Dr. Natalie Starkey: "Catching Stardust: Comets, Asteroids, and the Birth [...]" | Talks at Google

I. Said. Welcome dr. Starkey thank you I. Know, that we want to get to the point of talking, about how these things are going to kill all of us and we're all doomed. But, before we do that before we get started about that we should we should talk a little bit about what these things are that are going to kill us all so. Your. Your book of course is a nonfiction. Book but I couldn't help thinking while reading it that if it were a novel the main characters in it would be comets and asteroids so. Maybe we should start there talk about a little bit about what comets and asteroids are and how they are different from each other sure okay so I, guess, there's a lot of misunderstanding, now. About what what the difference is between comets, and asteroids and so. Classically, we had this idea that comments, formed. And they're very cold outer reaches, of the solar system so when our Sun first formed it was surrounded by this cloud, of gas and dust and ice and way, out in the outer reaches, of the solar system we pass where any of the planets are today we. Form the Comets and they're literally just like a size one described, as like a scoop of this cloud you basically just take this gas and dust and ice and and kind of bind it together a little bit but they're not very well like held together they're not very well consolidated. So they're, almost like a snowball essentially, with a lot of dustin but. What why they're so important, is that they're exceptionally, old so they're as old as the Sun 4.6. Billion years old which means they can tell us a lot about where. We came from where everything in our solar system came from right there they're sort of primitive objects, exactly, whereas. The asteroids is at hand they're also very old with, saying probably, nearly 4.6, if not 4.4 just about 4.5, billion years old and we. Can think of those as kind, of the leftover, building rubble from making, the planet so they formed in the inner solar system much closer to the Sun just as the rocky planets did like earth and Mercury Venus and Mars and. It was just these bits and pieces of planet that didn't get made into a planet they just got left out and then they collected, an asteroid. Belt which is now between Mars and Jupiter, so. The, asteroids. Are really important because they preserve, this history of planet building which is really hard to look at because if we just take earth we've. Had all sorts of evolution, on earth since it formed and we have plate tectonics as, most people know so. Specially living in. LA you probably, know too well there was an earthquake last night actually that you know while, plates are moving and we create earthquakes and volcanoes and this, changes, the surface of our planet so if we want to go back to the beginning of Earth's we want to see what it was made from and how it started out and how life got here and how our water got here it's really hard to do it's, really hard to pick apart that history so asteroids, are really important in that sense they can kind of allow us to to glimpse back at that time because, they didn't really evolve since they formed it's not a whole lot anyway they sort of preserve those conditions, so that's. The classic view and I think we're going to come on to in a bit kind of how that view, is maybe, not so accurate now it's not wholly wrong, but, but, we've kind of updated, our view about these objects so but we don't remember that that's the classical. Distinction, and, I love that that image of the the asteroids is kind of a leftover Legos from the solar, system you snapped, a whole bunch of things together into planets and these the ones that are kind of scattered on the floor so yeah. Yeah. And and. So because these might might come into the picture as well can we talk a little about what, meteors. And meteorites and meteoroids are, yeah, so okay that there's a lot of confusion about that so a meteorite is literally just a piece of rock from space on another, planet so on earth we can go and collect meteorite sitting on the ground and. It could be a piece of a planet it could be a piece of a comet or an asteroid and what happens is that collisions.

Happening Happen in space and they've happened for, millennia and little. Pieces of rocks will get knocked off planets, if another is an asteroid collides with them and some of this asteroid might end up just floating about in space but little pieces of it so it's. A meteoroid, in space and then when it comes through the atmosphere it becomes a meteor so you get we had the meteor shower recently that, you can see little pieces coming through often that's dust when we get a big fireball these, beautiful, scenes, that we get that's a larger piece of rock coming through if that, rock makes it to the surface if it doesn't explode, in the atmosphere and completely, disintegrates, a piece of rock on the surface as the meteorite so the, great thing about them is that we can collect them sometimes, we can actually see them fall if you see a fireball, you can sometimes, trace it and then find that fresh rock literally, just straight, from space and you, can sample it or we get older Falls where you know these are called finds where, we've kind of they fell while. Ago it could be millions of years ago. And we can then go and sample them and it's great because it means that we can get samples from space because we don't actually go into space very often like we. Go into space a bit and when we do we often don't collect samples, because if we want to go out and collect samples and space it's almost like two missions do you want to like this is why we haven't sampled Mars and people find, that quite surprising, when I say we, don't have any samples. From Mars we've been there a whole lot there's loads of instruments. On Mars but we haven't brought back any any, rocks from there speaking, out on purpose yeah right, so. We need to we will be we will be doing in the future at. The moment the only rocks we have from Mars are meteorites, so that's the only way we can sample them they're free samples which is great but we don't know exactly where they came from so if we send a mission there we can sample it exactly, in a particular Basin that we're interested in and then we can bring that back but that's basically, a second mission to launch relaunch. Off another planet or asteroid, or comet it's, it's really complicated so that's, why we haven't done it very often obviously we have a lot of samples from the moon thank goodness for that room yeah we've done it a bit but we need to do it more but we, have meteorites in the meantime which can really help us out right okay. So these are the asteroids, all live. Well not all live but or, mainly collected in the asteroid belt which is this region between the, orbits of Mars and Jupiter, and. They're, the the asteroid belt I learned. From your book isn't really all one thing right there's like an inner and an outer belt and there's a distinction between those two regions we talked about yes, when. We study the asteroids, and asteroid belt we kind of initially thought they were all going to be the same just these kind of rocky objects, that. Look a bit like you know failed, planets, and these small and they're all very small there are a couple of large objects there but actually when we look in detail from, the inner belt, which is going to be the bit that's closer to Mars and sure. Enough these things do look like asteroids in fact some of them are made completely of metals so if you take the core of earth that is made of metal we all probably, aware of that but actually we can sample sort of core from a planet if we sample some of these asteroids, and there's a NASA mission actually going in. The 2020s, called, psyche and it's gonna be going to look at one of these objects so we can sample those and they're very much like we consider the classical, asteroids but as we move out to the outer belt on the kind of Jupiter side what. We find is that they change. And. Actually become I see some of these objects, and they have a lot of carbonaceous. Materials, so what. I'm saying here is that we we've got organic matter now that's not uncommon we have organic matter in most, of the asteroids apart from the ones that are really made of just metal, this.

