot of enthusiasm around space stuff right now and that's just all there's they're trying to build a space hotel and i'm like man you guys are gonna have to deal with a lot of dookie yeah i guess you gotta have good vomit capturing devices as well oh yeah the moment people get up there it's not like these are astronauts no they're just rich people they're gonna be pukers