#474 Q&A: Constellation Curiosities, Comet Encounters & The Universe's Birthdate

Hi there, it's Space Nuts yet again. How many are we up to now? Four one hundred and seventy four? My goodness, it's a Q and A edition. My name is Andrew Dunkley. Thanks for joining us this time. We are going to be answering questions about what constellations look like from a different point in space. If you're traveling, when when does it not look like your neighborhood anymore? It's an interesting question. We're going to talk about a comet that's been in the sky recently, and I've seen lots of happy snaps from people on the Space Nuts podcast group facebook page about this comet, sou Chin Shan. We'll also be discussing the age of the universe and citizens science. That's all on this edition of Space Nuts. Fifteen second Channel ten nine ignition sequence. Space Nuts NI or three two one Space Nuts. As can I reported, Bills goods and joining. Us to answer all of those questions, it is Professor Fred Watson. Hello Fred, Hello on. Duh, Nice to see you here. Very yes, yes, hey you been since I saw you last. Sitting here? Really just waiting for something to help? Yes, funny that funny? Shall we get stuck straight? Into it. We should. Yeah, my coffee is going cold, so we should Oh. Yeah, yeah, get into that. We are going to New York first. This is a question from Roger. Roger truck driver. And then I'm traveling through the around Back Park in Upstate New York. I got a question about the constellations. I'm guessing that anywhere in our solar system you went, they pretty much looked the same. But how far would you have to go before things start to get disoriented? We were to we were to go to Alpha Centaur, like four light years away, would just still recognize some of them? Are? Would they be completely disoriented? And I'm kind of thinking of like science fiction shows where they show the stars flying by like trees when you're going down the road. I'm kind of guessing it wouldn't look like that because of the distance between them. They probably look like they stayed in the same place. But now the question is how far can you go before I think, before you don't recognize the neighborhood anymore? Right, loving the show, guys, keep on trucking. There he is. Thank you, Roger. I always love that. I haven't heard from Roger in a wall. Yeah, that was an interesting analogy about driving down the highway and the trees fly past. They do portray space travel that way with the stars, but I think it would probably be a much more boring viewed in that in real terms after a while, I mean, it'd be pretty extraordinary to look at, but eventually you'd be saying, oh, yeah, there it is, the stars still there. Yeah, and what check it in the thousand years time and see where it is. It might be a bit like that. It probably is actually. I mean, for first of all, we you know, on human timescales, with the technology that we have today, it takes a long time to get even beyond the little bit of Pluto as we know from New Horizons, which I think took nine years to get from Earth to Pluto on its epic voyage in the early part of this century. And it is interesting that that that has been used as a baseline to directly measure the distance to some of the stars. The fact that we know where star is from the Earth, and yeah, you get to what is it, thirty thirty astronomical units something like that. The distance out to Blueto it's thirty forty and an astronomical unit is one hundred and fifty million kilometers the distance from the Earth to the Sun. To get a view from there, their positions look very, very slightly different. You need to measure them accurately with the kind of equipment that New Horizons has on board. But yeah, you can see the difference there. You can see what we call the parallax, the distant the different position in the sky that a star looks to be from different things. Yes, in the name of a well known book by an author who has a voice very similar to the one that you're not listening to now, but you will be in a second. I think I know him. Yes, it just happened. It does happen to have a copy of the book on my desk. As you mentioned you were. Yeah, yeah, it's a great, great word and a great title from book. But you know, Roger's comments are right on the money. You've got to go a long way before the constellations start looking different. I think if you went to Alpha Centauri, you look at the sky and think that's pretty well the same sky that we see from except actually for except for you know, the Alpha Centauri itself, of the Alpha Centauri systems is a triple triple star system that would look pretty damn bright, and so you wouldn't really see the stars of Centaurus. But a lot of the stars in the sky are at distances which you measure in hundreds of light years. I guess with the naked eye we see out to about very roughly a thousand light years, and so traveling just for four and a bit light years is not going to change things that much. There'll be some constellations that will have the odd star looking as it's in the wrong place, and said Norris will be one of them, because you're right next to one of the stars of Centaurus. But I think generally speaking, you will be able to recognize them. They might look just slightly walked, but you're able to recognize them. It was certainly a common feature of textbooks that I used to read on astronomy when I was a youngster growing up and getting interested in astronomy. It's a common feature to have pictures of constellations as they are now, as they would be in ten thousand years, as they will be in fifty thousand years, and you know, and so it goes on. And that's because of the