Isn't Like people, get very excited when we say organic matter it's not life it's literally just carbon, hydrogen bonding, and and some oxygen and, it's, it's, organic, matter that is potentially. The precursor, for life so it's, really exciting these objects contain a lot of organic matter because we still don't understand how, life got to earth we. Obviously the only planet we know of that contains life. We. Don't know how it got here and it's kind of just it's ridiculous right I always find it quite funny that we still don't know how, we are, here and we're like these very intelligent, beings that can do all sorts of amazing things but how, we got here is a mystery so, we want to study these objects, to. Try and understand if they could have delivered life so these asteroids. On the outer belt they also contain ice so they look very much like the Comets that I described at the beginning and, actually this is where this kind of distinction between the two objects breaks down a little bit because these, actually might be comments, when they formed, the, idea is that some of them really could have formed in the outer solar system and then, there was a huge reorganization. Of the solar system after a large planets formed and some of these comments. Kind of got thrown into the inner, solar system and got trapped in the asteroid belts so we actually find that they're kind of comments but they are asteroids, so it's, it's kind of confusing in that respect but the same happen the other ways some of the asteroids that formed near the Sun got, a ejected out of the solar system some of them probably disappeared, from our solar system completely and others, ended up in one, of the homes of whether comets live now so, there's probably almost certainly some objects. In what, we call the cool the Kuiper belt where Pluto lives which, probably. Asked a riddle in, origin but now they're sitting somewhere very cold so there is a bill this is where kind of the overlap starts, to happen, right because the, solar, system is kind of crazy I loved, that image from your book of Jupiter, sort of throwing a tantrum and rampaging, around the solar system and kind of throwing stuff all over the place and kind of mixing it all up so it's not and ranged you know in this kind of neat tiny little categories, that we thought at first I think that's the thing we had this beautiful view because the solar system is very hard to understand obviously we need to visit it to understand. It and we haven't been told we've been to a lot of it but we still don't know how all the planets formed and Jupiter, is enormous like it's it really controls our, solar system and its, gravity, if it decides to move around which it did in the past and can just really cause havoc throughout you know it can just knock planets around and and particularly. Small objects like asteroids so. That is and that period, of our solar system history is very, very. Crazy yeah. You talked about it swapping, the orbits of Uranus and Neptune so, Neptune is further out currently, and Uranus is closer in but they were the other way around what. We really, reconfigured so yeah and, these are massive planets, you know and and they have huge gravity so it's, kind of crazy thing and obviously it's not going to happen now but what we can do now is look out to other solar. Systems around, other planet planetary systems around other stars and we can kind of look at what is happening now so I love that this is not my field but this is astronomy, and it's absolutely fascinating that we can look out and see, we, kind of see our solar system as it was billions, of years ago because we can look at other stars. And, see actually planets forming at this very time what, kind of was happening here so this is another way we can try and figure out what. Happened 4.6, billion years ago and afterwards, so it's fascinating right, so. So in much the same way that the there's, a there's these kind of two regions. Of the asteroid, belt there's kind of two regions, of the where, the Comets live as well you talk about the Kuiper belt which is the new year we j'en and there's also the Oort cloud because a farther region when I talk about the distinction between those two regions, as well yeah.

How Far away they are it's. Kind of crazy so. Distances. In space always I think everyone just cry so yeah it's really far it's like really far to Jupiter and you know very, far to Pluto. We know he went to Pluto with the New Horizons mission recently, and it's still going through the Kuiper belt so you know a couple years later I think was 2015, at met Bhutto and. It's, still going through the coif about so it is 25, times wider than the. Asteroid belt and the asteroid belt is already fairly, large right and it's. Just in, terms of distances, it's not that, far so it's just past. Neptune. Uranus, it's, kind of just, on the edge of the solar system but these objects, that are there that I see they're dusty they're kind of mostly, fairly, small and we can see most of them so we kind of know rough. What is there but. They're sort of found to our Sun by the gravity, they're not too far that they're not kind of bound to our solar system but, once you get to the edge of the Kuiper belt it sort of becomes no-man's land we, have a region, called the scattered, disc which, is just some random objects, which are probably mostly, cometary and and, they're. Kind of on crazy orbits, a little bit and we don't understand, them a whole lot that they are we, can't see all of them but, they're kind of we know that they're there but then we get to this theoretical, phase of the solar system which, is all cloud and, I was fascinated to learn when, I did a few years ago that but what cloud is not proven, like right it's. So far away and we, always talk about what cloud comets and, you do we have what we call long period comets which are these comets, that come into the inner solar system and orbit the Sun and, they have to have orbits of more than 200 years so the. Way we know that what cloud is there partly. Because we have to balance out the mass of the solar system somehow so we kind of you, know guess there had to be something out there but then we get these comets coming in it really round random, angles into this so basically, I should probably just, sidestep. A little bit the solar system is most people know all the planets on the same plane and. So is a quoit about so we're sort of all going around the Sun nicely, Pluto's. Doing something slightly different and then, we move out to the Oort cloud and this is literally a cloud around, the, whole Sun so, what happens is it's one one of these comets decides to come into the inner solar system they, can come in from all random angles they're not really coming along that plane so, that's how we sort of notice cloud is there because these little visitors, from the outer solar system come, in and and we can spot them but. We can't directly see them if they're there because they're just too far away you know these objects are tiny and too far away so this, is partly one so New Horizons got to Pluto we didn't really know much about it like we just could not really see it in any detail so I'm, really excited to see the next object it's going to in the coif about and, then the Oort cloud would just I don't you know we're never gonna get there in anyone's, lifetime it's, really the, spaceships, will continue going but we are not gonna know they will run out of battery by then anyway so right right doing. The math on the numbers from your book I got that. Light, leaves the Sun it gets to the near edge of the Kuiper belt in four hours okay so that's the Kuiper belt it gets, to the near edge of the Oort cloud and something like nine and a half M actually. That's the that's the magnitude, of the difference and we're talking about and then that will cloud it would take another cheers to cross right, something.

