#440: Earth Swap Hypotheticals & Europa Clipper Countdown

[00:00:00] Hi there, thanks for joining us on this a Q&A edition of Space Nuts, Andrew Dunkley here and Coming up. We'll be answering questions about Earth changing places with You know another planet in our solar system just a hypothetical we love hypotheticals

[00:00:16] 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 protoplanets and why they don't turn into stars and

[00:00:33] 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 Space Nuts

[00:01:06] Here is again to solve all of these puzzles as sent in by Space Nuts listeners Professor Fred Watson astronomer at large hi Fred I'm not sure about the solve word. I Think contemplate is a better word contemplate peruse

[00:01:24] Yes, I love that word. Yes. Well, we might as well just Go straight into it and our first question today comes from Karik. I think Watson this is Karik calling in from long a day in New Zealand

[00:01:44] What is that a quick question in terms of a episode I was recently listening to about Being tightly locked to the earth and it made me had a bit of a hypothetical question if we were to replace or somehow were able to get the

[00:01:59] 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?

[00:02:20] Would they be slowly sucked off of the earth and eventually we no longer have any liquid water on the earth or what the Earth essentially boiled to the point where that would happen You know, the water would boil off before the water was sucked off essentially

[00:02:36] Just 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

[00:02:48] Thanks, Karik. We're in Australia mate. So we're not we're not far away. We're just across the ditch so I think Karik you're going to be horribly disappointed with what will happen because

[00:03:01] 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 Fred? Well, yeah, that's right. The title yes I mean you're right under the moving Yes

[00:03:17] exchanging places with either of the inter 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

[00:03:42] Kind of quasi tidally locked to the Sun there 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

[00:03:57] Basically resonances of this kind, which is what title locking how the process works so And of course they have both very different worlds from the earth and Venus With this horribly thick atmosphere

[00:04:14] Kind of 90 times the pressure on earth and horrible temperature once it 460 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

[00:04:31] Hence the name the ugly sister which is the name we usually give to Venus so the Reminds me with some time ago. We did talk about Venus and Mars and earth all at one stage Possibly being livable planets Yeah, in the east and yeah done but So

[00:04:53] You know Venus has interesting attributes is highly volcanic It's it Probably has water vapor in its atmosphere, but it's well vaporized its way above Boiling point the atmosphere of Venus is perhaps the most interesting bit because now there are you know

[00:05:14] Heights above the surface of Venus where the temperature is sort of earth like it's 15 degrees Celsius or so Except it's now 17 degrees Celsius that's average temperature Certainly on one day two days last week the the

[00:05:32] But the bottom line is that the Venus's atmosphere is not 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 of biomarkers being discovered in Venus's atmosphere. There's nothing certain

[00:05:51] It's probably not the case but That would be your best bet if you were 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

[00:06:13] Swapping the earth around we yeah, we've been big trouble. Yes, the assertions will be Will be lost they'd be vaporized the atmosphere would not be in good shape You probably have a runway greenhouse effect like Venus has got and it would be nice at all

[00:06:28] Well, you know Venus and earth around about the same size The only other stark difference I suppose is that Venus Rotates in the wrong direction doesn't know yeah, that's that sort of resonance that I was talking about It may maybe

[00:06:45] Maybe it was clouded by something else in the early history of the solar system, but it also may just be a A phenomenon connected with tidal locking where you you slowing down the rotation. It's a very slow rotation And as you said in the wrong direction

[00:07:01] Yeah, so Karik 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

[00:07:18] In fact, I think dogs and cats are living together on earth already So it's sort of this sort of doing this household, but it's just generally a continuous standoff on the frame

[00:07:30] Thanks Karik 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

[00:07:47] 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

[00:08:01] Keep up the great work and never quit the dad jokes Brady, thank you Brady at least someone appreciates them Europa Clipper. Yeah, we are not getting far away from a launch I think It's slated for October the 10th of October 2024 is the launch window

[00:08:24] So we are definitely getting ready for that one and It's it's exciting because its primary goal is to search for signs of life That's that's right And just to answer one of Brady's questions it will going to always around Jupiter Planned anyway

[00:08:44] On the 11th of April 2030. 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, yeah Interesting stuff now The question about what it's going to do is

