Exploring Moons with Atmospheres, Hot Jupiters, and the Mysteries of Black Holes | Space Nuts:...

[00:00:00] Hello again and thank you for joining us on yet another episode of Space Nuts. I don't know what we're up to. 652. Blimey. And we only started yesterday. Coming up in this Q&A episode, we will be answering questions about moons with atmospheres, secret astronomy. This is a fascinating question.

[00:00:20] We've also got a question about hot Jupiters. We've talked about them before and a very rare, never before asked, black hole question. That's coming up in this Q&A edition of Space Nuts. 15 seconds. Guidance is internal. 10, 9. Ignition sequence start. Space Nuts. 5, 4, 3, 2. 1, 2, 3, 4, 5, 5, 4, 3, 2, 1. Space Nuts.

[00:00:49] Astronauts report. It feels good. Joining us again to resolve all of that is Professor Fred Watson, astronomer at large. Hi, Fred. Hello, Andrew. How are you? Good to see you again. I'm as well as I was the last time you saw me. Yes, all those years ago. That's right. Yeah. Minutes or seconds. Whichever comes first. We've got some good questions today and I thought we might just get straight into it if you're ready to...

[00:01:18] Oh no, I've got an announcement. Oh. Yes. Better do that then. It's a bit of shameless self-promotion. I've finally released my science fiction trilogy. Yay! It's out there. I'm just putting the final touches on a few bits and bobs, but the e-book is out. The paperback should be out by the time you hear this, unless you're watching us live on YouTube. Hello. It's called The Human Epoch.

[00:01:48] Hmm. Which I did look up to see if there are any other science fiction books with that name and there are not. So, The Human Epoch parts one, two and three. I released them all at once. Oops. I nearly released the microphone. Yeah, all at once. I thought I'm going to write the whole thing and release it as a batch rather than write one book and then release it and then make people wait a year. Now, the whole Banglot's out there already on its way. Seasons one, two and three. Yes, exactly. Yeah.

[00:02:18] I hope people enjoy it. Can't wait to get the feedback. Good, bad or indifferent. So, The Human Epoch, look for it. And you should be able to order it from bookshops. I don't know. I don't know how it works. But, you know, looking at the cost of printing and the sharing of spoils, if you sell a book for 20 bucks these days, you might get two or three dollars out of that. It's a tough industry. Very. Yeah.

[00:02:46] I mean, you've really got to sell tens of thousands of books to even scratch the surface. You do. Which I have not done. Yeah. Neither have I. No. But anyway, I thought I'd give it a mention. I've mentioned that I was writing it a few times. I thought I might have seen people. It's out there. So, that's done. So, you're not emulating Douglas Adams with a trilogy in four parts.

[00:03:13] No. But, you know, I might continue the story because I became very... I don't know if this happens to other authors. I'm sure it does. Well, there you are. It happens to Geordi. Yes, it does. He's a bit late. We could have used him in the last episode. We could. That's right. With the dogs. You get a bit attached to some of the characters you create. Yes. I believe that happens when you write fiction.

[00:03:38] But the main character in this trilogy, I've come to adore. I really love his attitude. That's all I say. Okay. All right. Okay. He's a different kind of character. Is he based on anybody real? No, I made him up. And I made him Canadian. Ah. I don't know why. I just did. I just thought... Oh, the Canadians. Canadians never get much of a mention in science fiction novels.

[00:04:08] So, I thought I'll make my hero a Canadian. Good on you. Yeah. Good on you, Andrew. All right. Before we do that, I better just go and see what's... Because I'm home alone at the moment. I just want to see what's upsetting Geordi. It won't be a sec. All right. Okay. This doesn't happen very often. He could have done that while I was spruiking the book, you know, because that would have been a nice filler.

[00:04:31] But now he's just left me swinging in the breeze, which happens occasionally. This used to happen on radio. I remember once, years ago, we were expecting some guests. So, I played an appropriate song. I think they were circus performers. And I played Circus by Britney Spears in the hope that they would actually arrive while the song was on. And I got lucky. They walked in the door just as it was finishing.

