StarTalk Podcast: Rocks In Space with Neil deGrasse Tyson

this episode of star talk is brought to you by curiosity stream hello youtuber verse Neil deGrasse Tyson here your personal astrophysicist coming up cosmic queries edition of star talk all about comets and asteroids this is Startalk I'm your host Neil deGrasse Tyson your personal astrophysicist and today is a cosmic queries edition of star talk and I've got with me co-host mark Normand mark nice the first timer hey big fan happy to be here thank you your local New Yorker local got lost in the museum like an idiot if you have to get lost anywhere let it be the American Museum of Natural History that's true the day yes that would be terrifying you don't want to get lost at night no I sadly I was using my night at the Museum knowledge oh I've seen the movie you using your your coordinate system from that movie yeah avoid nobody you got here in one piece which is excellent today's topic is comets and asteroids and I know a little something about it but I don't know as much as I should know about it to carry this episode alone so we went in for backup nice and there's a good friend of ours who's been a guest before Natalie Starkey Natalie welcome back to Startalk hi Neil hi Mark it's great to be here thanks for having me we've got you online you are in a lipstick oh so you're in the UK right now is that correct yes yes I am I was over in California for about three years living over there and now I'm back in the UK getting used to the rain again and the cold and I'm very miserable and he got spoiled that you were so accessible to us over those three years forget anything that you're basically a UK person so so there is yeah you're you're officially a science communicator that's like a title that you carry for the Open University just outside of London right yes that's correct yes so I've been a scientific researcher for about 10 or 11 years and I got into writing and I love communicating this I do see I'm getting into it more seriously now so I've sort of like I've got a serious science background I know quite a bit about comets and asteroids so hopefully I can be of yeasterday I'm hoping fingers crossed so we've got and I happen to have I think what is your latest book called catching Stardust yeah comets asteroids and the birth of the solar system I have it in my lap I had to do a bit of product placement you know exactly exactly but you had to come back one day and sign it definitely so we called questions from our fan base yes on this topic of comets and asteroids and so let's let's see what you got neither she nor I have seen these questions all right let's check them out okay kind of nerve-wracking I'm a bit I'm a bit worried I hate having my knowledge tested you know just say I have no freaking idea go onto the next question right okay all right these are pretty good I've read a few and I'm gonna go hand pick first one should I give the whole name and everything get away from ya all right this first one's from Kyle Ryan Toth he's a patreon member patreon we got to serve them first yeah exactly would it really be possible to hollow out an asteroid and use it as a starship okay so I'm gonna say no straight off just to be really boring but actually one of the reasons we couldn't really do this well with most asteroids anyway is that they're either just too hard or they're just not made of the right stuff so you know we've got some asteroids that are made completely of metal so I mean trying to hold that out would be almost impossible you know we've talked about you know mining these in the past and we talked about them to show you quite a bit and and it's incredibly difficult to do that so I think mining a pure metal asteroid would be hard and then the others that are made of you know there could be a slightly softer we described some of them as a bit of a rubble pile so they kind of just Rock that's not very well consolidated not very well pushed together so that would basically break up as soon as you try to stop excavating it in any way so you'd have a better chance maybe living on the surface but I think even then you know there's no gravity essentially so they're kind of hard beasts to work with don't think we're gonna live inside one so the very low gram they have some gravity right they do they do have a little bit and basically you would need to be tethered onto the surface of one it if maybe we went to the largest asteroid in the asteroid belt which is Sarah's it's about a thousand kilometers across so it's gonna have a little bit of gravity but if you jumped too high and you you would probably just end up floating off into space so it's not gonna be a great environment to try and live on or in rather yeah so I think that the lesson there is just make your own damn spaceship yeah but could you get a rudder on there I mean could you steer you know what I mean I feel like you wouldn't get any any directionality Oh I mean if it's just a hollowed out yeah yeah you need some kind of retrorockets affixed to the side of it so that you can maneuver exactly rather than just like a homeless shelter inside a shell yeah they were thinking of with that question yeah yeah I mean it's a fun thought all right let me throw it this guy he's ready go for it Kyle you blew it nice job he's smoking weed one picture on all right this from Michael Halterman can comets have different colors diversity may be when the ingredients in organic molecules are different can they spread molecules for the beginning of life yeah okay so there's sort of two questions there so the first bit was about the colors of them and yeah for sure when we see comets in the night sky they they can glow different colors and actually Green is a really common color in what when we look at these objects and for various reasons and when we look at a comet or an asteroid maybe in the night sky with the telescope then they can glow green and because of the oxygen that's in them but actually sometimes if you see a meteor coming through so basically if you get a little bit of an asteroid break off in the space and then head to the earth and you see that as a fireball in the night sky sometimes they can glow green and that's for a different reason so that's something because we have basically nickel which is burning up so I mentioned that we had these metal asteroids earlier and