[00:09:08] 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 launch mass of About six tons thereabouts It's full of instruments which are

[00:09:31] All designed to look at the surface of Europa in great detail and to probe beneath the surface as well So it's it's really As you said Andrew, it's its

[00:09:46] Main goals are to investigate the habitability of Europa whether there could be life there not whether there is life there We're gonna be like that and look for landing sites and so You know, it's it's that's one of them. That will be done from orbit, of course

[00:10:05] 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

[00:10:29] so I'm 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 in ocean

[00:10:41] Confirm the existence and characterize the nature of water within or beneath 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 ice the underneath of the ice layer composition

[00:10:58] Distribution and chemistry of key compounds and the links to ocean composition and the geology the characteristics and Formation of surface features including the sites of recent or current activity Is there tectonic activity in the ice layers of of Europa? And so, you know the instrumentation for

[00:11:19] For doing that I think there are something like 11 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 just described there I think That's a saxophone

[00:11:42] 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 high hyperspectroscope very much the stocking trade of Of you know remote sensing from orbit

[00:12:04] various imaging systems and ultraviolet spectrograph There's radar. This is Something that I like especially the acronym the acronym is reason rea so then and it's the radar for Europa assessment and sounding ocean to nearsurface there you go Very nicely done

[00:12:27] Interior characterization of Europe are using magnetometry another nice acronym ice mag To you know, they'll be magnetometers on board that will sense the magnetic field of Europa And that believe it or not is one of the key indicators of whether there's an ocean there and whether it's And

[00:12:46] 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 antenna to do other experiments To learn about how the spacecraft moves within Europe as gravitational field It's gonna have 45 flybys of Europa

[00:13:11] And we will no doubt learn a lot Beyond 2030 so I'm very interested and I'm delighted that Brady might be able to watch the launch and over he does Calling and tell us yeah, I'm jealous

[00:13:26] We don't get to see many of them out of this country, but 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 this is gonna be an exciting mission for all of those reasons

[00:13:42] How and how quickly will it be like it'll take? Between five and six years to get there I guess once it gets into orbit and gets itself organized and that's going to come in at a fairly close altitude at times 16 miles 25 kilometers

[00:13:56] How fast will it be able to? Start sending us telemetry. I Think we'll get up from the word go will start Very very quickly I think You know from the orbit and perhaps from some of the magnetometry

[00:14:12] I think these will all show up for interesting results quickly so though. Yeah, there might be really Really spectacular things coming from the Europe clip it okay very good. Thanks Brady great to hear from you This is Space Nuts with Andrew Dunkley and Professor Fred Watson

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[00:16:07] 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 Don't know why But I was lamely explaining the nebula hypothesis to my 11 year old son

[00:16:25] 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

[00:16:40] Fission is 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

[00:16:55] Ploto proto planetary dish one article I read said all that just theoretical We don't really know what they are or even if they exist. I thought hang on a minute What? But yeah, it does open up the question doesn't it yes, but there

[00:17:13] You've only to look at what the alder Telescope array in the Atacama has done it's image many many proto planetary 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

[00:17:34] so so the I mean the proto planetary disc is 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

[00:17:57] Massive compact object the temperature has gone up enough that nuclear fusion has started and the radiation pressure of that Nuclear fusion stops for the collapse until you've got effectively a star That's what keeps the Sun going it's that balance between gravity and

[00:18:14] Radiation the bottom line. I mean Matthew is absolutely correct the bottom line is that The stuff in the proto planetary disc has you know a tiny tiny mass compared with the mass of the star itself and it's It's far too Small to get to temperatures

[00:18:36] The first gravity to collapse things to temperature and course temperatures that are enough for nuclear fusion It's just not massive enough. There's not enough energy until you get cool planets for me by creation they stick together by their mutual gravity and That basically is the the story

[00:18:58] The remaining 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 Jupiter

[00:19:14] And we've got some yeah, so we've got a sort of stable solar system like our own I I think Matthew's Got it got it in one. It's yeah The protoplanets are not a lot big enough. There's an intermediate stage by the way called planet is a rules

[00:19:32] Pondels is a rules are things, you know Few hundred meters across and they group together to build proto planets Which then group together to build planets. So it's a hierarchy in process Do gas giants form in these proto planetary discs and if so

