”Jupiter’s not quite as big as we thought.” | Space Nuts: Astronomy Insights & Cosmic Discoveries

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Hello there. Thanks for joining us yet


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again. This is Space Nuts. My name is


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Andrew Dunley. Uh we're here to talk


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astronomy and space science. And on


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today's program, we're going to look at


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a tiny weeny itsybitsy Jupiter. Yes,


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it's not nearly as big as they thought


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it was. In fact, it could lose status as


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a consequence of this. Maybe not, but


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we'll talk about that. We're also going


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to look at a flipping interesting comet


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and uh solar gravitational lens focal


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points. Could we visit them and what


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will that mean? We'll find out on this


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episode of Space Nuts.


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>> 15 seconds. Guidance is internal. 10 9


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Ignition sequence start.


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>> Space Nuts.


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>> 5 4 3 2 1 2 3 4 5 2 1


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>> Space nuts.


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>> Astronauts report. It feels good.


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>> And joining us again to talk about all


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of that stuff and probably a lot more is


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Professor Fred Watson, astronomer at


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large. Hello, Fred.


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>> Hello, Andrew. Good to see you again.


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>> Yep. As always,


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>> love the hoopy shirt.


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>> Oh, yeah. Sorry. It's a very tatty old


00:01:09.520 --> 00:01:11.030
one. This shirt should be buttoning it


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up. This one's tatty.


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>> Tatty, but it's white and it's got more


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food on it than I've ever put in his


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stomach. So,


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>> has it got the Has it got the Space


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Notes logo on it?


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>> Uh, hang on. I'm I've got one here


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somewhere. A Space Nuts logo.


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>> Oh, yeah.


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>> No, I have It's not on It's not not on


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this shirt. It's on the other wide


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shirt.


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>> But um Where did that logo go?


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>> I've lost me logo. Anyway, we'll we'll


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find out better than losing your mojo.


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>> That's true, too. Yes, indeed. Uh let's


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begin because we got a lot to talk


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about. This uh first story uh looks at


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Jupiter, the biggest planet in our solar


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system until we find planet 9. And this


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is a story that's suggesting that


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Jupiter's not quite as big as we thought


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it was.


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>> Yeah. It's it shrunk by well 8


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kilometers.


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>> Yeah.


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>> At the equator and 24 kilometers at the


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poles. So what this is all about and and


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I should just give you the numbers. Uh


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so the revised radius of Jupiter at its


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equator is 71,488


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kilometers


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>> which is actually um I think 4


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kilometers less than we thought before.


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Uh which doubles up to up to uh 8


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kilometers when you're talking about


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diameter. uh but its polar radius uh


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which is


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um 66,842


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and those two numbers are quite


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different which is why Jupiter's


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flattened but at its poles just as


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Saturn is uh but that's actually 24


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kilometers less than the previous


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estimations so for the diameter. So, um,


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it's not a huge amount, but it's


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>> not not when you not when you're talking


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about the size of the planet. That's


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>> exactly that's what I mean. Yeah.


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71,0004. So, it's what 140,000


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kilometers or thereabouts in diameter,


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which is um Yep. 11 Earth diameters,


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which is what we always say.


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>> Um, so uh why well, first of all, how


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have these measurements been made? Uh


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and the answer is that the old


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measurements actually go back a long


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way. They come from the Voyager and


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Pioneer era of the exploration of the


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outer planets and that goes back to the


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70s and 80s. Oh, it does.


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>> Um they uh so what what led to the


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diameter or the size of Jupiter that


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we've been using since then uh is a is


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what's called a radio occultation. So


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the spacecraft is behind as it passes


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behind Jupiter uh its signals get


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refracted actually by uh the atmosphere


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of the planet probably scattered as


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well. Uh but you can time it very


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accurately. Uh you time when the the


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spacecraft disappears behind the planet


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and you know its trajectory. uh you can


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then time when it reappears and from


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that you can calculate the and knowing


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about Jupiter's motion and the


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spacecraft's motion you can calculate


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what the diameter is. Uh so those are


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the values that we've been using ever


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since.


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>> Ah you know I think I know where all of


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this went wrong. They didn't allow for


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it stopping for gas.


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>> Um the the planet or the spacecraft?


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>> The spacecraft.


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>> Well, it's a gas giant. That's right.


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The planet's a gas giant. So yes, that's


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a good point. Yeah.


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>> Um anyway, I let that one pass. Um so,


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moving on. Wasn't very good. It was It


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was all right for the start of the show.


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They usually get better as we go along.


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Um it's uh the new measurements come of


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course from the spacecraft that is


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currently in orbit and working away very


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hard uh at at Jupiter in orbit around


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the planet and that is Juno. NASA's Juno


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mission which has been orbiting Jupiter


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since 2016 uh and doing pretty well.


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It's Yes. It's a decade since we've had


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Juno which gosh it time flies doesn't


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it? Sure does.


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>> Anyway, um so that's allowed much more


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accurate measurements because the space


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that Juno spacecraft its orbit is very


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well understood. It's fairly close to


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Jupiter. Um, but you might think, you


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know, well, why are we so keen to know


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the diameter of the planet to such a


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high degree of accuracy? Uh, and the the


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answer is um to do with our model


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because it is. Yeah, that's right. It's


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to do with our modeling of the planet's


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interior. Um because a small difference


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like that can make a big difference to


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what we imagine the in interior of the


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planet is like and remember of course


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everybody that Jupiter all we see is its


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cloud belts when we look at the planet


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we don't see any surface or any hint of


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a surface so the internal structure of


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Jupiter is something we have to deduce


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from other measurements and the the an


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accurate measurement of the diameter of


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the planet comes into that um so That's


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that's the reason it also uh you know


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one of the other things that's of


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interest in Jupiter is the the behavior


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of the atmosphere itself and the winds


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that blow in Jupiter's atmosphere and


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that also needs an accurate


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understanding of the diameter of the


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planet. Yeah, I actually I was just


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looking at that diagram uh that shows


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the different potential diameter


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situations based on the behavior of the


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planet. And yeah, without wind it loses


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another what 14 kilometers in.


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>> Yes, that's right. It does. Um if you if


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you uh if you imagine the winds aren't


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there, it does. It shrinks. So So the


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And by 14 kilometers exactly, that's the


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radius, not the not the diameter. Um so


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um we we have um you know a tiny figure


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that looks minuscule compared with the


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diameter of the planet itself but it is


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important in understanding the upper


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atmosphere. It's uh if there were no


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winds uh then what we will be seeing


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will be 14 kilometers smaller. I I'm


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surprised that it's taken us a decade to


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figure it out. And Juno is there been


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there nearly 10 years.


