#463: Cosmic Collisions, Double Dwarf Discoveries & SpaceX's Stellar Strides

Hi there, thanks for joining us. This is Space Nuts yet again. My name is Andrew Dunkley, your host. It's so good to have your company. Coming up on this episode. We've got a lot to get through. As I tend to say, some clever work reveals where most meteorites come from. Some space scientists have doubled down on a brown dwarf mystery. What does that mean? Snow white? Snow white and white? Know the answer? And some good news and some bad. News for SpaceX. That's all coming up on this episode of Space Nuts. Fifteen second is in channel ten nine ignition sequence Space Nuts or three two Space Nurts. Can I report it? Neils Good? Joining me again is Professor Fred what's an astronomer? At La Tello? Fred? Hi, Andrew, how are you going? I'm going that way? Yeah, I'm good. I'm good. At the moment, all is well. How are you? I'm going that. Way too, good thing. We're both going in the same direction as it is. Yes, you don't want to be going backwards at this stage in our lives. It's that's absolutely right, very true, unless you could wind back time and get younger and yet take back all that knowledge you've got and you know I've made the same mistakes over again. No, I don't want to do that. Not enough for making mistakes. You just make different mistakes. I reckon, I think you do. Yeah, it's usually the kind of mistakes you make. Is where did I put my glasses? I can't remember? Oh yeah, and yeah, I've done that. I can't find mine. Now I give you a clue. Let me just adjust my glasses. And what was the answer? Yes, Judy and I have often talked about this and look back at some of the mistakes we've made, mainly financial, over the years, and we've both said, look, if we didn't make those mistakes, other things wouldn't have happened that have defined our lives. So, you know, you can't sort of dismiss the mistakes because they made other good things happen. You've got to think of it that way. So that's the only way I could reconcile my past history with any kind of satisfaction. Some of the mistakes have resulted in some brilliant things. Yes, Well, you know, to Err is human and that's you know, that's the definition of a human being. We make mistakes and hopefully learn from them. We've got to learn something now, Fred from some very clever work that's been done, and they reckon. They've nailed down around seventy percent of the meteorites that we know of coming from three basic events in recent history. So that's pretty exciting, and I think they extrapolated some more information out they can nearly account for ninety percent. Of all meteorites. This is quite an amazing story, it is, and it starts off with a kind of analysis of meteorites because they're not all the same now, and you know, the astronomers or planetary scientists, I guess classify them in different ways, which is all about their composition. The stony meteorites and metallic meteorites. They are the two sort of basic. Ones, but within those definitions there are different, you know, different levels of how stoney they are or how not. And I should just say at the outset that the metallic ones are actually quite rare, so that the most common meteorites that we found are something called well ordinary chondrites chondrites C H O, N, D R I T e S. Looks like chong drites, but it's chondrites usually. And they are what make up most of the it's tens of thousands of meteorites that are in collections around the world. I can't remember the exact number, but it's a lot. Which have you know, they've been collected by meteorites hunters, and of course they're free gifts from the universe, so they're always valuable to have because they tell us about the makeup of things. Anyway, the most common are these chondrites, which are sort of carbonaceous. They're stony objects. But the the conundrum is that the when you look at the asteroids, and they sit in the asteroid belt principally, and we believe that they are the main source of meteorites. So there are one or two meteorites actually it's several hundred, but a few that come that are known to come from the Moon or Mars, or in fact the asteroid Vestor, which is actually quite a large member of the asteroid belt, the fourth one to be discovered. I think. I think six percent of all meteorites come from either the Moon, Mars or Vesta. However, as I said, most of them are just chondrites. But here's the thing. The asteroid population, the chondrites are actually quite rare. They don't dominate the asteroid population, and so there is a puzzle there, why should all ours be commoner garden chondrites whereas condracts are relatively rare when you look at the asteroid belt in general. And so what this team it's actually I think three different teams of scientists who have produced I think there are three papers involved here. And what they've done is they've basically looked at the motion of the asteroids in the asteroid belt. And you know, one of the wonderful things that you and I talk about a lot is how predicted predictable gravity is the fact that we can we can actually get a really good idea of the motions of objects through space tens of thousands or even millions of years in the past and the future, because gravitation is such a well understood phenomenon, at least at the level of objects in the Solar System. And so what they've done is they've studied the asteroid belt and looked for events in the past that would have brought asteroids together, that would have been collisions, and they've