Astronomical Adventures: Exploring Titan's Ocean, Cassini's Legacy & the Future of Artemis

Professor Fred Watson: Good to see you. Heidi. I can't remember which astronaut that light this candle quotes come from. Do you remember which one it was? It was one of the early days of spaceflight, I think. Definitely early days. And you're testing my history and I'm failing. Professor Fred Watson: It's all right. Fred and I, we discovered, a new feature. So our, recording software is updated and now it does a very exciting countdown

for us. So that was, that was kind of fun, a way to launch into the episode, so to speak. Professor Fred Watson: Yep, we, we lit the candle. That's the main thing we did. We did. And so let's, let's, let's set this off. So our destination today for this first episode is we're going on a mission to some of the, outer planets

do we call. Well, Titan's not a planet, but, it's a moon around Saturn. Saturn is a outer planet. Professor Fred Watson: Yeah, that's right. One of the four gas giants in the solar system. The second one out, for many, many centuries, it was thought to be the edge of the sun's family of planets, even before the sun was known to be at the center. Because it's the furthest of the naked eye planets, the ones that you can see with the unaided eye. M. Uranus just makes it actually

into the, unaided eye category. But you really need to know what you're looking at and you need good eyesight and the dark sight. I've never seen Uranus with my unaided eye. Anyway, Saturn out there, one and a half billion kilometers from the sun, doing its thing. And of course from 2004 to 2017, Saturn was the star of the Cassini show, the Cassini mission, I think one of the most productive space missions ever. NASA, with an association with esa, the European Space

Agency, this fabulous mission. the spacecraft was in orbit around Saturn for 13 years doing marvelous things before it eventually dived into the Saturnian atmosphere. And I think some of the most exciting stuff, it's actually hard to pick what was the most exciting stuff to come out of the Cassini mission? the rings, the moons, the planet itself. But, for My money, Titan really stole the show, actually,

I should say with Enceladus as a close second. Enceladus was where we discovered geysers of ice coming out of the, out of the, subsurface ocean. But Titan, such a weird, weird world. And we knew it was weird before Cassini got there because there was evidence, from radar measurements from Earth that there was very smooth surfaces on Titan. And it was suspected that Titan would have lakes and seas, not of liquid water. Because the temperature out there is about minus 190.

That's the surface temperature. 190 Celsius. So should specify the unit, shouldn't I? And indeed it is known to have lakes and seas, of liquid natural gas, ethane and methane, which are predominantly in the Northern hemisphere. One of the other things that was an early discovery, about Titan and this kind of links to the story that we've got at the moment, was that the surface, of the planet is decoupled from the

interior. by that I mean that the rocky core of Titan rotates, in a certain way, but the surface actually swishes around a bit. you're kidding me. That's the conclusive proof that you've got a global ocean underneath the surface. It's a liquid interface between the surface and the rock. But if you're on Titan, your longitude changes without you moving because the surface of the ice moon is moving. So it's basically just a giant, what do they call those,

the little magic balls that you shake up. And it's got the little globe inside that rotates until the future. It's just a giant. Professor Fred Watson: Yeah, I've seen one of those, but I can't remember what it's called. The little, I think just the magic ball. Yeah. Oh, wow. I didn't know that. That's such a, that's such an incredible fact. So it's not frozen then?

Professor Fred Watson: The ocean's not. No, that's right. The surface is. And we don't know how thick the ice layer of Titan's surface is. It's probably many tens of kilometers. but underneath that, I mean, Titan is a big world. It's bigger than the planet Mercury. It's the second biggest satellite in the solar system. and so, a, significant rocky core and this ocean, which, you know, I don't think we've got any real estimates of what its depth is, but it's again measured in,

tens or perhaps even. Sorry, yeah, tens or tens of Kilometers is probably the best, best guess for something like that. Maybe even hundreds. anyway the, this, the reason why this links to the present story is that there's been a new analysis of of the spinning of Titan and its atmosphere. Titan has a thick atmosphere. It's 50% higher atmospheric pressure than we have here on Earth. So we probably feel like we were, I read yesterday that we'd feel as though we were in a

depth of 5 meters. 5 meters of water, what's that? 6 meters is 20ft. So you've so an average used in summer. Professor Fred Watson: Yeah, probably. Yes, that's probably right. so it's got this high pressure atmosphere, mostly nitrogen and methane, and they have clouds and rain and of liquid natural gas. It's a bizarre, a bizarre sort of parallel with the Earth where water is the Earth's climatic cycle. We think it's methane and ethane on

Titan. but the atmosphere has now been shown to circulate around Titan not in sync with the surface like our atmosphere is because we stand on the surface and we don't feel any wind because the atmosphere is moving with the rotation of the Earth Titans actually the atmosphere rotates faster than Titan does. So it's decoupled from the ah, you know from the surface which is a very strange phenomenon in itself. I might give a quote actually this, this story is actually the one I've read

is on Space.com. it's an article written by Victoria Corliss. Very nicely done. so it's basically data from the Cassini mission reanalyzing it. and Lucy Wright who's the lead author, not the leth order, the lead author of the new research and is at the School of Earth Scientists at the University of Bristol in the U.K. Lucy said the behavior of Titan's atmosphere tilt is very strange. We think some event in the past may have knocked the atmosphere off its spin axis causing it to

wobble. So not only does it not rotate in sync with the surface but it also wobbles. and m, basically that's the best guess that it was some sort of impact or some you know, event in the in the atmospheric history of Titan that's caused not just this out of sync rotation but also a tilt, a wobble of the of the atmosphere. that's incredible. If I was Andrew and I had the soundboard I would insert the little jingle from the X Files right there. Do do do do.

