Speaker 1: Hi there, thanks for joining us.
Speaker 2: This is Space Nuts yet again. My name is Andrew Dunkley,
Speaker 2: your host. It's so good to have your company. Coming
Speaker 2: up on this episode. We've got a lot to get through.
Speaker 2: As I tend to say, some clever work reveals where
Speaker 2: most meteorites come from. Some space scientists have doubled down
Speaker 2: on a brown dwarf mystery.
Speaker 1: What does that mean? Snow white? Snow white and white?
Speaker 1: Know the answer?
Speaker 2: And some good news and some bad.
Speaker 1: News for SpaceX.
Speaker 2: That's all coming up on this episode of Space Nuts.
Speaker 1: Fifteen second is in channel ten nine ignition sequence Space
Speaker 1: Nuts or three two Space Nurts. Can I report it?
Speaker 1: Neils Good?
Speaker 2: Joining me again is Professor Fred what's an astronomer?
Speaker 1: At La Tello? Fred?
Speaker 3: Hi, Andrew, how are you going?
Speaker 1: I'm going that way? Yeah, I'm good. I'm good. At
Speaker 1: the moment, all is well. How are you?
Speaker 3: I'm going that.
Speaker 1: Way too, good thing. We're both going in the same
Speaker 1: direction as it is.
Speaker 2: Yes, you don't want to be going backwards at this
Speaker 2: stage in our lives. It's that's absolutely right, very true,
Speaker 2: unless you could wind back time and get younger and
Speaker 2: yet take back all that knowledge you've got and you
Speaker 2: know I've made the same mistakes over again.
Speaker 3: No, I don't want to do that. Not enough for
Speaker 3: making mistakes.
Speaker 1: You just make different mistakes. I reckon, I think you do. Yeah,
Speaker 1: it's usually the kind of mistakes you make. Is where
Speaker 1: did I put my glasses? I can't remember? Oh yeah,
Speaker 1: and yeah, I've done that. I can't find mine.
Speaker 3: Now I give you a clue.
Speaker 1: Let me just adjust my glasses. And what was the answer?
Speaker 2: Yes, Judy and I have often talked about this and
Speaker 2: look back at some of the mistakes we've made, mainly financial,
Speaker 2: over the years, and we've both said, look, if we
Speaker 2: didn't make those mistakes, other things wouldn't have happened that
Speaker 2: have defined our lives. So, you know, you can't sort
Speaker 2: of dismiss the mistakes because they made other good things happen.
Speaker 1: You've got to think of it that way. So that's
Speaker 1: the only way I could reconcile my past history with
Speaker 1: any kind of satisfaction. Some of the mistakes have resulted
Speaker 1: in some brilliant things.
Speaker 2: Yes, Well, you know, to Err is human and that's
Speaker 2: you know, that's the definition of a human being. We
Speaker 2: make mistakes and hopefully learn from them. We've got to
Speaker 2: learn something now, Fred from some very clever work that's
Speaker 2: been done, and they reckon. They've nailed down around seventy
Speaker 2: percent of the meteorites that we know of coming from
Speaker 2: three basic events in recent history. So that's pretty exciting,
Speaker 2: and I think they extrapolated some more information out they
Speaker 2: can nearly account for ninety percent.
Speaker 1: Of all meteorites. This is quite an amazing story, it is,
Speaker 1: and it starts off with a kind of analysis of
Speaker 1: meteorites because they're not all the same now, and you know,
Speaker 1: the astronomers or planetary scientists, I guess classify them in
Speaker 1: different ways, which is all about their composition. The stony
Speaker 1: meteorites and metallic meteorites.
Speaker 3: They are the two sort of basic.
Speaker 1: Ones, but within those definitions there are different, you know,
Speaker 1: different levels of how stoney they are or how not.
Speaker 1: And I should just say at the outset that the
Speaker 1: metallic ones are actually quite rare, so that the most
Speaker 1: common meteorites that we found are something called well ordinary
Speaker 1: chondrites chondrites C H O, N, D R I T
Speaker 1: e S.
