Let's Learn About... #24: Titan: Saturn's Most Incredible Moon

Charlotte: Hello!

Ellie: Hello!

Charlotte: Welcome back. Do you want to try and do the tagline this time?

Ellie: Are you sure you trust me?

Charlotte: Yeah.

Ellie: Okay! Welcome to Learn About podcast, the show that teaches you all the things you didn't know you needed to know - but we're going to teach you about anyway. How was that?

Charlotte: There you go, that'll do.

Ellie: [cheers] I learned from the best. That makes it two episodes in a row now that we've got that. We're not allowed to lose the streak. Nope. Not gonna happen.

Charlotte: We'll have to try and count the streak. I'm gonna lose it next time, I know I will.

Ellie: No, don't jinx it!

Charlotte: So, if you didn't listen to last week's, it was all about... why have I forgotten what you just talked about already? Oh, it was it is all about Marvel, and representation in Marvel. I love some good representation. So go listen to that if you're interested. But today, it's my turn. And I'm... it's kind of a bit of a throwback to very early on, possibly even the first episode. I can't remember now.

Ellie: That's, what, 24 episodes or something like that?

Charlotte: Yeah. So, I'm going back to my favourite thing: space.

Ellie: [gasps] Space!

Charlotte: One of... I think one of the first episodes of the whole podcast was about Saturn, my favourite planet. And I mentioned in that episode that I wanted to do a whole episode about, like, a series of episodes about Saturn's moons, because they're just so cool. I started researching earlier - and by earlier, I mean 10 minutes before we were meant to record. I started researching some, kind of... what I can talk about about the moons and I realised that I could just do an entire episode about one moon. So that's what I'm gonna do.

[begin pre-recorded intro]

Charlotte: Before we get into this episode, we want to remind you of a couple of ways you can help support the show.

Ellie: Make sure you follow us on social media to stay up to date - we are @learnaboutpod on Instagram and Twitter.

Charlotte: You can also visit our website, learnaboutpod.com where you'll find notes and resources all of our episodes, and you can sign up to get notified of new and upcoming episodes via email. That's learnaboutpod.com

Ellie: Enjoy the show!

[end pre-recorded intro]

Ellie: Okay, this better be a really cool moon if there's an entire episode based on it.

Charlotte: I'm gonna be talking about Titan. It is Saturn's largest moon. It is almost the largest moon in the entire solar system, so it has a lot of facts and it's very cool. I think I mentioned Titan in my Saturn episode because it's just one of the coolest things in the entire solar system, so I can just do a whole episode on it. So I'm going to!

Ellie: Yes, because this is our podcast and we can do it on whatever we want.

Charlotte: Yep! Yeah, if we want to do an episode about one moon one, so be it.

Ellie: I don't know why I've got Noel Fielding from The Mighty Boosh in my head going, "I am the moon. The only moon."

Charlotte: I've got his songs in my head now! [sings] "He's so bright and milky white, shining down upon the ground."

Ellie: [laughs] BBC, don't come for us.

Charlotte: [laughs] Um, yeah. So let's get into it. I'm going to talk about why Titan is the solar system's coolest moon, or potentially one of the coolest things in the whole solar system except Saturn - because Saturn has my whole heart.

So, right back to the beginning. It was discovered by telescope in 1655 by a Dutch scientist. It was the first planetary satellite to be discovered after the four, kind of, biggest moons of Jupiter. I can't imagine discovering a new moon! Can you imagine, like, looking in the sky, and especially in 1655? People must have thought you were some sort of sorcerer or something.

Ellie: I was gonna say, was he burned at the stake after discovering the moon? I think we've talked about this in a previous episode, like the fact that like if you were to choose whether to go forward or backwards in time, just for the sheer fact of working... of just finding out how the heck they have the technology to discover something like that, all the way back then.

Charlotte: Yeah. But one thing about Titan is that it also has a massive atmosphere, and they didn't discover its atmosphere, like they didn't detect its atmosphere until 1944.

Ellie: Bit of a jump!

Charlotte: Yeah! Kind of crazy. And so I'm going to try and say this word... it was detected spectroscopically, which I had to Google. A spectroscope is an optical device for producing and observing a spectrum of light or radiation from any source. And that's how you can discover the atmosphere of planets or moons, is through a spectroscope. So, fun little tidbit. And that was in, like I said, 1944, by a Dutch-American astronomer.

Ellie: The Dutch have really got a thing for this moon.

Charlotte: Yeah! So I'll come back to its atmosphere later on. So it's the largest moon of Saturn, as I said. It's larger than the planet Mercury.

Ellie: That's a pretty big moon.