Like That yeah exactly, right yeah, it's it's like from one two three light, years, yeah distance, yeah so when you're talking just a spacecraft, speeds I mean this is gonna take, hundreds. Tens, of thousands of years I'm guessing yes, right it's one a 40,000, years or something something along those lines, yeah, yeah it's a very far, so I think I don't have batteries or less your subjects are barely bound, to, our Sun they, are actually influenced, often by in the galaxies the passing, of other stars like they can be knocked out of their orbit by. You know the literally, other stars nearby because they're almost closer to other solar. Systems or, stars then right that. Was the thing I was fascinated when it was just a little factoid I was fascinated by from your book that the the, outer edge of the Oort cloud which is around our Sun is actually closer to the next star than, it is to our Sun but they are literally, within our solar system so it's yeah it's right where you define the edge of the solar system and there are different definitions for where it is right, when you enter interstellar. Space which is a bit in between the Stars and, so, yeah the Voyager missions which set off in the 1970s. They, are now in interstellar, space but that just means they are past the. Coif about face rainy all right yeah yeah, as, long as we're talking about like awesome, little facts from your book the. The astra this is this is a thing that kind of blew my mind the asteroid, belt all the asteroids from the asteroid belt put together would. Have less mass than Earth's moon yeah, yeah which is very different from your picture of it as you know you think of the Millennium Falcon swimming. Through. The asteroid belt in the asteroids are all kind of like huge and close together and yeah but it's really kind of, and. That's a good thing otherwise they would collide more often and we don't have more issues in the inner solar system with potentially being hit by one so actually it's a good thing that they're nicely far apart so you can get through quite easily really good route, well. That well that's a nice little transition for us, so. Now, that we know we have a handle on kind of what all the players are that comets, and asteroids in the solar system and the meteors of course once they get here let's. Talk about how they're going to kill us all great. Yeah. So one of the things that you talked about in, the book is you kind of point. Out that comets and asteroids giveth but they also taketh away that they might have brought life to earth but. They also you know wiped out the dinosaurs and, could do the same to us I'm. A little hesitant to ascribe, properties. Like good and evil to inanimate objects, like that maybe, we should talk about them and helpful as or scary but how do you think about them do you think that they're things. That should be revered or feared or so, I mean it's probably no surprise as, somebody who's researched, these objects, quite a while that I revere, them, very. Kids what are the things about is yes they do have the potential to collide with us and we think we say for about a hundred years so probably all of us unless you know how to live a lot longer than 100 years then you're, going to be okay but the, thing is like our descendants, going to be okay and the more we can learn about these objects now the, better prepared, we are to do, something about one of them hitting us so if we don't understand, our enemy then we don't know how to fight it surely, so I, love. These objects because they can tell us a lot about where we came from about, our past and how everything started, in the solar system but yeah they do really have the potential to cause, havoc got a large asteroid could hit us past, that 100 G I mean it there's.

A Chance one could hit us within a hundred years but it's very unlikely past. That we at the moment don't know it's the kind of a continuously, updated list. Of potentially, hazardous asteroids, and comets which you. Know astronomers, are studying, and they need to understand, better how, they move in on their orbits and what you know their next orbit if the Sun is gonna do and if they're going to be altered by passing. Jupiter in the future or something so, we, need to understand exactly what, they're doing how. They're spinning and then we need to know what they're made of because if we don't know what they're made of well some. Ideas like you know Armageddon, if you've seen the Hollywood, movie they. Actually go and decimate some explosive. Inside, asteroid, to blow it up well it depends what you're dealing with if this asteroid is made of pure metal that might not work you might not even be able to drill into the thing to to, put an to put some explosive. With inside it but if we talk about a comment well maybe if it's coming towards Earth it might just explode on atmospheric, entry anyway, so it's. Kind of like okay we, need to know what we're dealing with if we want to go and deflect, or destroy one. Before it gets here right and you talk about this um in the book that that. Even even blowing up the asteroid might not be good because now you have a whole bunch of asteroids that are going to kill you instead of one big asteroid exactly, and I think one of the things is like the. More. Advanced notice, we get the better so if we can see that an object is heading for us and its large say a kilometer, or so and. It's, 10 years out then we have time to launch a mission this, is why we need to do a bit of work in advance because it's not that easy to launch a mission just straight, the next day so, we need our viewers to figure out how to launch the mission there it'd, be great if we had one ready to go for any of these objects or sure what we're currently working on in planetary defense it's. A it's a big topic at the moment in research and governments. Are actually interested, in this which is great because we need them to be to support the research community launch. Mission basically the longer you have the better if, you want to deflect something and it's way off it's going to be a smaller nun to deflect it if you just want to push it out the way then, if it's right next to Earth already you're gonna have to deflect it a long way for it to miss. Ideally. We'd want to deflect them we just want to put it on a different course and misses our planet we don't care if it's another planet but we want to protect our own planet, we. Could if, we're, stuck and we don't have much notice we could explode it in some way if we can find a way of course you might need to use nuclear, weapons which is not going to be fun if you're going to get the rain of this, nuclear, weapon falling down on the planet but and it's possibly in violation of treaties although probably given, if you were saving the entire thing if we yeah I think, nuclear weapons aren't allowed to be used in spaces right in a bad way so I think if we were saving our planet then we'd probably let it go and maybe some nuclear fallout wouldn't be as bad as just being hit by an asteroid so we drove you might allow it but you know it sounds. Like science fiction and it is science fiction but it's also now turning into reality these are really kind of what we're thinking of there's other crazier, ideas that we don't have to explode these things there's, other ideas like we can spray paint one side of this project so generally these objects are very dark and, as they go by the Sun they obviously heat it up now if you can change one side of the asteroid if you could spray paint it white or metallic, it's, gonna heat up differently, as it goes near to the Sun and it all starts spinning differently and if it spins differently it'll change its orbit gradually, so these are very gentle techniques, it sounds a bit mad trying to spray paint in space but this is literally one of one of the things we can do or cover it with something too, I've change its how, it reacts to the sun's heat I.