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>> Yeah. Um but maybe um you know the the


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accuracy that we're getting with this


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relies on many uh passages of Juno


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around Jupiter. um there will and


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because you're always you know that the


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chord that um of the Jupiter's disc that


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the planet that the spacecraft flies


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behind is different every time. And so


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we you probably need to um build up a


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statistically significant sample of


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entry and egress times when you're


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looking at you know the object


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disappearing by behind the planet.


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Occultation is what we call it. um uh an


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occultation is when one object hides


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another and that's how you're measuring


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uh these diameters. So yeah, it's


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probably it's probably taken 10 years


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partly to amass the data to give us this


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kind of level of accuracy.


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>> So okay, how accurate do you think it is


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now compared to those early um flybys


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with Voyager and Pioneer?


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>> That's a really good question actually.


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I haven't seen any error estimates on


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and um as you know in physics and


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certainly in astronomy too you always


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need a plus or minus an error estimate


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as to you know what the likelihood of


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your measurement um being that number is


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uh and I haven't seen it for these so I


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don't know the answer to that but my


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guess is that we're talking about in the


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region of a kilometer which is um pretty


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impressive for something that diameter


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uh and something that's that far away,


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half a billion kilometers away.


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>> Yeah.


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>> So, does this mean that our estimations


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of other planets in the solar system are


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probably a bit off as well? Uh when you


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consider that uh like Neptune, for


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example, I think we've only visited


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once. Would that be right?


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>> Yeah. Yeah, that's right. Uh so, yes, I


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I I think you're right. you know, you


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certainly the the um estimates of


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planets beyond Jupiter and Saturn in


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terms of their diameter and physical


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characteristics will have much bigger


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error limits on them just because we


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can't make the measurements as


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accurately as you can when you've got a


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spacecraft in orbit around one of them.


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>> Okay. So, um that's that's a work in


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progress. Whenever we go back, we might


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be able to


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>> fix that. But, uh I don't know. Have


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they got any missions planned for


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Neptune and Uranus or anything?


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>> There's there's always calls for them


00:10:04.399 --> 00:10:06.310
because they're such interesting worlds.


00:10:06.320 --> 00:10:06.630
>> Yeah.


00:10:06.640 --> 00:10:08.949
>> Um but I don't think I mean I think


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there are uh there are lots of proposals


00:10:12.000 --> 00:10:13.110
but I don't think there's anything


00:10:13.120 --> 00:10:14.949
funded. Might be wrong about that.


00:10:14.959 --> 00:10:16.470
>> Maybe our listeners can tell me if I'm


00:10:16.480 --> 00:10:18.630
wrong about that. They they may well cuz


00:10:18.640 --> 00:10:20.470
a lot of the actually we've got one


00:10:20.480 --> 00:10:23.190
fellow on Facebook who regularly uh


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researches some of the things we talk


00:10:24.959 --> 00:10:26.790
about and he publishes his findings on


00:10:26.800 --> 00:10:28.790
on the Facebook podcast group.


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>> Good on


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>> um yeah and I I think it's great. I've


00:10:32.160 --> 00:10:34.230
read a few of his um explanations and


00:10:34.240 --> 00:10:36.310
they're they're very good. Um so we're


00:10:36.320 --> 00:10:38.790
probably going to get sacked but uh it's


00:10:38.800 --> 00:10:40.870
um


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surprised them sacked us all.


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>> Well they they can afford us. that's why


00:10:46.320 --> 00:10:47.670
we're still here. Um,


00:10:47.680 --> 00:10:50.310
>> well, that's true. Yes, true. Very true.


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>> No, it's it's it's a really good


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discussion point. So, it sort of keeps


00:10:53.600 --> 00:10:55.590
the momentum going when when we discuss


00:10:55.600 --> 00:10:57.190
these things. So, I'm sure it'll work on


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our uh our tiny Jupiter story. Uh, which


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um


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>> Good.


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>> Yes. Which you can read about at the


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daily galaxy.com website or you can read


00:11:05.920 --> 00:11:09.430
the paper at Nature Astronomy. This is


00:11:09.440 --> 00:11:11.350
Space Nuts with Andrew Dunley and


00:11:11.360 --> 00:11:17.670
Professor Fred Watson.


00:11:17.680 --> 00:11:20.150
That's agre that's agreement. He's at


00:11:20.160 --> 00:11:25.430
for goodness sake. I'm really sorry.


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>> Okay.


00:11:26.399 --> 00:11:28.870
>> He gets very enthusiastic. Hang on. Hang


00:11:28.880 --> 00:11:31.750
on.


00:11:31.760 --> 00:11:33.430
>> Space nuts.


00:11:33.440 --> 00:11:35.430
>> I I couldn't help but turn that into a


00:11:35.440 --> 00:11:36.310
link.


00:11:36.320 --> 00:11:38.310
>> It's It's Yeah. Brilliant. I'll tell


00:11:38.320 --> 00:11:39.030
him.


00:11:39.040 --> 00:11:41.430
>> Oh gosh. It's just too good. It's just


00:11:41.440 --> 00:11:42.949
too good. But he was going off his nut


00:11:42.959 --> 00:11:44.230
that day, wasn't he?


00:11:44.240 --> 00:11:45.990
>> He was.


00:11:46.000 --> 00:11:48.069
He was. He does. Yes. He's very highly


00:11:48.079 --> 00:11:48.790
strung nut, though.


00:11:48.800 --> 00:11:50.310
>> Yes. He is. Well, that that's how he


00:11:50.320 --> 00:11:52.230
that's how he greeted us when we visited


00:11:52.240 --> 00:11:54.310
you late last year. He came tearing down


00:11:54.320 --> 00:11:56.069
the stairs.


00:11:56.079 --> 00:11:58.389
>> Yeah. Doing his rooster impersonation.


00:11:58.399 --> 00:12:00.870
>> No one could ever rob you, Fred. No one.


00:12:00.880 --> 00:12:03.750
>> That's the one good thing about it. Yes,


00:12:03.760 --> 00:12:04.790
that is the one good thing.


00:12:04.800 --> 00:12:06.230
>> They don't have to be big aggressive


00:12:06.240 --> 00:12:09.190
dogs. They they just have to be loud.


00:12:09.200 --> 00:12:11.030
>> Or or even, you know, a brush turkey


00:12:11.040 --> 00:12:12.389
going past the window in the middle of


00:12:12.399 --> 00:12:15.350
the night. That's enough as well.