nickel is is one of the metals that they have in them and actually when that burns up in the atmosphere that blows green so sometimes you see this kind of green streak with a meteor quite lucky if you see it I've never actually seen it so but I know people talk about it and so that's the nickel kind of burning up so yes they definitely have different colors what was the second part of that question I forgotten already this is not good no no your killing life whether the the ingredients within the tail of a comet are the right ones to possibly spawn life yes okay definitely so this has been quite a recent research finding actually there we've discovered with some of the recent missions to comment so in particular the European Space Agency sent the Rosetta mission to go and land on the surface of a comment back in 2014 now and and they discovered that was actually the life scene which is an amino acid and within the comments so we know there's basically these complex carbon molecules within them and so there's every chance that you know they have the right ingredients for life and this is why we sort of say well you know in the past we think earth was bombarded by comets and asteroids from space and so it's a plausible way that we could have bought life and water to earth because we know that these objects contain a lot of these ingredients and we know that asteroids contain hundreds of amino acids so so these objects in space they're very old they're very what we call primitive they're some of the most the earliest things that formed in the solar system but they contain all the ingredients that you need to basically build a planet and and build life on that planet so that this is why I find them such fascinating objects because they just they have everything we need and that would mean that life based on what you just said life could be vastly more common in the universe than people might have previously suspected yes so the problem is there's a bit of a leap it's from going from just having the amino acids and the basic you know carbon compounds and the molecules to then getting life okay so that's a massive leap because the problem is we might have all these ingredients in space everywhere in fact they might be in every solar system we've care to look at but the problem is it doesn't mean that we've got life because we need some very special conditions to let those ingredients become life like it isn't these are simple steps we think they're special conditions maybe they're common well this is very true we we have only safer observe life once and that is on earth but it doesn't mean that in the hundreds of billions of galaxies that are out there and all the stars that there isn't life somewhere else we just haven't seen it yet no obviously we don't actually know there's no other life in our own solar system we just haven't seen it but we're pretty sure it doesn't exist on the terrestrial planets the ones that are near to these are the rocky ones near to the Sun like Mercury Venus and Mars maybe they have life in the past we haven't discovered that yet and but there is a chance that there is life on some of these weird moons like Europa and Enceladus and things so we're not sure yet but there's there's a chance it could be because they've got a lot of the right ingredients for life they've got liquid water they've got and that basically they're energetic bodies they've got they've got heat that they're losing so they have all the energy that they could create life and and help it you know get along and move along so we just haven't found it yet we need to go and look we need some missions to go and and in look at these places in more detail but they're challenging environments to send spacecraft to so that's one of our problems at the moment as Frankenstein's new mmm-hmm dr. Frankenstein you can't just have the raw ingredients you need energy right and he had like that lightning bolt going through all that's right roads on the on the neck yes that's it Wow well that was well done no thank you Natalie also Nicolai didn't know about nickel no no please you know who knows about nickel no the gucci brothers for the fireworks ah there's all these metals that get burned in fireworks that give you all the beautiful colors oh I didn't know nickel copper what else do they have in there magnesium I think Natalie yeah yeah I think that's good yeah so basically it's a bit like doing that flame test you might have done that in chemistry labs at school basically it's the same principles each element burns of the different color and I remember doing this when I was 16 and you kind of burn the flames and you had some register what you'd seen with the colors and sometimes it wasn't very obvious because you didn't do it very well but basically this is the principles yeah of fireworks and everything and what we see burning from me Cheers we could tell a lot about what that asteroid was made of if we can see it glowing so yeah it's fascinating all right this is all news to be here's another one from Ashley vgt this is off Instagram mm-hmm I've read that water did not originate on earth but instead was introduced by asteroids but wouldn't the water evaporate away upon entering the atmosphere ooh burn up burn out coming in so what so the whole water on earth thing is is definitely a big open debate still scientists currently really don't have a good consensus on where our water came from so there's the problem is that if Earth started with all its water from the beginning so our planet is about 4.5 billion years old it was born out of this cloud of gas and dust really close to the Sun and and we think that that early cloud contained water because are we going to interstellar space where all our solar systems are made from and they sure enough there is water out there because as ice of course because it's very cold and now that gets kind of swept up into the forming star and and then all the planets are born out of the cloud of gas and dust that is around that star so so there's water ice there that could then be contained within the planets that we form but the problem is the very first few million / billion years of of a planet's infancy it's incredibly hot so it's basically just like a volcanic world it really wouldn't be able to support a lot of water unless the water was sequestered away very deep