Never Saw the movie Armageddon but I gather. What it's about is a shame I haven't seen it I, gather what it's about is they sent like basically miners, to space flag. Greece what is up that right Boyle, - yeah there was real is but, so it never occurred to be like I kind of get that but it never occurred to me that may go what you won't want to send its taggers that, could yeah spray-paint, yeah, they. Would put a nice mural on the side it would look pretty as it passed us by safely. That's. Your next. Novel. Yeah. But. Yeah I mean of. Course we're not actually gonna some people are if in reality what's gonna happen is that we use robots and in space of course all the time we use robots just because they're, more expendable we don't really care if we kill the robots we care because they cost a lot and a lot of people's careers go into making them something, is really thoughtful yeah. Don't. We all but yeah, it's not humans, so there's big, issues that sending humans into space and. Yeah. If we're gonna send them to land on an asteroid well asteroids, don't have enough lot of gravity because they're small objects, so they're gonna have to be tethered on I can't, remember what they did and I'm getting if they would think they were just roaming about freely, they, would probably a float off into space you know so it's. Not easy to send humans to these objects I'm sure it will happen in the future you know way into the future but for now it will be robots which. Again is not easy because as you know trying to run a robot, from Earth and millions, of miles away has, its issues communication. Times the tricky takes, a long time to communicate and. Things. Go wrong like I ran a lab instrument, for many years and I could be in there tinkering, with it and really something went wrong I could change things but if that instrument is way off on an asteroid there's nothing you can do if it breaks there's, not really an awful lot you can do so right yeah there's lots of issues so. But we have actually sent space, missions to these objects, to to comets and asteroids before and it, was it was I. Would, say it was it was pretty evident from reading your book that you're a big fan of both the Stardust and Rosetta missions yeah, and. Speaking of speaking of landing something on a one, of those objects. Rosetta, actually did that yeah, you, don't tell. Us a little bit about those missions and what I, mean the NASA Stardust, mission was, like, it, but it had bored its samples back like as I was starting my career in this in this area of science and so, the NASA status was really groundbreaking it was actually quite a cheap mission and it flew to. Comet vilt too and it. Wanted to bring a sample back but it didn't have enough money to land on this object and come back from it so they, flew through the tail of the comments so I mentioned that comments have a lot of ice and dust in them and, as they go by the Sun this material, gets heated up so sure enough that I streams, off the comment takes dust with it and, that's what produces the tail when you get the famous comments that you see all, the beautiful images of that's.

Hail Of material is literally the gas and dust coming off of that comment and. So what they did was just flew through the tail of this comment and literally just got impacting, particles, on this collector, and that was their comet samples and they closed up their little collector, and jettisoned, it back to earth and the rest of space core carried on and we. Had those samples back in 2006. And, they were our first example real samples of a comet because it's, hard to know if we've got any meteorites of comments because as I said earlier they probably explode. As the end to the atmosphere, so it's hard to know we've definitely got one on earth so. This, was a real, groundbreaking. Mission and then it also really turned the books on what how we thought comets, formed and what it showed us was that actually this we know it's a comment it behaves like a comment we know it's all bit that it comes from you. Know from the Kuiper belt and then, what we find is that actually, it, doesn't look like a comment when we look at the rocks with their net right they look like an asteroid, so, it, doesn't, sound very exciting me like hold on a minute this thing formed, way out in the outer solar system yet, it's got components, within it that look exactly like the planets that look exactly like the building blocks of the planets that form very close to the Sun so how do we get ice and hot material contained, within one object, so, this was why everything, got blown apart at this stage and the scientists, you know and they're still working on it we still are trying to understand how we get hot material from the inner solar system out, to the comet forming region to. Form a comet that then is covered in ice and dust and all the normal stuff that we expect it to contain and. And, there's lots of different theories but that is still an ongoing area, that we need to understand, so we know that the story is not as simple as. It could be as we'd like it to be as the. Textbooks would have us believe and before. We move on Devon said it start us to also brought us back in addition to bring us back the first sample from a comet brought us back samples of interstellar particles, right yeah, I'm the detector around the other way and exactly, what did a few of those is yeah, basically we have particles, from interstellar, space which is the space around all, the stars and the solar system and. These, particles are traveling exceptionally, fast and. They. We haven't really been able to sample them before but so this kind, of it was called like a tennis racket style collector it kind of just came up out of the spacecraft once I collect a comet particles and then the backside collected interstellar particles, and they're tiny they're like that's they're, so tiny that we can't like the colloid particles are, small I'm saying like probably a maximum. Of like the width of a human hair would be the largest particles, we collected if that the. Interstellar particles, are ten times smaller than that so they're very hard to see on the collector and they're very hard to analyze but, like there was a whole, instrument built somewhere. In LA or somewhere, in California I can't remember which University. Of that but they basically, made a whole instruments who measure these these these, particles, because we, can sample then or galaxies because we have no other way we haven't been able to go out to our galaxy but these particles, come to us so we can actually start to understand what our galaxy looks like and what it's made of which is fascinating, so yeah, it was immune it just did so much that mission it was fascinating, everything there, were there were some other really, interesting, things in there you go, into a lot of detail about you, know exactly how they were.