00:12:15.360 --> 00:12:17.190
>> Yes, that's uh that's all it takes


00:12:17.200 --> 00:12:20.150
sometimes. Now, let's move on to our


00:12:20.160 --> 00:12:22.629
next story. And this this is a story


00:12:22.639 --> 00:12:25.350
that's got scientists uh really well,


00:12:25.360 --> 00:12:27.750
the headline says scientists stunned.


00:12:27.760 --> 00:12:30.949
We're talking about uh a comet that has


00:12:30.959 --> 00:12:34.069
done something really really unusual.


00:12:34.079 --> 00:12:37.670
Unusual. We're talking about comet 41P.


00:12:37.680 --> 00:12:39.990
What's it done this time?


00:12:40.000 --> 00:12:42.310
>> Cuz it keeps making the news this one.


00:12:42.320 --> 00:12:46.230
>> Yes, it does. Tuttle Jacobini Cresac is


00:12:46.240 --> 00:12:49.269
its full name. Uh comet better known as


00:12:49.279 --> 00:12:53.030
41P. Uh it's an object uh probably a


00:12:53.040 --> 00:12:56.310
kilometer across. A flying iceberg like


00:12:56.320 --> 00:12:59.350
basically like comets are. Um and it


00:12:59.360 --> 00:13:01.430
orbits the sun I think about every 5 and


00:13:01.440 --> 00:13:03.590
a half years. So it's in a what we will


00:13:03.600 --> 00:13:07.750
call a short period comet orbit. Um and


00:13:07.760 --> 00:13:10.150
it's uh when it passes near the sun, of


00:13:10.160 --> 00:13:12.310
course it does what comets do. It uh out


00:13:12.320 --> 00:13:17.030
gases uh produces um u basically plumes


00:13:17.040 --> 00:13:20.629
of of gas leaving its surface. Um it's


00:13:20.639 --> 00:13:23.269
usually water ice being converted


00:13:23.279 --> 00:13:26.470
directly to water vapor by the process


00:13:26.480 --> 00:13:30.230
known as sublimation. Um uh but what has


00:13:30.240 --> 00:13:36.629
been recorded uh in uh uh in fact in


00:13:36.639 --> 00:13:38.150
quite a while ago actually I think this


00:13:38.160 --> 00:13:40.550
is eight years ago by a NASA spacecraft


00:13:40.560 --> 00:13:42.790
observations made by NASA Swift


00:13:42.800 --> 00:13:47.910
spacecraft um measuring its rotation and


00:13:47.920 --> 00:13:51.670
basically over 60 days what's that sort


00:13:51.680 --> 00:13:54.470
of nine weeks or something like that


00:13:54.480 --> 00:13:58.710
>> um it slowed down from rotating once


00:13:58.720 --> 00:14:03.110
every 20 hours to once every 53 hours.


00:14:03.120 --> 00:14:05.269
Uh so that is a you know it's almost a


00:14:05.279 --> 00:14:09.590
three factor of three uh in this the um


00:14:09.600 --> 00:14:12.069
level of spin that this comet has got.


00:14:12.079 --> 00:14:12.470
>> Yeah.


00:14:12.480 --> 00:14:16.949
>> Uh and it's there's suggestion


00:14:16.959 --> 00:14:20.470
that maybe it's now rotating in the


00:14:20.480 --> 00:14:24.150
other direction uh from what it was


00:14:24.160 --> 00:14:26.150
before that there's been some sort of


00:14:26.160 --> 00:14:28.470
reverse. It hasn't slowed down to about


00:14:28.480 --> 00:14:31.910
1/3. It's It's reversed. So, it's it's


00:14:31.920 --> 00:14:34.629
slowed down five times


00:14:34.639 --> 00:14:36.389
>> cuz it's going back the other way.


00:14:36.399 --> 00:14:39.189
>> It could be I mean, part of it could be


00:14:39.199 --> 00:14:41.750
due to how you measure the rotation


00:14:41.760 --> 00:14:43.590
because it could be tumbling as well.


00:14:43.600 --> 00:14:45.030
So, you might be seeing it going the


00:14:45.040 --> 00:14:46.310
other way around. But, it does seem to


00:14:46.320 --> 00:14:48.230
be I think you're right. It's I think


00:14:48.240 --> 00:14:49.670
what you've just said is correct that


00:14:49.680 --> 00:14:51.990
it's a it's a reversal, a genuine


00:14:52.000 --> 00:14:55.750
reversal of its rotation direction. Um,


00:14:55.760 --> 00:14:58.069
so yes, it's it's got much more than a


00:14:58.079 --> 00:14:59.430
factor of three. That's right.


00:14:59.440 --> 00:15:01.590
>> That kills my theory because my first


00:15:01.600 --> 00:15:03.350
thought was, well, this must just be an


00:15:03.360 --> 00:15:05.990
observational error. But an


00:15:06.000 --> 00:15:07.750
observational error wouldn't get it the


00:15:07.760 --> 00:15:10.069
wrong way round, unless of course you


00:15:10.079 --> 00:15:11.269
you're talking about the color of the


00:15:11.279 --> 00:15:15.030
universe, but we won't go there. But um,


00:15:15.040 --> 00:15:18.389
>> wasn't my fault.


00:15:18.399 --> 00:15:21.670
>> Um, so yeah. Uh, what else could be


00:15:21.680 --> 00:15:24.550
causing this change of behavior? it. I


00:15:24.560 --> 00:15:26.790
think if if it was anything other than a


00:15:26.800 --> 00:15:29.110
comet, you know, if it was an asteroid


00:15:29.120 --> 00:15:33.430
doing this or a planetisimal or or a a


00:15:33.440 --> 00:15:35.430
distant one of the distant Kyper belt


00:15:35.440 --> 00:15:37.269
objects or something like that, it was


00:15:37.279 --> 00:15:40.069
if it was any of those, we would be


00:15:40.079 --> 00:15:42.550
utterly gobsmacked. Uh because there's


00:15:42.560 --> 00:15:44.870
no physical mechanism to do that other


00:15:44.880 --> 00:15:47.509
than an interaction with another body.


00:15:47.519 --> 00:15:49.350
You know, if you had two bodies


00:15:49.360 --> 00:15:51.990
gravitating close together, it could


00:15:52.000 --> 00:15:54.310
have an effect on the rotation.