within the planet maybe and and it didn't evaporate at the surface so we're not sure whether we could have from the beginning had our water or whether sure enough it would have all boiled off during that process and then we needed to bring it in later on and we know we were bombarded by comets and asteroids about 4 billion years ago we just have to look at the surface of the Moon for that actually because you see that that beautiful cratered surface of the Moon and actually we were hit by as many things as the moon was hit by but we have this thing called plate tectonics where our surface gets continually change and updated and resurfaced so we've lost all their evidence of all those craters whereas the moon's preserve them for so we know that we were hit in the past and sure enough those comets and asteroids contained water some of them did anyway not all of them and and they could if they didn't if they were large enough and they didn't evaporate as and explode completely on re-entry through the atmosphere and remember our atmosphere was quite different back in the day in fact we might have had much much of a thinner atmosphere that didn't slow them down as much then potentially they could have bought a lot of water with them but for us trying to figure out where the water came from is very very tricky because we need to find out you know what the water looks like and it's all mixed up now we've got a mixture of all these different types of waters so if we want to measure it now it's very complicated to try and figure out exactly where it came from and and all the Comets are different all the asteroids are different so it's we need to just go out there and measure more of these objects so then try and kind of piece this story together but it's important so we want to understand why water's here why are we the only planet in our solar system with liquid water at the surface it's a question that we really want to answer to understand where life came from as well so that was a yes that was clear this room Donnie HUS one one three Oh from Instagram mm-hmm how much material do asteroids contain and how much are they worth it's like a comedian ooh let's sharpen that and say of the metallic asteroids that have like metals we care about can you estimate the value of them and what does the value mean if they're out there versus if we brought them back to earth and now they're just on earth-like value is just value is a is a flexible thing in this right exactly it's sort of like the diamond tissue like there's plenty of diamonds on earth we combine plenty of them and actually a lot of them have been mined but then the diamond market is controlled because if we released all those diamonds onto the market in one guy we'd flood the market and the price would drop so you know the big diamond companies don't want that to happen so they control that market so it's sort of the same thing with these asteroids and one asteroid okay so there's a mission a NASA mission actually going to an asteroid called 16 psyche and it's made purely of metal we don't understand a lot sestra but it's quite large and actually the team that are planning to go to this asteroid have estimated that it's worth ten thousand quadrillion dollars so and that's just the iron within that so basically if they were to mine that whole asteroid which would be impossible because it's too larger than we did we have no way of doing this at the moment but if we were to be able to figure that out and we bought all of that metal back to earth then sure enough we're gonna flood the market and it wouldn't just kill the metal market it would kill the entire economy because we wouldn't know what to do with all this so so they're worth a lot but one of the issues is we don't really know how to currently mind them we don't know how we would extract that muscle and we don't necessarily want to bring it back to the planet to be quite honest we would like to bring some back but actually one of the reasons we want to mine in space is to be able to further explore space itself so we could use these materials to actually you know make things so we might have a base on the moon where we actually manufactured materials to and spacecraft or whatever we needed and tools to actually go and explore further into space so there's a lot of economical questions around mining asteroids and it's not just the science of how we do it it's then looking at you know how it works and what we're gonna do with the materials that we get mm-hmm rebuttal no it's it's funny to just assign a value to something which if you obtained it would not have that value yes it's a weird a weird economic fact it's right right of this so I never woulda thought you'd get money out of an asteroid yeah well plus iron is not uncommon on earth right so I'm thinking that leave that if you are gonna bring a metal from an asteroid to earth you bring a rare metal that we can use in ways that we can't do now we can't if you bring all that iron is there something else you gonna do with iron that we're not already doing with iron mm-hmm no that's the thing and the thing about these asteroids is okay they contain a lot of iron but and they contain maybe less than a percent of precious metals that things like platinum and gold and these these metals that we use in technologies a lot in the modern day and now the thing is they contain very low percentage of these but that is still a lot more of these precious metals than we mine any one year on our own planet because the thing is about the precious metals on earth is that they're distributed throughout the crust of the earth and they're not very well concentrated so to mine them it takes a lot of effort we have to dig up a lot of land in order to get those metals rise if we just went to an asteroid they're a lot easier to obtain and they're sort of concentrated in these objects so these are the metals that are really important because at the moment we don't have a continued infinite supply so the kinds of industrial technologies we're looking and you know the advanced technologies who wants to develop a sort of held back a bit by the fact we don't have this infinite supply of some of these precious metals so if we knew that we could get a lot of them in space and bring them back then it does open up you know the engineering world to to new ideas because