Q&A - Space Potatoes and Christmas Stars

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With me, science journalist Izzy Clark and astrophysicist Dr. Becky Smethurst. Now the eagle-eyed or eagle-eared among you will notice that our last podcast of 2024 is not an episode about the scientific search for extraterrestrial life as we promised. A slight change of plan. We weren't quite ready for that one. No, it turns out getting, you know, someone who studies like the search for alien life in the universe trying to pin them down in December is just as hard as trying to find the aliens themselves. So we thought we'd just swap things around. So we're going to tackle some of your brilliant questions for this episode. And obviously we can't have an episode without Dr. Robert Massey, the Deputy Director of the Royal Astronomical Society. So I'm going to kick things off with an easy question for the both of you. Do you have a favourite festive astronomy fact? Well, I don't have a huge number, but I think there is a sort of Christmasy night sky object, which is the genuinely truly named Christmas tree cluster part of NGC 2264, which has got a nebular as well. It just happens to be visible right now. It's in the constellation Menoceros, the unicorn, to the east of Orion. So if you're in the North Amazon, that's looking to the left of it. And it just so happens that infrared images from telescopes of this Christmas tree cluster often happen to be coded to show it in green. I really can't imagine why they would do that in their PR. But yeah, it's a really lovely object. And it does look a little bit like in the lights of a Christmas tree. Yeah, why on earth would they make that false colour in the streets? It's impossible to guess, I mean. My favourite fact for this week, oh, I feel like I'm on the Know Such Things of Fish podcast. This is great. My fact for this week was, in 2017, undergraduate students at the University of Leicester calculated the number of Christmas lights you would need to add to the outside of your house to make it visible from space. Amazing. Yeah. I'm like, I want to find these students. I don't want to shake their hands because this is fantastic. So it turns out if you're interested, you would need 10,060 lumens, so that's the magnitude of lights you would need, or the equivalent of 2,638 LED Christmas lights. Oh my gosh. I know, it's wonderful. They were inspired by the Christmas film from 2006, a Deck the Halls, for those who've seen it, because I think that's the whole premise of the film. And they were like, well, that's physics. We could do this. Yeah. Also, speaking of Christmas films, Izzy, have you seen the new Netflix Christmas film, the one with Lindsay Lohan? It's called Our Little Secret. No, but it's on my list, and I saw how one from last year, which I would really recommend. But there is an astronomy link here, I promise people. But I was watching the opening credits, and the premise of the film is something happened in 2014, and they have to zoom through to 2024. And the opening credits of the scene is then basically going through a load of world events to show time passing, and three astronomy news stories made it in there, and they were the only science things that were shown in that global sort of news recap from 2014 to 2024. In an ex-links film. Yeah, it was Pluto's, so the New Horizons flyby of Pluto, with that first image of Pluto we got, it was Perseverance landing on Mars, and then the first ever image of a black hole in Messier 87. There was also William Shatner going to space, which I guess you could also count, but I didn't. And then for me, the best one was obviously the Eros tour from Taylor Swift at the end of it. But I figured that one of the projection team on the film must have been a big astronomy fan, you know, maybe they're listening now, who knows. Amazing, I mean, that's just maybe even more excited to watch this, Lizzie, but I'm just going to be honest. Actually, and I'm going to throw something in here as well, because I was looking at Christmas on the ISS, and then I got into a bit of a rabbit hole. So my fact that I want to bring to the table is in 1973, on board the Skylab orbital station, astronauts Gerald Carr, William Polk, and Edward Gibson made their own Christmas tree. They used discarded food cans and sort of pushed them all together to create a stem and then like various branches of the tree, and then used little stickers as decorations and put a cardboard cutout of a comet on top. That was so sweet. Do you know what, I bet that the kind of people that once they were back to Earth, they were like, yeah, your Christmas tree is nice, but it's not as good as the one we made. And yeah, exactly, exactly. Yeah, exactly. Nothing ever compares to it ever. Yeah, totally. Okay, so let's get on to the listener questions. And Robert, Mattp2401 wants to know, which star or planet do you think was most likely to have been the star of Bethlehem? Well, Mattp2401, definitely a perennial question there, I think one that funnily enough comes every year at this time of year. I think the answer is something we'll never know for sure, and as an atheist, I'm probably going to get into at least warm water over this. I'm treading carefully. But on the other hand, I'd be genuinely interested in astronomical phenomena that coat inside the suggested date or dates, actually, of the birth of Jesus. Now, there's actually a nice piece on the Vatican Observatory website, which is a respect to the Astronomical Institution, actually, and it invites us to use our sense of wonder over what it might have been. And I think that's absolutely fine. Yeah, that's a totally reasonable way of looking at it. And happy Christmas to the astronomers in the whole EZ. But turning to the suggested ideas, so it ranges from it didn't exist at all to all manner of things. And it could have been invented as this so-called pious fiction or midrash, where the star was added in to emphasize Jesus's divine nature. And in astronomy, though, there are quite a few obviously significant things in the sky that could be candidates. And for example, there was a really incredibly close conjunction of Jupiter and Saturn in 7 BCE, or an even ridiculously close conjunction in Jupiter and Venus in 2 BCE, where the two worlds would actually have a pitch of merge. That's very, very rare indeed. So I imagine if you were looking at that in the sky, thinking the astrological significance, rather than the astronomical significance, you know, if you're thinking about the mythology associated with that, you would have thought, wow, something very unusual is happening here. And that came after Jupiter and Venus were close together a year earlier, and they were also near the star regular, the bright star regular in Leo as well. Another idea is a comet, although they don't seem to be records, and the Chinese are really, really good at keeping those records at the time. Of anything that bright in that period of time, there's possibly one in 5 BCE, you know, just again, really quite uncertain what it might have been like. And there could also have been a supernova, although, you know, again, you sort of imagine somehow that would have had more of an impact in historical texts. But anyway, there could have been one in the year 4 BCE that happened to create the system with the unromantic name PSR 1913 plus 16, which happens to be the first binary pulsar discovered. But of all these things, my