Speaker 3: Looks like chong drites, but it's chondrites usually.
Speaker 1: And they are what make up most of the it's
Speaker 1: tens of thousands of meteorites that are in collections around
Speaker 1: the world.
Speaker 3: I can't remember the exact number, but it's a lot.
Speaker 1: Which have you know, they've been collected by meteorites hunters,
Speaker 1: and of course they're free gifts from the universe, so
Speaker 1: they're always valuable to have because they tell us about
Speaker 1: the makeup of things. Anyway, the most common are these chondrites,
Speaker 1: which are sort of carbonaceous. They're stony objects. But the
Speaker 1: the conundrum is that the when you look at the asteroids,
Speaker 1: and they sit in the asteroid belt principally, and we
Speaker 1: believe that they are the main source of meteorites. So
Speaker 1: there are one or two meteorites actually it's several hundred,
Speaker 1: but a few that come that are known to come
Speaker 1: from the Moon or Mars, or in fact the asteroid Vestor,
Speaker 1: which is actually quite a large member of the asteroid belt,
Speaker 1: the fourth one to be discovered. I think. I think
Speaker 1: six percent of all meteorites come from either the Moon,
Speaker 1: Mars or Vesta. However, as I said, most of them
Speaker 1: are just chondrites. But here's the thing. The asteroid population,
Speaker 1: the chondrites are actually quite rare. They don't dominate the
Speaker 1: asteroid population, and so there is a puzzle there, why
Speaker 1: should all ours be commoner garden chondrites whereas condracts are
Speaker 1: relatively rare when you look at the asteroid belt in general.
Speaker 1: And so what this team it's actually I think three
Speaker 1: different teams of scientists who have produced I think there
Speaker 1: are three papers involved here. And what they've done is
Speaker 1: they've basically looked at the motion of the asteroids in
Speaker 1: the asteroid belt. And you know, one of the wonderful
Speaker 1: things that you and I talk about a lot is
Speaker 1: how predicted predictable gravity is the fact that we can
Speaker 1: we can actually get a really good idea of the
Speaker 1: motions of objects through space tens of thousands or even
Speaker 1: millions of years in the past and the future, because
Speaker 1: gravitation is such a well understood phenomenon, at least at
Speaker 1: the level of objects in the Solar System. And so
Speaker 1: what they've done is they've studied the asteroid belt and
Speaker 1: looked for events in the past that would have brought
Speaker 1: asteroids together, that would have been collisions, and they've essentially
Speaker 1: found some and there are collisions between chondrite asteroids. Ah.
Speaker 1: You know, so it's making sense here that you've got
Speaker 1: a relatively rare population within the asteroid belt, but they're
Speaker 1: the ones that have collided, and they identify I think
Speaker 1: three collisions over the last Actually they go back quite
Speaker 1: a long way. There's one, the most distant one in
Speaker 1: the past, a collision which I think we've talked about already.
Speaker 1: Actually I think we talked about it in a different
Speaker 1: context a few weeks ago. It's about four hundred and
Speaker 1: sixty six million years ago, and we think that would
Speaker 1: have that was a collision that absolutely showered the Earth
Speaker 1: with meteorites and may even have formed a ring around
Speaker 1: the Earth. And I think that's what we've talked about,
Speaker 1: because there's a Massex, you know, there's an ice age
Speaker 1: not long after that, and the thinking is that the
Speaker 1: ring of asteroids around the Earth might have shaded in
Speaker 1: the sun the planet a little bit to reduce the temperature.
Speaker 1: So that's that's the furthest one. But there are other
Speaker 1: collisions that have been identified which are more recently than that.
Speaker 1: And I might read a paragraph, if I may, from
Speaker 1: a very nice piece on this from Sky and Telescope,
Speaker 1: one of the it is astronomy magazines in the world.
Speaker 1: I was addicted to Sky of telescope when I was
Speaker 1: a youngster, and what it says is two collisions involving
Speaker 1: H chondrites. These are two different sorts of condrits H
Speaker 1: and L chondrites, but they're all sort of common garden meteorites.
