#433: Marsquakes Surge & Parker Probe's Record Speed

Hi there, thanks for joining us again. This is Space Nuts. My name is Andrew Dunkley. Thanks for your company. Coming up, we will be looking at a couple of things. Mars quakes looks like they're happening at a faster and more furious pace than ever thought, and that's because we can detect them now with much more accuracy. Also, the Parker solar probe has made the news again. It is skimming around the Sun almost literally, but it's doing it at a thunderclap race a pace. And we'll also be looking at a super nova first scene in eleven eighty one, but now we know all about it, or at least more than they did back then. That's all coming up on this edition of Space Nuts fifteen second guidance in channel ten nine ignition sequence Space Nuts or three two one Space Nuts. When I report it. Bill's good and here again to furnish us with his knowledge, or at least help my son move furniture because he's got a new apartment in Sydney. Is Professor Fred Watson, Astronoment at large, high friend. Thanks Andre, just let me know, and yeah, we'll be there hoping. If we're planning the trip down he hasn't quite got it yet all the legal stuff, you know, well, how to deal with that? Whereabols is it? What suburb is in campsy more specifically a place called Clempton Park, which is very pretty leafy little suburb. And best of all, he's not on a main road whatsoever, so no traffic. Very hard to do in Sydney, very hard to do. We're kind of we're quite proud of him because he's managed to do this all by himself in the second most difficult real estate market in the world, which I think is really impressive. It is. So yes, ladies, he's a catch. Okay, there you go. Well, lad your friends note yeah, yeah, Now before we get into our stories, you've just come back from a little trip to South Australia where you took a tour group around and show them rocks and things. It must have been exciting. It was. It was a lot more exciting than you made it sound. So it was a round trip really. We started off in Adelaide, headed up to a Portagusta and then to Kuba Pede via Woomera, which is a name I've had in my vocabulary since I was about six because the you know, it was always in the news, was Woomera when I was growing up in the nineteen fifties, that this was the spaceport for British rocket tests and all kinds of other things, and it was all happening very much front of mine, very prominent in the media. But I've never been, Andrew never visited now and it's worth a look. Look you would enjoy it too. There's a lot of vintage space stuff there, reminiscent of I guess the Kennedy Space Center, but an earlier generation when rocketry was in its kind of the modern era of rocketry was in its infancy in the post World War II period. Lots to see some really interesting aircraft and missiles, rockets and all the rest of it. Is the Australia's first ever rocket still in that chuck shed. That's probably I didn't see it there somewhere apparently yeah, it will be, yeah, but of course it's still an active site. I think it's the OLAF that operates now. There's the Woomor Prohibited Area. It's a huge area of South Australia. I don't know how many thousand squareculus as it is, but they still do launches and people in the area, the station station dwellers, station halls, people have got sheep stations and things like that. They get to all every so often we're going to evacuate you for a day. So well they do. And it's very secret, so we'll just find out about any of that. But we did talk about the history and it was great. And then of course I should mention the reason it's called woomera is because that's a an aboriginal device to launch a speed it is gives it gives a spear a much greater and extra a great name, great name. They made some spaces too, we did. Yes, we followed the paths around two places like Williams Creek and Marie. Marie is interesting because it's got a it's got a man, the mari Mon, which when you see it from the air, is an Aboriginal elder probably has got a long beard and he's four kilometers long and nobody knows how he got there, but it looks as done by bulldozers or something like that. And then and then down to our karula of place where there's a dark SkyPark, and to a place called nil Pina, and in fact the Nilpina Ediacara National Park. Eddie Kara is the name of the hills in which some very interesting fossils were found some years ago, and these are the fossils of the first animals, basically the first things that moved around on beds of microbial mats in shallow seas. And we met the chief ranger there, Kim Goyer I think is the way his name is pronounced, who flashed his space Nuts t shirt as soon as as soon as we arrived, which was great. So it was good to see Kim and talk to him. And then a bit further on we met another space nutcase down on the Murray River. We were at a place called Manham at the time, but we had a lovely dark sky vet. All the locals came out and we did some talks and everybody dressed up in stars and spacey kind of stuff. One of our tour guests came fully cloud in an astronaut suit which she apparently needed a pump to keep the air blowing through it so he didn't die. Fantastic stuff. But there we also met Tracy Hill. There's another space nut and Tracy was very gracious in the fact that she took part in a charity auction which