personal hunch is either the star never existed at all, or it's probably, you know, the Jupiter-Venus conjunction seems to me like a good explanation, because the idea, which I don't think anything like that happened in the 20th century, it certainly hasn't happened yet in the 21st century, the idea that two planets are so close together that they're actually touching is extraordinarily rare. So maybe that was so significant that people drew on that. Yeah, there was a Jupiter-Venus conjunction. Was it like a few Christmases ago now? Like two, three Christmases ago? And I remember that was really nice to see that they were coming so close together, and they were so bright. But I mean, they came still like a thumb with the part or something. I can't even imagine what it would look like if they overlapped completely from our perspective here on Earth. Absolutely. And even the Jupiter-Saturn one that we all got very excited about again, that was what, 2021 or something, wasn't it? That's what I'm thinking of. Yeah, I mean, you could still see them separate. You know, they were very close. They were well under a fairly small fraction of degree, but they were still not touching, and it must be so extraordinarily rare that that happens. I want to look now when the next time that's going to happen, like, is it going to happen in our lifetime? We'll get back to you in a moment. You're going to check this. I have a feeling from memory knob, but we can check. So not my lifetime at least. Well, at least now we'll have an answer when someone asks, like, if you could go in the future, if you could go anywhere to see some of that, I'll go to the next conjunction. Yeah, sure. Okay, well, we'll stick on the theme of spotting things in the night sky, because Robert, there's a question here from Purring Pulsar. What a brilliant name, can we just say? And their question is, what's the furthest star that we can see with the naked eye? Yeah, I mean, Purring Pulsar, great name, great question. Well, I started funnily enough with the Google search, because it's not the sort of thing astronomers collate in papers. And part of the reason is, you know, it depends how good your eyes are in circumstances to what the faintest thing you can see with the naked eye. Mine is not very good. But you can probably see the Andromeda Galaxy, right? Two and a half million light years away. So, you know, for non-stars, but big things, it's a really long way. But so when I looked around, there were several articles saying, oh, this is variable star V762 Cassiopeia, which means it's in the constellation of Cassiopeia, 16,000 light years away. But then you dig around quickly, and the Wikipedia article said, oh, actually it's two and a half thousand light years. So I went into the SIMBAD database, which has things like parallax. So looking at how it shifts back and forth as the Earth goes around the sun, measured by the guy satellite. And indeed, that comes up with two and a half thousand light years, so a lot closer. You can get these numbers for yourself if you could, good luck remembering this. But if you put HD 7389 into that SIMBAD database, you get these numbers and then there are calculators to help you work it out. So then I was looking around a bit more, and there isn't, I don't think there's any definitive answer to this yet, at least. Somebody probably needs to be some sort of post-op with time on their hands. I'm thinking about Becky doesn't really have time on her hands. But you know, yeah, exactly. But and that's because the stars get fainted. We see a lot more of them. So unless something is very luminous or very notable, we can just about see if the naked eye, we might not have a record of it. Two examples are stars in Cepheus, which happens to be visible at this time of year quite well. And the one is Musephi, famous as an incredibly red garnet star. And it might be about 3000 light years away, but it's actually quite hard to tell the measurements are not that good. As it happens, that one is also so large that, you know, even with that uncertainty, it would fill the solar system as far out as Jupiter. Absolutely enormous colossal star. The other one called Musephi, and that's a white blue supergiant that might be as far away as 4700 light years, you know, with again, with a lot of uncertainty. But, you know, both of those are actually comfortably a lot brighter than the naked eye limit of about magnitude 6.5. And even the fainter one is about seven and a half times brighter. So somebody really needs to go out there and trawl through the catalogs, write some crawler software or something to try and work this out. And the one thing I'd add is if you get a supernova, then they're obviously visible over much greater distances. And exploding star is really very bright indeed. The one in 1987, which I remember but didn't see, down in the large Magellanic Cloud, seemed for months in the Southern Hemisphere. And that was 170,000 light years away. So supernova, single star, really are so bright. You see them a long, long way off, but nothing like that around at the moment. I really hope I get to see one in my lifetime. That is just like, I think it's Christ 2025, amazing, but lifetime. Four centuries since we have one in our galaxy. Four centuries, so we are over to you. Yeah. Oh, and Becky in true Q&A style. We have a question for you about black holes. And I think we've got quite a few on the way to go. I'd be disappointed if they didn't come through. I didn't know I was here about black holes this episode. I was a breeze. No. So Joe has a question about Planet X, which is also known as the solar systems Planet 9. We did an episode about this back in May 2021. So do go and have a listen back to that. I thought that was more recent than that, but time is doing its thing. Anyway, Joe says, I have a question about the possibility that Planet X could be a primordial black hole. I know it's unlikely, but if it were true, could it be close enough for NASA or ESA to send a probe to it? If they could, what instruments would they put on the probe? Would there be a point in having a camera? Could we push something into it to see if spaghettification is real? What observations slash experiments would be possible? Yeah, Joe, this is the dream, right? So if the solar system did have this baby black hole just hanging around, you know, and if you work out the maths from sort of like, okay, the reason we think this black hole might be the edge of the solar system is because, you know, there's all these dwarf planets at the edge of the solar system, sort of like asteroid style things, and their orbits are being affected by something, and we don't know why and we can't explain it, and people have been like, maybe it's a black hole. And so if you take their orbits and you think, okay, if there was a black hole out there, it's probably around 400 to 800 AU distance. So an AU is the distance from Earth to the Sun, so 400 to 800 times more distance than the Earth is from the Sun. That's like 10 to 20 times the distance of Pluto from the Sun to give you an idea. The Voyager probes, which launched at the end of the 70s, are not that far out yet. There is something around, well, around 115, 70, it's somewhat of that AU. So we would definitely need to send something quicker when we send the Voyager probes. Big problem there, though, is slowing something down once it's that far out so that you could actually maybe orbit this