essentially found some and there are collisions between chondrite asteroids. Ah. You know, so it's making sense here that you've got a relatively rare population within the asteroid belt, but they're the ones that have collided, and they identify I think three collisions over the last Actually they go back quite a long way. There's one, the most distant one in the past, a collision which I think we've talked about already. Actually I think we talked about it in a different context a few weeks ago. It's about four hundred and sixty six million years ago, and we think that would have that was a collision that absolutely showered the Earth with meteorites and may even have formed a ring around the Earth. And I think that's what we've talked about, because there's a Massex, you know, there's an ice age not long after that, and the thinking is that the ring of asteroids around the Earth might have shaded in the sun the planet a little bit to reduce the temperature. So that's that's the furthest one. But there are other collisions that have been identified which are more recently than that. And I might read a paragraph, if I may, from a very nice piece on this from Sky and Telescope, one of the it is astronomy magazines in the world. I was addicted to Sky of telescope when I was a youngster, and what it says is two collisions involving H chondrites. These are two different sorts of condrits H and L chondrites, but they're all sort of common garden meteorites. Two collisions involving H chondrites occurred so recently that the researchers could trace their orbits well enough to date the family's origin. This is the family of asteroids that resulted from that collision. The older collision occurred seven point six million years ago and yielded the family of objects with orbits similar to one five eight Coronis. Now one five eight Coronis is an asteroid. You remember that asteroids have a number, which is the number in the order of discovery, and Coronis is the name given by the discoverer, So one five eight Coronis. They seem to have come from a collision Coronis and it's similar family, a collision seven point six million years ago. Reading back again from the sky telescope, artic called a younger family dates back to an event five point eight million years ago in which Coronis underwent another major collision, splitting off the smaller asteroid eight three two. Karen and its family, and so you know, this is lovely detective work that gives you a picture of the dynamics of the asteroid belt that we just didn't have before, and gives us a really good understanding that that some of this, you know, some of this debris that we receive from space really comes from a very small number of collisions in the asteroid belt. Yeah, it's fascinating, and I'm guessing after reading through the article of this, this still has to be peer reviewed. The paper is out there to be analyzed and chopped up and debated, and uh, you know, others will probably study the claims and say, well, hang on, men, but they seem pretty confident. Yeah they do. I think these are pretty Yeah. There are two Nature papers involved, so obviously one of the leading scientific journals in the world. There's a lot of detail to this. It's a story with many twists and ins and outs, and what I've told you is the you know, cod of the bottom line. But it is worth a read. It. It's very nicely put for astronomy enthusiasts in perhaps one of the principal magazines for astronomy enthusiasts, going Telescope. Yeah, I'm just amazed that you can look at a situation and go okay, how did that happen and then sort of work backwards to a source billions of years ago. That just fascinates me. I think it's very clever, as you said, very clever detective work. Yeah, and that's in Sky and Telescope magazine if you want to read up. While we're talking about meteorites, Fred, I read an article or the other day which I think the BBC Science website ran about Earth getting bombarded by micro meteorites, which are tiny pieces of asteroid and they reckon. Between twenty and sixty million kilograms falls on Earth every year in micro meteorites. And if you were to I don't know who worked this out, but if you were to stand in the same spot for almost thirteen years, you would get a micro meteorite caught in your hair. There you are, there's a factoid if you like. But of course, assuming that you have fard. Well that's right. If you don't, it would probably bounce off and land in someone else's hair maybe the case. That's an interesting article in it. It kind of sparks memories for me of well, when I was in Edinburgh decades ago. There are things called brown lea particles. Did that crop up in the in the article you remember? I can't see the word there. I can see a couple of other interesting little tidbits, like there's one in four thy six hundred chances of being hit by a micro meteorite. If you stand in the same spot for twenty four hours. You probably you wouldn't know it. No, well, if you stood in the same spot for twenty four hours, I think you probably need therapy. Anyway, you're probably in line for Taylor Swift tickets. That's probably where you'd be. Oh, that could be it. That could yes, that could be right. Great, it's an interesting factoid. We should put that in Friends Flip the Right. Fled Fred's flippant Factoids, which we started doing on our TikTok if you want to look at us and look us up on TikTok when we do. Little previews of the shows. So, yes, that's an interesting story, as is this one. Fred. They've been studying a. Brown