[00:04:59] So, I got the interview on air in time. It's sometimes a bit scary like that. Anyway, welcome back, Fred. Is Geordi okay? Thank you. Yes. I don't know what was causing the ruckus. A butterfly, probably. Honestly, it's that level that sets him off. You know, a leaf moves 200 meters away across the forest and off he goes. That's right. He could probably use a GPS collar at some point.

[00:05:26] There are times when he could use a muzzle, I think, to stop. Yeah, well. Now, let's get into some questions. I think that's why we're here. Oh, I suppose it is. Yes. Yeah. So, first question comes from Chris in Exmouth in the UK. Just wondering, could a moon ever have an atmosphere? And is it possible for a moon to be close enough to a planet to share an atmosphere? Really enjoy the show. Thank you, Chris, for sending that in.

[00:05:57] Look, we already know in our solar system there are moons with atmospheres and I do believe they do share their stuff with their home planets, some of them? Correct. That's right. Although it's sort of not, probably not quite what Chris has in mind. So, yes, I mean the classic example is Saturn's moon Titan. That has a very thick atmosphere, atmospheric pressure, I think one and a half times that of the Earth.

[00:06:24] It's a dense atmosphere and also opaque because it's rich in hydrocarbons. It's the same stuff that makes smog in a city is why we can't see through Titan's atmosphere. So, yes, a moon can have an atmosphere, but you can't have a situation where you had a planet and a moon, which was sort of embedded in a much larger, dense atmosphere.

[00:06:53] And that's because you basically slow down the moon as it orbits the planet and it doesn't last very long. In fact, that's what brings satellites down from orbit, low Earth orbit above the Earth. They are slowed down by the Earth's atmosphere, even though it's very tenuous up there. And nevertheless, it slows them down and they fall deeper into the atmosphere and the deceleration continues.

[00:07:19] But the example that you've mentioned is the one that came to mind when I read this question as well, which is the dwarf planet Pluto, which has a large moon. It's about half the size of Pluto, actually. It's called Charon or Charon, not Charon. Some people call it Charon. They do. Charon. Charon for short. Charon, yeah.

[00:07:48] It's a large moon, as I said, half the size of Pluto. And so they are, in a sense, a binary dwarf planet system because they orbit around a point which is outside the body of Pluto, which is the kind of definition of a binary system, something orbiting around a common center of gravity. So you've got that unusual situation to start with.

[00:08:17] But it appears that because of that geometry, the atmosphere of Pluto, which is very, very thin, but it is there. I was once helping a project that measured the atmosphere of Pluto, not from space, but by Pluto passing in front of a star as observed with the Anglo-Australian telescope. We could see it dimmed gradually, the light of the star, rather than just switching off as it would have been if there'd be no atmosphere.

[00:08:47] So that atmosphere is mostly nitrogen gas, or the part that's escaping. And apparently it is basically captured by Charon. There's this flow of the nitrogen from Pluto to its dwarf planet companion.

[00:09:10] There's probably something similar happens with the Earth and Moon, but very, very much less intense. There's probably a bit of gas transfer from the Earth to the Moon, given that the pressure of the Earth's atmosphere doesn't just stop suddenly. It falls away very gradually. And in fact, there are some of the molecules of the Earth's atmosphere that are out at the distance of the Moon.

[00:09:39] So they probably do exchange, you know, some low levels of gas, but not very much. And it is, yes, it's a different situation from perhaps what Chris had in mind with an atmosphere with a planet and its Moon both orbiting within it. Yeah, I understand what he was saying. And as you suggested, it would be an impossible situation.

[00:10:02] Although we do see, I think around the gas giants, some of those planets, particularly the ice worlds, do shed some of their material, which is picked up by the gas giant. I think, is it Enceladus? Yeah, that forms, that's correct. So that's solid matter, actually. It's the ice crystals that come from Enceladus' ocean.

[00:10:28] They form Saturn's E-ring, which is a very non-dense, very rarefied ring. I think it's the outermost ring of Saturn. And it's basically, the orbit of Enceladus is embedded in that. So yes, that's a sort of similar sort of situation. Yeah. It's not sharing atmosphere, but it's sharing material. Yeah. In a way. So the answer to both of your points, Chris, is definite yes.