little baby black hole from a safe enough distance for the probe, for example. Otherwise, essentially, you're just going to eat something straight past it, which is not what you want. This is why we haven't put a probe in orbit around Neptune or Uranus or even Pluto, right? The New Horizons probe, it did a flyby of Pluto. Voyager did, the Voyager probes did flybys of Uranus and Neptune, because it's very hard to slow down and people have talked about this idea of atmospheric breaking, almost skimming a stone off the surface of the pond. It's what you do to your probe. You just skim into the top of Uranus or Neptune's atmosphere to slow it down. No luck there, though, with the black hole. Assuming we can solve that problem, then yes, we would totally send a probe to orbit around this black hole if it was there on the edge of the solar system. Of course, we send a camera, I think, would be stupid. It's not like they're overly expensive, right? It's not the most expensive part of sending a probe is the camera these days. And I think if you're thinking, oh, would we really even see anything? Like, yes, I think we would. We would definitely see the black hole's impact on the light from stuff behind it, for example. So as it passed in front of stars in the Milky Way, for example, we would basically have this perfect gravitational lens telescope, right? The light from stars behind it got sort of bent by the gravity of the black hole. In terms of other things you'd send, though, one thing we want to test for is gamma rays, because if this... So it's a black hole that's thought to be a primordial black hole, or someone that was forming in the very early days of the universe, like 13 and a half billion years ago, even 13.8 billion years ago, let's say. And so because it's been around for that long, it sort of would have collected like a little halo of matter over the years. Yeah. Like it's just sort of wandering through the solar system. And empty space is the vacuum of space, but it's not quite empty. It's like one particle every huge volume, right? It would have slowly sort of gathered those things like close to it and around it. So it would have gathered matter, but it also would have gathered like antimatter, right? And antimatter and matter when they collide and meet, they annihilate and produce gamma rays. So you might expect if there's quite a bit of a halo of stuff around that black hole from over the years, it might annihilate and we might see those annihilations going on, which would be really cool to see as well. And finally, the spaghettification question. I think we'd be stupid if we didn't send something towards the black hole. Like if we've got a probe orbiting it from a safe distance, and then we just send, you know, like a little CubeSat or something to almost do the like the test where it's like, okay, you've got an Alice who's observing Bob falling. And they'd be called Alice and Bob, but it would be the most physics nerd out ever, right? As you sent this little CubeSat that would probably have a camera on board as well, sure, but also probably send out some sort of beep of a signal that we would probably be able to see, sort of have that time dilation to it where we would detect that beep that was going off every minute, get slower and slower because of the gravitational effects as it got closer to the black hole and things like that. We could almost directly test it. And yeah, all right, you think, well, at some point it's going to get spaghettified around a black hole like that. But you know, it's like sending probes into Venus's atmosphere, right? And then you just get a cursed and destroy a vessel, we're a gasset, right? We still did it. You know, I think it's that to the extreme. Yeah, I was just like, we're sending something to break it. Yes. In a good way. In a great way for science. What do engineers always say? You learn something more when it breaks and then you go to fix it. Absolutely. Well, there we go, Joe. I hope that answered your question. And we have this question from Matt in Australia. Hi, Becky Izzy, Robert and producer Richard. We know that Richard always appreciates the invention. So there we go. Merry Christmas, Richard. Maze you. In the last bonus episode, Lizzie19 had a question about accelerating particles with mass to the speed of light. So I thought I'd throw a wrinkle at Dr Becky. If you accelerated an uncompressed medium sized potato to 99% the speed of light, would that potato become a black hole due to Einstein's mass energy equivalents? This question is so, so much, Matt. It was like, it was like an undergraduate maths question combined with a puzzle in the morning newspaper, like all in one. I was in heaven, honestly. Right. So let's go through this. So for those not aware, first of all, let's do a little Einstein's general relativity what I want. As you accelerate objects close to the speed of light, the more energy you put in, it doesn't go into increasing an object's speed, but instead increases the object's mass, at least when you get close to the speed of light. So that's what we were talking about in last month's bonus episode. So as for our potato, sadly, no, the potato would not become a black hole at 99% of the speed of light. So essentially the equation for this is quite simple. You have the mass of the potato originally, and it gets timed by this thing called the gamma factor to give you the relativistic mass, right? So the gamma factor is one over the square root of one minus the speed over the speed of light all squared. So if our speed is 0.99 times the speed of light, 99% of the speed of light, then our gamma factor is about seven-ish. So our potato only increases by mass about seven times, and that's not heavy enough to become a black hole. Like potatoes aren't that heavy in the first place. I don't know if you've noticed. I've seen lumps of metal that are seven times heavier than a potato. So you might ask Izzy and Matt and Robert since everyone's here. How fast does a potato need to be travelling to become so heavy? Well, yeah. It becomes a black hole. It's on my mind for Christmas. You know, I just can't fall asleep thinking of all the presents I've got a wrap and how big a potato a potato would need to be. OK, seriously. To answer this question, you have to make some assumptions about your potato. OK, so Matt said a medium-sized potato. So, you know, not a new potato, not a baked potato, a medium-sized potato. I've got loads of those in my cupboard ready for roast and on Christmas Day. Is it flowery or waxy? It's a Marist Piper, I don't know. Flowery, flowery. Anyway, so I grabbed a few, I had a little measure. I basically decided on some round numbers in the end because I was like, well, let's say roughly it's about a 10 centimetre wide potato. Let's assume it's a sphere because I'm a physicist and that's what we do. And let's assume it's around about 100 grams. For those saying at home, I should have done it properly and taken a specific potato. And I should have got the numbers right. You will very quickly see the numbers don't matter. So we are going to go with a 10 centimetre potato that's about 100 grams. So, because we know that black holes collapse when you squish an object into a volume, that's less than what's called its swatch shield radius, right? So that's essentially the radius of which you'd have to be traveling faster than the speed of light to escape it, right? So we need to work out the mass