[00:19:49] I mean they are just a step shorter becoming a brown dwarf which is You know a failed star I suppose you could say that's correct. Yes, so they do they do form in the protoplanetary discs but the The process that keeps a brown dwarf

[00:20:08] Heart is not nuclear fusion It's it's a it's a fission process called duty deuterium burning And so it's that these are not they're they Counting the stars because there is nuclear processes going on in their interior, but it's not the conventional nuclear fusion that runs a

[00:20:29] runs a star And and they by definition, they've got to be more than 13 times the mass of Jupiter So something 13 times Jupiter's mass will turn into a brown dwarf. You're quite right But it's not a star, but you're quite right. You've you've you've essentially pinpointed

[00:20:45] One aspect of of Matthew's question that I missed so well done Didn't mean to just my head as you're going alone. I don't know that any brown dwarfs are known in orbit around a big star in fact, we were talking in the last episode about

[00:21:06] The what's it eater in D 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 the nearest you get to brown dwarfs being in it all this around around your start

[00:21:23] Fair enough. All right, there you go. Matthew you were spot on and you can tell your son that What you told him was correct Now our final question comes from a regular who

[00:21:38] Always asks us some interesting questions, but this time he's taken it to a whole new level Can they take it? Who knows what question Lex and I thought of her win Gorgor Hello Space Knights And here's my latest question Mars is kind one Joel atmosphere

[00:22:11] If it were sort of comparable to the thickness of Earth's 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. It's in their right size. Oh And

[00:22:42] excellent job Dr. Watson Concealing the Bear about all the planet Falcon, which of course is Hidden within a planetary cloaking device since the unfortunate 2018 Wow

[00:23:09] 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

[00:23:19] Who knows what we're gonna get next but thank you Martin and well done on the production. That's a lot of work went into that What was he wanted what do you want to know Mars?

[00:23:29] If if at some stage it was similar to worth how long did it take to Eek away Vanish well, it's not vanished completely though has it. No, that's right, but it's very very small look it's The answer is of course it depends But in this particular

[00:23:50] Okay, so 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 then there is actually a spacecraft that's Investigating that Marvin or Maven

[00:24:05] Mars and sorry in volatile evolution mission, which is still active. It's a NASA mission Looking at the leakage of gas from Mars is atmosphere So we know that the sort of rate that that's going on now

[00:24:17] And so it means you're talking about millions if not billions of years for that leakage to take place It's it's the main cause is Well, first of all Mars is not massive enough to to hold on to an atmosphere permanently

[00:24:35] And you don't have a magnetic field that means the radiation from the Sun is you know 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

[00:24:58] It's pretty bleak really yes, it's bleak So if there were species on Mars would they notice? Yeah, probably and you know millions of years would take will be a slow process, but they'd Kind of realize because they'd have artifacts from previous eras that things were changing

[00:25:17] And so what they might have done is cast an eye on the next planet in towards the Sun and thought that looks like a better bet And headed that way. Yeah, that's probably why we're here for it. Could be right here

[00:25:28] Yeah, I think that was portrayed in a movie once that we were actually Seated here by Martians who left the planet because it was well it was dying because it got hit by an asteroid but

[00:25:41] 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 That's great films

[00:25:49] 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 Yeah taken off for Earth if they could Which we might have to do one day

[00:26:05] We're 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

[00:26:25] a joke from Misty West one of our Regular listeners and one of her administrators on Facebook Eating too much cake is the sin of gluttony. However eating too much pies Okay, because the sin of pie is always zero That's clever

[00:26:45] Too clever for me, but yeah, thank you Misty Fred. We're all done again. Thank you, sir It's a pleasure so I'm just thinking about Mr. Till thinking that's very clever Thank you. Thank you Andrew and we'll see you next week. I'm sure we will indeed

[00:27:04] Professor Fred Watson unless yeah, we'll keep an eye on that Martin will tell us and We'll see you soon Fred Watson astronomer at large And don't forget to visit our website if you haven't done so recently

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[00:27:44] That's just about it. Thanks to here in the studio as always and from me Andrew Dunkley So you on the very next episode of Spacenuts until then bye-bye Available at Apple podcasts spotify

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