Speaker 1: Two collisions involving H chondrites occurred so recently that the
Speaker 1: researchers could trace their orbits well enough to date the
Speaker 1: family's origin. This is the family of asteroids that resulted
Speaker 1: from that collision. The older collision occurred seven point six
Speaker 1: million years ago and yielded the family of objects with
Speaker 1: orbits similar to one five eight Coronis. Now one five
Speaker 1: eight Coronis is an asteroid. You remember that asteroids have
Speaker 1: a number, which is the number in the order of discovery,
Speaker 1: and Coronis is the name given by the discoverer, So
Speaker 1: one five eight Coronis. They seem to have come from
Speaker 1: a collision Coronis and it's similar family, a collision seven
Speaker 1: point six million years ago. Reading back again from the
Speaker 1: sky telescope, artic called a younger family dates back to
Speaker 1: an event five point eight million years ago in which
Speaker 1: Coronis underwent another major collision, splitting off the smaller asteroid
Speaker 1: eight three two. Karen and its family, and so you know,
Speaker 1: this is lovely detective work that gives you a picture
Speaker 1: of the dynamics of the asteroid belt that we just
Speaker 1: didn't have before, and gives us a really good understanding
Speaker 1: that that some of this, you know, some of this
Speaker 1: debris that we receive from space really comes from a
Speaker 1: very small number of collisions in the asteroid belt.
Speaker 2: Yeah, it's fascinating, and I'm guessing after reading through the
Speaker 2: article of this, this still has to be peer reviewed.
Speaker 2: The paper is out there to be analyzed and chopped
Speaker 2: up and debated, and uh, you know, others will probably
Speaker 2: study the claims and say, well, hang on, men, but
Speaker 2: they seem pretty confident.
Speaker 1: Yeah they do.
Speaker 3: I think these are pretty Yeah.
Speaker 1: There are two Nature papers involved, so obviously one of
Speaker 1: the leading scientific journals in the world. There's a lot
Speaker 1: of detail to this. It's a story with many twists
Speaker 1: and ins and outs, and what I've told you is
Speaker 1: the you know, cod of the bottom line.
Speaker 3: But it is worth a read.
Speaker 1: It. It's very nicely put for astronomy enthusiasts in perhaps
Speaker 1: one of the principal magazines for astronomy enthusiasts, going Telescope.
Speaker 2: Yeah, I'm just amazed that you can look at a
Speaker 2: situation and go okay, how did that happen and then
Speaker 2: sort of work backwards to a source billions of years ago.
Speaker 2: That just fascinates me. I think it's very clever, as
Speaker 2: you said, very clever detective work. Yeah, and that's in
Speaker 2: Sky and Telescope magazine if you want to read up.
Speaker 2: While we're talking about meteorites, Fred, I read an article
Speaker 2: or the other day which I think the BBC Science
Speaker 2: website ran about Earth getting bombarded by micro meteorites, which
Speaker 2: are tiny pieces of asteroid and they reckon. Between twenty
Speaker 2: and sixty million kilograms falls on Earth every year in
Speaker 2: micro meteorites. And if you were to I don't know
Speaker 2: who worked this out, but if you were to stand
Speaker 2: in the same spot for almost thirteen years, you would
Speaker 2: get a micro meteorite caught in your hair. There you are,
Speaker 2: there's a factoid if you like.
Speaker 3: But of course, assuming that you have fard.
Speaker 1: Well that's right.
Speaker 2: If you don't, it would probably bounce off and land
Speaker 2: in someone else's hair maybe the case.
Speaker 1: That's an interesting article in it. It kind of sparks
Speaker 1: memories for me of well, when I was in Edinburgh
Speaker 1: decades ago. There are things called brown lea particles. Did
Speaker 1: that crop up in the in the article you remember?
Speaker 1: I can't see the word there.
Speaker 2: I can see a couple of other interesting little tidbits,
Speaker 2: like there's one in four thy six hundred chances of
Speaker 2: being hit by a micro meteorite. If you stand in
Speaker 2: the same spot for twenty four hours.