Professor Fred Watson: Yeah well, that's right. Well, yes, very strange. He sometimes does that. We manage to keep him under control, though. That's all right. But yes, it is. It's weird. and, you know, it's a extensive study. Ah, one of the. Perhaps one of the consequences of this though, is, if the atmosphere's, not moving in sync with the surface, then it means you've got high winds on the surface. You're going to experience high winds. and that has not really been,

deduced before. Although there is evidence of wind ripples on, these lakes and seas, the radar reflections sometimes get very bright, which means you've got radar bouncing off a rough surface. If you get a very, faint radar reflection, you're looking at a smooth surface because most of the, radar has been reflected off in a different direction. it's like a mirror surface that will give a very dark radar reflection. So a bright radar reflection

corresponds to a rough surface. And that has been seen on some of the lakes and seas of Titan. So maybe that itself was a hint that, the winds are blowing more quickly than we thought. But what's really at stake here, and this brings us back to NASA, the Dragonfly mission, which is a quadcopter, that is planned for exploration of Saturn's moon Titan sometime in the next decade, sometime in the 2000 and 30s. That is going to be a bit like ingenuity was

with, perseverance. It's going to be a fantastic tool for exploring Titan, for exploring its surface, for investigating maybe what these seas look like. I don't know whether Dragonfly will dip its toes in the water, but it's, going to tell us a lot more than we

know already. But here's the problem. If we've got much faster winds than we thought we had, and you're launching a quadcopter into the atmosphere, then that could give us all kinds of problems for the navigation of the Dragonfly, drone, which might lead to difficulties in actually making the mission, succeed in all its goals. you could argue the same thing with Mars. We know that we get high winds on Mars and that's what causes the dust

storms. Ingenuity managed to cope with that. But remember, the atmosphere on Mars is only, it's less than 1% of the atmospheric pressure on Earth. Whereas here we're talking about an atmosphere that's 50% thicker than the Earth's atmosphere. So there's probably more at stake, I. Think yeah, it was almost, you almost need to look at more. You know, I'm not, I'm not, an engineer rocket scientist by a long shot. Far from it, but it almost seems like you would need to look at more amphibious

designs than aerospace designs. And it would need to be able to navigate in that thick, thick atmosphere. Almost like a, like a sub, like a submarine in the air. Professor Fred Watson: Yeah, that's right. I'm thinking of a zeppelin. Professor Fred Watson: Yes. a submersible zeppelin. That's what you need. I mean, something like a zeppelin will get blown around even more because they've got such a big surface area.

But your thinking's right, Heidi, because back in the early 2000s, when we were first discovering the, this extraordinary surface landscape on Titan, with a surface that's made of ice as hard as rock, but in that rock there are depressions that have these seas and lakes. when we're first discovering that, people were suggesting we've got to send a submersible to Titan, we've got to send a submarine up there to explore what's underneath the surface of these lakes. Some of them

are quite deep. I think, if I remember rightly, the deepest one is about 180 meters. That's a really significant depth. and people have conjectured that there may be life forms in them, which use liquid natural gas, ethane and methane as its working fluid. Unlike every life form on Earth, which uses water as its working fluid. If you've got a world where water's not common because it's frozen solid. but, you've got other

stuff that's a liquid. Maybe, maybe, just maybe you've got weird alien species that use liquid natural gas, to make themselves work. Yeah. Ah, there's just, there's so much, there's so much to discover out there. And I think we're, you know, I, I listened to the show for a long time and I've been helping out, for a little while now. But it's interesting. It seems like there is definitely an uptick in the

discovering a potential of life out there. We're really, we're really learning so much so, so quickly right now. Professor Fred Watson: Yep, absolutely. I agree with you. I think that's right. And then, you know, our, our, our next story, you know, we're talking about the, the teams that are making these discoveries. It's, you know, we're not just out there. It's not just one guy in a room observing these things. It is teams. And I actually, I, I Wish I could have my, my

book sitting next to me. It's downstairs. I would hold it up for those of you watching. I just recently purchased a few books about NASA teams and how they run their teams, their programs and their robust personality profiles and the things that they do to create these teams. But our next article is about the NASA Artemis science team and inaugurating their flight. Control room. Professor Fred Watson: That's right, yeah. And this is not very far from where you're sitting

now is it? It's at John Johnson Space center in Houston. it's. That's where the Artemis flights are going to be controlled from. when they are ah, when they carry a human crew. Artemis being, you know the, the big initiative by NASA, and other agencies actually to to take astronauts back to the moon, in the 20, 20 twenties. We hope, we hope the first landing will be 2027. It's already been pushed back a few times.