was to buy a copy of a book called wis Uranus Upside Down that had something to do with me. So she paid a handsome price for that, and Tracy well done. There was a slight mix up with Tracy's name when the winner was announced, so I had to rewrite the inscription in the book. But it was great to meet Tracy with a nice chart. And we'll stay in touch with both Kim and Tracy because these are people who are passionate about the district they live in, passionate about the things that they can show people wonderful. All right, Hello Kim, Hello Tracy, and thanks for being space Nuts followers. They're all over the world. I think you know, it would be hard pressed not to run into one these days, the way things are going. It fantastic to be like that, wouldn't it. I didn't run into any in China though when I was there. Yes, we've never had a question from China. I don't think more than welcome, more than welcome. Yeah. So you're back down to Earth now, so to speak, and back to normal for a little while. But Space Nuts continues, and we're going to talk about Mars quakes. Now. And this is a really interesting story because we have talked about Mars quakes before and they've been investigating them courtesy of the Insight mission. But now they're starting to come up with numbers that are a little bit bigger than they expected. That's correct. The the the analysis of this, Andrew, comes from a spacecraft that's no longer operational, our old friend Insight, which was fitted with a seismograph seismometers to measure mass quakes. And the bottom line with this story is that some of the mass quakes have been misinterpreted, which is easy to do when you're looking at a record of I guess little tremors that you know, you don't really have much of a clue with that tremor as to where they come from. We did talk about this recently actually because some people said, when you've only got one size bomby to how do you know where these tremors are coming from? And there's various signatures in the tremors that you can interpret as to what the what the path that these tremors have taken through through the you know, through the Martian crust, what that path is. So this is work that has been carried out by scientists at et h Jury, which you might know is the university that Einstein attended and Imperial College London, and I once did a course there, so it's a common ground for us in the world of astronomy. So these scientists, what they've done is they've essentially made a kind of estimate from the seismic data from Insight as to the global meteorite impacts, and that gives them a number of somewhere in the region quote between two hundred and eighty and three hundred and sixty meteorites striking the planet each year, forming impact craters greater than eight meters, which is about twenty six feet. So these are impact craters that you could detect from space, you know, with the various Mars orbiting spacecraft, and indeed they have they've managed to link and I think this is the crux of the matter. They've managed to link some of the seismic traces with what are obviously newly excavated impact craters, so that you can tell by the color if you're looking down from an orbiting spacecraft and you see something that has a particular color against the red of the Martian dust, you can get a clue as to whether that crater is a new one or not, whether that is the result of a recent impact. And in fact, I think they've been able to tie down some of the seismic traces with a particular new impact feature. And so basically what it means is that I think it's something like five times the number of impacts that we thought were hitting the surface is what is now estimated from this new new research and what the conclusion they come to. Actually, let me quote Geraldine zen Heisen from eh Turich who says the rate was about five times higher than the number estimated from orbital imagery alone. Aligned with orbital imagery, our findings demonstrate that seismology is an excellent tool for measuring impact rates. So there's that link between what you can see from orbit and what the seismograph is telling you. I'm fascinated by this because they're giving us numbers in the hundreds, but Earth gets hit to the tune of thousands a year and we don't seem to see those sorts of cratering effects. What's the difference? Is it because Mars atmosphere is so thin and yeah, chartistics, that's right. So you know, if Mark if we had the same atmosphere density as Mars two or three hundred, hate me to create us every year would be headline making news. Yeah, because we just sort of you really want to go anywhere without experiencing the risk of something hitting you all the head that could cause and ape me to create it. And so that's you know, that's the crucial part is the Mars's atmospheric pressure is point zero six sorry, it's point six percent. Zero point six percent of Earth's atmospheric pressure is less than one percent, So there's much less of a breaking influence by the atmosphere on Mars than there is on Earth. And by breaking that's br br a k i n G, not br e a k i n g. So what it means is that these meteorites always hit Mars's surface a very high velocity, what they call hYP hyper hypervelocity impacts, and it's that that really betrays the to orbiting spacecraft, that reveals that something's happened recently, because