Speaker 1: You probably you wouldn't know it. No, well, if you
Speaker 1: stood in the same spot for twenty four hours, I
Speaker 1: think you probably need therapy. Anyway, you're probably in line
Speaker 1: for Taylor Swift tickets. That's probably where you'd be.
Speaker 3: Oh, that could be it. That could yes, that could
Speaker 3: be right.
Speaker 1: Great, it's an interesting factoid. We should put that in
Speaker 1: Friends Flip the Right.
Speaker 2: Fled Fred's flippant Factoids, which we started doing on our
Speaker 2: TikTok if you want to look at us and look
Speaker 2: us up on TikTok when we do.
Speaker 1: Little previews of the shows. So, yes, that's an interesting story,
Speaker 1: as is this one. Fred. They've been studying a.
Speaker 2: Brown dwarf for the last thirty years, but there's something
Speaker 2: about it was off. So they've taken a closer look
Speaker 2: and when bam, thank you ma'am, it's not one but
Speaker 2: two brown dwarfs. They've only got five more defined.
Speaker 1: Yeah, essentially this a good question what the population of
Speaker 1: brown dwarf brown dwarf stars is.
Speaker 3: It's very high.
Speaker 1: It's subject that we haven't really talked about, no, Andrew,
Speaker 1: and it's probably not a very good thing that we
Speaker 1: haven't talked about it much because certainly one of my
Speaker 1: former colleagues at the Australian Astronomical Observatory, Professor Christiny of
Speaker 1: the University of New South Wales, he began his career
Speaker 1: as one of the world's leading experts on brown dwarf stars.
Speaker 1: He's now moved on to exoplanets, which I guess of
Speaker 1: the next step down the series, because brown dwarfs in
Speaker 1: a way they sit in size between the giant planets
Speaker 1: of the Solar System, for example, or any other Solar
Speaker 1: System and stars themselves. They're defined as having a mass
Speaker 1: a lower mass limit of thirteen times the mass of Jupiter,
Speaker 1: and that means that if Jupiter had grown to be
Speaker 1: thirteen times its present size, it would have not been
Speaker 1: a planet, it would have been a brown dwarf. And
Speaker 1: the difference is that brown dwarfs have low level nuclear
Speaker 1: processes going on in their interior, something called deuterium burning,
Speaker 1: which gives them enough of a temperature that they're visible
Speaker 1: in the infrared the redder than red waveband. So that's
Speaker 1: how brown dwarfs are found using infrared telescopes. And back
Speaker 1: in the day, it would be in the nineteen eighties
Speaker 1: and nineties when brown dwarfs first started to be being discovered.
Speaker 1: This new population of stars that didn't quite make it
Speaker 1: because they're not big enough. I think they need to
Speaker 1: be about ninety times one hundred times the mass in
Speaker 1: Jupiter in order for you know, what we call hydrogen
Speaker 1: fusion to take place and normal processes that make styles shine. Anyway,
Speaker 1: that's the background. So this is a brown dwarf which
Speaker 1: is called Gliza two to nine B. Gliza was an
Speaker 1: astronomer who made a catalog of these things, and in
Speaker 1: fact the discovery exactly as you said thirty years ago,
Speaker 1: nearly discovered in nineteen ninety five and is one that
Speaker 1: there is puzzle astronomers because they couldn't really work out
Speaker 1: why it was so massive and so dim. It should
Speaker 1: if it was the mass that we thought it was,
Speaker 1: it should be a lot brighter. Now, school with a
Speaker 1: couple of kids that fit that description.
Speaker 3: Massive button dim Yeah, okay.
Speaker 1: He didn't argue with them. He didn't argue with them,
Speaker 1: so yeah, yeah, I can well imagine. I don't just
Speaker 1: we probably shouldn't name them now that might get us
Speaker 1: in talk. Never mentioned Paul's name. All right, let's move
Speaker 1: on the brown dwarf gleaser to two nine B should
Speaker 1: be more, should be brighter than it is given its
Speaker 1: mass until now, and now we have had a paper
Speaker 1: that's been lead authored by actually a graduate student, which
Speaker 1: is you know, it's nice to see these post graduate
Speaker 1: students doing their graduate students doing their basically cutting edge research.