00:15:54.320 --> 00:15:56.230
>> But, uh, in fact, more especially a


00:15:56.240 --> 00:15:58.550
collision, that would do it as well. Um,


00:15:58.560 --> 00:16:00.389
but with a comet, you've got this


00:16:00.399 --> 00:16:02.710
process that it outgasses. what I was


00:16:02.720 --> 00:16:05.430
saying earlier as it gets near the sun


00:16:05.440 --> 00:16:09.030
um the there basically the ices start to


00:16:09.040 --> 00:16:12.470
vaporize and you get a thrust from the


00:16:12.480 --> 00:16:16.230
from the outgassing material uh which is


00:16:16.240 --> 00:16:17.829
what we call a non-gravitational


00:16:17.839 --> 00:16:21.030
perturbation. It's when uh when you know


00:16:21.040 --> 00:16:23.030
the the outgassing material is acting


00:16:23.040 --> 00:16:25.990
like a rocket engine and it's changing


00:16:26.000 --> 00:16:29.269
the dynamics of the object as it's


00:16:29.279 --> 00:16:31.910
orbiting the sun. Um, and you can


00:16:31.920 --> 00:16:35.590
imagine that if there was um a formation


00:16:35.600 --> 00:16:38.710
of ice on the on the surface of the


00:16:38.720 --> 00:16:41.350
comet that essentially tilted the blast


00:16:41.360 --> 00:16:46.069
of the of the um escaping material uh as


00:16:46.079 --> 00:16:49.910
it as it sublimated as the as the um the


00:16:49.920 --> 00:16:52.470
material the water mostly went straight


00:16:52.480 --> 00:16:55.030
from a solid to a gas. Um it's like


00:16:55.040 --> 00:16:57.670
having a you know a sort of verier


00:16:57.680 --> 00:16:59.829
thruster. It's like where you've got a a


00:16:59.839 --> 00:17:01.910
thrust that is changing the rotation of


00:17:01.920 --> 00:17:04.949
a spacecraft because it's not going um


00:17:04.959 --> 00:17:07.590
the line of of the of the thrust is not


00:17:07.600 --> 00:17:09.510
going through the center of gravity of


00:17:09.520 --> 00:17:11.270
the comet. If it's off the center of


00:17:11.280 --> 00:17:12.789
gravity, then it's going to impart a


00:17:12.799 --> 00:17:14.390
rotation on it. And if it's strong


00:17:14.400 --> 00:17:16.309
enough, then it might be enough to slow


00:17:16.319 --> 00:17:18.549
it down and perhaps even reverse its uh


00:17:18.559 --> 00:17:21.189
reverse its rotation. So that's what the


00:17:21.199 --> 00:17:22.710
thinking is, but it's never been seen


00:17:22.720 --> 00:17:23.429
before.


00:17:23.439 --> 00:17:26.949
>> No. Well, like retro rockets.


00:17:26.959 --> 00:17:29.270
>> Yeah, that's right. is a retro rocket,


00:17:29.280 --> 00:17:32.070
but one that that's not slowing it down


00:17:32.080 --> 00:17:34.230
in its orbit. It's changing its rotation


00:17:34.240 --> 00:17:35.830
because of the angle that the the


00:17:35.840 --> 00:17:37.990
rocket, if you want to call it that, the


00:17:38.000 --> 00:17:40.470
rocket exhaust is coming out.


00:17:40.480 --> 00:17:43.510
>> Yeah. At the moment, it's 774 million


00:17:43.520 --> 00:17:47.510
kilometers from Earth, 5.18 astronomical


00:17:47.520 --> 00:17:51.110
units. And uh as you mentioned, this


00:17:51.120 --> 00:17:54.710
unusual behavior was checked back in


00:17:54.720 --> 00:17:59.190
2017 and they've only just sort of put a


00:17:59.200 --> 00:18:01.669
paper together to try and explain it. Um


00:18:01.679 --> 00:18:04.390
it's got a 5.4 year orbit, so it comes


00:18:04.400 --> 00:18:05.830
back quite often.


00:18:05.840 --> 00:18:08.549
>> Yeah, that's right. It's um it it's it's


00:18:08.559 --> 00:18:11.190
capt basically captured by Jupiter.


00:18:11.200 --> 00:18:13.590
>> So its orbit is dictated. It would have


00:18:13.600 --> 00:18:15.590
been in its early history, it would have


00:18:15.600 --> 00:18:17.990
been a comet coming into the inner solar


00:18:18.000 --> 00:18:20.310
system from the or cloud, this spherical


00:18:20.320 --> 00:18:22.950
sort of reservoir of comets. Um, but


00:18:22.960 --> 00:18:25.190
would have had its orbit modified maybe


00:18:25.200 --> 00:18:26.870
several times by the influence of


00:18:26.880 --> 00:18:29.430
Jupiter, which is why it's now in this


00:18:29.440 --> 00:18:33.430
really short um short period orbit, 5.4


00:18:33.440 --> 00:18:34.310
years. Yeah.


00:18:34.320 --> 00:18:37.990
>> Um there has been a suggestion that if


00:18:38.000 --> 00:18:39.510
you've got these sort of oblique


00:18:39.520 --> 00:18:41.190
outgassing that we've just been talking


00:18:41.200 --> 00:18:43.590
about that would change the rotation of


00:18:43.600 --> 00:18:47.029
the object that that might also signal


00:18:47.039 --> 00:18:48.789
that there might be weaknesses in the


00:18:48.799 --> 00:18:51.350
comet structure and it may even be a


00:18:51.360 --> 00:18:53.430
precursor to it breaking up which is


00:18:53.440 --> 00:18:55.909
something that I think will be observed


00:18:55.919 --> 00:18:58.230
with great interest as to how it uh how


00:18:58.240 --> 00:19:01.190
it progresses uh since since this change


00:19:01.200 --> 00:19:01.830
of spin.


00:19:01.840 --> 00:19:03.750
>> Yeah, maybe. And we we'll find we could


00:19:03.760 --> 00:19:06.710
find out as late as or as soon as late


00:19:06.720 --> 00:19:08.230
2028


00:19:08.240 --> 00:19:11.750
I think is its next appearance near the


00:19:11.760 --> 00:19:14.310
sun or near us or whatever you like. So


00:19:14.320 --> 00:19:15.110
um


00:19:15.120 --> 00:19:19.110
>> yeah we'll keep an eye on 41p I guess


00:19:19.120 --> 00:19:21.830
>> 41p that's right. Um there was a


00:19:21.840 --> 00:19:26.310
proposal long long ago uh to send a


00:19:26.320 --> 00:19:28.549
spacecraft to it because it's a short


00:19:28.559 --> 00:19:30.470
period comet. So it's always in the


00:19:30.480 --> 00:19:32.789
inner solar system and that was what was


00:19:32.799 --> 00:19:35.430
then called Ezro European Space Research


00:19:35.440 --> 00:19:38.390
Organization the the precursor of the


00:19:38.400 --> 00:19:40.950
European Space Agency. Uh this is in the


00:19:40.960 --> 00:19:43.190
1960s. They looked at sending a probe to


00:19:43.200 --> 00:19:45.430
that comet but they changed their mind


00:19:45.440 --> 00:19:47.350
so it never went.