they they apparently cause a debris zone around the crater which is more than one hundred times bigger than the crater itself, so that they stand out from orbit. You've got to create maybe eight meters across, that's pretty big, but with something eight hundred meters you know, around it, that tells you that there's there's something's happened there. So actually the points made in the paper that they've written, knowing the number of impacts is going to be really important for the safety of any explore exploring spacecraft, whether they're robotic or whether they've got humans on board. And I suppose there'd be no pattern to this, so I guess if you had the time to analyze that, you might be able to figure out where and when these things might happen. But you know, yeah, it increases the risk. I mean, if this was Earth, our insurance policies just wouldn't be we couldn't afford them. But that's right, when you're talking space usitions in an environment that's hostile and we're not built to suit Mars's atmosphere, you'd want to collide as much data as possible to try and avoid these situations. I imagine, yes, So it's obviously something that will be taken into account in future future mission planning. It's a bit of a warning really that Mars is a rather more hostile environment than we expected at the same time, it's not it's not going to rule out Mars exploration, you know, I don't I think it's safe to say that we've had how many rovers on Mars? You know, it's probably it's probably, it's probably ten if you include the Chinese rovers, you include not just spirit an, opportunity, and curiosity and perseverance. They're the big four, But there were rovers before that Pathfinder was one of them. Maybe it's not ten, but perhaps six, seven or eight something like that. Rovers on Mars. None of them, as far as we know, have been zolked by incoming meteorite. So it's a risk, but it's a low risk, yes, yes, And I suppose we should also say that not all these earth tremors that have been picked up over the course of its mission are caused by meteorites, So yes, that's correct. There's been other factors as well, and some of them are still a bit of a mystery. Yes, So that's really the I guess, the pole point of their argument that they've been able to isolate the ones just by the characteristic signature. They've been able to isolate the ones that are caused by meteorites rather than by tectonic activity. There isn't much tectonic activity on Mars in that regard. Its core is much cooler than the Earth and so it doesn't drive the tectonic activity that we have. Okay, if you want to follow up on that story, it's been published in the journal Nature Astronomy. This is Space. That's Andrew Ankley here with Profess Fred what's an the piece MUDs. This next story is interesting too, fredd In that we've been hearing about, well, we've heard about this once before, but it's happened again. The Parker Solar Probe, which is orbiting the Sun and has been since oh gosh was it. It's been up there for five or six years, I think something like that. It's just achieved or equalled a speed record during one of its recent orbits. And we're talking numbers that are just mind blowing. I mean, tens of hundreds of thousands of kilometer, isn't it. It's amazing, it is. So. The Parker solo probe is interesting. It's one we've talked about much, but it's been it has been active, as you've said, for some years. It's just deleted its twentieth close approach to the Sun, and that's telling you that this is the the spacecraft that comes closest to the Sun. Of all the solar orbiting spacecraft that we have launched, this one is the closest, and in fact, its twentieth close approach was on the thirtieth of June twenty twenty four, not very long ago. Its distance was seven point twenty six million kilometers from the solar surface, and by that we mean the photosphere, the bit beyond which you can't see. The Sun doesn't have a surface because it's a ball of gas. That's about four point five one million miles, so it's you know, in terms of cosmic distances, that is grazing the surface of the Sun. It's very very close. And Kepler's laws tell us that the closer you get to the body that you are orbiting around, the faster your velocity is. Is how it works, and that's why we've got this record speed. In miles an hour, it's three hundred and ninety four thousand, seven hundred and thirty six kilometers per hour. It's six hundred and thirty five, two hundred and sixty six kilometers per hour, which, let me do it in my head, is somewhere under two hundred kilometers per second. I've got a calculator handed, but it's in that region. You divide it by three thousand, six hundred to get kilometers per hour into kilometers per second, So it seems in the region of two hundred. It's Yeah, that's a phenomenal velocity. And but that speed, you've really got to take relativity into account, not just because of the speed, but because of the gravitational potential that you're in. You know, you're in a strong gravitational field, and both of those things mean that Einstein's two theories of relativity, the special theory which is about speed, and the general theory, which is about gravity, those two absolutely start dominating your calculations. So really interesting stuff for all kinds of reasons. The park Asolo probe is fitted with heat shields