they would have enough supply to be able to do whatever they wanted I can't you know if my head think of something that they could do with them but I'm sure some engineers would have some great ideas of what they could do with an infinite amount of platinum for example a lot of implications of it I think that's the key point because it's not that you're just gonna sell the metal and someone is gonna then make jewelry out of it or something there's industry that uses metal yes and so it enables in it no matter the price it enables certain industry that wouldn't otherwise be enabled right perhaps we shouldn't think of it just as the metal as a pure thing but the metal esident as an enabler of other ideas that engineers would pull out of the box we got to take a break mark you're still here oh yeah dr. Natalie Starkey still there yeah out there outside of London thanks for piping in we are talking about asteroids and comets on this cosmic queries edition of Startalk we'll see in a moment speaking of space rocks did you know that Japan has recently created the first spacecraft to take subsurface samples of an asteroid curiosity streams breakthrough videos on Hayabusa 2 are incredibly fascinating they'll take you through the launch and everything it took to make it happen I couldn't believe that they set off a freaking explosion to make a hole in the asteroid wait where have I seen that before does anybody have Bruce Willis's number I think he's being ripped off the suspense of the probe landing was killing me while the mission is still going you can learn more about it by watching breakthrough on curiosity stream subscribe now it's just $2.99 per month and for Startalk fans the first 31 days are completely free if you sign up at curiosity stream dot-com slash Startalk and use the promo code Startalk you'll get unlimited access to the world's top documentaries and nonfiction series with curiosity stream sign up now start off we're back cosmic queries Edition mark Normand oh yeah first-timer oh yeah I love it here watching dr. Natalie Starkey you still there with us expert on comets and asteroids and that's our topic for the day yeah I might know a little bit and she knows a lot oh yeah that's why we brought her on for this for this episode and to mark my pet subject you've got questions on this I got a million we covered that nickel in the iron if you got a question - you can do it okay I just wonder if he's feeling it if you own it if asteroids contain diamonds and we mined them and we got the diamonds and diamond prices went way down on earth would women still want them that's yeah I mean the thing is they do contain diamonds and diamonds we have on earth so they're actually sort of like interstellar diamonds they're older then even better our solar system so they but they're tiny this is the problem size Queen's fine so you probably wouldn't you'd need a microscope to actually see it on your ring finger but you know you can tell everyone how special it was a mere you can't see it but it's interstellar yeah all right here we are I've read this is from IO I did that one already this is from Kimberly dot IO on Instagram underscore Kimberly IO how often is an asteroid come across our solar system we actually had and well we don't really know if it's an asteroid or a comet but there was an object recently called a mu a mu ER and which is a Hawaiian word for basically kind of like foreign traveler or something and and it's this object that appeared and it was traveling very fast or our solar system and some astronomers in in Hawaii saw it and found it first and that's why it got a Hawaiian name and it was traveling so fast that they figured out you couldn't have come you couldn't have originated within our solar system so they actually decided that it must have come from another star system somewhere they have no idea where exactly they're still trying to figure that out and but basically it didn't it was going so fast it didn't get captured you know with to our Suns so it just kind of scooted by and so it didn't enter into orbit into our solar system and this object has probably been traveling for you know potentially billions of years across interstellar space we don't know if we're the only solar system it's traveled through but it's going on this massive long journey now of course this object could have actually collided with the planet and we wouldn't have seen it coming because it was going so quickly and it was relatively small it was very dark and it's a really really hard to spot but the thing we realize now is that we've spotted it because our technology has got so much better at trying to spot things in the night sky it's actually probably happened before probably we've had these visitors from other parts of you know the galaxy many times before but we've just not seen them and sure enough our own comets and asteroids could be out there visiting other star systems and it's just something that happens during the process of forming a star and the planets around it that is a little bit chaotic and so comets and asteroids are essentially the bits and pieces leftover that didn't become a planet and sometimes because they're small they can get a ejected out of the solar system or they get thrown into the Sun and they end in a fiery death but some of them get thrown out and and they just you know end up leaving the Sun's gravity and they go off into space and then there's nothing stopping them they're gonna keep going so so yeah it's really cool that we've got these objects if we can start to identify more of them in the future and actually look for them then we might got some launch mission to go and maybe sample one one day which would be amazing cuz we'll find out about the chemistry of another star system which is something that I would be really interested in and but yeah at the moment we've only seen one and it's kind of gone now it's exiting the solar system and it's going on its merry way into the abyss Wow it's very way into the abyss beautiful poetic I looked up how more and more I think it means scout first Scouts journey person onto a new lamp into a new place let's go yeah it is quick question may not be answerable from Paul Pimenta on Facebook can we track where asteroids came from specifically where they originated mm yeah yeah definitely um so actually I mean it's even