00:19:47.360 --> 00:19:51.190
>> A yes. I'm sure that happens a lot in in


00:19:51.200 --> 00:19:54.070
astronomy. I mean, it's not an easy not


00:19:54.080 --> 00:19:58.070
an easy thing to um to do to to, you


00:19:58.080 --> 00:20:00.390
know, set up a mission and actually


00:20:00.400 --> 00:20:01.909
execute it. You got to come up with the


00:20:01.919 --> 00:20:05.190
dollars and Yeah. You know, it's only


00:20:05.200 --> 00:20:07.029
only so many 10-centent pieces can fit


00:20:07.039 --> 00:20:10.310
on a jar on the mantle piece. So,


00:20:10.320 --> 00:20:12.950
>> yeah. Yeah, that's right.


00:20:12.960 --> 00:20:15.830
>> Yeah. All right. Um, you can read all


00:20:15.840 --> 00:20:19.350
about uh comet 41P


00:20:19.360 --> 00:20:22.310
uh at um it's at the daily galaxy.com


00:20:22.320 --> 00:20:23.909
website, but you can also read the


00:20:23.919 --> 00:20:26.070
paper. I think it's just uh been


00:20:26.080 --> 00:20:29.110
pre-published or pre there's a pre-print


00:20:29.120 --> 00:20:32.789
available uh on the archive. Uh this is


00:20:32.799 --> 00:20:34.710
Space Nuts. Andrew Dunley here with


00:20:34.720 --> 00:20:38.630
Professor Fred. What's that?


00:20:38.640 --> 00:20:42.549
>> I'm going to step off the limb now.


00:20:42.559 --> 00:20:47.830
That's one small step for man,


00:20:47.840 --> 00:20:50.789
one leap for mankind.


00:20:50.799 --> 00:20:52.549
>> Space nuts.


00:20:52.559 --> 00:20:54.789
>> Now, Fred, to our final story on this


00:20:54.799 --> 00:20:57.350
episode, we've talked many times about


00:20:57.360 --> 00:20:59.830
gravitational lensing and some of the


00:20:59.840 --> 00:21:01.590
strange things that it does. You can


00:21:01.600 --> 00:21:03.590
watch something happen two, three, four


00:21:03.600 --> 00:21:06.070
times over the course of many years


00:21:06.080 --> 00:21:07.830
because of gravitational lensing because


00:21:07.840 --> 00:21:11.350
the light is redirected and takes longer


00:21:11.360 --> 00:21:12.789
to get here. And so you can see


00:21:12.799 --> 00:21:14.789
something and go, "Oh, what was that?


00:21:14.799 --> 00:21:16.310
Hang on. I'll I'll know again in a


00:21:16.320 --> 00:21:18.470
couple of years." Because


00:21:18.480 --> 00:21:21.430
yeah, not quite. But um what we're


00:21:21.440 --> 00:21:22.470
talking about in


00:21:22.480 --> 00:21:23.110
>> Yeah.


00:21:23.120 --> 00:21:24.630
>> What we're talking about in this


00:21:24.640 --> 00:21:27.590
particular case though is actually going


00:21:27.600 --> 00:21:31.750
out to a solar gravitational lens focal


00:21:31.760 --> 00:21:33.830
point. Is that the crux of the story?


00:21:33.840 --> 00:21:36.390
>> It it is. That's right. It's a this is a


00:21:36.400 --> 00:21:38.630
really interesting kind of essay really


00:21:38.640 --> 00:21:42.070
on the universe today website by Andy


00:21:42.080 --> 00:21:45.750
Thomas Wick uh about um about the solar


00:21:45.760 --> 00:21:47.510
gravitational lens and about how you'd


00:21:47.520 --> 00:21:49.750
get there. Um but the solar


00:21:49.760 --> 00:21:51.590
gravitational lens itself is really


00:21:51.600 --> 00:21:54.310
interesting. So the idea is exactly as


00:21:54.320 --> 00:21:57.750
you've said if you've got a an object of


00:21:57.760 --> 00:21:59.909
any mass and it happens with planets as


00:21:59.919 --> 00:22:03.590
well as stars uh it's going to bend the


00:22:03.600 --> 00:22:05.350
light passing around it because it's


00:22:05.360 --> 00:22:08.390
distorting space uh under the uh under


00:22:08.400 --> 00:22:12.390
the protocols introduced by um not in


00:22:12.400 --> 00:22:14.390
sorry as we understand it by the


00:22:14.400 --> 00:22:16.870
protocols introduced by Einstein's


00:22:16.880 --> 00:22:18.870
general theory of relativity that's what


00:22:18.880 --> 00:22:20.789
lets us calc do all the calculations


00:22:20.799 --> 00:22:22.390
about this sort of So, you've got an


00:22:22.400 --> 00:22:24.470
object in space. It's bending the light


00:22:24.480 --> 00:22:26.149
around it, which means it acts kind of


00:22:26.159 --> 00:22:28.630
like a lens. It's a very odd sort of


00:22:28.640 --> 00:22:32.230
lens, though. Um, I've seen a glass kind


00:22:32.240 --> 00:22:34.470
of interpretation of a gravitational


00:22:34.480 --> 00:22:38.230
lens. Um, there's a specialist who uh


00:22:38.240 --> 00:22:40.230
who works on this stuff in Melbourne who


00:22:40.240 --> 00:22:42.390
showed me her glass version of a


00:22:42.400 --> 00:22:45.750
gravitational lens. And it it resembles,


00:22:45.760 --> 00:22:47.669
you know, the the bottom of a wine glass


00:22:47.679 --> 00:22:49.510
where the the stalk comes up out of the


00:22:49.520 --> 00:22:51.430
middle of that. I I know them very well,


00:22:51.440 --> 00:22:52.230
Fred.


00:22:52.240 --> 00:22:54.710
>> Yeah. Yeah. Um well, if you break the


00:22:54.720 --> 00:22:57.669
wine glass off and you're left with that


00:22:57.679 --> 00:22:59.270
sort of flared part at the bottom,


00:22:59.280 --> 00:23:01.270
that's more or less the same as a


00:23:01.280 --> 00:23:02.870
gravitational lens in the way it would


00:23:02.880 --> 00:23:04.710
act on the light going around it.