Speaker 1: And this gentleman Jerry Clan who is at the California
Speaker 1: Institute of Technology, and Jerry can be either.
Speaker 3: So I should just.
Speaker 1: Qualify that by seeing saying this person, Jerry quann is
Speaker 1: a graduate student at Caltech, the California Institute of Technology,
Speaker 1: one of the leading organizations in the world for this
Speaker 1: kind of work, and lots of other fields of studying too. Anyway,
Speaker 1: he or she they have written a paper in Nature
Speaker 1: which explains what the issue is and it's that Lisa
Speaker 1: two to nine B isn't one, but is actually two
Speaker 1: brown dwarfs thirty eight and thirty four times the US
Speaker 1: of Jupiter, and they have a twelve day orbit around
Speaker 1: each other and something close to our hearts here in Australia.
Speaker 1: They were observed by using instruments at the very large
Speaker 1: telescope in Chile run by the European Southern Observatory, which
Speaker 1: we in Australia have a strategic partnership with. Now, so
Speaker 1: the fact that this star is actually not a single star,
Speaker 1: it's a binary, which is what we call two styles
Speaker 1: orbiting around another is a great discoverer. Yeah, great discovery
Speaker 1: and pushes forward our understanding of brown dwarfs. In fact,
Speaker 1: it clearly solves a problem if this thing was more
Speaker 1: massive than it should be for the amount of radiation
Speaker 1: that it gives out.
Speaker 3: So yes, really really.
Speaker 1: Very nice, a very nice study. There's a nice quote
Speaker 1: from one of the people who actually discovered Gleezer two
Speaker 1: to nine B back in nineteen ninety five, Rebecca Oppenheimer,
Speaker 1: who says, these two worlds whipping around each other are
Speaker 1: actually smaller in radius than Jupiter. They look quite strange
Speaker 1: in our night sky. If we had something like them
Speaker 1: in our own solar system, they would indeed yeah.
Speaker 2: Wow, No, that's a great discovery and it sorts out
Speaker 2: a problem about this thing they've been looking at for
Speaker 2: thirty years not being bright enough.
Speaker 1: And yeah they've they've figured it out.
Speaker 2: And Jerry is a bloke, so and look forgive me Fred,
Speaker 2: but I think the Chinese pronounced their exes as ship
Speaker 2: so Shun I would suggest his surname Jerry chu Anne
Speaker 2: from the cultake yep, yes, originally from China and ultimately
Speaker 2: in Canada. Yeah, yeah, very very good pick up by
Speaker 2: him about the brown dwarf situation. How close is the
Speaker 2: nearest one to us?
Speaker 1: Have we ever figured that out? Yes, we probably do
Speaker 1: know that, and it's probably not that far, but I
Speaker 1: don't know the answer to it. I'm sure while we're
Speaker 1: talking about the next story, you can google closest.
Speaker 3: Brown draft you know, I will, and.
Speaker 1: I'm glad you do it, because, like, as we've just discovered,
Speaker 1: it's very nice that, yeah, you can chill in these gaps.
Speaker 2: The nearest Brown dwarfs are located in the Lumen sixteen system,
Speaker 2: which is about six and a half light years away.
Speaker 3: Yeah, I thought they would be quite close.
Speaker 1: I mean, it's because we have a relatively nearby population
Speaker 1: of brown dwarfs. So they're probably very common in the galaxy.
Speaker 1: It's because they're not great distances that we know about
Speaker 1: them at all, because they are so dim, they're kind
Speaker 1: of broiled.
Speaker 3: That's why they got that. Yeah.
Speaker 2: Yeah, not weak enough to be plants, not strong enough
Speaker 2: to be stars. They're just somewhere in between, wondering about
Speaker 2: their identities.
Speaker 3: Normally, they're probably very confused and very.
Speaker 1: Confused spatial objects.