better than that sometimes we get a meteorite that ends up on the on the planet so this is just a rock from space that will usually come from NASA right or it can come from another planet if we've seen that coming through the night sky and coming burning up through the atmosphere and then there's lots of basically camera networks out there now and one of them is in the deep Australian outback and they just basically have cameras set on the night sky to register these objects as they're coming in and what they're trying to do is figure out an exact trajectory for them so that they can basically backtrack that with some amazing math and and actually figure out where that object originated and try and track it back to the asteroid belt itself and we can sort of check our calculations in a certain way by analyzing the chemistry of those rocks so we can go and pick up that rock because basically they know where it's landed because they've got that trajectory coming in on the cameras they can go and pick that rock analyze it in the lab and compare it to what we know about the objects and the asteroids that already and from telescopes studies or from having analyzed them before and actually we've started to be able to figure out like different families of objects so we can say oh it's from this type of asteroid and and we know that they're in this part of the asteroid belt maybe in the middle part or the outer part of the belt so yes it's actually possible it's very complicated work but it and with making much more progress with it in probably the last decade or so and but yes we can definitely start to figure out and we also know if it came from another planet that's much easier to work out actually it came from another planet than than any old particular asteroid because there's kind of billions of them out there so that's it is tricky billions of asteroids but many fewer planets yeah there aren't there aren't too many planets and kilometer in the asteroid belt so there's an awful lot of them and there's millions more smaller ones so there are a lot of objects out there but a lot of them as I said they're in these these groups they're in families they are all different they all there are groups that share similarities and where they were made and what they contain it's like a 23andme but for an actual it is I'm Jewish all right how large does from Rene Douglas patreon listen up how large does a captured asteroid need to be in order to be called a moon and can a comet also be captured mm-hmm yes so the first part I mean in fact the it depends what you cast as a moon ray because some of the asteroids themselves have moons around them and we've actually started to scar I think we've found about 200 moons around asteroids now so these are just small objects orbiting and basically attached to that asteroid in some way that they're associated with it and now the thing about the asteroids themselves is that even the largest asteroid we know of which is Sarah's is only about a quarter the size of our Moon so even the biggest one and even if you pack them all together so you take all the asteroids in the asteroid belt and put them all together in one blob and they would only be about four percent of the mass of the moon so there's a lot of them out there but they're just not very big so if you wanted to capture an asteroid well you wouldn't be capturing one of the largest ones and because this sort of like you know a thousand well hundreds of kilometers in diameter so it is too large to capture when NASA have actually done some studies looking at potentially capturing an asteroid with sort of a bag or something it sounds kind of crazy but that's literally what they're sort of planning or a scoop and and and they're looking at something around 40 meters and so it's not going to be particularly massive and it's not going to pose a problem to earth if it goes very wrong although that would still be an issue if that collided with the planet so see ya in terms of capturing them you wouldn't capture something really massive because you I mean if it went wrong you'd be really in trouble and if that collided with earth wow this is alright how do we know that more of them I mean I don't know any I'm on Molly right now but why don't we get hit by more asteroids and realize it and feel it well we do get hit ok their plows through now a correct me if I'm wrong several hundred tons of meteor dust a day descend on earth just by plowing through interplanetary space and does it make a dent no most of it just just settles as dust because it lost all its energy coming through the atmosphere it was big enough to hold a relationship an inverse relationship so the bigger the asteroid that's heading for the planet or it's going to come through the atmosphere the less frequently it hits so the really small pieces of just they're literally raining down all the time and they're called micro meteorites or basically Stardust and and then if you go to the larger objects like the ones that killed off the dinosaurs for example then they don't hit very frequently you know every 10,000 maybe 1 million years or more and probably more in fact for once that size we had an event in Russia back in 2013 it was called Chelyabinsk and it was about a 20 meter asteroid and so it's fairly large I guess kind of like a double-decker bus and that didn't actually kill anybody but it did cause quite a lot of damage in the region and it had this big sonic boom as it came through the atmosphere and actually it blew windows and everything in the inch elements town and so and we didn't know that was coming because it was actually quite small we didn't we didn't see it we hadn't spotted it before it arrives so you know yes they happen and obviously if that I'd hit central London I'm pretty close to central London that's about 60 miles across maybe if you take Greater London into account and actually that would be quite an issue if that had landed in the centre of London so it just it's sort of lucky that most of the planet is sort of empty and a lot of these asteroids tend to land in the ocean so me don't see them and they don't cause us any harm but yeah they do hit all the time and they're just larger ones not as often well have you gonna hit somewhere I think Russia's the place come on is that a political statement of work or jus Geographic State