[00:10:59] But no in terms of them both sharing the same atmosphere. Holus bolus, as we say. So yeah. But great question, Chris in Exmouth. Where's Exmouth, Fred? Down in Devon. It's a lovely part of the country. And it's not far from Exeter. The River X runs through both of them, as you'd expect. Owned by Elon Musk? Probably, yes.

[00:11:27] It's spelled slightly differently from Elon Musk's Ex, but yes, probably still the same thing. Thanks for the question, Chris. Our next question comes from somebody who's keeping their name a secret, and it's about secret astronomy. Oh, hang on. I've got to change pages. Here we go. Here we go. I have a question about secret astronomy. We know that gamma ray bursts were first detected by spy satellites looking for nuclear testing.

[00:11:56] We know that satellites use star tracking and star catalogs for calculating their position. And we know that the Nancy Grace Roman, launching hopefully in August, uses, is built out of a spy satellite that the National Reconnaissance Office, the US spy satellite agency, donated to NASA because they weren't going to launch it. They donated two and only one is being used yet.

[00:12:20] And we know that the Space Force released a bunch of observational data around bolides to help with planetary defense and asteroid detection and understanding. So by their nature, spy satellites tend to point at the Earth. But obviously, like they push into a lot of astronomy and astronomy adjacent things.

[00:12:40] I just wondered if you could speculate, you know, given their budgets and constantly improving capabilities, where they might be ahead of public astronomy or running into things that, yeah, might be pretty interesting in a few years. Thank you so much. Thank you for the question. Yeah, I don't know who that was, but that's okay. It happens from time to time. But interesting question, Fred.

[00:13:10] Really, it's not just an interesting question, but a very well posed one as well, because everything our anonymous questioner said is true. And so we are being invited to speculate on what else might be up and running. We didn't know for a long time that there were two more Hubble telescopes, because, you know, the company kept their, built it, I think it might have been Perkin Elmer, I'm not sure.

[00:13:36] But they kept their cards very close to their chest in terms of the existence of the Hubble telescope. But it turned out, subsequently, we found out there were two more built for surveillance. Something else that did find its way into astronomy that was originally secret was President Reagan's Star Wars technology, which required adaptive optics.

[00:14:03] And those are optical surfaces that change in response to basically things like scintillation in the atmosphere or twinkling for a star. So that adaptive optics technology is now used very commonly in astronomy. It's not used here in Australia. We don't have a natural, a site that is naturally good enough to be able to compensate for the atmospheric, this atmospheric turbulence.

[00:14:32] Whereas some of the better sites in the world, like Mauna Kea in Hawaii and Seroparanal in Chile, they do. And so they use adaptive optics very, very commonly for their work. It basically allows you to take out the twinkling of a star, which is something that ruins the images as you see them through telescopes. And as I said, came from Star Wars technology.

[00:14:58] That technology, by the way, this is not really along the lines of the question, but it's leapfrogged as well from astronomy into ophthalmology. So people are now using adaptive optics to compensate for the turbulence inside your eye when they're doing sort of retinoscopy and things like that.

[00:15:22] So that adaptive optics technology is now gone from defense through astronomy and is now being developed for health reasons, which is very, very good. I don't know if it's quite the same thing, but my optometrist was telling me they've invented a new kind of lens that replaces your human lens that can now do the same thing as a human lens.

[00:15:50] Like when you have a cataract operation, they replace the human lens that's all fogged up with a, you know, generally a plastic lens of some kind, but it was a fixed lens. It could only do one thing. They've now advanced the technology to the point where they can put a lens in that will be able to be controlled by your brain and give you various focal lengths. Yeah. Which I think is amazing. It's what your eye naturally does. It's called accommodation.

[00:16:20] The eye accommodates to different distances by changing the shape of the lens. Yeah. Yeah. So that's pretty, yes, quite remarkable and would be a real breakthrough for, you know, for vision, for poor vision. Anyway, we've strayed off the topic here. We have a bit. And I do, I'm sure… Never happens usually, sir. Never happens usually, sir.