Able To get some of the samples, out and so on but and, we might, want to come back to that but I did want to also give you a chance to talk about rosetta as well yeah fascinating, such. A great mission so I was just really well placed on say I'm really lucky to be where, I was working when, the Rosetta mission was ongoing now I have to say I wasn't in it from the beginning because it took 20 years to plan this mission in fact I think when it was originally, planned I was probably still in school like. You know primary, kind of school very early and. Then. It took a long time to build the mission and then it, took 10 years for it to actually from, launch to get to its comment so it, had this massive journey, in in the solar system to get to catch up with this comment so this comment and call it 67p, churyumov-gerasimenko. Yeah. I can't do that I just I like everybody else I just say cherry Jerry yeah, you can say CG or SNP, yeah it's a long name but, it. Was traveling in a solar system and the idea was that they launched and had to do some gravitational slingshot. Planets, to catch up with it again enough speed because you can't just launch and go directly, into a comment that's literally not how it works so, we have to just, catch up with it so it got onto an orbit eventually it's catch up with a comment came up on it from behind and then entered. Into orbit around this thing and we've never done this before so you know Stardust has flew through the tail but. Rosetta, was just amazing it got to the comment and it basically had to do a powered it couldn't get into orbit around it cuz this object small it, was a real orbit of gravity. Fly around it, so these people, doing this engineering. And all this science for this mission they're just I just AM amazed by how they did this but they didn't even know what this object looked like before we got there we had no idea of its shape its exact size we, were expecting it to be sort of round because we always kind of envisage, these objects to be sort of round and and. We got there and it turned out to be like a rubber duckie all right I think that sounds like it caught everyone's, attention in the media quite a lot because it literally is looks like a rubber duck right there's head on this body and. I, can't, imagine how you figure. Out how to fly around that thing without bumping into it or whatever but we started to get images, back from this comment and they mapped a hundred percent of the surface of the comet because they had to pick somewhere to put a lander down right, again. They they built, this Lander 20, years previous and they. Didn't know what they were gonna be landing on do. You call it candy floss here the stuff you eat at the fair yeah. Cotton. Candy thank you okay, so we call it candy floss say one of the scientists likened it to late they didn't know if they were getting maligning on candy floss or cotton candy all right man you know they would like they had no idea if its concrete hard or very soft and they were at a sink in so they had to build a lab and just have to you just have to build a spacecraft. That's going to land on something that you don't know what it is years. From now exactly. So. You know a little, land ago and, the lander is called fillet and it just dropped, to, the comment but again remember there's not much gravity so the comet is not attracting, that thing to it the Comets still rotating in space so they have chosen a landing spot and they're like yeah we will land exactly here and sure enough it. Did initially land exactly where they wanted it to go on this object that's like three by five kilometers, in size so it's not big and. It all hurtling towards the Sun at the same time unfortunately.

Some Stuff went wrong. One of the, harpoons. That was meant to fire when they landed in order to kind of hold, it onto the surface and tether it there they already knew when they were going through their procedures before, they were going to release fillet. That it wasn't working so they already thought okay okay what, can we do about this there's nothing we can do this you know we have to just go for it now we have to test it so you, know they did their job right they got exactly where, they wanted to but the little, Lander bounced and it bounced about kilometer, up into the air now the issue is that it could have just completely left, the comment because it wasn't going to go back it, didn't bounce quite high enough that it left so it went back down again and. And, it took a few hours and then it landed again and had a lot of bounce so, it's, kind of hilarious it did the kind of three landings in space and they were only planning to do one and. 40 where it ended up was. Not the, optimal, position for the. Solar panels so it were kind of under a slight cliff but we then learnt that comets have cliffs on them and you know overhanging. Sections, it's kind of crazy and. But, it did run it ran its primary science sequence when it got initially, to the comet so, we actually ended up sampling. Some of the comic gases and some of the dust that was on from that initial landing site and then it's inferred science later on so we still learn an awful lot so it kind of seems like a failure but it wasn't a failure at all huge. Mother science done and. And. We had where, I was working the Open University and. The UK we, had one of the instruments on the lander so we had a mass spectrometer that measures, some of the components, from from the gases in there so we got to learn what was what was on the comment right and to your surprise you got you got that you got samples, from like three places exactly. Work with this guy ray, Arvidsson great guy who would. Say all the time there's no bad data, and. So you you, know just because you didn't get the exact data you plan to get doesn't mean you didn't get some great stuff you got the stuff from you know because it was bouncing you got it from like multiple. Locations, right and then we still have the orbiter that was you know still orbiting, around or flying around that comment at the time and, doing its own work it was measuring. Lots of other experiments and doing lots of other work and measuring dust coming off it and collecting that and looking at the the plasma, environment how, they have, a comet reacts to the Sun which is very important, because we didn't we don't really know how comments react to someone we know that they get heated our thermal comes off but. We we, found out that actually every, time this comment 67p, went via the sun it loses about a meter of material off its surface so it gets smaller and smaller because those volatile, ices, and everything get heated up and blown off the comment later dust, that is sitting, above it that's that kind of dehydrated, layer on top and it will come off so you lose a huge amount of material and so it's a very active environment, a comet is constantly, changing when you go oh yeah these old objects, and they they preserved a very old history of our solar system but actually if they come by the Sun they're changing all the time and and, we see that they have seasons, we notice that the comet had different seasons on it depending on on where you were on the comet and where it was in relation to the Sun so, in that Wow moves material, around the comment we see movement of you know like active, processes, like you would see on a planet it's crazy yeah that's amazing I hadn't. Heard that before that's really cool. So. Long, as we're talking about these space missions I just want to give a quick shout out to the dawn mission which. After 11 years of exploring the, asteroids Vesta and Ceres is. Is. Running, out of maneuvering fuel kind of middle of next month and so, it's going to say goodbye to us but but, just a little shout-out to to dawn for a long, and honorable, mission. Increasing. Understanding of the very objects that we're talking about here yeah. So. So. You. Were talking about the. The we, talked about this earlier that there isn't necessarily a sharp distinction between these asteroids and comets and so now that we've had these missions to, kind of look, at asteroids, close up and look at comets close up we're kind of learning more about how like there, isn't asteroids. And comets there's, more like kind of attractors, in in these space where there's there's things that we would constantly call asteroids, and things we would constantly call comets but also a lot of things kind of in between yeah, so, so what have we learned in these missions that kind of helps us understand, that continuum, a little better so I think we've, we've, learned that for, me I think what I've learned is that almost doesn't matter okay.