Charlotte: Yes. And it has more mass than Pluto. And in a lot of different ways, it resembles a planet more than it does a typical moon. So the only reason it's a moon rather than a planet is because it orbits Saturn. If it didn't orbit a planet, then it could potentially be its own planet, which is just mad. But yeah, the only reason it's a moon is because it is in another planet's orbit - so it's just a technicality.

Ellie: That's not fair! Give it the attention it deserves. Like, we orbit the sun and we're considered a planet! Why does the fact that it orbits Saturn doesn't make it a planet? ...I wasn't made to be a scientist. I'm sure, there's a reason other than the fact that just, you know, goes around Saturn, but still.

Charlotte: So, how massive it is... the actual solid body of it, not its atmosphere, is 5,000... just over 5,000 kilometres, which is 3,200 miles in diameter. So pretty big! And it's only about 75 miles less than Jupiter's moon Ganymede, which is the largest moon in the entire solar system. So that's why it makes it, like, just shy of being the biggest moon in the whole solar system. But it has hundreds of kilometres of atmosphere - like, its atmosphere is massive. And if that was included in the size of it, then it would massively exceed Ganymede. So it would be - like, if the atmosphere was included, then it would be the biggest object in our entire solar system. It's just mad.

It's the only moon in the solar system known to have clouds and a dense atmosphere. So it actually has its own clouds, and it's the only body other than Earth that is known to currently have liquid on its surface, which is what makes it so cool. Like, it actually has a liquid! It has lakes on its surface and it's the only object known to also, other than Earth, known to have liquid on it, which is really... well, apart from Mars. I know recently they did studies that they found liquid on Mars, but...

Ellie: There's a difference between finding liquid and there being lakes.

Charlotte: Yeah, like actual lakes. Yeah, yeah. So the... back to its name. Like, it has the coolest name. It's named for the Titans of Greek mythology.

Ellie: Yay!

Charlotte: And its appearance, if you're interested, if you ever get hold of a telescope and you want to try and find it - it appears through a telescope as just kind of like a brown blob, kind of like a brownish, red globe. And its surface is permanently veiled by a thick haze. So you'll just see kind of like a brown, reddish circle with like a weird haze around it. So yeah, if you ever get hold of a super strong telescope, and you want to try and find Titan, that's how.

So one of the reasons that I love this moon so much is because of its similarities to Earth. I think I mentioned this in the Saturn episode that I said that Saturn has a moon that could potentially support life - and that is Titan. So there's, like, a whole load of reasons why it has similarities to Earth. So its atmosphere is similar to Earth in the fact that it has predominance of nitrogen gas, and a similar surface pressure. But the atmosphere is much colder with a temperature of 94 Kelvin, which is -290 Fahrenheit, or -179 Celsius.

Ellie: We complain about the British winter.

Charlotte: Yeah! And it also contains no free oxygen so there'd be no oxygen to breathe, so that would be an issue. But yeah, with the actual gas in the atmosphere and the surface pressure, it's almost, like, it's really similar to Earth.

Ellie: Just a cold... it's a cooler Earth, if you will.

Charlotte: Yeah. I was thinking, when I wrote the notes, I said "the coolest planet". And I was just like, I'm thinking of this figuratively and literally. Yeah, so scientists think that conditions on Titan are similar to Earth's early years. So it's kind of interesting to think what it could become as things kind of evolve - if Earth has turned into this, like, what Titan could turn into if its qualities are really similar to the early years of Earth. Really cool. And the only main difference is because Earth is closer to the sun, it's warmer. So if Titan was closer to the sun, it could potentially be as warm as Earth and then it could have like the same qualities.

Ellie: So there is the potential, basically, for... if it goes the same way Earth does, it could eventually have its own life

Charlotte: It could, yeah.

Ellie: Life on Titan!

Charlotte: So like, people talk about life on other planets, but I think people forget that you can also have life on moons. Like, I feel like it's a proper dystopian thing. Like, sci-fi stories of people, like, humanity moving to a moon could actually happen.

Ellie: It's always our moon though, like the barren... I love our moon, but the barren rocky wasteland that is ours versus Titan, which could actually have scientifically-proven support of an ecosystem.

Charlotte: Yeah. According to NASA, they've said that in many respects Titan is one of the most Earth-like worlds we'll find to date.

Ellie: So even NASA think that it's promising, and NASA is pretty cool.