[00:16:43] I'm sure that our listener is on the money suggesting that there are technologies that are being used in secrets or restricted environments that would be of great value for astronomy. I guess the kind of thing that comes to mind is quantum detectors and things of that sort.

[00:17:09] There is no, I don't think there's any equivalent, for example, in the field of gravitational wave astronomy. I mean, I don't think there's anything that the military are doing that could feed into that, although quantum optics are being used in that now. So I suspect it's in, you know, in relation to the tools that are developed for our observations. We owe infrared detectors, the things that see redder than red light or heat radiation.

[00:17:38] We owe them to the military. That's a spin-off from military work. I do remember one of the first infrared instruments on the Anglo-Australian telescope when it was being delivered. I think the detector came under armed guard almost.

[00:17:56] It wasn't quite like that, but there was a lot of hoops to jump through when this detector was delivered because it had to be certain not to stray into the hands of certain foreign nations who… …the Americans who developed this detector didn't want them to get hold of.

[00:18:15] So those technologies do eventually kind of sprinkle down to astronomy where the poor relations in that regard, although we do push the limits perhaps more than anybody else in technology. So, yes, I don't have any definite speculations except to say that nothing would surprise me in that regard when it comes.

[00:18:44] I'm not a conspiracy theorist, but I do believe there's a heck of a lot going on up there that we do not and probably will not know about. Yeah. And I truly believe that the technology available today in space and on the planet in those dark corners of government buildings is far, far more advanced than we could possibly imagine.

[00:19:12] I think given what we've got access to in a domestic sense in the public arena today, what's been developed already behind closed doors that we're unaware of and it's probably up there circling the planet as we speak. Yeah, I think it works both ways though because I think we're now seeing the military adopting what would have been thought of as commercial products before.

[00:19:41] And that's happened, you know, certainly in Ukraine, there's been an adaptation of all sorts of commercial products for military purposes. So, what I guess I'm saying is that the technology that we use every day is not as far removed from what the military use as it would have been 20, 30 years ago. I think that's probably fair to say, but that's me going out on a limb and who can prove me wrong?

[00:20:11] Well, that's a good point too. That's a really interesting question. Thank you for sending it in. This is Space Nuts. Andrew Dunkley here with Professor Fred Watson. Let's take a short break from the show to tell you about our sponsor, NordVPN and to discuss your online privacy. Because let's face it, these days, whether you're browsing at home or jumping onto public Wi-Fi at a cafe or an airport or wherever, your data is constantly at risk.

[00:20:40] Hackers, trackers, even companies you've never heard of, they're all trying to get a piece of your digital life. And that's where NordVPN comes in. Our sponsor is fantastic. It's one I've been using for many years now myself and I have absolute faith in their product. NordVPN encrypts your internet connection, hides your IP address and keeps your personal information safe from prying eyes.

[00:21:08] It's like putting an entire online world inside a secure tunnel. They've got over 7,700 servers worldwide. You can browse fast, safely and without restrictions. Plus, features like threat protection and ultra-fast speeds with NordLynx mean you're not sacrificing performance for security.

[00:21:31] You get both. Right now, you can grab our special Space Nuts deal and get four months extra for free. Plus, there's a 30-day money-back guarantee. So, it's completely risk-free to try. Just head along to our special URL, nordvpn.com slash space nuts.

[00:21:50] That's nordvpn.com slash space nuts. And don't forget to use the code space nuts. That's nordvpn.com slash space nuts. Stay safe, stay private with NordVPN, our sponsor. I believe that this nation should commit itself to achieving the goal before this decade is out of landing a man on the moon and returning him safely to the earth.

[00:22:19] Bees nuts. Another audio question from Fenton. Hi, this is Fenton calling you from St. Paul, Minnesota in the U.S. I have a question for you regarding the solar systems that contain so-called hot Jupiter planets, those which are very close around their suns. Is it reasonable at all to expect that they will have smaller planets, rocky planets?