00:23:04.720 --> 00:23:06.710
>> So, it's not it's not like a magnifying


00:23:06.720 --> 00:23:08.310
glass, which is what you'd like it to


00:23:08.320 --> 00:23:11.750
be. It's this very peculiar cuspshaped


00:23:11.760 --> 00:23:16.149
lens. And so it gives you um a focus


00:23:16.159 --> 00:23:19.510
that is blurred, but it's because you


00:23:19.520 --> 00:23:21.750
know the properties of the of the object


00:23:21.760 --> 00:23:23.350
that's doing the lensing. And in this


00:23:23.360 --> 00:23:25.830
case, we're talking about the sun. Uh


00:23:25.840 --> 00:23:27.350
because you know the properties of the


00:23:27.360 --> 00:23:29.830
sun, you can calculate what that


00:23:29.840 --> 00:23:32.149
blurring does to the image and you can


00:23:32.159 --> 00:23:34.710
essentially compensate it. So you could


00:23:34.720 --> 00:23:36.310
recreate


00:23:36.320 --> 00:23:38.789
uh the light coming from a very distant


00:23:38.799 --> 00:23:42.390
object um and recreate the image that


00:23:42.400 --> 00:23:44.630
the sun is forming as though it was a


00:23:44.640 --> 00:23:46.950
proper lens rather than a peculiar


00:23:46.960 --> 00:23:49.669
cusped lens. And that's what's sort of


00:23:49.679 --> 00:23:51.350
being proposed. Could we send a


00:23:51.360 --> 00:23:55.350
spacecraft to uh the solar gravitational


00:23:55.360 --> 00:24:00.390
lens focus where you could look directly


00:24:00.400 --> 00:24:03.830
back at a planet on the other side of


00:24:03.840 --> 00:24:07.990
the sun around a distant star? So you're


00:24:08.000 --> 00:24:10.070
looking into another solar system a long


00:24:10.080 --> 00:24:12.149
way away, but you're using the sun's


00:24:12.159 --> 00:24:15.909
gravity to bend that light by relativity


00:24:15.919 --> 00:24:18.950
and focus it to a point. Uh, and if you


00:24:18.960 --> 00:24:21.190
put a spacecraft there with a camera and


00:24:21.200 --> 00:24:23.830
a fancy computer, you might be able to


00:24:23.840 --> 00:24:26.950
reveal continents on an exoplanet, for


00:24:26.960 --> 00:24:28.149
example.


00:24:28.159 --> 00:24:30.870
>> Um, or even cities. That's the sort of


00:24:30.880 --> 00:24:33.110
thing that people are thinking of. So,


00:24:33.120 --> 00:24:35.029
here's the snag, though. That's a great


00:24:35.039 --> 00:24:36.630
idea, but snag.


00:24:36.640 --> 00:24:39.990
>> I think I just read that exact paragraph


00:24:40.000 --> 00:24:41.909
as you were about to say it, so I might


00:24:41.919 --> 00:24:43.510
blow the whistle.


00:24:43.520 --> 00:24:45.269
>> Yeah. Well, you can.


00:24:45.279 --> 00:24:47.669
>> No, no, you do it. It it's the distance,


00:24:47.679 --> 00:24:50.950
isn't it? It's it's Yeah. Um about


00:24:50.960 --> 00:24:53.350
somewhere between 650 and 900


00:24:53.360 --> 00:24:55.510
astronomical units is what's quoted in


00:24:55.520 --> 00:24:57.190
this in this article. And an


00:24:57.200 --> 00:24:59.669
astronomical unit is 150 million


00:24:59.679 --> 00:25:02.390
kilometers. So it is a number with a lot


00:25:02.400 --> 00:25:07.190
of zeros after it in kilometers. Um and


00:25:07.200 --> 00:25:09.590
you know it's getting your spacecraft


00:25:09.600 --> 00:25:11.909
there that is the issue. Uh we're


00:25:11.919 --> 00:25:13.990
talking about well the estimate here is


00:25:14.000 --> 00:25:15.909
four times further than Voyager 1 has


00:25:15.919 --> 00:25:19.590
traveled and that as we know is 23 light


00:25:19.600 --> 00:25:23.110
hours away. Um they reckon that it would


00:25:23.120 --> 00:25:28.070
be um more than another 130 years to uh


00:25:28.080 --> 00:25:31.669
for Voyager 1 to get to the the sun's


00:25:31.679 --> 00:25:34.230
gravitational lens point. By my


00:25:34.240 --> 00:25:36.310
calculation, and and this is probably


00:25:36.320 --> 00:25:39.430
way wrong, 97,500


00:25:39.440 --> 00:25:41.350
million kilometers.


00:25:41.360 --> 00:25:43.430
>> Sounds about right. Sounds like a lot.


00:25:43.440 --> 00:25:43.990
>> Yep.


00:25:44.000 --> 00:25:45.750
>> I didn't think my calculator could fit


00:25:45.760 --> 00:25:48.390
that many numbers on it.


00:25:48.400 --> 00:25:50.230
>> Remember the old the old calculators


00:25:50.240 --> 00:25:51.669
when they first came out? If you gave it


00:25:51.679 --> 00:25:53.110
too big a problem, it would just give


00:25:53.120 --> 00:25:54.950
you a little E.


00:25:54.960 --> 00:25:55.269
>> Yeah.


00:25:55.279 --> 00:25:57.590
>> E for error. No, I can't do that. Sorry.


00:25:57.600 --> 00:25:59.669
>> Yep. Yeah. This computer says no,


00:25:59.679 --> 00:26:00.630
really, isn't it?


00:26:00.640 --> 00:26:02.870
>> That's right. Yeah, that's a long way


00:26:02.880 --> 00:26:06.390
away and very difficult to achieve, but


00:26:06.400 --> 00:26:08.630
I think one day maybe we could do that.


00:26:08.640 --> 00:26:10.549
>> Yes. So that that's really the thrust of


00:26:10.559 --> 00:26:12.549
this article. How about you know what's


00:26:12.559 --> 00:26:16.549
the way to do it? Can you can you get to


00:26:16.559 --> 00:26:19.830
that point and they um the author's done


00:26:19.840 --> 00:26:21.510
some nice calculations which I haven't


00:26:21.520 --> 00:26:23.590
checked so I hope these are correct. I


00:26:23.600 --> 00:26:27.269
should check them. Anyway, um if you


00:26:27.279 --> 00:26:29.029
were trying to get to that solar


00:26:29.039 --> 00:26:32.149
gravitational lens point, focal point in


00:26:32.159 --> 00:26:34.870
20 years, then you need your spacecraft


00:26:34.880 --> 00:26:38.789
to travel at about 150 kilometers/s.


