#456: Safeguarding the Moon, Titan's Liquid Sounds & Dark Matter Drifts

Hi there, thanks for joining us yet again on Space Nuts. This is a Q and a episode where we answer your questions. You ask the questions, we as in the Royal we as in Fred answers them. We should do it the other way around. One day we ask you the questions why don't you get a job for a starter. But anyway, coming up on. Coming up with this, we're going to answer questions about protecting the moon, the sound of liquids on other worlds, interesting dark matter movement, shocker dark matter question, and how atmospheres are formed. That's all coming up on this episode of Space Nuts. Fifteen in Channel ten nine ignition Space Nuts side or three. Two Space Nuts. As can I report it? Neils good. One man who's got a job is professor friend, what's an astronomer at large? Unlike me, I don't work anymore. I've chucked at all. This is not a job. This is fun. This is a hobby. Hi Fred, Yeah, it's fun for me. Excuse me, it's fun for me too. But you're right, I do have a job. And yes, there we go. Yes, now we have got a lot to get through, so I think we'll just plow straight into it and our first question comes from a regular sender in Erra. His name is Mikey Andrew. It's Mickey once again way too Hot Illinois. Got a question for you, guys. I know we have like a planetary protection for incoming asteroids that threatened Earth, but do we have the same thing for the Moon, Like what it a genormous asteroid? Where to hit the Moon and blow it the smitherenes or knock it our course or alter it in some huge wacas. The Moon is very important to the lake on Earth, right, So I guess first of all, what would happen if something happened to the Moon, would we still have a good chance of surviving? And secondly, is there a protection plan in place? Like there is ready Earth for the Moon? Thanks guys, love the bad guest. Thanks. Mikey always asks interesting questions. The answer is no, and yes. Well it is yeah, yeah, we've we've had questions about the loss of the Moon before and what might happen to us? And I do believe that we have discussed. Maybe once or twice, that the protection of the planet includes the Moon. We realize that we. Can't just protect ourselves, We've got to protect the Moon. Otherwise, you know, if it gets obliterated. We're in big trouble. Yeah, okay, so obliterated that would have to be a huge j object. That's the point. There's nothing there's no scenario that we can envisage at the moment that would involve such a collision. So we're talking about asteroids. You know, even something measured in kilometers hitting the Moon would be of concern to us because the Moon's very close to the Earth, and you know, that's one of the things that we need to know about. So the bottom line is that our protection of Earth in terms of it's not actually planetary protection is something slightly different. That's a biological thing. Planetary defense is what we're talking about, and defending the Earth effectively means we defend the Moon as well in the sense that if we are looking for hazardous objects, and that's you know, that's a well established technology which we're doing. We think we've discovered most of the objects that might threaten Earth and the Moon which are more than a kilometer in size. It's the objects of a few hundred meters that we're looking at now. Now. The detection of those is parcel of modern astronomy. And we find them with regularity. If one was on a collision course with the Earth, then we'd do something about it. And we've discussed that before many times, andrew. Is the theory of deflection. Yes, indeed, it was a. Dark mission, that's right. But if one of them was shown to impact the Moon, we wouldn't do anything about it. I think we would let it happen because it's just part of the natural cycle of events. And unless there was a threat to humans on the Moon, you wouldn't do anything about it. And in fact, if you knew enough about such an object going to hit the Moon, you bring your humans back, you get them off them, because that's a lot easier than trying to deflect an asteroid. So it's that, you know, the lunar defense is basically wrapped up within planetary defense of the Earth, with the one exception that we would not try and define deflect an asteroid. If one of any particular size was shown to be targeting the Moon. It gets hit a lot anyway, doesn't it. That's right. Yeah, it's getting and because there's no atmosphere on the Moon, you know, they get clouded. The Moon gets clouded much more forcefully than the Earth does by these incoming objects. So, yes, it's a work in progress. It's happening all the time, and sometimes there's interesting physics involved. You know, if you can see the flash of an impact in meteor or asteroid, then you've got you've got a new new data to look at and to work with. If something was big enough to destroy the Moon, we probably wouldn't have a prayer of stopping it anyway, would we. No, we wouldn't. There isn't anything, So it's okay. Yeah, well, well not within our solar system. But maybe you know, maybe something that's extra soul might come through. We've had a couple of those over the years. Yeah. The thing is, the bigger the object is, the easier it is to detect. And you know, there's just nothing on the horizon even of that kind of. Although the Moon being made of cheese would absorb and impact quite easily. Unless it was a particularly hard chadder that might that, you know. Yes, so that's a point. Yes, yes, all right, I can think of a few cheese puns. But let's move on. Thanks Mikey, good to hear from you. Our next question comes from somebody else, and I've actually managed to lose it here we go. I don't know how that happened. Thank you Windows, gooday