[00:22:47] Or are there good reasons that come to mind where that should not be the case? I'd appreciate hearing your theories on this, what the variables would be in this. And I, of course, enjoy listening to your show. Thank you very much. Goodbye. Thank you, Fenton. Fenton's one of our semi-regular Sendorinners and he's always got a very interesting question in mind.

[00:23:14] So, yeah, I'm guessing that what he is asking is if you've got a solar system with hot Jupiters that are orbiting their parent star in close proximity, could those systems have rocky planets further out? Now, the downside of exoplanet detection is rocky planets are very hard to find at a distance. You generally find the gas giants fast or first. We do know there are a lot of hot Jupiters out there because we've talked about them.

[00:23:44] But, yeah, what's the likelihood that that's a common thing? Not that there's anything absolutely common about anything you find when you start looking around at other solar systems. Yeah, that's exactly right. Our solar system is very neat and tidy compared with most of the other ones that we've detected. But you're absolutely right, Andrew. The rocky planets are the tricky ones to observe.

[00:24:12] And so it might well be that what we're seeing is effectively a selection effect. We're selecting the easiest ones to discover. And that's why we see a lot of hot Jupiters without any evidence of rocky planets in the same solar systems.

[00:24:28] I think, and I haven't looked at this for some time, but one of the ideas for why we've got this situation with hot Jupiters is basically the planetary migration. This is where planets change their positions in the solar system.

[00:24:48] And that might have happened to some extent in our solar system, but not in a really sort of kind of existential way, not in a way that will totally alter the shape of the solar system. Because we've got four rocky planets, which are the innermost ones, and they exist within a zone where water exists as a gas.

[00:25:12] Whereas beyond the orbit of Mars, and we sometimes call that the frost line or the ice line, water exists as ice. And that ice is what has allowed the gas giants to grow to the size that they have, because the ice basically collects and the planets absorb it. So you've got not just a massive rock being formed, but ice as well. And then you end up with a gas giant planet.

[00:25:42] So the four gas giants, we think, are like that because they're outside the frost line. Now, if you've got planetary migration taking place, then some of those planets could wander in to the inner solar system. And it may essentially leave your solar system looking like some of the ones that we see with a hot Jupiter orbiting very close to the parent star.

[00:26:06] But also, perhaps with some rocky planets lingering, moaning around or moping around where they've been projected to by the rearrangement of the planets. Because some of them could be ejected by planetary migration. If you've got, you know, your gas giant wanders too near your little rocky planet, it's going to boot it out of the solar system altogether. Yeah.

[00:26:30] But I suspect that there will be solar systems that will turn out to have both hot Jupiters and rocky planets. And as our technology improves and allows us to detect these things at lower masses, I think we'll be finding them as well. So watch this space, Phantom. That's the bottom line there. Theo was a wandering planet. Yes, that's right. Theo wandered into the Earth back in the late 4000 BCs.

[00:26:59] Yeah. 4000 million BCs, I beg your pardon. 4 million BCs, yeah. I think the train of thought these days is that in terms of solar systems, just about every star has at least got one planet. Yeah. That's based on an average assumption. But it also stands to reason that solar systems are as many and as varied as there are stars in the sky.

[00:27:28] Ours, which has the four rocky planets, then the gas giants as you move out, and then the dwarf planets beyond that. Ours seems to be quite different from most. It does. That's what I meant. It's very neat and tidy compared with what we see elsewhere. Certainly, you know, if you were on the planet of a star 100 light years away, our rocky planets would be very difficult to detect.

[00:27:56] And you'd just think, you'd probably think all it had was Jupiter because you'd be able to detect Jupiter relatively easily. If it passed in front of the sun, it would produce a 1% drop in the light of the sun. Yeah. And that's easy to measure. So, yes. So, you know, is the future of our solar system one that does involve planetary migration? It doesn't seem to be. The planets seem to be in very, very stable orbits.

[00:28:25] And maybe that's just something to do with the geometry of the solar system itself. But maybe it's something to do also with why intelligent life has evolved on one of those planets, because we've had this long-term stability over many millions of years. Which is why it's going to be near impossible to find another intelligent communicative civilization, because the circumstances are unique. Could be. Probably. Yeah. Could be almost unique. Yes. Thank you, Fenton.