Artemis 2 is the next mission, probably next year sometime which will be basically a rerun of Artemis 1 which was a flight around the moon, but this time it will carry a crew of four astronauts. So what's happened? Well, at the Johnson Space center in Houston the room which will contain the Mission control for the Artemis 2 miss and subsequent ones has been inaugurated. It is technically called the

Science Evaluation Room, the ser. and it's been very cleverly designed to be much more maybe m. To allow much more integration between the members of the team. you and I, Heidi. Certainly. I have got in my mind what the old mission control, basically rooms or studios look like. I've seen some of them actually at the Kennedy Space center.

and you've got these rows of desks with screens and the rows of desks are basically like a classroom with rows of people all doing their thing and talking as best they can. This is different. This is set up in a sort of U shape with the real nucleus of the people who are key players in the center and everybody else in this sort of U shaped ah, array of tables around the edge. And in order to test it they've actually undertaken a dummy run. They've basically simulated the Artemis

2 mission. I don't know whether they did the full 10 days of simulation or just the key parts. but they've actually simulated that mission to give them an idea of how the scientific results will come back to it, in what they call a real world scenario. and so, you know, the evidence seems to be that it's going well. but I thought that was a very nice story to relate. people ask us what is happening with Artemis. It's a process that is quite

slow. it's because NASA is progressing very carefully with this mission, as you would expect. but there are news items coming out all the time and this is one of them. And I think this is a big step forward, in the Artemis, I won't say Race to the Moon, because it isn't that, but the Artemis lunar missions. Yeah, the. We're going back. Yeah. You know, and it's so funny, I'm looking at the picture of the room and it's ah, I have the. I've been to mission Control. It's so

impressive. I didn't know they were going to be decommissioning that old room and moving to this new room. you know, it's just like the films you watch growing up, Apollo 13 and any of them, there's this big impressive control center. And this one almost looks like, with everyone sitting around the table with all their computers. And the other crazy thing, there's so much more technology in this room, but there's so

much less in the room. I think that's the most impressive thing to me because you think of these older control, centers and there's big, robust machines. So you're thinking, wow, those big powerful machines must be doing so much. And these scientists are sitting around with a laptop. So they almost look like college students in a study, in a study, study setting. there's some big flat screen TVs, but it's, it's a lot more bare bones than the,

classic mission control center. So I think that's the most impressive thing to me is there's so much more technology in here and power in those machines, but it's just a bunch of scientists with laptops compared to the huge room of the big machines. Professor Fred Watson: I think you've hit the nail on the head there, Heidi. Absolutely. So we're seeing, you know, 21st century technology, versus 1960s technology. and that allows you to be much more focused on the ergonomics

of this interaction. You know, the way the people interact with one another and how they communicate. it's probably going to be in some ways a little bit more informal because you do have folks sitting around looking at their laptops. Hopefully that'll have good outcomes for the mission. Yeah. And that's something I don't want to get too off track here. But that

is something that. The psychological, component to how NASA forms teams and how any, you know, if you're working in any corporation or military teams is a very, very interesting concept that I have. I have been reading a lot of research on. I actually. I don't know if I mentioned this on the show. I was a final candidate for the NASA HERA Analog, which is. The HERA stands for Human Exploration Research Analog. so I signed up to be, a analog astronaut, which is.

You are not a real astronaut. You are a fake astronaut. You guys can think of it, you're just larping as an astronaut for a predetermined amount of time. but this was a NASA, Johnson Space center analog. So it's inside of Johnson Space center and is run by NASA. But what they're. They're doing a lot of different tests in there, but one of them is, is they're looking at crew dynamics. And some really interesting research has come out of that.

so I'll just. I'll just paint a really quick picture of this so we can move on to our. Our last story. But this is so fascinating to me. So they look at the crew of four. Four. There's four people in this analog. And they give them simulated scenarios that will allow for them to build relationships a certain way. So they might give two crew members a problem that's hard enough to solve. That when they solve it, they feel really accomplished and they feel more bonded.

But it's just easy enough that they're guaranteed success. So they'll artificially create a stronger bond between those two crew members by doing something like that. And then the other two crew members, they might do this the same thing. And then they might do other scenarios where it's like, these crew members, these three are closer. This third person, there's. This fourth person is kind of cut out. And, I can. I will give you guys the link so that you guys can

all read this research yourself. Because I just. I. I'm obsessed with this, this. This study. But basically what they found is they have the integrated model where all four crew members are working together. And they're all in sync. And their mission success was around 100% successful. Then they have the subgroup models where, okay, these two are closer, these two are closer. Everyone still works together, but these two subgroups have formed a

closer bond. Surprisingly, their mission success would drop to around 80% successful. And then the isolated model where these three crew members are working really closely together. And the third crew member was kind of isolated. Their mission success dropped to around 50% successful. And they said that this works across any scale. So they've done a lot of research with

sports teams. So if your offense and defense identifies more as offense and defense rather than the whole team, the team is less successful. And, you know, and then I think you guys have figured out by now I'm kind of a cheeseball here on Space Nuts. I'm the, I'm the space. I'm a nerd. But it's like, I think about it on a global scale. What if humanity was thinking that we're all on the same team instead of I'm

this company or I'm that company, or I'm this this, or I'm that nation. If we were all, if we were all playing for the same team here and to see what our mission success would be. But I don't know, that was, that's just kind of what I get out of that. And so there's, there's a level of informal that I think sometimes really helpful because it helps us form those bonds. Professor Fred Watson: it's key to, I mean, it would be wonderful if the

whole world was on the same team. God knows we need that, the way things are at the moment. but, the, idea of having the right individuals and the right team structure for, say, a Mars mission, where you've got people cooped up in a small, place millions of kilometers from Earth for six months before you actually get to Mars, and then you've got to do all the stuff there that, that's going to be key to the success of the mission.

