#440: Earth Swap Hypotheticals & Europa Clipper Countdown

Hi there, Thanks for joining us on this a Q and A edition of Space Nuts. Andrew Dunkley here and coming up we'll be answering questions about Earth changing places with another planet in our Solar system, just a hypothetical. We love hypotheticals. We're also going to talk about the Europa Clipper mission and what it's all about, because it's getting close to launch time and well Brady and his son want to know all about it. We're also going to talk about proto planets and why they don't turn into stars. And Martin has sent us a very unusual question indeed, and it involves Mars, but it's the production that went into the question that we're so well, we. Just want to share it with you. That's coming up on this edition of Space Nuts. Fifteen in Channel ten nine Ignition. Space Nutsie or. Three two Space Nurse than I report it. Neil Wood here is again to solve all of these puzzles, as sent in by Space and Arts listeners. Professor Fred what's an astronomer at large? Hi? Fred? I'm not sure about the soulf word. I think contemplate is a better word to contemplate Peru's I love that word. Yes, well we might as well just go straight into it. And our first question today comes from Carrick. I think, hello Andrew and besa Fred Watson. This is Carrick cooling in from Loganay and Zealands. Why is that a quick question in terms of a episode I was recently listening to about the Moon being titally locked to pre made had a bit of a hypothetical question if we were to replace or somehow we're able to get the Earth to replace. A position with. Venus or even mercury, I would assume that eventually the Earth would become tightly locked with the Sun of sorts. Now, if that was to occur, or even if that wasn't to occur, what would happen with our atmosphere or with our oceans? Would they be slowly sucked off of the Earth and eventually we no longer have any liquid water on the Earth, or would the Earth essentially boil to the point where that would happen, you know, the water would boil off before the water was sucked off essentially. Just had a bit of a curiosity in relation to that as a bit of a hypothetical question. Otherwise, hope you have a lovely day or night wherever you are and give up a good work. Thank you, Thanks Kerk. We're in Australia, mate, so we're We're not far away, We're just across the ditch. So I think, Keric, you're going to be horribly disappointed with what will happen because we are exactly where we need to be. At the moment. Any closer. I don't want to think about it. What do you reckon for it? Well, yeah, that's right, yes, I mean you're right, Andrew the moving Exchanging places with either of the inner planets would not be a good outcome because our atmosphere is so delicately poised to be appropriate for living organisms at our distance from the Sun, so you change that. But it's an interesting thought about tidal locking, and mercury and Venus are kind of quasi tidally locked to the Sun. They're not like the moon is where it simply faces one side to the Earth. That's the real tidal locking. But they've got very peculiar rotation properties which are due to basically resonances of this kind, which is what unlocking, how the process works. So and of course they're both very different worlds from the Earth Venus with this horribly thick atmosphere kind of ninety times the pressure on Earth and horrible temperature once it four hundred and sixty degrees celsius something like that. You can imagine that swapping places with Venus, because Venus and the Earth might have at some stage been very similar planets. Not now, hence the name the Sodly System, which is the name we usually give to Venus. So it reminds me some time ago we did talk about Venus and Mars and Earth all at one stage possibly being livable planets. Yeah, in the history and yeah, but so you know, Venus has interesting attributes. Is highly volcanic. It's probably has water vapor in its atmosphere, but it's well vaporized. It's way above boiling point. The atmosphere of Venus is perhaps the most interesting bit because there are heights above the surface of Venus where the temperature is sort of earth like. It's fifteen degrees celsius, so except it's now seventeen degrees celsius average temperature certainly on one day two days last week. But the bottom line is that the Venus's atmosphere, it's not the really the bottom line. It's the top line because that's a place where life may have formed. And we've had a few interesting false alarms recently about the prospects Biomarchus being discovered in Venus' atmosphere. There's nothing certain. It's probably not the case, but that would be your best bet if you were on a planet that was you know, if you'd evolved on a planet like Venus, your best bet would have been to evolve as an aerial organism in the atmosphere. And so I think swapping the Earth around, you know, we'd be in big trouble. The Earth, the assertions will be will be lost, they'd be vaporiyed. The atmosphere would not be in good shape. You probably have a long the way greenhouse effect like Venus has got, and it would be nice at all. Well, you know, Venus and Earth are around about the same size. The other stark difference, I suppose is that Venus rotates in the wrong direction, doesn't it. That's that sort of resonance that