that seem to bewithstanding the stresses and strains on the spacecraft that come from being so close to the Sun. And we look forward to hearing what data have been collected during that twentieth close approach to the Sun. Yeah, it seems to operate in a very complex orbittle pattern because it uses gravity assists from Venus in some situations. Just depends on what's available at the time, I think, but it would all be mapped out. But it will be doing its next pass on the twenty fourth of December, and they expect it will probably crack near seven hundred thousand kilometers an hour in that pass. And that's just unthinkable, isn't it That this has got to be the fastest thing ever? Yeah, that's well, that's right. It's you know, it's not the fastest that was launched, but because it's been wound up by all these gravity assists to push it so near the Sun. Yes, it probably is the fastest spacecraft ever. I wonder how to survive so the environment that it's exposed to, I mean just the radio radiation it's bombarying it for one. But it would be exposed to tremendous heat, wouldn't it. Yes, that's right. So it's got a pretty substantial heat heat shield, which if I'm remembering correctly, I think it the spacecraft is turned so that when it's closest to the Sun, the heats the heat shield is doing all the work, and you know, well the spacecraft kind of behind the heat shield is faking the measurements so yeah, very intriguing and very very successful mission. Actually, so I think it's got is it four more or three more close passes to the Sun? I think it's three more, and actually I know it's four more. It's got four more close passes. So the mission is sort of coming to its closing phases. But we will, no doubt here more about it. We probably should do a nice story on the parkasolo probo sometimes down the track when we see some of these results. Yeah, I just found that the final pass will be next year, the twenty fourth fly by the Sun. So it's mission comes to an end in twenty twenty five. And that's how long it takes to sort of work its way into position to do a pass. Because it's going so fast, it just can't just sort of stop and go back. It's got to go out and do another lap around whatever it can do. A lap around Mercury would be involved, I imagined it. Yeah, it's quite extraordinary, what a fascinating mission, And yes, we should talk more about it when they start releasing some of the data. I guess who knows what they could learn. There's so much we don't know about the Sun, which makes it such an interesting thing, and it is the nearest star to our planet, so we can learn a lot about things that are so far away and untouchable just by observing what's right next door. Fred, Let's get onto our final story. This one I also find intriguing, and this one dates back to the year eleven eighty one when there was a super nova recorded, but we're only now starting to learn more about it. Yeah, that's right, eleven eighty one. It's a time. We often associate these super and over ancient super and ova explosions or observations with Chinese scientists, and in fact, probably the best known is the super and over of ten fifty four, which was observed by Chinese scientists, if I can call them that, there were certainly a US observers of the sky. That ten point fifty four super and over is what produced the crab Nebula, one of the most famous super and ova remnants in the sky in the northern constellation of tourists, the Bull. The crab Nebula is well studied, and in fact we've in the last few months seen some extraordinary images of it from the web Space Telescope Gene web Space Telescope. But this one is different. The super and Ova of eleven eighty one was recorded. It was recorded throughout Asia, but mostly in Japan. Japan was, you know, again the home of people who were very, very clever and careful skywatchers. And it's a time actually when Japan was at war with you know, as often was the case in past history. It seems to be still the case today, but Japan was at war and there were records kept of that time which were put in a kind of it's what's described by our old friend fizz dot org, which is the website that's carrying this story, described as in diary format, so you know, it's like a journal I guess called the Azuma Kagami, I hope pronouncing that correctly, which chronicled what was going on, the events taking place, mostly to do with the war. This was all not very far from modern day Tokyo. But other things, including this appearance of the new star. They they they are called a guest stars in those ancient texts because they are just a guest in the sky that then goes away. And indeed there is a note here that they weren't that. This one was also observed in China and Korea as well, and was bright enough to be quite noticeable. It wasn't a daylight supernova, which we think the ten fifty four one was, but was bright. It's comparable in brightness to the planet Saturn, which is certainly noticeable. It's not the rightest of the planets, but it's up there with the with the ones that you really do notice in the in the night sky. Apparently it was visible for about one hundred and eighty one hundred and eighty days and then dimmed away and was lost, and it took a long time for modern day scientists to find it. They what's happened is that basically using the the the you know, the text