00:26:38.799 --> 00:26:43.909
Um uh it's which is very hard uh when


00:26:43.919 --> 00:26:45.750
you're pointing away from the sun. The


00:26:45.760 --> 00:26:47.990
Parker Solar Probe, they point out, and


00:26:48.000 --> 00:26:49.269
we kind of know this because we've


00:26:49.279 --> 00:26:51.110
talked about it, has actually got to


00:26:51.120 --> 00:26:53.590
nearly 200 kilometers/s,


00:26:53.600 --> 00:26:55.350
but that's only when it's at what we


00:26:55.360 --> 00:26:57.669
call perihelion. It's at its closest


00:26:57.679 --> 00:26:59.669
point to the sun where it's going


00:26:59.679 --> 00:27:02.310
fastest. Um, and what we're talking


00:27:02.320 --> 00:27:03.590
about here is something going in the


00:27:03.600 --> 00:27:05.350
opposite direction, going away from the


00:27:05.360 --> 00:27:07.510
sun. For it to travel at that sort of


00:27:07.520 --> 00:27:09.830
speed, you need an extraordinary amount


00:27:09.840 --> 00:27:12.710
of thrust. Um, I don't think you're


00:27:12.720 --> 00:27:14.470
talking about chemical rockets to get up


00:27:14.480 --> 00:27:16.549
to 150 kilometers/s.


00:27:16.559 --> 00:27:17.350
>> Light sales.


00:27:17.360 --> 00:27:20.950
>> So, light sails. Yeah, that's uh one of


00:27:20.960 --> 00:27:22.470
the things that you and I have spoken


00:27:22.480 --> 00:27:24.149
about before. If you can


00:27:24.159 --> 00:27:28.630
>> beam out laser light to a solar sail, a


00:27:28.640 --> 00:27:31.350
gigantic um piece of, you know,


00:27:31.360 --> 00:27:33.190
something very thin like myar that's


00:27:33.200 --> 00:27:35.350
reflective. Uh then the light itself


00:27:35.360 --> 00:27:37.269
pushes it along and you just keep going


00:27:37.279 --> 00:27:39.830
so that it just keeps up building up


00:27:39.840 --> 00:27:40.789
speed.


00:27:40.799 --> 00:27:42.870
>> Um there are um


00:27:42.880 --> 00:27:44.390
>> the trouble with that is when you get


00:27:44.400 --> 00:27:46.149
there, how do you stop it?


00:27:46.159 --> 00:27:47.750
>> Yeah, you don't. You just keep going.


00:27:47.760 --> 00:27:48.710
That's right.


00:27:48.720 --> 00:27:50.710
>> Unless Unless it had something on board


00:27:50.720 --> 00:27:54.630
to like you turn off the light and


00:27:54.640 --> 00:27:57.029
>> reverse or something. I don't know.


00:27:57.039 --> 00:27:58.630
>> Yeah. You're never going to slow it down


00:27:58.640 --> 00:28:01.190
because even if you turn off the light,


00:28:01.200 --> 00:28:03.269
it stops it accelerating, but it's still


00:28:03.279 --> 00:28:05.590
going at that speed. That's right.


00:28:05.600 --> 00:28:11.190
>> Um there's a a possibility that um you


00:28:11.200 --> 00:28:14.870
know, could you could you do the solar


00:28:14.880 --> 00:28:19.909
sail trick um and and


00:28:19.919 --> 00:28:23.029
basically um make it successful? The


00:28:23.039 --> 00:28:25.990
problem with solar sales is you you can


00:28:26.000 --> 00:28:28.470
only carry objects that are very light


00:28:28.480 --> 00:28:30.549
in weight or have low mass. And you


00:28:30.559 --> 00:28:33.029
might remember we've looked at this uh


00:28:33.039 --> 00:28:35.590
with um what was it the Breakthrough


00:28:35.600 --> 00:28:38.149
Starshot program which I think has now


00:28:38.159 --> 00:28:40.389
ceased. Breakthrough Starshot looked at


00:28:40.399 --> 00:28:42.549
the feasibility of using a solar sail to


00:28:42.559 --> 00:28:45.430
send a a spacecraft to Proxima Centuri


00:28:45.440 --> 00:28:48.710
which is only four light years away. Um,


00:28:48.720 --> 00:28:51.110
and uh, it could be done, but your


00:28:51.120 --> 00:28:54.470
spacecraft would basically consist of


00:28:54.480 --> 00:28:57.750
uh, one um, what's it called? Printed


00:28:57.760 --> 00:29:00.310
circuit board and a detector. Uh,


00:29:00.320 --> 00:29:01.590
there's not really room for anything


00:29:01.600 --> 00:29:03.830
else. It will be so it'd have to be so


00:29:03.840 --> 00:29:05.669
light in weight. It would be measured in


00:29:05.679 --> 00:29:09.110
grams rather than kilograms or tons. Uh,


00:29:09.120 --> 00:29:11.430
so that would be the problem with your,


00:29:11.440 --> 00:29:13.430
you know, with sending a a spacecraft to


00:29:13.440 --> 00:29:16.230
the uh, solar gravitational lens using a


00:29:16.240 --> 00:29:18.070
solar sail. So, you're talking then


00:29:18.080 --> 00:29:20.870
about nuclear sources and uh things of


00:29:20.880 --> 00:29:24.470
that sort that this very nice article uh


00:29:24.480 --> 00:29:27.269
goes into some of the uh the nicities of


00:29:27.279 --> 00:29:29.830
nuclear thermal propulsion and things of


00:29:29.840 --> 00:29:33.190
that sort. Even so, it's still a very


00:29:33.200 --> 00:29:37.750
tough ask to send a spacecraft to that


00:29:37.760 --> 00:29:40.389
interesting part of the sun's


00:29:40.399 --> 00:29:43.669
environment where you've got the solar


00:29:43.679 --> 00:29:47.430
the solar um uh gravity forming a focus.


00:29:47.440 --> 00:29:50.710
Uh even to get there, it's really to get


00:29:50.720 --> 00:29:53.190
there in, you know, 20 years or so, uh


00:29:53.200 --> 00:29:54.470
you're talking about really new


00:29:54.480 --> 00:29:55.990
technologies that we simply don't have


00:29:56.000 --> 00:29:57.029
at the moment.