intrinsic motions of the stars themselves. It's not because we're changing our vantage point, but it was always the same. You could see the basic outline of a constellation and it would just change slightly sort of, you know, you realize that it's not quite the same, that something's a bit different about it. So I think that will be what you'd see as you journeyed deeper and deeper into space. Yeah, so you'd have to go a heck of a long way before yeah, really sort of went where the hell am I? Yeah? I think I think fifty light years a hundred light years you would start seeing a completely different set of you know, set of star patterns. You really would worry where you were. This would be a very alien sky to you. Yes, yes, indeed, a really interesting question. And that's brilliant and you know, not surprising that it's come from Roger, who spends a lot of time traveling and he probably is driving along in the trees were flashing past, and he went, wait a minute, yep, there's a question in that. So there it is. Thank you, Roger, Well done, Space MUDs. Our next question comes from Lisa. Lisa is from Prince George in British Columbia in Canada. Hello, Professor Fred and Andrew. I was lucky enough to have clear skies to comet. I'm going to get it right this time. Soo Chin Shan was passing by. He was passing by and got to observe it two nights in a row. I shared a few pictures on the Space Nuts podcast group Facebook page. If anyone is interested, I probably saw them, Lisa, I did too. Yeah, witnessing such a rare event was truly awe inspiring, and it got me thinking. We know this comet has an orbital period of eighty thousand years, but do we know for sure that it's been here before. Is it possible that it dropped out of the oort cloud more recently and is on its first lap, so to speak? Is there any way to tell other than direct observation if a comet is a repeat visitor. Thanks for a wonderful podcast. I've been listening since twenty eighteen and love of both the show and the community that has formed around it. Lisa, Oh, that's lovely, Lisa. I'm glad you're enjoying being part of a space nuts podcast group on Facebook. And if you're not yet, maybe you should go along and have a look, because it is a great little page. And yeah, I think everyone really enjoys there, their time there and their company and the conversation they have with each other. However, we have an important question to answer with Sue Chin Shan the comet that was in the sky recently on the nights I was best able to observe it. It was cloudy, and then when it finally cleared up, the darn thing was too low on the horizon for me to get a look at it, so I never ever got to see it myself, which I'm very disappointed about. But I'm pretty sure it won't be the last one to pass by in the next several years, so I might get a shot at another one. Oh you will. And I've got a similar story to you, Andrew, which is that when it was at its brightest in the evening sky here in Sydney, we had really overcust weather, which we've got now it's been like this for a month and it's not very conducive to astronomy. But I was lucky enough when we were I think I told you we were many. Now we're down at a place called Sea Lake near Lake Tyril in northern Victoria for a star fest, and there were lots of telescopes there, and one of them had his. One of the astronomers who was using these telescopes had his telescope coupled to a detector, a real time detector, in other words, a TV camera, and he was showing the results on a screen and he was actually pointing it at Tushin Chan Tu Chin Shan, and so I did see it, but not through the telescope, but I saw it live as it was on the screen. So that cheered me up quite a lot. Now to Lisa's question, that's a really good one as well. And this business of the eighty thousand years, it's a little bit of a moveable face because comment often their orbits are perturbed strongly by the gravity of other objects in the Solar System, including in particular the planet Jupiter, which is the biggest of the planets, and so often the orbital period of these very long period comets changes. Now to the nub of the question, could this be its first visit into the inner Solar System? I think it could be. I'm not sure in this case, and I should have read up on this, because there are markers in a comet's emissions when it gets near the Sun that give you some idea as to how many times it has been around the tracks, in other words, how many times it's passed close by the Sun, because it changes the structure of the comet. Every time it goes around the Sun. You get more of the volatiles blown away and you're left with a more dusty body. And I think think there's you know, the rate at which these chemicals, the elements within and molecules within the comets I see body, The rate at which these are dispersed into space changes depending on which compound you're talking about, And so I think by looking at the mix of chemicals that is being emitted by a comet when it gets near the Sun, you can get some idea of how many times it's visited the Sun. Now, I'm only saying things that I recall from having looked this up a long time ago. So there might be nuances in that that aren't correct, and there might also be details that I haven't really explained. But at the bottom line is that it may have been the first time around the Sun. If not, we might have ways of knowing about it, and I should check them out just to see what the pondits say. About that. Yeah, well I was only discovered last year's. Right it was, so it was on its incoming orbit last year, so we know the first thing. I just did a quick search. And now I've said, has the commet been here