Speaker 2: Yeah, if you want to read all about that, it's
Speaker 2: in the Cosmos magazine website. This is Space Nuts with
Speaker 2: Andrew Dunkley and Professor.
Speaker 1: Fred Broad space Buds.
Speaker 2: Okay, Fred, we've got a couple of stories involving SpaceX.
Speaker 2: We've been talking about them a lot lately, and in
Speaker 2: this case there's some good news and some not so
Speaker 2: good news. Let's start off with the good news about
Speaker 2: SpaceX making so many inroads in rocket technology.
Speaker 3: It is.
Speaker 1: It's really quite amazing what SpaceX has achieved so last
Speaker 1: week as we stand at the moment. In late October,
Speaker 1: SpaceX carried out it's ninety ninth operational flight of the year,
Speaker 1: and that was styling another Starlink launch, So twenty Starlink
Speaker 1: satellites launchtrom Cape Canaveral and basically a successful mission. The
Speaker 1: booster had already flown sixteen lames beforehand and made after
Speaker 1: the seventeenth flight, made a good recovery on the drone hip,
Speaker 1: which is called just read the instructions. Yeah, that this great,
Speaker 1: isn't it? So? You know, it's it's really quite remarkable.
Speaker 1: So the Space Coast as it's called where Canaveral is
Speaker 1: seventy one so far this year. Because SpaceX also launches
Speaker 1: from other places as well, so seventy one from the
Speaker 1: Space Coast, of which all but five of them have
Speaker 1: been flown by SpaceX. It's quite an extraordinary track record.
Speaker 1: In fact, one of them was one we saw where
Speaker 1: we were in Florida back in May.
Speaker 3: The others and.
Speaker 1: The other five were flown by the United Launch Alliance.
Speaker 1: But you know, that statistic in itself tells you how
Speaker 1: much of a game changer being able to recover your
Speaker 1: booster rocket is and that because that's what gives space
Speaker 1: X the edge on this, that they can pull the
Speaker 1: booster rocket back and launch it again. Yes, so, and
Speaker 1: of course there's been other, you know, other other missions
Speaker 1: that the breakdown is of the ninety nine launches is
Speaker 1: ninety one Falcon and five Falcon Heavy missions. And I
Speaker 1: don't think that includes the theybeating does the Starling Sorry
Speaker 1: Starship launches? I can't remember how that fits into the
Speaker 1: into the statistics the Starling launches, which of course culminated
Speaker 1: in that extraordinary event a couple of weeks ago when
Speaker 1: when the Starling Sorryes Starship boost of the Falcon Super
Speaker 1: Heavy which are grabbed by the chopsticks. Yeah. Down there
Speaker 1: a book a Chica in Texas. So, yes, that's the
Speaker 1: good news. A lot of activity.
Speaker 4: Yeah, they reckon Fred that they could reach around one
Speaker 4: hundred and forty four launches by the end of this
Speaker 4: calendar year, which would be an all time record.
Speaker 2: That would, Yeah, an amazing achievement. I think they're launching
Speaker 2: on average once every couple of weeks.
Speaker 1: Well, yes, it's more than that. It's more than twice.
Speaker 1: It's three times a week, basically three times a little. Yeah,
Speaker 1: it's a lot. Yeah, it's kind of almost every day,
Speaker 1: which is sort of what you know, what we It's
Speaker 1: not quite that, but it's it's what we expected would
Speaker 1: happen with all this. Now. Of course, most of those
Speaker 1: launches were for styling satellites space butts.
Speaker 2: Therein though, lies a problem, and this is where we
Speaker 2: get onto the not so good news for SpaceX because
Speaker 2: people have been analyzing their activity, and it's not just them,
Speaker 2: there's a lot of organizations that use similar technology. And
Speaker 2: the concerns have been raised about pollution in our atmosphere.
Speaker 1: That's right, and this is something that's been growing in
Speaker 1: I guess attention over the past well a few months
Speaker 1: perhaps the past year. Is what happens when the spacecraft
Speaker 1: re enters the atmosphere, so it burns up if you know,
Speaker 1: less bits of it actually get down to the Earth,
Speaker 1: which we do know happens from time to time.