So We have objects that set at either end of this continuum but. If we want to study our, solar system it really doesn't matter which ones we study too much and the ones in the middle are probably the most fascinating because, they, contain, the primitive, material so the ones that contain a lot of carbon, and, a lot of organic matter the. Ice is not you know it is important, but actually understanding. The dust that came from this beginning of the solar system is great and the organic matter and so the, next emissions that are going to study these objects are both going to asteroids, so we've got a cyrus, rect which is the NASA mission and there's a Japanese mission called Hayabusa, 2 they, did hide bezel one already and that reelected some some sample and brought that back and. So we've had it didn't go completely successfully. So they're taking another try and gonna do it perfectly this time but, these two missions have arrived at their asteroids, and they're both basically, primitive. Asteroids. So they're, all maize they're not they're not comet tree-like there's still asteroids, but they have a lot of primitive material in so we can try and understand these kind of beginnings, of the solar system so they're both going to bring be bringing samples back I've forgotten right. Now what dates we're talking about but it's kind of within five, years I think something. Like that will be returning materials so they've, started their mapping phase at these objects and they're going to be looking where they're gonna put their Landers down and sampling. But it's proper, science fiction stuff I love it it's just fascinating they can do this yeah, we are going to the solar system and like going to visit comets and asteroids where they live and like bringing stuff but yeah they're yeah. That's that's really amazing stuff, so. So, we talked a little about you. Know how they're going to kill us all and, and. And, what we would do about it so you talked about kind of like spray-painting and asteroids. And things like that one. Of the the techniques, I had. Not heard. About before before, reading your book was gravity, tugs which is another interesting way of diverting asteroids. Or comets, off, their path. And it is nice because it works with unconsolidated. Things as well yeah I want to explain how our gravity tugs work okay, so some, of these objects, even the asteroids, like I said the comments will not very well consolidate, or not very well held together because this is a scoop of cloud kind of thing and, so the asteroids, on the other hand also a consolidated. They might be made of rocky material, but imagine just getting like a load of big pebbles and kind of sticking them together and they're sort of held there because it's a bit of gravity and there's, nothing reacts on them in space that would mean that they wouldn't just all fall apart but they so they sort of loosely bound together and, these, objects are particularly dangerous because they're, hard to move if you want, to hit them with something they're probably just going to break up so, we have to be very gentle with them if we know one, of these objects is heading towards us it's.

Hard To know how they're going to behave when, they come through the atmosphere, so, the gravity tractor thing is almost just taking, a spacecraft, up and and using. Thrusters on one site to sort of gently. Nudge and. Basically it's the attraction, between that, rubble pile and that. Spacecraft, which, isn't very much but if you've got enough advance warning you start doing that little playing, game and like nudging it back and forth early, enough then it will change its orbit so essentially you just you kind of want to nudge it very gently, it's, just that gravitational, attraction between the two objects which obviously happens even, if they're small there, is still something there so that, would be very useful if it were a rubble pile style, asteroid. I could, work with other ones but I think that's probably the safest way to move one of those maybe. Yeah. You know more research needed right yeah yeah yeah and, that's not that's something we haven't done before we actually have fired a bullet. Basically. Deep Space 1 right fired a bullet into into the side of a comet well we haven't tried these other techniques at all yeah, it's all kind of theoretical it's. A mission called deep impact which to a movie. Deep impact and that was refusing my book editor, was like you've got a mission Corey but that was also Hollywood movie career impacts and I was like yeah that's complicated, so. I think I ended up taking our. Mission. Called Armageddon yes that would be good. Right. Yeah this mission actually basically. Pushed. A boulder, I fired a boulder into the side of this comet to, see well, basically, to see what would happen because it's fun but. Also to. Excavate, a hole so, that we could see inside the, comment and it, was kind of maybe a little bit wrong because they, created so much dust, from this you, know impact, that the spacecraft couldn't, then see anything, there was just, so much dust everywhere but like actually the Stardust mission when it carried on when it had to call it samples and some of those back the starters next mission had carried on and. It was, managed to image that whole nut crater that was created so we got to see processes. Happening and again they saw changes happening, over time in that crater they created, so you see they've got this kind of active comet thing again REM which is which is really cool so yes it it's kind of one space mission did it and then we came back and have another look so.

So. We're, just about 40 minutes here and probably about time to start kind of mixing some audience questions while. We're kind, of finding the first victim and, giving, them mic one. Of the one of the major, another, major topic in your book was about mining yeah, asteroids, and comets. So. That so, they actually contain material, that would be useful to us on earth it's. Not just organics but but also nickel, and platinum. And things like that you. Want to talk a little bit about kind of mining techniques and so the state of the art there is so of course again it sounds like science fiction it's, like do we really need to mind in space but you know there's companies, a lot of them you know a lot of stuff going on in California where, we want to you know that's actually companies are investing in this trying to think alright can we go mind these objects we, could mine the moon there's lots of materials. On the moon that would be useful but. Equally it might be easier to mine asteroids they can be easier to get to and they don't have gravity so they're easy to get back from if we want to launch a emitter back and they contain a lot of precious metals so we all love our smart phones and everything computers. Obviously wearing Google so we, we like all, these materials, that require precious. Metals and if we're going to continue creating new technologies in the future we need to know we've got a reliable source of things like palladium, platinum all, these things that are used in in, technology. We. Were able to develop new technologies, if we don't know we've got a continued, source of this stuff and on earth things, like platinum well, it's expensive because there's not much of it we find it very hard to mine it's very dispersed throughout the crust of the earth and it's, expensive to mine and often not very good for the environment to get out if, we go to an asteroid well, there's tons of it actually there's probably more, platinum, in some. Single asteroids, than we've ever mined on the whole of the planet so we. Run into economical, issues if we were to mine it and bring it back to earth well we'd crash the market and obviously then it will probably be not worth having done the whole mining thing right maybe we store it like we do with diamonds, and we release it gradually and control the market anyway I'm not an economist but there are issues to doing that it, may cost trillions of, dollars literally, trillions of dollars to actually launch these missions and go in mind these objects but the chances, you could actually you, know they could be worth way, more than that so. There. Is I guess if you have a lot of money and you think it would be fun to go mine asteroids there is the potential you could make a lot of money of. Course we need reusable rockets because, it's just too expensive other ways we need to so that obviously a lot of companies are working on that right now being, able to cheapen. Getting. Stuff into space it's just massively. Expensive, but. If we can find, ways around this and I think progress is definitely being made at the moment we. Can get to space cheaply and we could start to mind these subjects but we don't have to bring all that stuff back to earth it could be useful in space and we.