of a 10 centimetre diameter black hole that matches our 10 centimetre potato. So that's a swatch shield radius of five centimetres, which if you do the maths is 30 trillion kilograms. It's about 5.6 times the mass of Earth. Or instead of, you remember our gamma factor before being seven-ish, it would be 300 trillion trillion potatoes. So a gamma factor of 300 trillion trillion, which unfortunately actually makes the maths very, very difficult because if you try to get back from your gamma factor to what the velocity would be, remember I said gamma was like one over the square root of one minus the velocity over the speed of light all squared. To get back to it, you need to do like one over gamma squared, which if you've got a gamma factor of 300 trillion trillion, if you square that number and then do one over that massive, massive number, most calculators are going to be like, you've got zero. If you're going to do one minus zero, you've got one. So I managed to hack this with Python code, thankfully that lets you go out to a ridiculous number of decimals to get you an accurate answer for this potato. And it is 99.529 percent of the speed of light is the speed. A medium sized potato would have to be travelling at two collapse into a black hole. And there you go. Amazing. That's actually Christmas sort of. I mean, who knew that that's where it would lead us? Matt in Australia, thank you so much. Honestly, Matt had an absolute joy answering that question. And that's all I'm going to be able to think about this day, making a roasties. We know what you're going to be talking about on the dinner table. Did you know? Okay, Robert, Jay Payne on Instagram asks, what do we need a moment to regroup? We probably do. I'm just thinking whether it applies to sprouts or what size of turkey would be. Oh, we had a medium sized sprout. Exactly. Big or small turkey, geese, you know, and some nuts, you know. Oh, brilliant. Okay, Robert, Jay Payne on Instagram has a question and they ask, is there a certain criteria for a planet or moon to become tidally locked? Yeah. Well, I'm going to say good question probably for the last time this year. Yeah, the answer is yes. And it's, but first of all, I should say what it is. So tidal locking is or captured rotation is where the rotation period of a body or how long it takes to spin on its axis matches its revolution period. Or how long it takes to complete an orbit around its parent body. So the example being the moon and the earth as the classic one, because the moon more or less keeps the same face to us. And we see a bit more than half of it because if you're further north or south, or depending on where you're looking at moon rise or moon set, or the fact the moon's orbit is an ellipse, you get to see a bit round the back. But there are still two fifths of the moon we never see from earth for this reason, because its face is locked towards us. Now it happens because you get energy dissipated through tidal heating the object and stretching and so on. And that eventually over a long time scale, typically billions of years, it depends on the system, means that the rotation that object slows down until it locks into place. And that happens to both of them actually. So, you know, it will happen to the earth as well. And about 50 billion years time, which unfortunately is much, much longer than the lifetime of the sun, the earth, moon system would do the same thing. And the earth and the moon would both be tied and locked with each other. But to give you a kind of number for when it happens is quite hard, because it depends on what the object is made of, it depends on how rigid it is. What you can say is that the more massive it is, that you know, compared with its parent body, that the quicker it will happen, and the closer in it is, the quicker it will happen as well. And it's very strongly dependent on that. It goes to the power of six in the equation. So, you know, if it's close in, it really is going to rapidly lock. And I think with the earth, moon system, that might have happened very quickly as well, because we think the moon was much, much, much closer to the earth when it formed in this big collision between the proto earth and a Mars sized body and the debris forming the moon. And we, you know, it may have been that the moon locked into place quite quickly as a result. It's really hard to say exactly how long though. But if you sat around, if you had an infinite amount of time, then in theory, all systems will eventually end up like this. It's just that it takes a very, very, very long time if they're further apart. And if the body is less rigid and all of those things. So, there's no easy answer, but the criteria is just really that they're in orbit around each other and that this process is going to happen if you sit around long enough. But that, you know, that could be, I guess, hundreds or even billions or even trillions of years in particular cases. We do, by the way, also see it with lots of satellite planet systems in the solar system and famously Pluto and its biggest moon, Sharana, already mutually tightly locked. They keep the same face to each other all the time as they orbit round. And, you know, we see it with other moons in the solar system. I think it's about 20 of them doing that, particularly the big moons, the Jupiter and Saturn. And also with planets going around other stars as well, because if you get, say, a planet near, very near to its star, then it's locked in place in the same way. So, I'm not giving you a very precise answer, but the criteria are essentially, you know, pretty much everything will do if you've got enough time to wait. You know what you should have done, Robert? You should have worked out how long it would have took to medium sized potatoes. You're testing it tightly not. It probably is more than the lifetime that you use. But yeah, you're right. Now, that is another Christmas dinner question. Well, we should do it with a sprout this time. Yeah, it's more round. We do a sprout. So, yeah, it would make more sense. Discover an impeccably curated collection of hotels. The luxury collection. 130 unique hotels and resorts across 40 countries. 500 orders a month was manageable. 5,000 is madness. Embrace intelligent order fulfillment with ShipStation. The only platform combining order management, warehouse workflows, inventory, returns and analytics in one place. What used to take five separate tools, ShipStation does in one. Go to ShipStation.com and use code START to try ShipStation free for 60 days. I want to take a moment to break from the questions and reflect on the year in space. So, for the two of you, what have been some of your favorite astronomy moments of 2024? Mine's from the very start of the year. I'm still not over it. And that is that Neptune is not as blue as we all collectively thought it was. Do you remember this story? Is this all wild? Yes. So wild. Yeah, so this was, we were at the Resonant in Oxford, actually. It was by Irwin and collaborators. And the thing that makes me laugh about this is that they started wanting to study Uranus. And then they were like, oh, it's about this thing about Neptune. And we're like, oh, no. But yeah, they were trying essentially to work out sort of with the seasons on Uranus, as it orbits the sun. How does that, the color of Uranus change? And so to do that, you need obviously like observations of Uranus over the past like, as many decades as you