dwarf for the last thirty years, but there's something about it was off. So they've taken a closer look and when bam, thank you ma'am, it's not one but two brown dwarfs. They've only got five more defined. Yeah, essentially this a good question what the population of brown dwarf brown dwarf stars is. It's very high. It's subject that we haven't really talked about, no, Andrew, and it's probably not a very good thing that we haven't talked about it much because certainly one of my former colleagues at the Australian Astronomical Observatory, Professor Christiny of the University of New South Wales, he began his career as one of the world's leading experts on brown dwarf stars. He's now moved on to exoplanets, which I guess of the next step down the series, because brown dwarfs in a way they sit in size between the giant planets of the Solar System, for example, or any other Solar System and stars themselves. They're defined as having a mass a lower mass limit of thirteen times the mass of Jupiter, and that means that if Jupiter had grown to be thirteen times its present size, it would have not been a planet, it would have been a brown dwarf. And the difference is that brown dwarfs have low level nuclear processes going on in their interior, something called deuterium burning, which gives them enough of a temperature that they're visible in the infrared the redder than red waveband. So that's how brown dwarfs are found using infrared telescopes. And back in the day, it would be in the nineteen eighties and nineties when brown dwarfs first started to be being discovered. This new population of stars that didn't quite make it because they're not big enough. I think they need to be about ninety times one hundred times the mass in Jupiter in order for you know, what we call hydrogen fusion to take place and normal processes that make styles shine. Anyway, that's the background. So this is a brown dwarf which is called Gliza two to nine B. Gliza was an astronomer who made a catalog of these things, and in fact the discovery exactly as you said thirty years ago, nearly discovered in nineteen ninety five and is one that there is puzzle astronomers because they couldn't really work out why it was so massive and so dim. It should if it was the mass that we thought it was, it should be a lot brighter. Now, school with a couple of kids that fit that description. Massive button dim Yeah, okay. He didn't argue with them. He didn't argue with them, so yeah, yeah, I can well imagine. I don't just we probably shouldn't name them now that might get us in talk. Never mentioned Paul's name. All right, let's move on the brown dwarf gleaser to two nine B should be more, should be brighter than it is given its mass until now, and now we have had a paper that's been lead authored by actually a graduate student, which is you know, it's nice to see these post graduate students doing their graduate students doing their basically cutting edge research. And this gentleman Jerry Clan who is at the California Institute of Technology, and Jerry can be either. So I should just. Qualify that by seeing saying this person, Jerry quann is a graduate student at Caltech, the California Institute of Technology, one of the leading organizations in the world for this kind of work, and lots of other fields of studying too. Anyway, he or she they have written a paper in Nature which explains what the issue is and it's that Lisa two to nine B isn't one, but is actually two brown dwarfs thirty eight and thirty four times the US of Jupiter, and they have a twelve day orbit around each other and something close to our hearts here in Australia. They were observed by using instruments at the very large telescope in Chile run by the European Southern Observatory, which we in Australia have a strategic partnership with. Now, so the fact that this star is actually not a single star, it's a binary, which is what we call two styles orbiting around another is a great discoverer. Yeah, great discovery and pushes forward our understanding of brown dwarfs. In fact, it clearly solves a problem if this thing was more massive than it should be for the amount of radiation that it gives out. So yes, really really. Very nice, a very nice study. There's a nice quote from one of the people who actually discovered Gleezer two to nine B back in nineteen ninety five, Rebecca Oppenheimer, who says, these two worlds whipping around each other are actually smaller in radius than Jupiter. They look quite strange in our night sky. If we had something like them in our own solar system, they would indeed yeah. Wow, No, that's a great discovery and it sorts out a problem about this thing they've been looking at for thirty years not being bright enough. And yeah they've they've figured it out. And Jerry is a bloke, so and look forgive me Fred, but I think the Chinese pronounced their exes as ship so Shun I would suggest his surname Jerry chu Anne from the cultake yep, yes, originally from China and ultimately in Canada. Yeah, yeah, very very good pick up by him about the brown dwarf situation. How close is the nearest one to us? Have we ever figured that out? Yes, we probably do know that, and it's probably not that far, but I don't know the answer to it. I'm sure while we're talking about the next story, you can google closest. Brown draft you know, I will, and. I'm glad you do it, because, like, as we've just discovered, it's very nice that, yeah, you can chill in these gaps. The nearest Brown dwarfs are located in the Lumen sixteen