it's, you know, notwithstanding all the technical issues, all the habitat issues and all the rest of it, just having people who get on and can get on and work productively must be the number one priority. So that's my guess where that study, that sort of study is heading. And, hopefully it will all be 100% successful. Yeah. And that's what they do a lot in, Chapia and Hera and a lot of these, extended duration analogs. And I might still do it. I told them that at the.

I was the one who dropped out. They, they were ready to actually give me a mission, but I dropped out because it just wasn't good timing for me. but you know who's really good? You love my segues. I don't know. This is my thing is, you know, what species is wonderful at working on A team. Professor Fred Watson: Let me guess. Yeah, isn't that is a lovely segue. And you know, this is a story that. Yes, we're going to talk about

Wales. Wh. Not. The country next to England doesn't have the H. And we could talk about that some other time probably. I'm sure they're wonderful team players as well. Professor Fred Watson: Yeah, I think they are, yes. Yeah, they're good singers too. so this is a study about whale behavior. And the reason why I thought this would be a good one to talk about on Spacenauts is that it's got, sort of overtones of how we might deal with communication

with extraterrestrial aliens. And you and I have mentioned already the movie Arrival, which was a fabulous account of exactly that problem. Yeah, I love that movie so much. Professor Fred Watson: Yeah, so this is the same sort of thing, but you're not talking about people who land in weird looking spaceships, you're talking about whales. And there is a paper now that has been. It's actually reported in in Nature magazine, which is the. One of the two leading journals

in the world for scientific results. But I think, there's a publication in one of the, one of the journals related to, you know, to living organisms. But the bottom line is humpback whales, we, we've known for quite a long time that they use what are called bubble rings as a trap for the prey that they want to eat, probably krill. I'm not sure whether humpbacks eat bigger organisms, but krill is certainly, part of their diet.

And what they do is they blow these bubble rings, which act as a sort of net and then they swim inside it and gobble up all the stuff that's been netted. But it turns out that these bubble rings actually, come in different shapes and sizes. Some are exquisitely circular. there's actually an image, which is on this nature. It's a perfect circle and it almost looks like a whirlpool too. Like, I'm like, how is this real? Professor Fred Watson: That's right. Which is an

amazing. You know, it's like a foam in a perfect circle a few feet in diameter. But they also, sometimes make multiples of these. So you get a ring of perfect circles or a spiral shape.

And the focus of this research is that it turns out when you look at the statistics of these bubble ring appearances, that there are more of them that occur when humans are watching than occur in the natural world when there's nobody around. And so this is they might be. Trying to talk to us. Professor Fred Watson: That's exactly it. This is the thrust of this article.

Are we seeing ah, a behavior in Wales that suggests that they are doing something that is all about whale to human communication rather than, you know, rather than just a random sort of thing. it's actually the publication is Marine Mammal Science. That's the, where this, where this paper appeared. But I think it's been commented, I think this commentary comes from Nature magazine. and there's yeah some, some lovely examples of

these. Ring, ring production. There's one quote here that comes from the researchers who've done this work. Out of the 12 episodes of Ring production reported here, 10 episodes were collected near a boat or human swimmers, while six had more than one whale present. Despite these ample opportunities for intra and interspecies aggression, there was no evidence of antagonism towards

conspecifics. I think that's ah, a marine mammal word for like minded or aggression towards boats or swimmers in any of the ring episodes. quite the contrary in fact. Far from showing signs of avoiding humans, eight of the nine of nine ring blowers approached the boat or swimmers with exceptions to when they were blowing bubbles while feeding. So there's more statistics in the article which I won't go into but it does look as though there is a predominance of

these ring bubbles of a particular kind. And these I think are the most symmetrical and kind of elegant ones in a way, being blown when there are humans present. make of that what you will. And you know I'm guessing that a lot of the other others that have been observed and I do know that quite a lot of these ring bubbles that have been seen have been observed by drones and you know, other sort of remote sensing equipment so that there weren't humans present in those instances.

Well you know language in and of itself is such a fascinating topic and both verbal and written language is so interesting and that was something to keep it space related. That was something that was widely discussed with Voyager and they initially wanted to have a map of Earth with an arrow pointing to Earth. And there was a lot of discussion, well what is an arrow? An arrow is a man made thing. We can't say if ah, intelligent life

form would understand what an arrow meant. So that's why they ended up doing more of kind of like a little bit more of a mathematical model because math is universal. So that's that was the logic behind that is math is A universal language. and same thing with music. And they did also include whale songs and a number of other beautiful things. You can actually find a lot of those tapes, on Spotify. They have people singing from around the world.