Want To go to Mars we want to venture. Out further into our solar system but we need first, of all fuel it's very expensive to bring fuel from Earth if we want to go out into the solar system fine. We have enough fuel for a little while but then if we want to land somewhere and go and visit somewhere else we, need fuel and if we launch it from Earth it's, just very, very expensive, the more fuel you take the more fuel you need to take that fuel and there's an exponential relationship, and it just gets crazy so if we can find the fuel in space and sure enough we have water if, we can split water needs to get into hydrogen oxygen we can create rocket fuel in space so again, it sounds like science, fiction but, we can then also use, these objects to make materials in space 3d print what we require instead of taking a lot of tools from Earth which we currently do if we go to the International, Space Station let's take everything with us and we have to launch. Missions just to you know resupply. It well we wouldn't need to do that we could just actually go in 3d print so they're actually tests our 3d printer on the International. Space Station right, and. It. Sounds crazy but yeah that is something we could do we just mined the asteroid get the materials we need and make the tools we require into space so yeah, it's, it's, happening, it seems like I think the, first steps in us in, asteroid, mining are probably going to happen within the next few decades the. Very tentative, steps of like getting there prospecting. Basically, seeing what these objects contain and then, figuring, out what, kind of missions we require to maybe tuck them into an orbit where they're sort of safe and they're going to sit quite happily so that we can then launch a mission to to, mined them in some way whether, we need humans it's unknown at the moment this. Is what people talk about needing a moon base for, a lunar base for humans to live and that they could then mine, from. The moon kind of thing so it's. A lot of unknowns at the moment but there's definitely progress being made and there you know there's like the US has created laws about. Now about mining.

A Space and who owns the, materials. They've mined so any US citizen theoretically. If they mined something in space they can own that stuff them which, is kind of crazy and I don't know what the rest of world thinks about this at the moment I think a Luxembourger following very similar yeah laws, I don't know if they've passed them yet but again Luxembourg is tiny I don't have you fiend but there's not many people that live there so I'm not sure how many people are Luxembourg, citizens, but. Yeah it's that fair I kind of think well okay I'm not yes then I want to go in mine space but I wouldn't be allowed at the moment to own the space I okay. So yeah. A lot of issues and. A lot of global, issues they think that but it seems like they're worth working out because there's so much there's. So much potentially, so much wealth there and, it's not just you know wealth in terms of making you rich but wealth in terms of as you said things like resources, to make smart phones and stuff like that clean it you know never I'd never really thought about this before but asteroids. Like have all these resources that we need and a whole lot of fuel that we can use to help further explore the solar system asteroids, are basically the convenience, stores of outer space yeah I kind of said like that the gas station right yeah yeah right kind, of pop there and get what you need and then carry on of course it's not that simple but yeah. I kind, of like that idea that, it might happen in the future. Okay. So I think we have an audience question waiting to go, yeah, I was gonna ask about asteroid, mining so oh okay. Okay. Good I've ruined your question okay I'm. Sorry Brian I actually have a question have you ever seen the movie melancholia. Never. Heard of it no I check, it out okay, basically, the premise of that movie is that a large, planet. Sized, body is heading towards Earth okay about, the size of Jupiter. Huge. Just. Ginormous. But the whole thing is that the scientific, community, sees, it well in advance like, several, years I mean you would see that, right. They're planning it and they're they're releasing all this information, I don't give away too much of the movie but premises, that have basically slingshots, around the earth and they think it's gonna pass but the slight tug of gravity from, the earth is just enough. Where it reaches its apex that it turns around and comes straight, back, so. My. Question would be like, you're. Kind of doing, the theoretical, science around how we would deflect or move something that is smaller, than yeah, is, there any science, or theoretical, physics and science going on about how we would move something that, could be much, much. Larger. I. Think it's almost zero percent. Chance of anything larger than hitting, Earth because, the, earth, to settle down now so like I mean 4.5. Billion years ago earth was hit by a mars-sized, body we, think and that's what actually formed the moon so, it collided with the earth we're not sure the details of that whether it was a direct impact or as a kind of side, shot but it probably almost, certainly vaporized, the earth and then from that we formed we'd formed on earth again but also our moons so that's. The kind of thing that would happen you know or just be completely obliterated, if, anything, larger than Mars were to hit us but at this stage the solar system settled, and I, mean I think it just couldn't happen but. I'm. Sure it makes for a good movie all, the same have you seen this Mike by the way that's really cool toss, it around I did wonder what it wasn't it was out of here. So. I was fascinated here about the inner and outer asteroid. Belt. And. It sounds like they're, materially. Different, assai mean the outer one has a bit more ice which maybe you'd expect it's farther from the Sun but other.