Wow I don't know anything about collusion it's the country with the largest landmass good that's what I was saying so it's gonna get more asteroids than any more comet collision I know to say that's that's good but that's what they get for conquering you conquer you gotta realize that you gonna hit more asteroids there you go it's alright here we go natalie is from Frank Cain patreon member out of Orlando Florida is there a really clear distinction between comets and asteroids I mean comics generally have some rock in them and asteroids have a lot of frozen gas in them right where do we draw the line oh yeah other way around so the asteroids are kind of the rocky hard metallic ones classically and then the comments are sort of the icy dusty dusty snowballs or whatever you want to call them and but yeah this this sort of works and it is a pretty like old distinction that we always fall back on and but it's a very classical view of these objects and actually what we're finding as we go and look at more and more of them is that we've got a lot of asteroids that can contain quite a lot of water ice and other ices like methane and things and we have some comments that are completely dry because for example if they've been around the Sun a lot of times and and they've been basically having their volatile ices burnt off all the time then and they're going to be dry and they sort of looked there for like an asteroids so there's a lot of there's almost like a continuum we think potentially as a continuum of compositions we've got some things that definitely look like this classical asteroid some things that definitely like a comment that's very icy and then a lot of material in between and at the moment we're still trying to piece together that story of basically where these objects formed and therefore what they're then made of today and they've also been affected by what they've gone through in that 4.6 billion year history since they formed so yeah basically we have that distinction but it doesn't always work but we have yet to see a Metallica Comet true but they do yeah but yeah that's very true we haven't I mean if you had a purely metal object out there then it's definitely an asteroid in fact you know this 16 psyche asteroid that they want to go and look at they think could be the center of a planet and that was kind of blown to pieces at some point in the past and when a lot it might maybe collided with another asteroid so it had basically in the earth we've got this metallic core and that's what happens to these the large objects in the solar system they differentiate so they're a big ball of magma and then the heavy material in that magma the metal falls to the middle of the planet and the lighter stuff is on the outside so if they experience an impact all of this what we call the crust and the mantle which is the lightest stuff on the planet it gets kind of blown off the surface and you get left with this solid core which is very hard to break up so that's what we think that's one theory of what this asteroid could be so we can study it to actually look at the core of a planet which is incredibly hard to do because we can't drill to the core of a planet so these objects are really valuable scientifically for that reason Wow and how come could we film them and watch them hit each other I feel like there'd be a great pay-per-view be cool very cool pay-per-view you could bet on them like with the mob so we gotta take a break we'll be back for our third of three seconds of cosmic queries asteroids and comets edition with dr. Nathalie Starkey when we return this episode of Star talk is brought to you by curiosity stream star talk we're back cosmic queries asteroids and comets edition with our friend and colleague Natalie Starkey Natalie Sohn and in from London outside of London yes you in the stateside you were here for three years and then you just left us I know I know I miss California as well but um it's really far from home so it's quite nice to be back in the rain said no one ever shishi brexit it yes sorry so mark yo I'm my co-host for today yeah what do you have for us here we go go voidwalker 92 off Instagram are there any asteroids with their own natural satellites currently known if so how common or uncommon is this and how does the dynamic effect tref tracking and understanding trajectory of the asteroid oh nice yeah that makes it a little bit of n really really know that quite a lot of asteroids have moons so natural satellites around them and it's probably other bits of a material of that same asteroid but we're not sure because we haven't them in detail one of the problems is that we can't actually see them very easily because the asteroids themselves are small and therefore their moons around them are even smaller so we found about I think is over 200 moons around asteroids now so we definitely know they're there we want to study them more detail because it will tell us more about that object itself and how that object formed do you think those asteroid do you think those moons dislodged from the asteroid itself to become a means one option or it could be that they captured them like so some of the moons that we see around planets are either captured moons so they're formed somewhere else in the solar system to that planet and then basically that planet was large and so it's gravity attracted other objects to it and our own moon for example didn't form in that way it formed from the earth itself during a massive collision about four-and-a-half billion years ago and and it basically threw off a bit of our own planet and then it coalesced into a moon and it was then you know trapped with the earth so there's different ways to form them but we need to study more of them to figure out exactly how they formed all right that's question well said well said Richard Stenhouse from Facebook hi guys love the show I've been listening on Spotify since September 2018 whilst I'm at work and I'm as far back as season two can't get enough it's like a regular Natalie get to it is there a point between stars where comets or asteroids are under no influence of gravity at all and if they somehow lost momentum would they hang in that space till the end of time from North Wales UK I love it love the questions a great question oh my goodness cuz I actually only found out recently myself that some