Professor Fred Watson: That's, the gold disc that was on, each of the two voyages. The Pioneer spacecraft also had. They just had plaques, but they had sort of mathematical representation of where the Earth was, which, if I remember rightly, was in terms of the direction to specific quasars, which are very, distant. It might even have been pulsars, I can't remember. But, the idea was to.

To denote what the source of this spacecraft was, using things that would be recognized by an extraterrestrial intelligence because they would make astronomical observations as well. And so they were trying to link, you know, the directors, direct people to where this had come from by the astronomical information around us. I, was speaking, with a friend of mine the other day who's a mathematician, and she said the reason why she loves music so much is because music is math in motion.

Professor Fred Watson: It is, absolutely. I'm exactly the same, Heidi. If I hadn't been an astronomer, I would have been a musician. Oh, that's beautiful. Yeah. I mean, it really is. And whale song is something I think everybody connects to. And it is really incredible to see the crossover between humans and animals and intelligence and math and maybe, who knows, maybe the whales are going to help us figure out something. Maybe they have it all figured out and they've been just trying

to tell us. Just need to listen better. Professor Fred Watson: Just look at these bubble circles, for goodness sake, and then you'll work it all out. So if any of you guys can figure out the math, formula that the whales are sending us, please let us know. Professor Fred Watson: Yeah. Fred, this has been lovely. This is. This is a really. This was a fun episode. A lot of, uplifting and very interesting, conversations today.

Professor Fred Watson: Thank you, Heidi. I think. I think so, too. It's been fun talking to you, as always, and we'll speak again very soon. All right, see you later, space Nuts. Welcome back to another episode of Space Nuts. I'm your host for this summer, filling in for Andrew Dunkley. My name is Heidi Campo, and joining us is Professor Fred Watson, astronomer at large. Professor Fred Watson: Good, to be here, Heidi, as always. And you're also our host for this winter here in Australia.

So, yeah, lovely to talk. And, I think we've got some pretty great questions from our, listeners for this episode. We do. We have some. We have some really fun not episodes. We have some fun questions. our first question today is Martins from Latvia. And here is his question.

the same, age. I mean, yeah, there's something to do probably when you're reaching speed of light that time slowing down or something. But why it's slowing down? Why isn't it, like, yeah, just curious. And, yeah, and I have, some dad joke for your, arsenal. Andrew. So, how do you put a space baby to sleep? Your rocket. So anyways, guys, cheers, then. Yeah, have a good one.

places in winter, through snow and woodlands. And it trundled along at something like nine miles an hour. Maybe it was a fast walking pace because it was a very old line, but it was a lot of fun. Anyway, enough about Latvia. let's get to the speed of light, which is basically what Martin's question is about. this is. It's one of the fundamental aspects of relativity. Einstein's two theories of relativity. One was about motion, the other was about

gravity. It's the one about motion that covers this. That's called the special theory of relativity, dated 1905. And it turns out that the thinking that Einstein had had, leading up to this was that we know that the speed of light is a bizarre quantity because in a vacuum, it's always the same. We know also that it's the maximum speed that anything can attain. In fact, you can't actually achieve the speed of light with an object because you would have

to put infinite energy in to get it to the speed of Light. And we don't have infinite energy. So light and its other electromagnetic waves. They are the only things that can travel at the speed of light. But if you had something that you are accelerating. Well, let me just go back. The speed of light is, almost like a magic number. It's not magic because it's a very round number. It's about 300,000 kilometers per second. it is, however, the fact that it

doesn't change in a vacuum. And it doesn't matter how

fast the source is moving. You'd expect if you have a source that's moving. That sends out a beam of light. The source's speed would add to the speed of light. And the speed of light would increase. But it doesn't doesn't work like that. And once you establish that, then it turns out. And there's some quite sort of simple ways of seeing how this might work. Which we don't really have time to talk about. But some of the books about special relativity. That talk about people looking at somebody

moving on a train. Show you how the geometry works. That, Because the speed of light is always the same. Then what it tells you is perceptions of time and distance must change. And so the key thing here. And the point that, Martins is raising. Is that if you've got an observer who is stationary. Compared with somebody who's moving at a very high speed. Nearly, the speed of light or yeah. It doesn't matter whether it's near the speed of light or not. It's the effect

works. But it's when you get nearer the speed of light. That it becomes noticeable. the time that you observe that moving person, experiencing is slower. So your time's ticking away as normal. And the person who's moving past you. Their time is ticking away as normal. But when the stationary person. If you could see the clock on the moving vehicle or whatever it is. Train going at nearly the speed of light. Just to mix a few metaphors there.

what you would see is their clocks would seem to be going much more slowly than yours is. And that's the time dilation effect. And yes, it means that, if you can then bring these two back together. The moving person has experienced less time relative to you than you have. And that's the it's sometimes called the twins paradox. Because if you take two twins. One goes off at the speed of light, comes back again. Or nearly the speed of light, comes back again.