Than That are these different, populations, and yeah so what segregates, them so it's just probably, more like, based on density so. The the inner objects of denser and formed under hotter conditions so they're more consolidated, their rocky their metally the ones on that outer edge probably. They, probably form where the comments formed and one knocked into there so they, are lot less dense they probably have a lot of pore space so actually when, we got to the Rosetta comment and 67p, we weren't. Able to measure its density which. Is really cool because although it's made of rock and it's, made of ice it's, actually has a really low density, because. It's it's got lots of holes in it so they're not because it's not like gaping big holes, in the side of it like cavities, but, it's very, important. But very porous like it's got a lot of gaps in it so it's just not very well pushed, together whereas. The objects on the inner asteroid. Belt are very kind of probably. Noble space whatsoever so. That basically, controls it so these as you move on out you've just probably got a transition. Gradually, from, the inner to outer. Thank. You. In, college, I did something. Where. We. Had. We. Had designed these transmitters, to put on near-earth objects, that, there was a lot of concern that the. Smaller objects, that were harder to detect, could. Be the thing that does us in instead. Of the larger objects that are easier to detect yeah. And. It was just a is a design, class we didn't actually deploy, it but is there any like movement and trying to to. Do anything to look at near-earth objects, so yeah we are currently. Tracking, basically. All the near-earth objects that we can possibly, see the. Ones that are sort of in normal orbits I say that those ones because there, could be some random objects that are at the moment far out that are gonna become near-earth, objects but we, don't know they're coming yet because they're very small but so those are kind of the under, unknown unknowns, I guess but.

The Ones that we can see and we are tracing, the orbits of all the time so we're constantly, updating where, we think they're going and how they're spinning, because, it's very important to understand how they heat it up I said earlier about to Fleck to them if you paint one side a different color it will spin differently, well, there's two effects, that happen in space you open your cob ski effect and that and they that determines, how these things spin and how it affects their orbit basically, as they heat it up by the Sun so it's, we sort of know most, of them aren't gonna hit us but we need to just define those two phenomena. Very clearly and then we can know exactly where, they're going to go so some of these objects, are on sort of a hazardous list but we just need to better define exactly where they're going in them they can be removed from that list but. Yeah when we're talking about the size of these things it's, funny because even if it was just a couple hundred meters across it could still cause, a lot of damage dependent, what it was made of if it's a pure piece of metal yes your honor if it's it's, going to probably get through the atmosphere quite easily and wherever, that hits okay it might not cause global, devastation like, we saw with the dinosaurs. Being killed off but, you know it could cause quite, a lot of issues and we've had impacts, in the past which haven't been massive, but they can create things like you know nuclear, winters essentially, you can have years, and years like when you get a massive volcanic eruption, like it's the same kind of thing you can change the climate of the planet for, a considerable, time and I, would, suggest that humans are fairly kind of. Vulnerable. Species we, clean. Water we, require. Movement, around the planet quite a lot and I think if anything like that happened, we, could be quite vulnerable species, so even, if it was a smallish, impact it, could just cause quite a lot of issues but I see the large impacts, if we're talking kilometer. Size bodies or larger there, gonna be a bigger, problem so, understanding. Those kind of small ones there's still quite large is a really important area kind of four hundred metres across and so is they're, pretty, dangerous, and, they're hard to see so we need to understand those especially they're dark if they're proper like dark. Carbonaceous, asteroids, they're very hard to see because they don't give off much light so that's what astronomers rely on these things giving off light that's my comments are easier to see they, shine, whereas, asteroids, can be a bit sneaking you so we. Have to be careful I. Have. A question about the interstellar, dust that's, collected. It. Might, be outside. The scope of this conversation, but I was wondering if it gives, us any kind of. Understanding. Of the original, big bang and and maybe supporting. The theory. Of the Big Bang or. Is it really more. Like stuff that's 4.6. Million years old and it's very, localized, dust so I'm, gonna have to say I don't know so what some of that actually because I've not kept up with that interstellar, stuff. Very well but I know that it's. Basically allowing us to look into our local galaxy, and. I don't exactly, know when that dust was formed, but, what they've been able to do is actually measure like the isotopes, of the elements, of that material and. That allows us to understand, a lot about our local, environment like, what our solar system formed from and, obviously we expect that different, galaxies, are going to be different compositions. Because. They formed at different times maybe I mean, then we still don't really understand, all of that so because really I'm sample, it or you know you look at it very clearly because these things are so far away so it's, kind of understanding, a little, bit further back in our history what.

Is In there but yeah I'd have to say I'm not too sure. So. Recently, there was big news about this. Asteroid. From, outside, the solar system that, blitzed, through glad. You mentioned this I haven't mentioned it yes yeah okay great, is. That's something, that, was. A one in a hundred year event or, was that a question of our sensors, are getting better and we can expect to see more of them the more we know exactly the latter so we think so I'll just backtrack, a little bit so this object. Came. Through our solar system we actually think now it was probably a comet but we're not 100% sure we weren't able to measure it very well because we didn't know it was coming but so. It wasn't on the normal orbit that all the other comets and asteroids and planets are on it just literally came zipping through our solar system it was so fast that, it didn't even get caught into the gravity of our Sun it just zipped, by and, it came from some other star system we have no idea where and it's probably being some like interstellar, traveler for forever. Who knows when it formed it came from very far away so. It's been going for at least billions of years and. It. Just it through so we don't know a lot about it we just know that it's I think it's called mumu, earth is it called Miramar like I think it's Hawaiian for yeah. I. Think and. I think, it's Hawaiian for something like in just. A traveller or something like this I probably, pronounced it wrong I don't know Hawaiian but. Basically, we if we knew one of these was coming we could launch a mission again, so go in sample, it because this will be fascinating, we'd learn about that star system that it came from which could. Be completely different to what we're seeing here probably would be and it, could be the same who knows but we know it came from somewhere else and we just haven't seen one of these before I think probably. Other objects, like that have gone through the solar system but we haven't spotted them they go very fast I think wishes chance that it was seen as well but. It is fascinating, and I would love to have some sample of that comment it would be so cool to analyze but yeah. I'm hoping you know in the future as we get better at seeing these things coming again it wasn't very big it, was also really weirdly shaped it, was like a cigar shape really, long and kind, of like you know maybe at some alien spaceship who knows so. We're being basically, you're saying we're being visited by cigars and

2018-09-26 16:36

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