before? And it says it has never reached the inner solar system in human his view before? Now apparently, so there you are. So it's call for it. It's a pristine comet, isn't a thought? Okay, So we just have to wagit eighty thousand years to have another look at. It and see what's changed. Yeah, yes, indeed there's a few that are going to be quicker than that's that's the good news. Thank you, Lisa Tho. Really good question, and yeah you're right, it's the first time it's been here. Apparently. This is Space Nuts with Andrew Dunkley and Professor Fred Watson, the road. Piece Nuts. Now Fred to our next question, although we're not moving far around the globe because this one comes from David who happens to live in Canada. Hello Andrew and Professor Watson. David here from Saint John's Nufuna in Canada, just wondering how did we measure how old the universe is Thanks love forcast. Thanks David. I'm going to ask David a question that every time I travel and I tell people I'm Australian, they'll say, oh, do you know John faith Waite? Oh, David, do you know Lisa? Now I gather from the provinces they live in. They're probably not very close. Together at all. But you know, I get that. You get that a lot. I get that a lot when I travel. It's ridiculous. Well, I might know him, except there are thirty million other people that you know. Ah, yeah, it's funny. It is funny. Ah to the universe. How do we know it's right? How did we measure it in the first place? What's the goss there? So? Yeah, So the first measurements made of the age of the universe were when we started measuring what's called the Hubble constant, And the Hubble constant is the current rate of expansion of the universe. It's how fast it's expanding now. And it's an easy calculation to go from that. If you assume the expansion has been constant throughout the history of the universe, it's an easy calculation to go from the expansion velocity back to when everything was at the same point in space, and you get the answer. You get an answer of about if I remember this, about fifteen billion years. So that was the first way that we evaluated the age of the universe. And I guess that was in the early sixties seventies when the Big Bang theory was really becoming very much the theory of the universe as we know it rather than one that was just a hypothesis. And so that's the first way. But there are there are other ways of doing it, and we can you can sort of again it comes to it's all about accurately measuring distances and things of that sort, because that's what you need to do to get a good idea of well, first of all, the hubble constant. You've got to you've got to evaluate what that is, and it needs the measurement of distances. And there are two ways of measuring distances in this kind of context. One is standard rulers and the other is standard candles. So standard candle is is a light source that you hold up whose intrinsic brightness that you know, and then you see how bright it is from your vantage point. And if you know the intrinsic brightness, you can work out the distance, and that's how the super and ova work works. People are doing investigation of the in fact, in particular the dark energy and the accelerated expansion of the universe. They look at super and ova explosions of a particular type that we know has a certain brightness, and from that you can deduce the supernova's distance, and from that you can tell whether your value of the Hubble constant is right or whether it needs tweaking. And the standard ruler method actually goes back to the early universe when there are characteristic separations of galaxies, and even before that, the characteristic separation of the hot and cold features, of the warm and cool features in the cosmic microwave background radiation give you an idea about the you know, the age of the universe, the state of the universe at that time. So all these things come together and you've got a much more subtle value for the age of the universe. We now think it's thirteen point eight billion years, but that's not that different from just taking a straightforward, you know, linear expansion since zero to determine the age of the universe from the hob directly from the Hubble constant, So thirty point eight billion years. It's got a lot of input into it, but even the crudest method gives us something similar to that. While you were talking, I thought I'll do a Google search and I asked what is the exact age of the universe? And the answer was interesting. According to estimates, the universe is thirteen point seven billion years old with an uncertainty of two hundred million years. We can't really be exact, can we. No, that's right, so our technology has to improve. I have always had not a theory, but the notion that when we do get down to the exact age of the universe, it will turn out to have been created on the first of April, and that will tell us things about the universe that we probably don't really want to know. If it's just one big joke, yeah, oh, how are you loved? Yes? Imagine So so there it is. David several ways of making the measurement, and they all come up with around about the same number. Finally, Fred, we have a question from Sandy. I love these short form questions. Hi, Fred and Andrew, are there citizens science programs that you know of where average people I e. Me help with scientific data for asteroid occultations, occultations and light curve data submission for stars and asteroids. Wow, thanks Sandy. Yes, another great question and good on you. Some do that means you're making measurements, and citizens science is a great way of getting those measurements into our knowledge base. So the first