can get your hands on from the ground. But then essentially you need to calibrate all of that data from the ground with the Voyager probes flyby of Uranus that actually took like true color images of what Uranus would look like. And so that calibration, you need to grab the true color images from Voyager. And they were like, oh, OK, well, we should probably reprocess them ourselves again. And they were like, wow, we're here. We're doing Uranus. Should we do Neptune as well? Yeah. Should we grab the Voyager images? And they did it. And they realized, oh, the true color of Neptune isn't like the blue image that we, you know, is like the image that you always show for Neptune. And they realized that NASA like very clearly communicated like in the press conference from the Voyager probes back at the end of the 80s, like, oh, hey, we fiddled with the sort of levels here and the saturation just to show you the features in Neptune's atmosphere, that like Uranus is super smooth and Neptune has all these features. And you can only see them if we like play with the levels. And they released that image to be like, hey, look, you can see the features and people were like, great, that's Neptune. And like amazing blue color. And instead, like if you actually make like a true color image of Neptune, yeah, you don't see the features as much because the color difference, you know, isn't quite as apparent. But actually the color looks more like what we're used to seeing for Uranus, that sort of hazy pale blue rather than that sort of dark royal blue. And I still am like, but that's Neptune's identity. Yeah, I have to reprogram my brain to accept that. You know, it's still a bit, it's like I'm in 11 months and I'm still thinking about it. And Robert, how about you? Well, hopefully not quite such a traumatic answer. No, I think, look, I mean, this year, wow, we had two displays the Northern Lights. Honestly, when does that happen? If you live in the south of England, this is absolutely impressive. And we had a bright comment as well. So, you know, really brilliant actually, a phenomenal, and I'd start the year, I thought, oh, it's only that exciting in terms of night sky events, you know, not much in the way the clips is and stuff. And there you go. It just shows what I knew and my powers of prediction were completely useless again. Wasn't there a clips in the US though this year? I guess that was last year. I wanted to give like, so I wanted to give a trick from it. Yes, because that was going to be one of my highlights. That was going to be one of my highlights. So just like honorable mention to the occluses. I mean, I'm just resenting my colleagues across the Atlantic who had that too. And the aurora and the comet. But I loved, I also, not a discovery, but I did love the JWs team. It is all of them, obviously, but particularly the horse said nebula, which is always a special horse-like object in the sky. And it's, you know, taking a really, really powerful telescope and putting it, pointing it at something familiar is always great. It's always just fun as well. Did you see the recent release to sombrero image as well? So I did. The sombrero galaxy, sorry. Yeah, not on the sombrero. On the sombrero. I couldn't have to hang you getting friends in the dark. Yeah. But that one was wonderful for me to see because I studied galaxies and their black holes and stuff. So it was really cool to see the differences between the Hubble image that you get, which is just looking at the starlight and then the JWs team, which that they released was looking at the dust light. So like light that was giving off by dust that was glowing. And it's a completely different shape. Like it's completely lost that like hat-like shape that the Hubble image earth so famously has. So it's really nice to see that, you know, the dust is doing very different things to the stars, which was quite cool. Yeah, very cool. Okay, back onto the questions. And we've had a great question here from Yalf on Instagram, which is, are there jobs you can do with an astrophysics degree outside of academia? So I think there's got needs to go to both of you and I'll chip in if I have anything else to add. Yeah, exactly. I'm going to answer this first. I mean, the answer is definitely emphatically yes. And you know, you're probably not going to be working in astronomy, but hey, you know, there's loads of things you can do with it. I mean, the big secret is that most PhD astrophysics students, let alone astronomy undergraduates and then graduates go on to work in completely different areas that shouldn't really surprise as only a limited number of hired astronomers. Or there's a vast number of amateurs and vast number of people that interested in it. And we at the RIS actually collect examples every so often because we want to know what people are doing. And the last time we did it, we found people using their skills in this amazing number of areas and they were doing things like data science in the city. So no surprise there, kind of processing all these big data sets, doing that in the home office too. Detecting cancer cells, you know, like using machine learning techniques to try and identify cancer cells because they've done that with galaxies as well. Right, it's just a science of imaging. Exactly. Yeah, exactly. Yeah, exactly. School teaching definitely, because astronomy is really inspiring for teachers, really good subject for them. And even conserving paintings in the National Gallery. And I think we also, you know, it's a fact that the technique is being used in archaeology and a whole range of things they could really do with them. So it is a good course to do for that reason. You know, you don't have to use their skills in those areas, but you're going to get essentially a physics degree. You're going to be a mathematically literate. You're going to be able to do a lot of different things. And if you're good enough to do astrophysics, you're pretty much good enough to try your hand at a lot of other things too. I'm going to have to say in my case, I'm not recommending say, I take up music, for example, because the world really doesn't need that. But you know, but there are lots of astronomers who do that very, very well. Terence, who's not going to encourage me to sing. I can tell you, Becky, Becky, your time will come. I promise that duet is waiting. I mean, yeah, I think for this question, though, I always say astro is basically applied many things, right? Applied status signs, applied problem solving, applied software development these days as well, applied teaching, applied math. There's so many skills that you learn from doing astrophysics. Like Robert was saying, you can't even measure in so many different things. And I mean, even I'm an example, right? Fresh out of my undergraduate degree in physics and astronomy at Durham, I got hired on an engineering graduate scheme. So that was like in the world of work in engineering. And they sort of their thought process was like, yeah, we hire both physicists and engineers because almost the physicists haven't learned the bad habits at university. We could like train you up fresh, you know, how we want you to be trained. Obviously, I realized that wasn't for me and I did come back to academia. But I've got mates that did, you know, physics and astronomy at uni with me that are in data science, teaching, finance, you know, there could be anything from like insurance and all the stats