00:29:57.039 --> 00:29:59.110
>> Yeah. Well, one day it might be a long


00:29:59.120 --> 00:30:02.070
way off, but uh the time may come and uh


00:30:02.080 --> 00:30:03.590
but then again, we might have figured


00:30:03.600 --> 00:30:07.830
everything out by then. So, yeah.


00:30:07.840 --> 00:30:09.830
Yeah. I mean, you you know, the other


00:30:09.840 --> 00:30:12.070
thing is you'd want to choose So, you've


00:30:12.080 --> 00:30:13.830
got to choose the direction that you go


00:30:13.840 --> 00:30:14.310
in.


00:30:14.320 --> 00:30:14.630
>> Yeah.


00:30:14.640 --> 00:30:16.470
>> Uh to be in the opposite direction to


00:30:16.480 --> 00:30:18.310
the planet that you want to observe.


00:30:18.320 --> 00:30:21.430
>> Y the exoplanet. And if you get that


00:30:21.440 --> 00:30:23.350
wrong, if you choose a a planet that's


00:30:23.360 --> 00:30:25.029
completely boring and has no surface


00:30:25.039 --> 00:30:27.190
features whatsoever,


00:30:27.200 --> 00:30:30.070
uh then you uh you don't really


00:30:30.080 --> 00:30:31.590
contribute much to our knowledge,


00:30:31.600 --> 00:30:32.789
particularly our knowledge of whether


00:30:32.799 --> 00:30:34.310
we're alone or not, whether there's life


00:30:34.320 --> 00:30:35.110
anywhere else.


00:30:35.120 --> 00:30:36.789
>> It's sort of like leaving the lens cap


00:30:36.799 --> 00:30:39.830
on the camera when you land on a Venus.


00:30:39.840 --> 00:30:40.870
>> Yes, that's right.


00:30:40.880 --> 00:30:42.230
>> Actually, they didn't leave it on. It


00:30:42.240 --> 00:30:43.269
melted on. I think


00:30:43.279 --> 00:30:46.230
>> it it Yeah. Well, one of them fell off


00:30:46.240 --> 00:30:48.149
as well, didn't it? fall offs on top of


00:30:48.159 --> 00:30:50.310
the on top of the scale that was going


00:30:50.320 --> 00:30:52.870
to give the uh the you know there's a


00:30:52.880 --> 00:30:55.669
ruler that they jettisoned to give the


00:30:55.679 --> 00:30:57.590
camera something to look at so you could


00:30:57.600 --> 00:30:59.110
measure the size of things and the lens


00:30:59.120 --> 00:31:00.630
cap landed right on top of it. I think


00:31:00.640 --> 00:31:02.470
that's what happened. We've had quite a


00:31:02.480 --> 00:31:05.909
few venous disasters over the years, but


00:31:05.919 --> 00:31:07.669
yeah, you're right. This would be very


00:31:07.679 --> 00:31:10.070
very difficult to swallow if you're


00:31:10.080 --> 00:31:12.630
bugging it up cuz you couldn't go and


00:31:12.640 --> 00:31:13.750
fix it. Not like


00:31:13.760 --> 00:31:15.110
>> Yeah. Well, that's right. You can't move


00:31:15.120 --> 00:31:17.510
it in any direction. You You're stuck on


00:31:17.520 --> 00:31:18.789
one planet really.


00:31:18.799 --> 00:31:21.269
>> Indeed. But it's it's food for thought


00:31:21.279 --> 00:31:23.830
though. Um but one day we'll figure out


00:31:23.840 --> 00:31:26.070
a way. If you'd like to read about that


00:31:26.080 --> 00:31:29.590
story, it is at univertoday.com as Fred


00:31:29.600 --> 00:31:31.430
said. And we're done. Fred, thank you


00:31:31.440 --> 00:31:32.549
very much.


00:31:32.559 --> 00:31:35.029
>> Oh, uh, yeah, that was that was great to


00:31:35.039 --> 00:31:36.310
talk about all those things. I hope


00:31:36.320 --> 00:31:37.430
we'll do it again sometime.


00:31:37.440 --> 00:31:39.750
>> Fun topics. I'm sure we will. Uh, if you


00:31:39.760 --> 00:31:42.389
would like to, um, visit us in the


00:31:42.399 --> 00:31:44.710
meantime. Don't forget to visit our


00:31:44.720 --> 00:31:46.789
website, spacenutspodcast.com or


00:31:46.799 --> 00:31:49.269
spacenuts.io IO or visit our social


00:31:49.279 --> 00:31:51.430
media platforms, the official Space Nuts


00:31:51.440 --> 00:31:54.389
Facebook page or Instagram page or


00:31:54.399 --> 00:31:56.870
YouTube channel or whatever you like. Or


00:31:56.880 --> 00:31:59.830
if you want to talk to likeminded Space


00:31:59.840 --> 00:32:01.990
Nutters, you can do that on the Space


00:32:02.000 --> 00:32:04.389
Nuts podcast group on Facebook, which is


00:32:04.399 --> 00:32:06.070
always a lot of fun. Thanks, Red. We'll


00:32:06.080 --> 00:32:07.909
see you soon.


00:32:07.919 --> 00:32:09.590
>> Yes, I hope so.


00:32:09.600 --> 00:32:11.269
>> Well, he said that. And uh thanks to


00:32:11.279 --> 00:32:13.509
Hugh in the studio um who couldn't be


00:32:13.519 --> 00:32:15.990
with us today. He was invited by a


00:32:16.000 --> 00:32:18.470
friend to see a comet and he couldn't


00:32:18.480 --> 00:32:20.070
wait so he ran over there. It turned out


00:32:20.080 --> 00:32:21.909
to be a goldfish.


00:32:21.919 --> 00:32:24.789
Some people will get that. And from me,


00:32:24.799 --> 00:32:27.190
Andrew Dunley, thanks for your company.


00:32:27.200 --> 00:32:28.710
See you on the next episode of Space


00:32:28.720 --> 00:32:29.909
Nuts. Bye-bye.


00:32:29.919 --> 00:32:30.950
>> Space Nuts.


00:32:30.960 --> 00:32:33.029
>> You've been listening to the Space Nuts


00:32:33.039 --> 00:32:35.350
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00:32:35.360 --> 00:32:38.230
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00:32:38.240 --> 00:32:40.870
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00:32:40.880 --> 00:32:43.269
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00:32:43.279 --> 00:32:46.149
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