There they have aged much less than the twin who stayed put. So that's the bottom line. And it's, you know, it's such a counterintuitive concept. That it is really hard to get your head around. But we know it works. in fact, the demonstration. the practical demonstration of this phenomenon happening in reality, I think it was just before the Second World War. Might have been round about the same time. But there are things called cosmic rays. Which are bombarding the

Earth all the time. These are subatomic particles that come from space. and they are, predominantly a species of subatomic particle called a muon. So these muons were observed coming down through space. At, nearly the speed of light. And we know how long they take to decay in the laboratory. But their decay time was much longer. When they were observed coming in at the speed of light. Nearly the speed of light. The time had dilated. So their decays were much longer. Than what we observe in the

laboratory. When they're not stationary. But they're going much more slowly. So it is a proven fact this works. if we could build a spacecraft that would get us to. I can't remember what it is. I think it's 99.999998% of the speed of light. Head off for 500 light years, come back again. you will be 10 years older. whereas everybody else on Earth will be a thousand years older. So it's that sort of thing, you know. Your time has slowed down relative to what they've experienced.

I had a weird nightmare about that the other night. Professor Fred Watson: Oh, did you? It was the strangest thing. I had a nightma. somebody put me in, like, some kind of a cryo sleep. And I woke up and so much time had passed that everyone I knew had died. And so I had them put me back in cryo sleep for thousands of more years. Until we discovered the technology to travel back in time. So I could go back in time and link back up with everyone I loved.

Professor Fred Watson: That's a pretty good one. Is that I have a very active dreamscape. Professor Fred Watson: Ah. At night I wake up exhausted. Professor Fred Watson: Okay. All right. Well, our next question, has a little bit of philosophy in it. this. This question is coming from Art from Rochester, New York. And it's a. It's quite a long question. So let's, grab a cup of tea here. Art says, I was listening to the June 13 program

concerning the Flying Banana. Which prompted me to submit my first question to Space Nuts. It is a question I had been pondering for some time. You will be glad to hear it is not A black hole question, but rather a, what if question. The great American philosopher Julius Henry Marx once postulated, time flies like an arrow, fruit flies like a banana. Based on empirical evidence, I can confirm that fruit flies like a banana. My question revolves around time flying like an arrow.

To the best of my understanding, when we shoot off rockets to the moon or Pluto, in order to get there accurately, the rocket scientists use an infomeris. You'll have to correct me on the pronunciations of that or possible amphimerdes as a sort of a map. If faster than light space travel were possible, how could one navigate from point A to point B? Is it possible to develop an ephemeris for faster than light travel? Thank you, Art from Rochester, New York.

Professor Fred Watson: A great question, Art. And, yeah, your pronunciation is correct. Ephemeris is what these things are, and ephemerides is what a lot of them are. So what's an ephemeris? Well, the original meaning, and I guess this really is still the meaning of the word is, to predict where, planets are going to be, in the future, where celestial objects are going to be. So, going back to my master's degree, back, you know, 150 years ago, my work was on, the orbits of asteroids. And

so there were two problems. First problem was how do you take observations of an asteroid? And remember, all we had in those days was the direction that you could see measured with a telescope. How do you turn that into knowledge of the orbit of the asteroid in three dimensions? And you can do it. You need at least three observations to do that. But you can do it. You can mathematically deduce the orbit from just three directions in space.

But then once you've got the orbit, what you want to know is where it's going to be in the future, what's its direction in space going to be? And that is what an ephemeris is. It's how the position of an object changes, in the sky, over time. so it comes from the word ephemeral, meaning stuff that's temporary. so an ephemeris, is the. Basically, it's a table, of where an object will be over a given amount of time. And of course, it's critically important these days because we now know that,

which we didn't know when I did my master's degree. We now know that the Earth's locality is pretty heavily populated with asteroids. And there's, you know, we might want to know where they are just in Case, one's heading our way. So, I, you know, I think the question, Art's question is a good one in the sense that, okay, he's saying, yes, we, we use ephemera, ephemerides to, to basically navigate

to objects. it's actually a little bit more than that because we, we use effectively a three dimensional map of where these planets are, in order to dictate where they're going to be when your rocket arrives there. And that's critically important of course, because you want the rocket to get to the orbit of for example Pluto, as Art mentions, when Pluto is going to be, whereabouts the rocket is. You don't want to reach the orbit of Pluto and find

Pluto somewhere else. That's why you need an ephemeris. but if you could travel faster than the speed of light, and we've already shown that that's impossible, in this episode because you need infinite energy to do that, ah, to reach the speed of light. But if you could, the ephemeris would still work, you would need to put in a negative number for the I think the speed of light actually goes into ephemeris calculations. I remember it well, but I think you put in a factor.

It wouldn't be a negative number. It would be a factor that would allow for the fact that you were traveling at faster than the speed of light. So you could do it. It's not an impossible mathematical problem. For what it's worth. Well, that was fantastic. I just about understood that too. Professor Fred Watson: Sorry. no, you always do such a great job of explaining these. my IQ is going up every time I'm involved on these, these episodes. And also great questions. We have some of the smartest,

smartest listeners. I mean these people are, are brilliant. our, our next question is another audio question, from David from Munich. And it's a little bit of a longer question as well. So we are going to go ahead and play that for you now.