that come with that to, you know, investment or anything like medical physics, I said, right, it's just whether that's working with the big machines or doing a lot of the sort of research side of things for the sort of skills you've learned from astrophysics. There's people in publishing as well, whether that's like, you know, publishing public science books like nonfiction books, or it's publishing like as in academic publishing. Yeah. People working in the civil service. See, we've got a friend that works at the Met Office, right? Because yeah, whether again, it's satellites, you're just pointing the satellites in a different direction, right? Looking down at Earth and not open to space. And I think one thing I want to get across right now is that there is a weird sort of like idea that pervades academia that like if you do like a science degree or like a science PhD and then you don't go on to be a scientist, it's weirdly classed as a failure, but I don't see it like that at all. No. Like I'm like, yeah, if you want to spend three years doing a PhD in, you know, some area of research or four years doing an undergraduate degree, because you love the subject and you think it's really cool and you want to contribute to the tiny, you know, in your tiny way to the sort of collective human knowledge that we have, that's a great way to spend three years of your life. Do you know what I mean? And then if you go on and do something else that's another great way of spending how many years of your life, then that's great. It's my direction. I totally agree because I think I, so I did physics at Nottingham. I did a masters. I didn't do a PhD because I knew that I didn't want to do a PhD, but I still loved physics. I didn't let that, you know, I just thought of a different way that made it more suitable to my skills and what I could do. But I've got friends that have gone on to be science patent attorneys and medical physicists. Some are doing coding for like massive supermarkets as well. And it's just like, oh, okay, this is just really, there are so many skills that you pick up. The path from astrophysicists to Google, by the way, is worrying. Yeah. Well, yeah, exactly. So I think, I mean, I totally agree with you both that if you can get your head around astrophysics, I think you can get your head around quite a lot of things and it's totally fine if that is not something in academia. You can make podcasts. Hey, I know. I'm doing it, but not this one. Okay, we're just really contributing to the whole, what do you want to be when you grow up, kid? I'm going to be a podcaster. You can be anything you want to be. Yeah. Now they say, I want to do an astrophysics degree and then do a podcast. They'll blame you, is he? Yeah. Hey, that's fine. It's fun. Okay, so Becky, can you help with this follow-up question from Sam after listening to our Fast Radio Burst episode and they've written to say, after listening to your podcast on Fast Radio Burst, I would like to know more about how experts decide where to look for Fast Radio Burst. Your guest, you had mentioned being able to get time on JWST and a sample sky shot, but since FRBs are so short and so unpredictable, how do experts decide where to aim? It's a great question, Sam. So the big radio telescopes that detect these Fast Radio Burst, they don't aim, right? They stare at the biggest patch of sky that they can at one time in the hope of detecting one, in the hope of pointing in the right direction at the right time. But they could easily be missing so many Fast Radio Burst in a night just because wrong place, wrong time, right? In terms of JWST follow-up, the field of view of JWST compared to a radio telescope is very, very small, right? This isn't something you can, like, you can't search for FRBs in the hope of detecting one with JWST because you just can't mobilize the telescope quick enough to follow up on one that's just gone off. They last like milliseconds, right? Like, unless it's a repeating source, there's nothing you can really do with JWST in terms of discovery. With JWST, what it's more about is finding the host galaxy that the Fast Radio Burst has gone off in. So whatever object is producing this Fast Radio Burst, which galaxy does it live in? Basically. And oftentimes, there doesn't seem to be a galaxy in the direction that the Fast Radio Burst seems to have come from, at least in sort of like the archive imaging we have from like ground-based telescopes, right? That obviously, you know, can't see things as faint as JWST can or in any sort of resolution. So what we do with JWST is this sort of, as you said, like a sky shot where we point JWST in the direction we think that the Fast Radio Burst has come from and just sort of like collects as much light as possible and be like, is there a galaxy there that we can now detect the JWST? Or sometimes, we do find that there's a smudge of a galaxy there in the direction we think the Fast Radio Burst has come from, but we don't know the distance very well because again, we can't really resolve it. We've not been able to get what's known as a spectrum where you take the light and you split it into its like trace of how much light each wavelength you're receiving. And from that, you can pinpoint things to say how much has the light been redshifted by the expansion of the universe to work out how far away it is. And so with JWST, we can actually look at that galaxy in more detail, get that spectrum that we need to pinpoint where the Fast Radio Burst is coming from and how far away it is. And that gives us a lot of information because if we know how far away the Fast Radio Burst is, then from how bright it appeared to us, we know how bright it was when it went off. And so we can put some limits on like how much energy was involved in the production of this Fast Radio Burst and things like that. That gives us a better idea of like what's producing them, you know, is it magnetars like everybody suspects. And also perhaps if that's changing with how distant we go out as well and with how distant we find Fast Radio Burst is there different things that produce them and does that change with time in the universe? Like lots of questions like that. Amazing. Thanks, Becky. And Robert Lucy on Instagram asks, why can't we predict or understand the sun's magnetic field? Yeah, thank you Lucy. When I read this, I thought, oh, is that Lucy Green, solar physicist who I know quite well trying to catch me out, but probably not. She's secretly mocking you. Exactly. I definitely feel judged. But it is a very fair question. I mean, the answer is we can predict the 11 year solar cycle of activity reasonably well. So we know that the number of sunspots rises and falls over that time. And then when there are a lot of sunspots, the sun is generally more active. So there are more solar flares, there are more coronal mass ejections when big eruptions of material are rejected in space, and those rise and fall over that time. And then a new cycle begins with the poles, the magnetic field reverse. So you get north to south and south to north. And right now we are at solar maximum. That's why we've had two amazing displays of aurorae this year. And interesting, we've also already seen signs of the next cycle start starting up. And there was a researcher presenting that at our National Astronomy Meeting in Hull back in July. But the details are much, much harder. And I remember a decade ago, when some solar