[00:28:59] Our final question comes from Ed. Now, this is not dissimilar to a question we had recently, but it's not quite the same either. We believe that nothing can escape from a black hole. And yet, when two black holes merge, the mass of the surviving black hole is significantly less than the combined mass of the two merging black holes. It would appear this missing mass, which I understand is converted to gravitational waves, has to come from the black holes.

[00:29:26] Hence, energy matter does escape from black holes. Is this wrong? Ed asks. Hello, Ed. Thanks for the question. Black hole questions. Ed, it's not a week goes by we don't get a black hole question. No, it's a great one. It's a good question that Ed's raised.

[00:29:44] So, yes, gravitational radiation is quite different from the electromagnetic radiation that's coming from a black hole, which does get trapped. It can't pass the event horizon. That's what the event horizon is all about. Because gravitation is a property not of the black hole, but of the universe itself.

[00:30:13] It's the underlying sort of fabric of space that is what carries gravity. And so, if you've got these colliding black holes, they shake the space itself rather than emit something. So, that's the difference. So, that's the difference. The gravitational waves, yes, indeed, they're caused by a loss of mass from the black holes,

[00:30:39] but they're not a property of the black holes, if I can put it that way. It's an effect. It's an effect rather than something being emitted. So, Ed's quite right that nothing can escape a black hole. But gravitational waves apparently do, but they're not. They're basically what you're seeing is something to do with the universe, not the black hole. Okay. Yeah, I get it. It's the old pebble in the pond trick. Yeah, that's right. Yes, it is. Yeah.

[00:31:10] The ripples in the pond don't come from the pebble. They come from the fact that the pebble has disturbed the underlying fabric of the water. In fact, I can put it that way. Yeah. It's a really good analogy. Yeah. I come up with all sorts. You do. That's a cracking good one, Andrew. Well done. I like that. I think you told it to me once before. Maybe. Maybe. Maybe. So, that's the simplicity of it really. There's not much more to tell.

[00:31:39] No, no, that's right. It doesn't defy the logic of nothing being able to escape a black hole. It's because you're, yes, Ed's right, nothing can. Nothing solid or electromagnetic. Particles can't either. But the gravitational field is different. It's something to do with the underlying universe. Indeed it is. Thanks, Ed. Great question.

[00:32:07] And answered very simply in the end, which doesn't happen often, does it really? No, but no. Usually they're not answered at all. Or just adequately. Yes. Adequately, that's right. Thanks, Ed. Thanks to everyone who sent in questions. And if you would like to send a question to us, please do go to our website, Spacenutspodcast.com or Spacenuts.io. And there's a little button up the top or a tab or a link or whatever. It's a link.

[00:32:37] AMA stands for Ask Me Anything. And you can send your questions in through that particular interface, text or audio. Don't forget to tell us who you are or where you're from. Although sometimes people forget and you're not going to get into trouble for that. We're not that kind of people. No, we're not. No. And while you're there, have a look around, visit the shop, become a supporter. And don't forget to leave reviews wherever you listen to us. Maybe the people listening live right now via YouTube could leave reviews.

[00:33:06] That'd be nice unless they hated us. Just don't do anything. No, I'm just kidding. They're stuck around. So we must be doing something right. Yeah. And we're all done. Fred, thank you very much. Thank you, Andrew. We'll talk again soon. I look forward to it. I hope so. Professor Fred Watson, astronomer at large, thanks to Hugh in the studio who couldn't be with us today because he's got a black hole problem. He called a plumber and neither of them can get out.

[00:33:35] And from me, Andrew Dunkley, thanks for your company. I'll catch you on the next episode of Space Nuts. Until then, bye-bye. Space Nuts. Your views to the Space Nuts podcast. The complete easement. Available at Apple Podcasts, Spotify, iHeartRadio or your favourite podcast player. You can also stream on demand at Bytes.com. This has been another quality podcast production from Bytes.com.