And I wonder how Is that, is it due to the fact that or is this like the redshift because they're moving away, which I kind of doubt, but I don't know what, what is it else? Or is there so much material of a different, of different kind in the galaxy that he appears for us more red or more blue. So be nice if you could explain that. And also I wonder a bit. Let's imagine we would travel to this far distant galaxies. if you could do it potentially, would it not be some kind of

travel through, through the time? So because when we look back there, right, we see them on their early stages. So till it, it's a long time until the light reaches us. And if you would travel to that far distant, galaxies you would basically. Or what I imagine is like you would travel through time, right? So if you did, the moment you come closer and closer the galaxy, or maybe let's think of a single planet would then change

its appearance, right? So you would see that it's alter, it shifts maybe its base or it merges with another galaxy. is my thinking correct? Would it like the far, the closer you come, the more it would change its shape and I don't know, colors maybe, and things you would see. yeah, thanks for taking my questions. like the show and till then.

And that's the bottom line. But there's a few caveats here. Let me just explain what I mean. redshift is the phenomenon that as light travels through an expanding universe, the universe is expanding, light is making its way through the universe, but as it goes the universe is getting bigger and so the light's wavelength is actually being stretched. and ah, as you stretch the wavelength of light, it goes redder, it goes to the redder end of the spectrum. And so that's what's happening.

But the caveat that I mentioned is that these are actually false colors in the sense that the James Webb telescope is an infrared telescope. So it is looking at light that our eyes are not sensitive to. It's actually redder than red light that it's looking at. So what the mission scientists do is they, they take the shortest wavelengths that the web can see, which are

really beyond our. They're redder than red for us, for our eyes, but they're the shortest wavelengths that the red can detect, and they make that blue in their colors. And then the longest wavelengths that the web can detect, they make it red in their colors and that. So that mimics what we would see with our eyes, with visible, you know, visible light, but it mimics it moved into the

infrared. So it does mean that as objects, you know, get redder, in the infrared spectrum, we see them redder in the James Webb telescope images. And that's exactly the reason the most distant objects are so highly redshifted that you're seeing them as red objects compared with the white objects, which are the much nearer ones. So David's right on that front. His second question, what would some of these

galaxies we're looking back, you know, up to? I think the record is looking back 13.52 billion years at the M moment, which is 280 million years after the birth of the universe. It's a big puzzle as to how galaxies got so big and so rich, in that short period of time. But that's for the cosmologists, not for us. they'll work it out. It'll be okay. the bottom line, though, is that if you could forget about the journey because we can't

travel the sort of speeds that you need. But if you imagined yourself, instantly transported from our, vantage point here on Earth to one of These early galaxies, 13.52 billion years, billion light years away, what you would see would be a galaxy that might look a lot like ours. It has evolved because you're seeing it. I mean, you've got to imagine we're being transported instantaneously so that what we see is what's happening now. That galaxy will have had

13.52 billion years of evolution. It'll be quite different. It might actually be quite a boring galaxy compared with the very, energetic, infant galaxy that we look at with the James Webb telescope. Complicated answer to a simple question, but David's right on the money. That is such an interesting way of thinking about that. I'm going to be spending a while wrapping my head around that one. our last question of the evening is from Daryl Parker of South Australia.

Daryl says G' day, space nuts. I'm not sure of the best way to ask this question. So I'll just ask it the best way I can. That's usually the, the, the best way. do objects, meteors, asteroids, comets, planets, stars, solar systems and galaxies produce heat as they move through space? Is it friction or is friction a thing in the vacuum of speed, in the vacuum of space? Thank you in advance. And that's Daryl from South Australia.

Professor Fred Watson: another, another great question. so if this, if space was a complete vacuum, and as I'll explain in a minute, it's not quite, but if it was a perfect vacuum with nothing in there, then, there would be no friction, as, Daryl's calling, would be, you know, there'd be nothing to, limit the speed of motion, of an object moving through it. And it wouldn't get hot. There would be

no friction to heat it. and I think the way Daryl's thinking here, and he's quite right to, when a spacecra enters the Earth's atmosphere, it's the friction between the spacecraft itself moving against the air molecules that causes it to be heated and gives us this heat of reentry. There are a few subtleties to that, but that's basically the way it works. So things moving through an atmosphere get hot. now, space beyond the Earth's, atmosphere is not a vacuum.

It's very nearly a vacuum. And that's why you can put a satellite up and it'll stay up for 200 years or whatever. And it's why the Moon doesn't come crashing down to Earth. In fact, the Moon's going the other way. It's moving away from the Earth, very slowly. but, it's nearly a vacuum, but it's not quite so There is basically a very, very slight breaking effect, which in the Earth's vicinity. The Earth's atmosphere doesn't just stop.

It sort of fades away. So even, you know, even 10,000 kilometers away, there's still a little bit of residual atmosphere, which would have a slowing effect on a spacecraft. When you get into interplanetary space, there's a lot of dust and there's also subatomic particles there. When you get to interstellar space, the space between the stars, there is something that we call the interstellar medium, which is basically the radiation and particle environment

of interstellar space. There are subatomic particles all through space. Now there, it's still so much of a vacuum that there's nothing really to heat a spacecraft. So Voyager, as it ventures through interstellar space, is on the brink of interstellar space. Now, that won't get hot because of that, because the friction is far too small. But when you do see its effects,

they are on very big scales. And we do see, when we look at some objects deep in space, for example, in a gas cloud, a nebula where, maybe there are stars forming, sometimes you see objects which are moving through that gas cloud and what you can see is a shock wave, being generated. And sometimes that causes star formation, that shockwave of the gas cloud. now, yes, that's Jordi agreeing with me there. he's just come back from his walk, so he's very enthusiastic about this idea. he's