I was talking about. It may maybe maybe it was clouded by something else in the early history of the Solar System, but it also may just be a phenomenon connected with tidal locking where you're slowing down the rotation. It's a very slow rotation. As you said, it's in the wrong direction. Yeah, so, Carrick, not a good idea. Everything you theorized is probably what would happen. Yeah, the oceans would vaporize, runaway greenhouse effect. Dogs and cats living together, it just wouldn't be wouldn't be very nice at all. In fact, I think dogs and cats are living together on Earth already. They're sort of doing this household, but it's generally a continuous standoff on the frame. Thanks Kerk, lovely to hear from you, and our next question comes from Brady. Hello from the great state of Florida. As we get closer to the Europa Clipper mission, I wanted to learn more about it, like how it will be searching for conditions that could create life. Also how long it will take to get there and how long until we start getting data. I can't wait to watch the launch in person. I may make the one and a half hour drive to be at Titusville. Keep up the. Great work and never quit the dad jokes, Brady. Thank you, Brady, at least someone appreciates them. You wrote a clipper. Yeah, we are not getting far away from a launch. I think it's slated for October. The tenth of October twenty twenty four is the launch window it is, indeed, So yeah, we're definitely getting ready for that one. And it's exciting because its primary goal is to search for the signs of life. That's that's right, And just to answer a lot of Brady's questions, it will go into or a Jukiter planned anyway on the eleventh of April twenty thirty, so we've got a six year rather less than six year journey. It's it's going to be a Falcon Heavy that will launch it, by the way as well. Oh wow, yeah, it's interesting stuff. Now the question about what it's going to do is well, rather a lot. It's actually one of the biggest planetary exploration spacecraft that's ever been launched. It's a very sizable piece of kit, a launch mass of about six tons thereabouts. It's full of instruments which are all designed to look at the surface of Europa in great detail and to probe beneath the surface as well. So it's really as you said, Andrew, its main goals are to investigate the habitability of Europa, whether there could be life there not whether there is life there, it could be life there, and look for landing sites and so you know, it's it's that's one of them that will be done from all of it. Of course, it's going to sense whether there is liquid water there, which we believe there is underneath the surface, what the chemistry of the of the materials that we find on Europa is all about, and what the you know, energy requirements are for for any chemical reactions to take place. So just just quoting from from this actually from the Wikipedia page on Europa. The objectives are, it says, to study first of all the ice shall and ocean, confirm the existence and characterize the nature of water within underneath the ice and processes of sub ice ocean exchange. That's an interesting one, how you know, material exchanges between the ocean itself and the and the ice the underneath of the ice layer, composition, distribution and chemistry, key compounds and the links to ocean composition. The geology, the characteristics and formation of surface features, including the sites of recent or current activity, is their tectonic activity in the ice layers of Europa, and so you know, the instrumentation for doing that. I think there is something like eleven different it's actually nine different instruments that will study Europe as interior and ocean and the geology and the chemistry and habitability the things we've just described there. I think that's a saxophone trumpet. As long as there's a guitar on board, I'm quite happy. Yeah. So look, just running down the list, Thermal imaging systems, mapping, imaging, spectrometer, that's very much. It's what's called hyperspectroscopy. Very much the stock in trainin of of you know, remote sensing from orbit, various imaging systems, and ultraviolet spectrograph. There's radar. This is something that I like, especially the acronym. The acronym is reason r E as r N and it's the radar for Europe assessment and sounding ocean to near surface. There you go, very nicely done. Interior characterization of Europe. Are using magnetroumetry. Another nice acronym ice mag two. You know, there'll be magnetometism board that will sense the magnetic field of Europe and that believed it or not is one of the key indicators of whether there's an ocean there and whether it's water and other plasma instruments, plasma instrument for magnetic sounding, mass spectrometer for planetary exploration, surface dust analyzer, gravity and radio science. These are using the radio anten to do other experiments to learn about how the spacecraft moves within Europa's gravitational field. It's going to have forty five flybys of Europa and we will no doubt learn a lot beyond twenty thirty. So I'm very interested, and I'm delighted that Brady might be able to watch the launch, you know, if he does call in and tell us. Yeah, jealous. We don't get to see many of them out of this country, but in some parts of the world it's yeah, you can