physicists were absolutely adamant that solar activity was headed to record lows. And that was going to happen in the next few years. And it was going to be like the kind of very low numbers we saw back in the 17th century, not long after people first started observing the sun properly with telescopes. And it didn't work out like that. You know, it was low, and now it's high again. And we also definitely can't predict exactly when a large sunspots group is going to produce a flare. You know, we see them, we don't know exactly when they're going to erupt if at all, when a coronal mass ejection will happen, the direction it'll take. And we can only guess that it will probably be happening if we see a big sunspot group in the first place, we just don't know exactly when. And that's because the sun is not this sort of super smooth, easy to model object. It's a ball of plasma, it's an electrically charged particles with magnetic fields with currents of material, you know, eruptions, flows in and out of the atmosphere, even tornadoes on an under its surface and trying to work out how that hangs together is really hard. Not not in the sense that we don't understand a lot of the processes that make it happen on a micro scale, but understanding or predicting how it will change over time is quite hard. So we do understand how the magnetic fields work, we do understand that, you know, the interaction with charged particles, the fact they're tied together in electric with electromagnetic forces, that's okay. But trying to estimate those long term trends is really very, very difficult indeed beyond that basic 11 year cycle or 22 year cycle, if you prefer, if you're going from, you know, when the poles go back to the position they were in before. So really, you know, frankly, Lucid, I don't know what you're doing, but if you take up a solar physics PhD and you solve this problem, then you probably be on your way to stuck on for a Nobel Prize because astronomers are really struggling with it. Okay, I'm making we have another black cold question for you. Yeah, obviously. Abby Gelsmith says, hi, love the podcast. My question is, why do black holes expand and shrink? Oh, good question. So, I mean, expand and shrink, I think you mean they're like the size of them. So like the size of the event horizon, which like inside that we cut like classes the black hole, right? So the size of the event horizon is actually correlated with the mass of the black hole. So how heavy it is. So black holes expand if they grow in mass. So if they take in more material over time, so we see that in what we call x-ray binaries where you've got two stars that are orbiting around each other, one goes supernova becomes a black hole and the other star is close enough to start almost like feeding the black hole and like the black hole pulls material off that one. And so in that respect, the black hole will expand its radius, its event horizon will grow. And therefore, the black hole is expanding if you will as it's growing in mass. Shrinking, however, is an interesting question because you think, okay, well if black holes expand because they get heavier, then they should shrink when they get lighter and they lose mass. But the whole point of a black hole is that all the material and the light and everything is trapped there, right? That's the point of a black hole. However, it enters Stephen Hawking's stage left because Stephen Hawking was very concerned about like the fact that black holes seem to break one of the fundamental laws of physics, fundamental laws of thermodynamics, right? And is that the entropy? It's almost like the chaos in the universe should increase over time. Whereas black holes, they're sort of like the Marie Kondo's of the universe, they really organized little boxes, right? And the entropy seems to go down. And so when he was looking at the mass of trying to figure this out, he sort of came up with this hypothesis that essentially there's sort of like an interaction of the black hole with sort of what's going on in terms of quantum physics, sort of in this sort of like vacuum energy of space. I won't go into the details here because it gives me a headache every time I try and it takes me a good chapter of a book every time I try to explain this. But essentially what happens is you then get radiation given off at the event horizon of a black hole. You get like a pair of particles created, one of which escapes and one of which ends up going back into the black hole. And as Einstein told us, E equals mc square. So if you've got lights, energy escaping, you've also got mass escaping. So Stephen Hawking theory is that you have what's known as Hawking radiation that allows the black hole to evaporate over time or to shrink as Abigail put it, right? That however is still just complete hypothesis. Like those papers were published in the early 70s. We have no observational evidence that this does happen. That we've ever detected like this kind of radiation that you could get from a black hole. It could just be that it's so rare that this ever happens that of course we haven't ever detected it yet. Or there's not a black hole close enough for us to detect the tiny amount of radiation that you would expect. Maybe if there's a Planet 9 in the source system. I was just about to say, well, who knows if we're sending a probe to a primordial black hole. Exactly. If there's a Planet 9 that's primordial black hole in the source system, that would be an ideal place to test for this as well. So I guess this brings us back to the question that was alien. So we know why black holes expand, whether they can shrink or not is another thing entirely. Okay, thank you. And a final one for both of you from Sam Downs on Instagram. Do you think there are aliens out there, Robert? Oh, you know, I kind of do. But with the caveat that they might be really simple aliens, you know, really much harder question is whether there's any advanced life even remotely like us, which might be extraordinarily rare. I mean, I have to say, of course, as well, we at this point in time, we haven't found any evidence for any life. Us are no hard evidence. Anyway, we found hints of things, you know, we found worlds that could support it chemical processes that allude to it, but no more than that. So, you know, we're a long way from confirming this. But you know, they're not here. The Fermi Paradox is applying, you know, the aliens haven't definitely haven't visited the earth, whatever, whatever you might hear on some YouTube channels. And that's not really surprising, given how big the distances are. It's a really difficult thing to travel between the stars. Becky. Sorry, one sec. There was a strange noise. And now I'm convinced that the cat's in here with me. The cat is in there because I saw it walk past. Oh, disturbing noise in the background. The door opened. I didn't even realize. Yeah, I saw her wandering in the background. Yeah, your cat is in your room. I can't used to play the piano at random. By walking, that used to terrify me. She's scratching like on the far back of the sofa. Cause I almost interrupted your previous answer me like, oh, hello. Anyway, pips in the room. Aliens aren't in the room with us, but the cat is. I agree with Robert, right? I think there has to be life that has started on another planet somewhere in the universe, whether that's in our own galaxy, the Milky Way, I don't know, or, you know, more likely a far flung