of the comets like that are in our all cloud which is that the cloud of material that's outside of our but it kind of surrounds our solar system so everything in our solar system is on a plane it's on a disk all the planets and all the comments and all the asteroids and then we've got this all cloud around us which is all these icy objects of which we actually have never really seen any of them because they're so far away and some of them on the edge of that all cloud are so far away that they're almost not gravitationally bound to our own and they're almost closer to the next star system so so sure enough I don't know what happens at that point I mean I guess maybe some really clever astrophysicists maybe figure out what is happening to these objects out there but but yeah they could easily be perturbed we would say they might be pushed around by the gravity of another star system and then and then either thrown out of our solar system completely or pushed in so that they actually come in and visit visit the Sun and the inner solar system but but that's a great question yeah they're susceptible but we the Sun the planets and everything that the family we're all orbiting the center of the galaxy nah among other stars so even if you have a precariously positioned comet at the edge of this Oort cloud and it doesn't have a gravitational Allegiance eventually it will because we're moving past other stars somebody's gonna snatch it yes and or perturb it and have it descend back down into our star so so yeah the things are always in motion and if you're without Allegiance that wouldn't be for long mm-hmm I'm so jealous and just to be clear or it is named for a guy named yon court who is a Dutch astronomer of mid-century no I'm serious Ron who first proposed the existence of this reservoir of comets was he still not really proven as such but because we've not really seen it so it's just so far away we'll never get there and you know even if there's a spaceship out there now like Voyager they are not gonna get there for tens of thousands of years say yeah jeez it's a tricky one could we get a GoPro on one I know if you think why not Plus this was mid 20th century you asked if he was persecuted for suggesting this oh sorry relatively modern time right 1950s right we're not persecuting they were very religious then right right you know what a mess with it all right here we go Brett LaRue also patreon if we were to mine a significant amount of a comet would this change its orbit and if so how could we be sure this would not set into motion future collisions would result in a major earth impact hmm oh let me generalize that question as we start poking around with astral landing on them mining them what risk does that pose to taking what was previously a safe orbit and turning it into an earth crossing orbit that could then kill us yeah it's a huge risk it is a huge risk but this is why and the people that are looking at doing it are probably looking at focusing on the smaller asteroids all comments if they want to look at comments but it's generally asteroids we're talking about at the moment and because then if they were to dislodge it onto an orbit that was then a hazardous one for our planet then it hopefully would burn up in the atmosphere and not cause us any issues but in terms of mining them we probably wouldn't just go to them in mind then we'd want to drag them somewhere to what we would consider a safe orbit and so this might be near the moon where basically you can just kind of dump the stuff and it just sort of sits there it's this gravitational sweet spot where and the thing basically if there's small enough object it's not going to go anywhere and then what you could do is have a base on the moon and go back and forth to that object and mine it gradually so you'd basically just want to get it somewhere safe first because sure enough if you start mining it you are gonna you're probably gonna change this orbit in some way and then it's hard to predict how it's gonna spin and where it's going to end up in the future good question Wow all right coming fascinating stuff here I wish I cared when the asteroids headed your way you'll care that's true become the most important people in the world the day that happens yeah I've seen the Bruce Willis movie generally jealous because you guys care so much that you it makes you learn I'm gonna die alone and an idiot because I don't care about anything I'm dead inside all right Doug Bartlett on Facebook I know we have found organic material in tardigrades on asteroids my question is are these tardigrades thriving quote-unquote on these asteroids or in a state of hibernation if alive could it be possible that two asteroids collide or contact and crossbreed organisms organisms okay so I'm entirely convinced we have found tardigrades on asteroids nailed you that's true because living and we haven't found anything living so these toiling rates are like these crazy organisms that can basically survive anything they're insane and they can extreme pressures and temperatures and they can also just go into hibernation for I think like millions of years and they can just basically survive anything and then come back to life again I literally this is the very edge of my knowledge about these things this is a very much astrobiology which is not what I do but they haven't been found on asteroids but I think the theory they're talking about is panspermia where we're basically looking at transporting biological material around the solar system and from one object object to another and and that's one of the theories of how life got to earth in fact it's not that we'll accept it in I don't know I don't if it's fair to say that but I mean I I don't believe it personally I don't think that's how I've got to earth and but you know there is a chance that the basic building blocks for life the the more basic carbon molecules came you know from comets and asteroids and were delivered to earth in that way but the actual organisms themselves weren't as far as I'm concerned anyway well but you just said that the tardigrade can survive anything so it could survive a trip through space as a stowaway yeah in the nooks and crannies on a rock that got catapulted from one planet to another so you've said that earlier in this program Wow I did I did just say that and now you're