probably seen the shockwave. So, and a shockwave is what you get when something moves rapidly through the atmosphere. You know, that's what causes the sonic boom of a supersonic jet. so with very big objects in gas clouds in space, then you do get that sort of effect. The interaction between the moving object and its surroundings generates a shockwave and would generate heat as well. So under certain circumstances the answer is

yes, Darrell. But, but probably for most things it's no. So, Fred, I don't know if you'd have time for a follow up question of my own. so I guess I never really thought of, the gravity atmosphere around planets having different layers. It's like, I knew there was layers, but it's like to really think, okay, it gets thinner and thinner and thinner, but there's still particles being pulled into that atmosphere. But it just, it spreads out quite a ways

well beyond our atmosphere. Are there points of space, and you may have already mentioned this, but are there points of space where there's particles floating around that are not being affected by any gravity at all? Or is every part of space affected by something's gravity? Professor Fred Watson: yeah, pretty well. the thing about gravity is it, it goes on for infinity. it's it's a bit like actually light is the same. Electromagnetic radiation will not stop. It just keeps going

until it gets too weak to be detected. And you're talking about a dribble of hardly any photons. Gravity is the same. We don't know whether gravity has a subatomic particle equivalent. We think it might have, and we call them gravitons, but they haven't been discovered yet. But yes, that's actually, you know, it's why, an object like Pluto, way out there in the depths of the solar system,

is still in orbit around the sun. Even though it's all these, what is it, five, six billion kilometers away, the gravity of the sun is still a force because gravity goes on forever. but, of course, when you get way out into interstellar space, then you might feel the sun's gravity, but you'd also feel the gravity of other stars. and so I think you're right that there is always going to be a sort of gravity background ground, because of the objects

which are in the, in the universe. Maybe it's pretty near zero in the space between galaxies, which is pretty empty. Although there are subatomic particles there too. but, yeah, but no, it's a, it's a very, a, very compelling force is gravity, which is just as well because otherwise we wouldn't exist. There's always something pulling. It's just going to be stronger or weaker. No matter if it's.

No matter if it's the biggest gap in the known cosmos, there's still a little thread pulling us together. Oh, that's so beautiful. That's kind of cool. We're all connected somehow. Professor Fred Watson: That's a connection. That's right. Yeah. Fred, well, this has been a very enlightening Q and A episode of Space Nuts. Thank you so much for sharing your wealth of knowledge with us. while you're. Rooster. I'm sorry? Your dog sings his song in the background.

Professor Fred Watson: That's what he sounds like. I know. It's, His voice hasn't broken yet. It's, it's kind of cute. It's endearing. thank you so much. This has been, this has been fantastic. And, we will, we will, I guess, catch you guys next time. Please keep sending in your amazing questions. And, real quick before we go, we are going to play a, another, another update for you. So this is your little treat for listening to the whole thing. We've got an update from Andrew,

your beloved regular host. I know you guys probably miss him because your questions are still addressed to him, but, he's on his trip around the world, so we're gonna let that, that, that playback now.

much worse. We were having lunch in one of the restaurants at the back of the ship ship and we got hit by a weather front. It felt like we'd been rammed and the, the ship tilted over 7 degrees and it stayed there for the rest of the day. It just hit us out of nowhere. The captain had to do some heavy maneuvering to get us into a, you know, better position and they had to move the ballast to keep the ship balanced and upright. Fight as much as they could. yeah, it was pretty harrowing.

And the weather never got better until we got into Adelaide and were in protected waters. But the Adelaide was fantastic. Went to Handorf as I mentioned, that little German village where the, the German people came in all those years ago. They were they were basically escaping Prussian oppression when they came out here in the 1800s. And yeah, made it, made a German town town which is fantastic. had a good look around Adelaide although the weather was terrible. We went to

Mount Lofty which is one of the best views in Australia. And all we saw was cloud and very strong winds. It was it was quite nasty. Got back on board. We had to stay the night in Adelaide because of the conditions, hoping they'd settle down. And we, we did have some good sailing until we got to the West Australian border and then another weather front hit us and it got rough again and yeah, gosh. And just to top it all off, we had a galley fire in the middle of the night at one

point which they dealt with very, very quickly. So it's been a bit of a dog's breakfast of a cruise in some respects. But we're still having a fantastic time. We stopped at Fremantle again, because of the weather. We were very late and so we stayed the night. We have friends in Fremantle so we spent the evening with them. It was fantastic. And we set sail again yesterday, headed west. We leave Australia now, headed for Mauritius. That'll be a seven day crossing of the Indian Ocean.

So that's where things are at with our current tour. we're really enjoying ourselves, I must confess. The crew here is fantastic and you know, with over 2,000 Aussies on on board, we outnumber everybody about 10 to 1 which is, which is good. But so many nationalities. Hope all is well back home and in Houston of course. Heidi, look forward to talking to you next time. no, Aurora Australis missed out completely. Couldn't see that.

So hopefully when we get up north, we'll see the other end of the, country and see if there's any lights up north. So until next time, Andrew Dunkley signing off. Off.