thing that came into my mind was the universe, and Zuniverse is a kind of suite of citizen science programs that started, I think with the Galaxy Zoo project, which was citizens science citizen scientists looking at images from the Sloane Digital Sky Survey, and that's a telescope in New Mexico that surveyed the northern sky in very great detail. Discovered all these weird and wonderful objects, and they are among them galaxies, I mean, the weird and wonderful galaxies is probably what mostly this was about, hence the name Galaxy Zoo, which produced some quite extraordinary discoveries. Hanni's object is one that comes to mind. I think we might have mentioned that recently, a green blob next to a galaxy, which was eventually traced to gas fluorescing after an outburst from the center of the galaxy probably are burnt by the black hole at the center of the galaxy some millions or even billions of years ago. Haney's vote. It was called because I think that's the Dutch word for objects, and she was a Dutch school teacher, which probably still is. So that sort of thing was a particular version of cities and science, but that sort of spread its tentacles and became something called the zuniverse, which I think has a number of different projects in it, and I think there may well be they may well be asteroid occultation you know pages or like data like curve pages. I actually just googled cities and Science asteroid occultations. They came up with a number of interesting websites. Unistella has one Unistellar Citizen Science. Unistellar is a company that is actually manufactures a very particular kind of telescope, and they have an asteroid occultation citizen science page. That's one to look for. I also googled light curves, I think cities and science like curves. That came up with a whole lot of things. One of them is it's actually, you know, the Hubble telescope has global cities and science projects of its own. But zooly versus perhaps the classification that's biggest and perhaps most popular, and they certainly do have a variable star like curve citizen science project. There are specialist astronomical societies that do both of those things, as well as societies dedicated to asteroid observations and dedicated to variable star work. Most of them are international and very well established, and they're not that hard to find. So have a look around, Sandy, and you're sure to find the right one for you. Oh yeah, I thought I'd just throw one out there and say, you know, what is the greatest discovery by astronomical discovery by a citizen sign scientists? And it went straight to an August twenty twenty four article in fiz dot org Citizen science projects identify twenty new astronomical discoveries and that included previously unidentified supernovae. And there's more than two thousand volunteers across one hundred and five countries that are working on these projects. The project is called Killer Nova Seekers, and they're aiming to find kilo novae, the explo cosmic explosions of neutron stars and black holes colliding in distant galaxies. So there's all sorts of stuff going on out there. If you've search deep enough, you'll find what you're more in terms of citizen science in the realm of astronomy. So yeah, there's a lot going on. I don't do it with astronomy, but I do do a little bit of a thing that's not I don't suppose you call it citizens science. So I downloaded an app called dream Lab d am Lab, and what it does is at night, when I put my mobile phone on a charger, I open up the dream Lab app and I just click start session and it starts crunching numbers using my phone as part of a giant computer to sort out whatever scientific problem somebody's trying to solve. The last one I did, which took two years to crunch, was a COVID nineteen calculation. Right now, I'm doing one through dream Lab, supporting the Tropical cyclone Modeling Phase four study. So it's all sorts of subjects that you can sell. Identity Hunter Phase two, which is an Italian study. The Imperial College London is doing a study on long COVID. So if you want to download, if you want to use your phone for very positive reasons, you may find astronomical studies that you can do through a mobile phone app, or if you want to help in so many other areas, just have look for dream lab. Dream Lab with a little purple cloud is the icon. I basically let my let whoever use my phone when I'm asleep to crunch calculations. So it's a good way to use mobile technology for the greater good. I reckon. But yes, Andy, I don't. Think you'll have any trouble finding citizens science groups in those areas that you are asked about. Thanks for your question, and if you do have questions for us, go to our website and send them to us there. It just clicked the AMA tab on the space nuts dot com Space Nuts podcast dot com website and send us your textra audio questions there. Don't forget to tell us who you are and we from just lately they've all been from Canada or Brisbane as it turns out, but I'm sure other people around the world sides as well. Jordie who's always asking for dinner and Fred, thanks, thanks so much for your company and answering those questions today. It's been good fun. Yeah, thanks again. I think Jordy is telling me it's time I gave up on this. Don't pro walk. So you know you very much, Andrew, and we'll talk again, so we will. Professor Fred Watson, Astronomer at Large and to here in the studio. Nothing much to say there, no movement at all, and from me Andrew Dunkley, thanks for your company. See you again and Jordy on the next epre Sad of Space Nuts by Bie. To the Space Nuts podcast. 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