system, which is about six and a half light years away. Yeah, I thought they would be quite close. I mean, it's because we have a relatively nearby population of brown dwarfs. So they're probably very common in the galaxy. It's because they're not great distances that we know about them at all, because they are so dim, they're kind of broiled. That's why they got that. Yeah. Yeah, not weak enough to be plants, not strong enough to be stars. They're just somewhere in between, wondering about their identities. Normally, they're probably very confused and very. Confused spatial objects. Yeah, if you want to read all about that, it's in the Cosmos magazine website. This is Space Nuts with Andrew Dunkley and Professor. Fred Broad space Buds. Okay, Fred, we've got a couple of stories involving SpaceX. We've been talking about them a lot lately, and in this case there's some good news and some not so good news. Let's start off with the good news about SpaceX making so many inroads in rocket technology. It is. It's really quite amazing what SpaceX has achieved so last week as we stand at the moment. In late October, SpaceX carried out it's ninety ninth operational flight of the year, and that was styling another Starlink launch, So twenty Starlink satellites launchtrom Cape Canaveral and basically a successful mission. The booster had already flown sixteen lames beforehand and made after the seventeenth flight, made a good recovery on the drone hip, which is called just read the instructions. Yeah, that this great, isn't it? So? You know, it's it's really quite remarkable. So the Space Coast as it's called where Canaveral is seventy one so far this year. Because SpaceX also launches from other places as well, so seventy one from the Space Coast, of which all but five of them have been flown by SpaceX. It's quite an extraordinary track record. In fact, one of them was one we saw where we were in Florida back in May. The others and. The other five were flown by the United Launch Alliance. But you know, that statistic in itself tells you how much of a game changer being able to recover your booster rocket is and that because that's what gives space X the edge on this, that they can pull the booster rocket back and launch it again. Yes, so, and of course there's been other, you know, other other missions that the breakdown is of the ninety nine launches is ninety one Falcon and five Falcon Heavy missions. And I don't think that includes the theybeating does the Starling Sorry Starship launches? I can't remember how that fits into the into the statistics the Starling launches, which of course culminated in that extraordinary event a couple of weeks ago when when the Starling Sorryes Starship boost of the Falcon Super Heavy which are grabbed by the chopsticks. Yeah. Down there a book a Chica in Texas. So, yes, that's the good news. A lot of activity. Yeah, they reckon Fred that they could reach around one hundred and forty four launches by the end of this calendar year, which would be an all time record. That would, Yeah, an amazing achievement. I think they're launching on average once every couple of weeks. Well, yes, it's more than that. It's more than twice. It's three times a week, basically three times a little. Yeah, it's a lot. Yeah, it's kind of almost every day, which is sort of what you know, what we It's not quite that, but it's it's what we expected would happen with all this. Now. Of course, most of those launches were for styling satellites space butts. Therein though, lies a problem, and this is where we get onto the not so good news for SpaceX because people have been analyzing their activity, and it's not just them, there's a lot of organizations that use similar technology. And the concerns have been raised about pollution in our atmosphere. That's right, and this is something that's been growing in I guess attention over the past well a few months perhaps the past year. Is what happens when the spacecraft re enters the atmosphere, so it burns up if you know, less bits of it actually get down to the Earth, which we do know happens from time to time. We've talked about that as well. But fac the spacecraft burns up. If you've got a like a Starlink satellite, which way is about a quarter of a ton about three meters by one meter, they basically are completely burned up in the atmosphere, and that means there's a quarter of a ton of stuff gone into the atmosphere, and the stuff is mostly aliminium oxide because they're must be made of aluminium. They burned up and generate aliminium oxide. And that is well, it's one of these gases that contributes to the hole in the ozone there and so it is not that and gentle on the atmosphere. There's an estimate which is that at the moment, about half a ton of burned up satellite trash as it's called, you know, by some of the authors who are written about this, and I'm looking at the space dot com website. At the moment satellite trash half a ton comes in per day. And that's because you've got you know, a lot of Starlink satellites burning up their they're a quarter of a talent. But you've also got the upper stage of the Starlink launch vehicles. So it's the top part of a Falcon heavy, the bit that does not get returned to Earth, the cheaper bit. I think it weighs about four tons when all the fuels out of it, and so that's they're coming down as well. So if Starlink are launching twenty at a time, which is about the standard number at the moment, then that every twenty satellites you get another four tons of debris, which is the