get along and. Watch them fairly regularly these days in Florida. That's right. Yeah, absolutely, this is going to be an exciting mission for all of those reasons. And how quickly will it be, Like it'll take betwenty five and six years to get there, I guess once it gets into orbit and gets itself organized, and it's going to come in at a fairly close altitude at times sixteen miles twenty five kilometers, how fast will it be able to start sending us telemetry. I think we'll get that from the word go. We'll start very very quickly. I think you know, from the orbit and perhaps from some of the magnetometry. I think these will all show up for interesting results quickly. So yeah, there might be really really spectacular things coming from so Europe. Okay, very good, thanks Brady. Great to hear from you. This is Space Nuts with Andrew Dunkley and Professor Freed Watson. Let's take a quick break from the show to tell you about our sponsor, in Cogny, and I'll give you a particular URL very soon because as a space Nuts listener you'll get a special deal. 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But you can do individual plans, family and friends plans. It's a very small price to pay for security. In Cogni dot com slash space nuts, click on get the deal to protect your personally information online. Now back to the show. Okay, we take being with the girl space nuts. Okay, another text question and it comes from Matthew. Hey, guys, First of all, I'm a power line worker, so my knowledge is very minimal. I don't know why, but I was lamely explaining the nebular hypothesis to my eleven year old son. But when I got to proto planets, he asked me an interesting question. He asked why don't the proto planets become stars themselves. I did a bit of digging and I think I came down to it came down to a lack of mass and fuel to achieve nuclear fission fusion. Is this correct? And are you able to explain this in more detail? Thanks and appreciate everything you guys do. Matthew Raisin, Thanks Matthew. I was doing a bit of reading on this thread and proto planetary disc. One article I read said oh, just theoretical. We don't really know what they are or even if they exist. I thought a minute, what, But yeah, it does open up the question, doesn't it. Yes, but there you've only to look at what the Alder telescope array in the Atta Kama has done. It's imaged many many protoplanetary discs. Then they're definitely a reality. We can even see planets forming inside them. So I think that article might have been very old or possibly so. Yeah, so so the I mean, the protoplanetary disc is the swirling disc of gas and dust which is in orbit around a new, newly born star. So the star has collapsed, its gas content has collapsed to form basically a massive a massive compact object. The creature has gone up enough, the nuclear fusion has started, and the radiation pressure of that nuclear fusion stops further collapse until you've got effectively a star. That's what keeps the Sun going. It's that balance between gravity and radiation. The bottom line, I mean, Matthew is absolutely correct. The bottom line is that the stuff in the protoplanetary disc has you know, a tiny, tiny mass compared with the mass of the star itself, and it's far too small to get to temperatures for its gravity to collapse things to temperature and course temperatures that enough for nuclear fusion. It's just not massive enough. There's not enough energy until you get cool planets for me by accretion. They stick together by their mutual gravity, and that basically is the story. The remain dust and gas that isn't isn't used in that process. Some of it's blown away by winds from the star, some of it the gas. Some of the gas goes towards the envelopes of gas giant planets like Juply and we've got some. Yeah, so we've got a sort of stable solar system like our own. I think Matthew's got it. Got it in one. It's the protoplanets are not are not big enough. There's there's an intermediate stage, by the way, called planets wolves planetism waves are things, you know, a few hundred meters across, and they group together to build protoplanets, which then group together to build planets. So it's a hierarchy process. Do gas giants form in these proto planetary discs, and if so, I mean they are just a step short of becoming a brown dwarf, which is, you know, a failed star. I suppose you could say that's correct. Yes, so they do. They form in the protocolantry discs. But the process that keeps a brown dwarf hot is not nuclear fusion. It's it's a fission process. It's called deuterium burning. And so it's that these are not they counted the stars because there is nuclear processes going on in the interior, but it's not the conventional nuclear fusion that runs a runs a star. And they by definition, they've got to be more than thirteen times the massive Jupiter. So something thirteen times Jupiter's mass will turn into a brown dwarf. You're quite right, but it's not a stark. But you're quite right. You've you've essentially pinpointed one aspect of Matthew's question that I missed, so well done. Didn't didn't meant to just my head as we're going along. I don't know that any brown dwarfs are known in orbits around a big star. In fact, we were talking in the last episode about the what was it eater in the a The eater in this