Fred and Andrew. As a native minnetonin Minnesotan, Minnesota, all right, Minnesotan, I quite enjoy taking holiday time along the north shore of Lake Superior. I love the sound of the waves washing onto the shore, and that got me to thinking about lakes and rivers on Titan. Would they sound comparable to what we have on Earth, or because it's not water, would there be some kind of distinctive difference to the sound of the liquid ethane methane interacting with its surroundings. I realized this is probably out of Fred's area of expertise, but that's par for the course here on space Nuts. Thanks very much, Gods from James Greenfield. Yeah, James asks an interesting question because we've talked in the past about different types of suns and if life existed on work surrounding those suns, you know, the trees might have different colored leaves and things like that. But I would imagine also that sounds on other planets and other moons would vary depending on the conditions, would they not. It's it's yes, they would, and there's two things at play here. First of all, there's the liquid, which may be quite viscous. We don't really know. It's sort of oily. It's a hydrocarbon. We know what liquid hydro carbons are like here on Earth. But there might be you know, compounds within it that make it a bit more viscous. We think we covered the story not long ago that suggested that if you look at the shape of the lakes on Titan, you can tell that there are waves there, wind blown waves. Yeah, that's right, And. But the likelihood is they're not very high, because radar reflections from Titan's seas are very very smooth indeed, and so I mean, I've read some papers that suggest that the waves are only millimeters high, which probably wouldn't make much noise. The other thing, though, that is the atmosphere, which is a different pressure from our atmosphere on planet Earth. One point five bars is the atmospheric pressure there, and so it basically is fifty percent higher than our atmospheric pressure here. So that's going to change the speed of sound, it's going to change the way things sound. It's really hard to imagine what the waves on Titan might sound like. And I think, James, pose is a really interesting question. There'd probably be a way of working it out though, if you really needed to know that. There would be, but it will do a simulation if yeah, if needed, But theories theory would help as well. It would also change the picture of your voice, wouldn't it. Yes, probably hello and joining you. Yeah, well you'd probably be going hell and that'd be the end of that. Yeah, but yeah, everything would probably be different in one way or another. So yeah, definitely, James, would you would have a different sounding liquid scenario on somewhere like Titan and any other place with liquid surfaces? Good to get your question, Thank you, James. This is Space Nuts Andrew Duncley with Professor Fred what's a Let's take a quick break from the show to tell you about our sponsor, Nord VPN and a virtual private network is something that a lot of people use these days to protect what they're doing online from scammers and hackers and anybody else who wants to download your information and sell it on the dark web, which has become all too common. Of course, identity shift is another big reason that people get hacked, and it just goes on and on and on. So how do you protect yourself well. 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Doesn't interact with other things through gravity, So could don't matter get thrown around or out of a galaxy due to other gravitational efense kind of like planets and other stuff? Does? That's my question? Love the show, Thanks, thank you Bill. Bill from a very watery part of the world as well, San Francisco Bay. It would have some sloshy sounds around it. Indeed, dark matter, we did talk about it recently in light of the fact that they discovered that it may well interact with itself. But that's not what he's asking. He's asking about dark matter movement. Can it Can it move around? We also, I think, discussed that it seems to concentrate around galaxies and in places of saturation, I suppose of other objects. So it's an interesting question. That's right. So dark matter basically is where normal mutter is. We think that's the accident. We think that the dark matter cosmic web provided basically gravitational centers for the for normal mutter to collect and turn into stars and galaxies. But you've highlighted one of the rucial aspects of this that we did talk a couple of weeks ago. I think it was about the idea that dark matter might interact with itself. Some evidence that seemed to suggest that, although I think the common view is still that it doesn't. And the evidence for that comes from something that directly answers Bill's question, dark matter move And the answer is, yes, there is, if I remember rightly. I think it's called the Pandora cluster. It's a cluster of galaxies which is actually two galaxy clusters colliding, and what you can see there is the material of the galaxies themselves, the gas and dust that we can see sort of piles up in this color. And so you've got a galaxy cluster that's made up of two galaxy clusters in the act of colliding, but the dark matter which is around them, and we can detect that by means of gravitational lensing. The dark matter just carries on. So what you've got is this galaxy cluster. It's two galaxies that have collided and they've wound up together. But then on either side of them, on each side is a blob of dark matter. The dark matter has passed through itself, the two dark matter halos of each of the two clusters has gone through itself and not interacted. And that's why people think dark matter has not interact does