saying that you're not buying it oh yeah calling you out so I think the issue is we need you know we like some scientific proof so we need to do those experiments we need to take close bugs into space and I'm you know I'm sure actually on the outside of the International Space Station they've taken organisms and they're basically seeing how they react to that radiation environment because it's not only temperature and pressures obviously we don't like radiation our biological cells can't deal with it we get cancer and we die very quickly in fact you know the astronauts are going to space there are much higher risk of radiation poisoning than you would be on the planet so this is one of the problems that biological material has in space so we need to do those experiments we need to take those bugs out into deep space and see if they survive and then see if we can grow things out there as well and so until we do that I'm I'm sure that things can survive in deep space with no sunlight for kind of billions of years that we that we'd require but you know I may be totally wrong that's a good way to end every statement you make I prefer the term special needs grades okay tardigrades yeah I see what you did there well done both this is quite a speed date so so Natalie we're running out of time do you have any sort of reflections simple reflections you'd like the viewer listener to take with them as a lesson for this program yeah I think I think you know someone like me you probably like wondering why I'm so interested in these objects and I think it's just because I'm inherently interested in where we came from you know we're not on this planet for very long most of us a hundred years if we're lucky and and in that time I think well let's give a purpose to our life I'd love to figure out why we're here how we got here and and what we're leaving to our future descendants and if basically we may have only got here because of comets and asteroids and actually in the future we may die off because of comets and asteroids they could collide with us and you know devastate all of humanity so all I want to understand these objects for many reasons because of how we got here but also to protect us in the future and we need to understand what these things are made of and what their orbits are and understanding so much details that we can actually protect the planet I think it's important I think everyone should be concerned about it but not worried I don't think we need to be worried it's tomorrow we're all gonna die in an asteroid impact although it could happen but I think it's something we need to be concerned with for this for the future so no we're not leaving a ruined planet to in may be it will be ruined in other ways but we're not gonna leave it ruins with an asteroid impact in the future and we can hopefully do something about it and yeah asteroid before hits I'd like to think I just picking up on your point Natalie it is in truth it's an intriguing and underappreciated fact that asteroids and comets may have been the bringers of life if not the ingredients of life but perhaps even life itself and yet they can also serve as harbingers of doom for the very life that it brought well Yoda planet and that is a cosmic perspective you've been listening to possibly even watching this episode of star talk cosmic queries asteroids and comets edition I want to thank Natalie Starkey friend and colleague who went back across the pond good luck in your your new science teaching exploits at the Open University in the UK and it's always great to have you and how do how will people find more of you out there and I am Starkey Stardust on Twitter and Instagram I need to not be struggles is my name others say Starkey Stardust great band from the 60s and you also one of our star talk all-stars I am yeah so I have other shows that you can go and listen to I've had about four now so I've got some of water in the solar system and a lot of our story stuff I'd lick turns the Mars insight mission which is actually on Mars at the moment so there's a few things you can go and check out nice very good and we'll put a link to those shows in the description excellent excellent and Mark you're you get around I get around I'm on the road every weekend doing the road again my comedy stylings in a comedy club near you and go to mark Normand comedy dot-com and I love your dates insightful and clever and funny I love yours what more can we ask for what the world needs today your big inspiration your traffic light tweet a joke that's a bit oh my god yeah I'm obsessed with jokes and that's a great joke oh you know I tried joking but it's you know they don't always land but you know I'm coming from I love it I love coming all right that's boom star talk I've been your host Neil deGrasse Tyson your personal astrophysicist and as always I bid you to keep looking up thanks to curiosity stream for supporting this episode of star talk if you enjoyed this episode about space rocks you'll love curiosity streams breakthrough series about japan's Hayabusa 2 spacecraft it'll bring a subsurface sample of an asteroid back to earth by the end of next year well that's if everything goes right I watched direct from an asteroid and curiosity streams breakthrough series and it really broke down what it takes to get to an asteroid blow up part of it and grab a sample and get back to earth fascinating stuff you can watch it for just $2.99 per month and if you go to curiosity stream comm slash star talk and use code star talk your first 31 days are free go there right now with over 2400 documentary features and series to enjoy it's a great deal you

Channel: StarTalk

Views: 193,878

Rating: 4.8590469 out of 5

Keywords: StarTalk, Star Talk, Neil deGrasse Tyson, Natalie Starkey, Mark Normand, comets asteroids, cosmochemist, star shield, asteroid mining, ‘Oumuamua, interstellar visitor, solar system, Comet Shoemaker–Levy 9, Jupiter, Earth, planet, Panspermia, universe, Oort cloud, space debris, Chelyabinsk meteor, podcast, space podcast, science podcast, astronomy podcast, space, science, astronomy, astrophysics, mark normand podcast

Id: lAXUAJC2cqU

Length: 49min 15sec (2955 seconds)

Published: Thu Jul 25 2019

Reddit Comments

[u/Larsnonymous]

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Yeah, brutal. Comments are not nice to our main man.