system actually contains two brown dwarfs. It's a triplet system with a red dwarf and two brown dwarfs. So that's near as you get to brown dwarfs being in orbits around around the start. Fair enough, all right, there you go, Matthew, you spot on, and you can tell your son that what you told him was correct. Now a final question comes from a regular who always asks us some interesting questions, but this time he's taken it to a whole new level. Who knows what question? Election in corfar low space knots and years. My last question, Mars is primeorgial atmosphere if it were sort of comparable to the thickness of Earth's press day atmosphere, roughly how long would it have taken to leak away into outer space? And might any intelligent creatures there have noticed it happening in real time as it were with in their lifetimes. Oh and excellent job. Doctor Watson concealing the whereabouts of the planet Falcon, which of course is hidden within a planetary cooking device since the unfortunate shoots Charleston eighteenth Discovery. Wow, Martin, he's changed. He's set a new level. I don't know if it's up or down, but he's set a whole new level for audio questions. So who knows what we're going to get next. But thank you Martin, and well done on the production. That's there was a lot of work went into that. What was he wanted? What do you want to know? Atmosphere? If it's some stage It was similar to worth, how long did it take to eke away vanish? Well it's not vanished completely though, hasn't. No, that's right, but it's very very small. Look it's the answer is, of course it depends, but in this particular Okase, I think we can say it's over millions of years. So you've got a process that is a leakage of the atmosphere, and there is actually a spacecraft that's investigating that Marven or Mayven Mars Atmosphere and Volatile Evolution Mission, which is still active. It's a NASSA mission looking at the leakage of gas from Mars's atmosphere. So we know that the sort of rate that that's going on now, and so it means you're talking about millions, if not billions of years for that leakage to take place. It's the main cause is well, first of all, Mars is not massive enough to hold on to an atmosphere permanently, and you don't have a magnetic field. That means the radiation from the Sun is you know, it reaches the surface, it can essentially damage the atmosphere and so basically you've got this stripping off the atmosphere by the effect of the Sun and the lack of gravity. Already bleak. Really, yes, it's bleak. So if there were species on Mars, would they notice, Yeah, probably, you know, millions of years would take will be a slow process, but they kind of realized because they'd have artifacts from the previous eras that things were changing. And so what they might have done is custod eye on the next planet towards the Sun. And so that looks like a better bet and headed that way. Yeah, that's probably why we're here for it. It could be why we're here. Yeah. I think that was portrayed in a movie once, that we were actually seeded here by Martians who left the planet because it was well, it was dying because I got hit by an asteroid. But yeah, good. What was that red planet? I think it was called Mission to Mars. I can't remember which. They both came out around the same time, but both great films. Did we finish. Answering Martin's question, yes, it would happen over millions of years, and yes, people probably if they were there, would have noticed and ye had taken off for Earth if they're good, which we might have to do one day, are still around, If. We're still around, we might. That's correct, and I dare say that by then we may well have the technology to do so, who knows. Yes, Thank you Martin, great question, and again congratulations on the production. One more thing, Fred before we go. A joke from Misty West, one of our regular listeners and one of our administrators on Facebook, eating too much cake is the sin of gluttony. However, eating too much pie is okay because the sin of pie is always zero. That's clever, Yes, too clever for me. Yeah, thank you, mistery Fred. We're all done again, Thank you, sir. It's a pleasure. So I'm just sick about mister thank you. That's very clever. Thank you, Thank you, Andrew. And we'll see you next week. I'm sure we will, indeed, Professor Fread Watson unless yeah, we'll keep an eye on that. Martin will tell us and we'll see you. So, Fred Watson, Astronomer at Large. And don't forget to visit our website if you haven't done so recently, Space nuts podcast dot comspace Nuts dot ao, where you can deposit your question through the AMA tab or to send us your questions tab on the right hand side, and have a look around. While you there, you can subscribe to the Astronomy Daily News. Latter you can visit the shop. We've got a shop all sorts of bits and bobs in there if you are looking for something different and plenty more on our website, and don't forget to hit subscribe if you're. A YouTube follower. That's just about it. Thanks to here in the studio as always and from me Andrew Dunkley. See you on the very next episode of Space Nuts. Until then, bye bye. You'll be listening to the Space Nuts. Podcast, available at Apple Podcasts, Spotify, iHeartRadio, or your favorite podcast player. 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