aluminium oxide that comes from the upper stage of your rocket. That's it's a concern. It's starting to worry people. As I said, in particular, particularly it is in regards to its effect on the ozone lare. Now you and I have to before about the lifetime of Stalink satellites. They are about five years and you will recall probably that the first tranch of Starlink satellites was launched in May twenty nineteen. That's five years ago, more than five years ago. So they are starting to come back. And this is going to constantly rotate over time. They launching more. Than the getting back that have past. They use by date, so they come back and burn up. They put a bunch more up there. They ultimately want to put like what one hundred thousand of these things in orbit, and I. Think it could be one hundred thousand when you added all the different constellations. At the moment, Starlink's twelve thousand aiming at but with possible extension of another thirty thousand spacecraft in case two. I don't think it's called that anymore, but it was called that. But then on top of that, you've got one Web which has something like six hundred spacecraft in orbit. You've got Koiper which is another another of these constellations fun which is the Chinese answer to starlink. That's fourteen to fifteen thousand such a lites. When you add all these up, it could be that by the end of the decade we have one hundred thousand satellites in orbit, which would actually impact on the sky very significantly. Well, that's the problem. One problem for observational astronomers is the pollution that creates for observations. But all of these things are going to come back down, They're designed to come back down and burn up on re entry, and we're putting all that aluminium oxide into the atmosphere. And I read the word but it's escaped me. But it basically means that with the effect this could have on the ozone layer, it would affect here. It is the albedo, the ability for our planet to reflect sunlight. So this is yet another potential greenhouse effect problem. Yes, that's right. Indeed, that's right. It's clearly shaping up to be an environmental problem that is a direct result of the space age. And there's not many of those that you can point to. You know, a lot of people think it's the exhaust gases from the rockets, which in a particular way it is because solid rocket fuel is very bad for ozone depletion, and apparently the solid rockets that are used for some of the launchers United United Launch Alliances Atlas five uses strap on solid rocket boosters. China's Long March eleven has solid rocket fuel boosters, and actually the new Ariana six, the European one, also has these strap on boosters and they give out chemicals that are pretty horrible. There's chlorine in there, and the low with all sorts of stuff, and the worst of it is that they are putting these exhaust plumes into the stratosphere just basically where the ozone is. So it's a really bad effect of those on depletion, more so actually than the burning up of re entering satellite. So this is all looking like a pretty gloomy story for space, that we're putting all this stuff into the atmosphere that we could probably do without. Well, unless somebody in authority acts quickly and says, okay, you can't do that anymore. We know what could happen. We don't want that to happen. You're going to have to find another way. It sounds like a simple answer. I'm sure it's not. No, it's not. I mean you're kind of reduced to something like the space Elevator, which is probably. A non starter anyway. Yeah, so yeah, yeah, interesting, really interesting analysis. Indeed, it's not good to finish on a down I like that. But for all their achievements, there is a price to pay, and it sounds like our atmosphere is paying that price and we'll do for some time to come unless something can be done about it. And there's an alternative on the horizon, but it doesn't appear to be the case. If you want to read that story, as Fred said, it's on the space dot com website, and that story about the SpaceX launchers is at fizz phys fizz dot org. And don't forget if you would like to contact us or visit our website, you can do that. That's space Nuts podcast dot com or space nuts dot io. And have a look around. Christmas isn't far away. Maybe you want to get somebody a nice space related gifty pooh, we've got them at our shop. And if you want to be a supporter of space Nuts, don't forget to click on the supporter tab and maybe become a patron. We're not telling you to we would never tell you to do that, but it's an option and we certainly send our thanks out to the several hundred members of. Various patron based organized website who support Space Nuts. We really do appreciate it. Thank you so very much. Lots of benefits come with being a patron, which Hugh looks after. So that's all on our website, Spacenuts podcast dot com. Fred, We're all done, Thank you so much, so nice to talk to. You again, and I will speak again. I'm sure we will. Could be a few minutes, could be a few days, you never know. Professor Fred Wat's an astronomer at large. And thanks to Hu in the studio for I'll get back to you on that. And from me Andrew Dunkley, thanks for your company. We'll catch you again on the next episode. Of Space Nuts. Bye bye, Sauts. Listening to the Space Nuts podcast. Available at Apple Podcasts, Spotify, iHeartRadio, or your favorite podcast player. You can also stream on demand at bites dot com. This has been another quality podcast production from nights dot com.