Speaker 3: We've talked about that as well.
Speaker 1: But fac the spacecraft burns up. If you've got a
Speaker 1: like a Starlink satellite, which way is about a quarter
Speaker 1: of a ton about three meters by one meter, they
Speaker 1: basically are completely burned up in the atmosphere, and that
Speaker 1: means there's a quarter of a ton of stuff gone
Speaker 1: into the atmosphere, and the stuff is mostly aliminium oxide
Speaker 1: because they're must be made of aluminium. They burned up
Speaker 1: and generate aliminium oxide. And that is well, it's one
Speaker 1: of these gases that contributes to the hole in the
Speaker 1: ozone there and so it is not that and gentle
Speaker 1: on the atmosphere. There's an estimate which is that at
Speaker 1: the moment, about half a ton of burned up satellite
Speaker 1: trash as it's called, you know, by some of the
Speaker 1: authors who are written about this, and I'm looking at
Speaker 1: the space dot com website. At the moment satellite trash
Speaker 1: half a ton comes in per day. And that's because
Speaker 1: you've got you know, a lot of Starlink satellites burning
Speaker 1: up their they're a quarter of a talent. But you've
Speaker 1: also got the upper stage of the Starlink launch vehicles.
Speaker 1: So it's the top part of a Falcon heavy, the
Speaker 1: bit that does not get returned to Earth, the cheaper bit.
Speaker 1: I think it weighs about four tons when all the
Speaker 1: fuels out of it, and so that's they're coming down
Speaker 1: as well. So if Starlink are launching twenty at a time,
Speaker 1: which is about the standard number at the moment, then
Speaker 1: that every twenty satellites you get another four tons of debris,
Speaker 1: which is the aluminium oxide that comes from the upper
Speaker 1: stage of your rocket. That's it's a concern. It's starting
Speaker 1: to worry people. As I said, in particular, particularly it
Speaker 1: is in regards to its effect on the ozone lare.
Speaker 1: Now you and I have to before about the lifetime
Speaker 1: of Stalink satellites. They are about five years and you
Speaker 1: will recall probably that the first tranch of Starlink satellites
Speaker 1: was launched in May twenty nineteen. That's five years ago,
Speaker 1: more than five years ago. So they are starting to
Speaker 1: come back.
Speaker 2: And this is going to constantly rotate over time. They
Speaker 2: launching more.
Speaker 1: Than the getting back that have past.
Speaker 2: They use by date, so they come back and burn up.
Speaker 2: They put a bunch more up there. They ultimately want
Speaker 2: to put like what one hundred thousand of these things
Speaker 2: in orbit, and I.
Speaker 1: Think it could be one hundred thousand when you added
Speaker 1: all the different constellations. At the moment, Starlink's twelve thousand
Speaker 1: aiming at but with possible extension of another thirty thousand
Speaker 1: spacecraft in case two.
Speaker 3: I don't think it's called that anymore, but it was
Speaker 3: called that.
Speaker 1: But then on top of that, you've got one Web
Speaker 1: which has something like six hundred spacecraft in orbit. You've
Speaker 1: got Koiper which is another another of these constellations fun
Speaker 1: which is the Chinese answer to starlink. That's fourteen to
Speaker 1: fifteen thousand such a lites. When you add all these up,
Speaker 1: it could be that by the end of the decade
Speaker 1: we have one hundred thousand satellites in orbit, which would
Speaker 1: actually impact on the sky very significantly. Well, that's the problem.
Speaker 2: One problem for observational astronomers is the pollution that creates
Speaker 2: for observations. But all of these things are going to
Speaker 2: come back down, They're designed to come back down and
Speaker 2: burn up on re entry, and we're putting all that
Speaker 2: aluminium oxide into the atmosphere. And I read the word
Speaker 2: but it's escaped me. But it basically means that with
Speaker 2: the effect this could have on the ozone layer, it
Speaker 2: would affect here. It is the albedo, the ability for
Speaker 2: our planet to reflect sunlight. So this is yet another
Speaker 2: potential greenhouse effect problem.