of this die record of the supernova, the Azuma Kagami people have narrowed things down to the constellation of Kassiopeir, which is another It's a far northern constellation in the northern sky. We see it from certainly from the latitude where I am in Sydney. But it so that gave me scientists enough of a clue to look for a remnant from this explosion, and it's quite different from the remnant from the crab nebula, which is just like a tangle of material dust gas that's that's obviously got shock waves propelling through it in all different kinds of directions. This is something quite different. First of all, it's visible in X rays, and what we have is an X ray image from the XMM satellite with some infrared components as well from an infrared spacecraft called WISE, so we're looking at this in two different wavebands. And what we can see in the structure is it's, first of all, it's a spherical object which has some really detailed what we might call contours in it, where you've got things like, first of all, in the middle, we've got the wind bubble. This is coming from the paper about this. Then there's going outwards a wind termination shock, and then a region of unshocked ejector that's material that's come from the explosion but hasn't had a shock wave going through it. And then there's something called a reverse shock and then a forward shock, and all this complexity can be sort of seen in the X ray image and it sounds like my Golove game got forward sharks in it. I can just see you doing a reverse shop with your number five iron or whatever. Anyway, but that study has given enough detail that scientists can now work out what this super and ova was, and it's a very rare one, something that does not normally happen. Two white dwarf stars, now white dwarf stars are what our Sun will end up as it's basically a thing the size of the Earth with the density with the mass of the star, so very very dense and very hot. That's how the Sun will end its days in a few billion years time. But two of these objects apparently have collided, and that's what has caused this very unusual type of super and over. A lot of the work has done has been done with computer modeling, of course, and analyzing the observations and the rarity is this double shock formation that we've just spoken about, the forward shot and the reverse shock and then the inner shock. And so there is a sort of footnote to the story though that comes from these observations. The sort of winds that blow from this event, what we call stellar winds. They are thought to be relatively recent in their formation, so that they say, perhaps only with the past twenty or thirty years, these high speed stellar winds have been blowing from the surface of the star, which is quite extraordinary really just you know, we happen to be looking at it at the right time to see some of the action. Yeah, indeed, And it's you know, we get very lucky sometimes with observations. But I suppose we could also suggest that these things are happening so regularly. Maybe it's not luck. We're just picking them up because they're happening and at a rate of a dime. A dozen't But this one, this one's different. This one's been quite unusual and a very lucky discovery. Indeed, my hope Fred one day is we do get to see one for real in our lifetime, Beetle juice being the optimum candidate. I suppose, Yeah, that's correct. It's it's we don't want want too close, Andrew, But yeah, Beatle, this is about battle Jos, however you pronounce it. It's about seven hundred light years away, I think, which is it's far enough away that we would certainly see something visible in the daylight sky. It will be very bright, but it's not going to be lethal to life on Earth, which a nearer one might be. Yeah. Yeah, And in recent discussions we've talked about things that have happen been so far away from us that have actually affected our atmosphere. So yes, that's right. It is really mind boggling to consider that there's so much influence out there that is so far away and we think we're all safe and well, and we are, but you've just always got to consider the possibilities, I guess. But yeah, that story was published in the Astrophysical Journal, if you're interested in finding out about the SN eleven eighty one supernova. Fred, we've reached the end of the program. Thank you so much. Well, it's a great pleasure, and it's not a pleasure to have reached the end, but it's always a pleasure to talk about these things. The end is nigh. Yes'm we'll see you on the next episode. Sounds good. Thanks very much, and we take care and we'll speak to Fred Watson, Astronomer at Large, and thanks for listening. Don't forget to follow us on social media or if you're on YouTube, hit the subscribe button, and don't forget to visit our web website, Space Nuts podcast dot com. Oh, and thanks to here in the studio who couldn't be with us today, but all the best to his wife who's dealing with some medical issues. As we all are when we reach this age and from me Andrew Dunkley, thanks for your company. See you on the next episode of Space Nuts. Bye bye Spacenuts. You'll be listening to the Space Nuts podcast available at Apple Podcasts, Spotify, iHeartRadio, or your favorite podcast player. You can also stream on demand at bytes dot com. This has been another quality podcast production from sights dot com.