galaxy. I think just because everything we see when it comes to life, like, she's scratching again, the cat, like tardigrades, like surviving in, you know, the vacuum of space on the outside of the interstellar space station. And we recently saw that, you know, a chunk of asteroid that we brought back from the asteroid Ryu-Gu, right on the Hayabusa-2 mission, Jax's mission, like went to the asteroid and brought it back to Earth. Like Earth life colonized the surface of that asteroid very quickly and very happily. Like that's, you know, alien rock that has never been exposed to, you know, Earth systems. I've been in a clean room and anything and like it's got slight contamination that all of a sudden just proliferated. So I think as Ian Malcolm in Jurassic Park, so wonderfully puts it, life finds a way. And I think it would be very rare indeed if, if nothing, if we'd be the only one, you know, where those conditions are right. I think if you think about the numbers of how many stars there are and how many galaxies in the universe and how many planets they must have, blah, blah, blah. Yes, I think life must exist somewhere, but I do not think that they have visited us at all. Okay, well we'll be getting into that topic more in January 2025. So thank you to everyone for your questions. Do keep sending them in. And Robert, as always, what can we see in the night sky over the holidays? Over the holidays, well the bleep midwinter, you know, cue some carols or something. I'm not going to sing, but it is, you know, we're just after the December solstice. So for the Northern Hemisphere, it's the longest nights the year pretty much. The other way around, if you're in the Southern Hemisphere, wherever you are in the world, Orion is now really dominant in the late evenings. So the brightest constellation, the whole sky, two first magnitude stars, Betelgeuse and Rigel, the belt term, you know, a wonderful thing to see. Particularly, it's a signpost of the stars around it, so you can, you know, you can follow up and down and all that kind of thing. Do look at the nebbitter under the belt and definitely have a look around if you were given a pair of binoculars that we recommended for Christmas, you know, as a potential gift, or maybe you got some for yourself or borrow some, but you know, really opens up your enjoyment of it. Why are you there if you're in the Northern Hemisphere? Look down from the belt stars down to Sirius, which is the brightest star in the whole night sky. Now, apart from that, Jupiter is sitting above Orion in tourists. It's completely unmissable, very, very obviously bright. And if you've got a small telescope, then you could look at it, look at the belt, the weather systems, and you might also, if it's half decent, be able to see things like the moon's passing in front of it and their shadows. And I was looking up, there's a predictor on the sky and telescope website, which you should probably link to actually, but on Boxing Day, the closest in moon, Io does this for people in the UK, starts at 8 16 in the evening, and it moves away by 10 48. So it's really well placed. If you have a clear sky that night, have a look, you know, it's really quite a nice thing to see the shadow moving on and off. Venus is high in the sky after sunset, looks slightly fatter than half moon through a telescope, obviously dazzlingly bright, and it's good for the next couple of months. And if you're up before dawn and you've got a good southeastern horizon, it's also one of the best times to see tiny Mercury. It's visible in the dawn sky. So don't wait till sunrise. Obviously, it won't be there. But as it as it's getting light, you know, maybe when you're getting up for work, it'll actually be easy. Although it'll actually be easiest to spot over Christmas itself. So you might not be working at all over those days. And finally, do look out for the Quadrantids meteor shower that's peaking on the night of the second, third of January, more or less, it depends on where you are in the world. It's very, very sharp in its peak. And that's actually best for the Pacific this year. But even if you're in the UK, you might see, say, 25 meteors an hour and helpfully the moon is a thin crescent, a waning thin crescent. So it won't interfere too much. Now, I have to say, I've always really struggled to see it because weather in January in the UK is not always what it could be. I'm going to try again. I'm going to try. I'm determined to try again. And I encourage you to do the same. Do go and have a look. You know, wouldn't it be great if we actually got that? It's really quite a strong shower. It's just I've never managed to see it in 50 years. Well, maybe not 50 years, 40 years of trying. I have something to add to this as well for the Christmas stargazing period. I want to give a give a warning to all the parents of children out there that the International Space Station can look very convincingly like Father Christmas's sleigh. And I wouldn't want anybody to confuse the two because it was very fast. It's very bright. So there is actually an International Space Station Passover of the UK at 6 a.m. on Christmas morning. So if you have been gotten up that early because you have children, maybe a little look out of the window to see it passing directly overhead just past six o'clock. And you know, just be very careful that your children don't confuse it for Santa Claus because I obviously wouldn't want that confusion to happen. So no, it's good public health warning. They're public safety warning. Yeah. And if you'd like to know for your own region so that no confusion happens, spot the station from NASA is the website that you should Google. You can put in your area and see where to look and when to look as well. Yeah, it's brilliant. Oh, well, I think that's it for this episode. And for this year, we'll be back in a month's time starting with the search for intelligent life. We will come back with that. It is going to happen. We've said it so much that now I have to go and find people to talk to. We know the people to talk to the people to talk to were like, sorry, we're busy with searching for the earlier life. I don't know what you want us to say. So we will get that to you. But thank you to everybody who sent in questions for this episode. I really enjoyed this episode. Thank you so much. We do have a growing pile of questions and we will keep adding to it as well. So please do because we have these bonus episodes, right? Where we always do the Q&A as well. So if you have a burning question for the team, email it to podcast.ris.at.uk or you can find us on Instagram at supermassivepod. And we'll of course try and cover your questions in a future episode. And if I can be really cheeky and ask for a Christmas present for us, if anyone would mind rating and reviewing the podcast, then it really helps. And we love seeing all of your reviews. So thank you for anyone that's already done that. Yes, yes. And we will be back with more episodes for you in 2025 as well. But until then, everybody, happy holidays and most importantly, happy stargazing. Business where you want to supercharge your business today with the help of zero. Discover an impeccably curated collection of hotels, the luxury collection, 130 unique hotels and resorts across 40 countries. My dad, he could always fix anything. He had this knack, made him a pretty sick welder all those years. 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