Charlotte: So yeah, so Titan's atmosphere is complex, mainly composed of 95% nitrogen and 5% methane. I think it's the methane that make up the lakes - like, there are methane lakes and methane rain. Kind of terrifying. It also has a presence of organic molecules that contain carbon and hydrogen, which are often, which, obviously, oxygen and other. There are other elements similar to what's found in Earth's atmosphere and that are essential for our life. And they are found in Titan's atmosphere. So you never know if things change, like if the if the kind of surface gets warmer, and it already has carbon and hydrogen. So who knows? I mean, we're talking about millions of years here. We won't be alive for it.

Ellie: Damn it!

Charlotte: I know! I want to live on Titan.

Ellie: Or I'd love to meet someone from Titan.

Charlotte: Yeah. But we're literally talking about changes over millions of years. Another reason why it's similar to Earth is the atmosphere kind of escapes to into space in a similar way that Earth's atmosphere does. So the Cassini spacecraft, which -- it was a spacecraft that launched in 1997 I think, and it was sent to explore Saturn and it was also sent to drop a probe on Titan to go and explore Titan. The spacecraft detected polar winds that draw methane and nitrogen out along Saturn's magnetic field and out into the atmosphere. And a similar process is believed to happen on Earth with our own magnetic field. So kind of like taking all of the... kind of, sending it off and out into the atmosphere is the same way that Earth does. And as I was saying about it being potentially habitable: if the sun increases its temperature... okay, you know I said millions of years? It could be potentially 6 billion years from now.

Ellie: No! Hurry up, time travel.

Charlotte: So yeah, definitely not in our lifetime. It would basically--the sun would have to increase its temperature so much that it would become a giant red star, so it would have to increase it a lot. That's how Titan's temperature could increase enough for stable oceans to exist on the surface. And if that happens, then conditions on Titan could be similar to Earth's, allowing conditions that are favourable for life! So even though it's not going to happen anytime soon, 6 billion years from now, it could be the new Earth.

Ellie: Earth 2.0. To be honest, at that point, Earth 1.0 might turn into a crispy cinder. So yeah, we might need it. Yeah.

Charlotte: Well, actually, have you seen all the stories about Earth kind of healing while everone is staying indoors?

Ellie: Yeah!

Charlotte: With all the stuff that's going on where everyone's, like, not travelling, and there's no planes in the sky or whatever. There are loads of stories about how Earth is actually starting to recover a bit from our mess.

Ellie: Like considering all that, like, climate change activism was really ramping up at the beginning of the year, it is amazing to see. I think one of the things was--was it two weeks after they enforced lockdown in Italy? The canals in Venice cleared up so much that life came back to them. Like two weeks, after 40 years or something of them actually having tourism on the canals, they became so clear that you could finally see to the bottom of the Venetian canals. And I think the other one was that they could finally -- the atmosphere cleared so much in India that you could finally see the Himalayas.

Charlotte: Yeah. So it's, like, actually clearing up the atmosphere. But yeah, as soon as the lockdown is done, and we start destroying Earth again, Titan will be ready in 6 billion years, so there's

Ellie: Yay, Titan!

Charlotte: Who knows, and like the, what, 70 years or something we have left alive, hopefully they'll invent time travel. That'd be great. So yeah, experiments on Earth suggest that Titan could be more habitable than previously thought as well. They're kind of finding more and more evidence, as days go on that it could be even more habitable than we originally thought.

There are complex organic chemicals that were once thought to hover really high in the atmosphere, but they discovered that they are actually, kind of like, closer to the surface. So all of the chemicals that--like, the organic chemicals that are kind of needed, that could potentially support any sort of life, are actually a lot closer to the surface than they thought. I mean, still, 6 billion is quite a long time, but it could be decreased.

Like they're still doing a lot more research into--like, they're still kind of sending probes and things out and they're getting more and more research each day to kind of support its life. So, really cool. So this is this is why Titan is just, I think it's why Saturn is my favourite planet because it has... Saturn itself is really cool. If you don't know much about it then as I said, there's a whole episode about it, but it also just has so many amazing moons, like it has over 60 of them. And all of them are just really interesting in their own way. Like, there's -- when you've got a planet that has moons that could support life, like... so cool! This is why I want to get a Saturn tattoo.

Ellie: And if we reach 500... [laughs] No, I'm not going to do that to you.

Charlotte: No, I so would, actually!

Ellie: If we reach like 500 downloads or something you'd get a Saturn tattoo?

Charlotte: Yeah! I mean, I have to wait for the lockdown to be over first, but still.

Ellie: Alright! Challenge for you all.

Charlotte: We're only a few away from 400. So... I mean, maybe, if this is going out in like a few weeks after we record it, we might already be at 500 by then. What should we make the goal?

Ellie: Let's do 1000. Let's do a cool thousand.

Charlotte: Okay, yeah. As soon as you get there, I'll go and get my Saturn tattoo.