Speaker 1: Yes, that's right. Indeed, that's right. It's clearly shaping up
Speaker 1: to be an environmental problem that is a direct result
Speaker 1: of the space age. And there's not many of those
Speaker 1: that you can point to. You know, a lot of
Speaker 1: people think it's the exhaust gases from the rockets, which
Speaker 1: in a particular way it is because solid rocket fuel
Speaker 1: is very bad for ozone depletion, and apparently the solid
Speaker 1: rockets that are used for some of the launchers United
Speaker 1: United Launch Alliances Atlas five uses strap on solid rocket boosters.
Speaker 1: China's Long March eleven has solid rocket fuel boosters, and
Speaker 1: actually the new Ariana six, the European one, also has
Speaker 1: these strap on boosters and they give out chemicals that
Speaker 1: are pretty horrible. There's chlorine in there, and the low
Speaker 1: with all sorts of stuff, and the worst of it
Speaker 1: is that they are putting these exhaust plumes into the
Speaker 1: stratosphere just basically where the ozone is. So it's a
Speaker 1: really bad effect of those on depletion, more so actually
Speaker 1: than the burning up of re entering satellite. So this
Speaker 1: is all looking like a pretty gloomy story for space,
Speaker 1: that we're putting all this stuff into the atmosphere that
Speaker 1: we could probably do without.
Speaker 2: Well, unless somebody in authority acts quickly and says, okay,
Speaker 2: you can't do that anymore. We know what could happen.
Speaker 2: We don't want that to happen. You're going to have
Speaker 2: to find another way. It sounds like a simple answer.
Speaker 2: I'm sure it's not.
Speaker 3: No, it's not.
Speaker 1: I mean you're kind of reduced to something like the
Speaker 1: space Elevator, which is probably.
Speaker 3: A non starter anyway.
Speaker 1: Yeah, so yeah, yeah, interesting, really interesting analysis.
Speaker 2: Indeed, it's not good to finish on a down I
Speaker 2: like that. But for all their achievements, there is a
Speaker 2: price to pay, and it sounds like our atmosphere is
Speaker 2: paying that price and we'll do for some time to
Speaker 2: come unless something can be done about it. And there's
Speaker 2: an alternative on the horizon, but it doesn't appear to
Speaker 2: be the case. If you want to read that story,
Speaker 2: as Fred said, it's on the space dot com website,
Speaker 2: and that story about the SpaceX launchers is at fizz
Speaker 2: phys fizz dot org. And don't forget if you would
Speaker 2: like to contact us or visit our website, you can
Speaker 2: do that. That's space Nuts podcast dot com or space
Speaker 2: nuts dot io. And have a look around. Christmas isn't
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Speaker 2: And if you want to be a supporter of space Nuts,
Speaker 2: don't forget to click on the supporter tab and maybe
Speaker 2: become a patron. We're not telling you to we would
Speaker 2: never tell you to do that, but it's an option
Speaker 2: and we certainly send our thanks out to the several
Speaker 2: hundred members of.
Speaker 1: Various patron based organized website who support Space Nuts.
Speaker 2: We really do appreciate it. Thank you so very much.
Speaker 2: Lots of benefits come with being a patron, which Hugh
Speaker 2: looks after. So that's all on our website, Spacenuts podcast
Speaker 2: dot com. Fred, We're all done, Thank you so much,
Speaker 2: so nice to talk to.
Speaker 3: You again, and I will speak again. I'm sure we will.
Speaker 2: Could be a few minutes, could be a few days,
Speaker 2: you never know. Professor Fred Wat's an astronomer at large.
Speaker 1: And thanks to Hu in the studio for I'll get
Speaker 1: back to you on that.
Speaker 2: And from me Andrew Dunkley, thanks for your company. We'll
Speaker 2: catch you again on the next episode.
Speaker 1: Of Space Nuts. Bye bye, Sauts. Listening to the Space
Speaker 1: Nuts podcast.
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