not interact with itself. But it does prove the answer to Bill's question that dark matter can move. It can move. Okay, we don't know a lot about it, Bill. And with we're trying to find out what we can. There's there's studies into it, but it's elusive because it's dark matter. It's it doesn't it's not of our realm technically speaking, does it. Yeah, it's a. Nice way to put it. It is not of our realm. That's right. Yeah, thank you, Bill. Great to hear from you too. And our final question today comes from Brady. Hello, from the Great State of Florida. I just I have a questioned, Fred, why does everyone who lives in Florida call it the Great State of Florida. Most of the questions we get say, hey, I'm from the Great State of Florida. Are they just saying Florida abbreviate it? Is it actually called the Great State of Florida. I'm being a bit coy here, but it gets local pride. I think it is too. We go from other states as well. Everybody's you know, happy about where they live, which is great. Well I can I can get it. I mean, they've got fifty states to to sort of talk about. We've only got, you know, half a dozen. But when we all we want, we're one country split into states. But during the football season in New South Wales and Queensland hate each other. So just a temporary thing. Yes, Other than that, we're really good friends. So from the Great State of Florida, Brady asks, I was wondering how atmospheres are formed. How do they go from a ball of rock and lava at having an atmosphere. Good, good question. Yeah, I have never pondered that, and I'm glad you asked. It is a good question. So you know, if you've got a world at the temperature at which the volatile material, the stuff that easily turns into gas is gas, then you're going to have a gas envelope around a planet. It's a good it's a great question. H And you know when you when you think of the way planets are formed, they start off as dust and gas, and so you've got this kind of bedding down process where the dust turns into planet sysmals and they all bash into each other and that probably heats up everything so that the temperature gets exceeds where things like nitrogen and oxygen and carbon dioxideer gas. Then what you end up with is is a solid world because the the other things, the silicates and things like that, are at temperatures that are solid, you know, within the places like the Goldilocks zone. And so you've you end up with this natural, natural scenario of a solid, rocky body with a gas envelope. And that's turned on its head when we get out to the to the giant planets, because the rocky body there is very small and probably has quite a lot of water ice in it, because you'd be on the frost line and the gas is the main part of the body. So the atmosphere of a gas giant is formed in a rather different way from the atmosphere of a rocky planet. Yeah. In fact, yeah, gas giants are very different because you're basically looking at depending on the size. But you're getting on towards star formations. Some of those gas giants are actually failed stars, aren't. They, effectively. Yeah, Jupiter's often described as a failed star. It would have to be about ninety times bigger, I think, if I remember rightly to be a star. If it was only thirteen times bigger, though, it would be a brown dwarf star, which is a different kind of category star. But yeah, yeah, yeah, So it's got a lot to do with proximity to the star golilock zone. All those things come into play. Although you get you get gas giants that are close to their parents' star too, which is seemingly so far, fairly normal in the discovery of exoplanets. Yeah, and you get them a long way from planets as well, sorry, a long way from their stars. Like yeah, like the planets and the gas giants and the solar system. Okay, so it's just part of a process. Yes, that's I think that's the ways to put it's. Thank you, Brady. You've kind of highlighted my thinking about these planets and their atmospheres and it is a process. That's the way to putting us. All right, good question, Brady. Look, I don't think it'll happen, but one day someone might send a question in where I go that's just not interesting and it's a bad question. No, it hasn't happened yet. It hasn't happened yet. I'll get a half of our drew. It's all right, definitely not But if you do have questions for us, go to our website because that's where you send them through. AMA is the little tab at the top and when you click on that, it tells you to go away. But if you don't want to go away, you can put your name, your email address, and your message into the system and send us a text question. Or you can press the start recording button and it will record your question using your voice. And don't forget to tell us who you are and where you're from, and if you're a follower of Space Nuts on social media. Don't forget to like us, follow us, join us, or hit the subscribe button, depending on the platform that you prefer. We're all done, Fred, thank you very much again. It's a pleasure. I'm always happy to be on space Notes. Thank you, Andrew. I'm glad you are, otherwise you probably would have left eight years ago. Professor Fred wattsont Astronomer at large. And thanks to here in the studio, who's busily making lunch. I think, yeah, come and see. I can't see him. He's not on the camera. No, no, it's a brush turkey sandwich by the look of it. Good on you and from me Andrew Dunkley, thanks for your company. Has always catch you on the very next episode of Space Nuts. Bye bye. You'll be listening to the Space Nuts podcast. Available at Apple Podcasts, Spotify, iHeart Radio, or your favorite podcast player. You can also stream on demand at bytes dot com. This has been another quality podcast production from nights dot com.