Ellie: I'm down. I'm so down for you to get your Saturn tattoo.

Charlotte: If anyone doesn't know, I'm planning on getting a little Saturn, and then I want to get, like, 68 little dots all around it to present every single one of its moons.

Ellie: You gotta look like you got a lot of freckles.

Charlotte: I'll just do it in a pattern or something. I'll just, you know, like a little circle of dots.

Ellie: You could like write the word Saturn out in the dots. Or you could put the dots as the rings. Oh, what's it called? Pointillism. You could do a pointillism tattoo and the little dots that make up the rings could be the 60 moons.

Charlotte: Yeah. As soon as that happens, it'll go up on our social media.

Ellie: Oh, could you imagine if someone drew your tattoo for you? Would you put it on your body if you found one that someone drew for you that you love?

Charlotte: I mean, I already want something that... my best friend is an illustrator. I already want something that she has drawn before. She did a little astronaut man that I use on my blog and stuff.

Ellie: Aw, your little astronaut dude!

Charlotte: Yeah! And I'd love to get the little astronaut as a tattoo as well. I've already told her and she's like, yeah, cool. Fine. I said it would be good promo. But yeah, as usual, I kind of got going off on a tangent.

Ellie: You knew it. This is a little sort of insider as to some discussions we have before and after. We were discussing the idea of doing 10 minute minisodes. You know, if we keep going off on tangents...

Charlotte: Yeah, I was thinking when I wrote the notes for this, "oh, I probably I won't have much for this. This can probably be just a mini one." And then ended up talking about tattoos instead.

Ellie: Easily done.

Charlotte: But yep, there you go - a thousand downloads, I go get my Saturn tattoo.

Ellie: I'm down if you are. All right, yeah. Okay, it's up to you guys now - get us to 1000 downloads, because I want to see this tattoo.

Charlotte: Yeah, do it. But yeah, so that's everything that I... there's a lot more about Titan. There's so much I could talk about but so much of it goes proper scientific, like it goes into the chemistry and I was kind of reading some of it like, I kind of understand this but I'm not going to be able to actually talk about it from my own mouth on the podcast - I'm just going to mess it all up.

So if you're interested in learning more then I'll put all the links as usual in the show notes for this episode, but it is just so cool. And there's some really good articles about it. There's like Encyclopaedia Britannica articles about it. There's also -- they link to articles about all of the moons, and I feel like I could easily just do an episode about every single moon but it might get a bit repetitive. I'll have to start another podcast! I'll have to do the Saturn podcast. [laughs]

But yeah, if you want to see more episodes like this, then let me know. I'm always happy to do astronomy based space ones - anything about planets or stars or anything I could talk about for days, so if you're interested then let me know and go listen to that Saturn one as well if you're interested in that. And yeah, you can find us on our social media - we're @learnaboutpod and you can also head to our website which is learnaboutpod.com.

Ellie: If you fancy sending any of those links to Professor Brian Cox so he can come on the podcast and explain Saturn in more detail...

Charlotte: Yes! I'm actually - I've only just remembered I'm actually wearing my Brian Cox t shirt.

Ellie: No way! I wanna see! Why aren't we recording this as video?! [pauses to look at shirt] Oh, wow. That's really cool. Because he did like an entire, like a whole documentary. It's like an hour long documentary on space-time travel.

Charlotte: Yeah! He did a tour and I went to see him in when he was in Cardiff. It was like a whole talk all about space-time. And it kind of blew my mind. It was all about like how everyone's paths are different throughout space-time and like how time can be different depending on what path you take. And I don't even know - it blew my mind. But he's incredible.

Ellie: He's just got this way of talking - because I saw one that he did on TV, which was part of the Doctor Who Anniversary Special. I think it's like the 50th anniversary special. So yeah, and he - I don't know whether it was from the tour that he did or whether it's a special episode, but he did one about space-time and the possibility of time travel and how basically Doctor Who is actually rooted in some scientific... because he was talking about the whole science behind "bigger on the inside", and even just that hour special I was sitting there going, "tell me more!"

So yeah, feel free to send this episode or any of our links to Professor Brian Cox because I think my heart would explode if we got him on to one of our episodes to explain science to us and the planets, and hey, if he wanted to do an episode...

Charlotte: Oh my god, imagine.

Ellie: Dream, big, people. Dream big. One day it might happen.

Charlotte: Yeah, why not? But yeah, we will see you soon with a new, completely random episode.

Ellie: That we will research more than 10 minutes before the episode goes out.

Charlotte: Yeah, I will try my best.

Ellie: See you next week, everyone. Bye!