StarTalk Podcast: Cosmic Queries – Lunar Geology

this is star talk cosmic queries edition co-host chuck nice check hey hey neil what's happening feeling good today absolutely man it's a great day to be doing star talk okay what is going on outside for you to say that i just wonder it's cause the sun is shining because we're having a little we're having a little battle locust here no i think the real answer is every day is a good day today that's exactly the real thing that's the real deal so today's cosmic aquarius are they're all based on the moon really and i know a little bit about the moon you know a little bit but being modest no no no i know it as an astrophysical object okay i don't want more wait a minute what what more is there it's an astrophysical lobster no no no that is what you do like yes however it's also a geological object so people who think about rocks and minerals and and igneous rocks and cratering they're people who have that expertise and that's who we have on this show right now raquel nunez recall welcome to start hello such an honor to be here thank you for having me excellent excellent and so you are a doctoral candidate at ucla and uh university california los angeles right that's what that stands for and so how much does your mother pay somebody will get you in there what did your mom lie about us ucla was on the list it's my daughter she's an archer [Laughter] so okay well i guess we'll find out chuck what kind of expertise she actually has um so you're you're in the department of earth and planetary sciences excellent and uh your doctoral candidate so we expect your phd in within a couple years perhaps hopefully within the next year my my advisor told me he wants me out by june so oh yeah well that works i keep having babies during grad school so it's delayed the process a little bit but i think he's he's like you're ready just just well if you get into the world during graduate school and you successfully graduate graduate school then you got that done right and now you by the way yeah you get something called degree plus so that's right it's got to be something yeah you get extra you get a p you get a phd plus i like that disney plus and all you guys right well congratulations on pulling all that off and but just in particular uh you know to the astrophysicist and to the biologist the moon is just kind of a dead place and it's and it's you know it's just there's no color it's and and yet this is the subject of your phd thesis so what's up with that what do you see that we don't see so it is my goal to change your mind with this thank you thank you cosmic query episodes so it actually turns out that we don't know very much about the moon we know something but um we still don't know how it formed we think we know but it it's not a solved case and so what's really interesting to me is i've always looked at the moon you know we see it and when we go at night we see the moon and it's beautiful so it's always been a thing for me to appreciate and i think that's what's so appealing for me the moon is that i i've seen it ever since i was a child and just wonder like what is it is there are there beings on there but of course there's not there's there's no life on the moon um but um it's it's something that has been with the earth since the almost since the beginning of the earth so everything that the earth has experienced essentially the moon has witnessed and i like to think of the moon as a witness plate to what has happened here on earth and that's what's so exciting can i get a witness yes right hello i'm the moon i like to watch so so raquel you make a fascinating sort of point of scientific romance where you have an object of interest that you study and when you go home there it is in the sky oh yeah just and it's there to remind you to come back the next day guess because so much of science involves things you can't see it's too far away you need a big telescope and you have it right there as this daily and it's the only place where we've actually been yeah yeah but even so that we hardly know hardly anything we we've landed in six spots imagine landing in six spots on earth and saying yeah i know we got earth all sewn up you know yeah but i'm just saying like it's it's it's kind of cool that we can go there like i'm surprised that we haven't gone back more and more but we can go there is that we once went there we don't know how to go there today we got nothing to get us there so what why are you serious yes dude come on what are you working on we can't go to the moon today yeah that's why for most of the last 40 years the comment we can go to the moon but we we can put a man to move we can't and the answer is we actually can't any longer put a man on the moon or anybody on the moon yeah okay this this show has depressed the hell out of it okay well look raquel is here to sort of to brighten our day yeah you've got the questions raquel we solicited questions from our fan base on our social media platforms chuck has them i haven't seen them these are coming out of the blue or out of the dark because the universe is not blue it's just dark so what do you have chuck so let's get to it let's start off with patreon we always start with the patreon patron because they give us money they pay that's right pushes them to the front of the line there you go thanks guys because that's the american way there you go um this is tracy uh scrub it and she says what is the most surprising thing we've discovered from studying the moon rocks and samples that we brought back from the moon also have there been any unmanned missions to collect more samples except two i will answer that second question because it'll be quick yes there have been uh uncrewed uh samples collected from the moon uh by ussr so they sent there's three i don't remember what they were luna and then a number i don't remember what number missions they were but they brought back i think it was about about a pound of rocks and dust from the moon moon weight or a pound earth weight [Laughter] i see what you did whereas the apollo missions brought back i think it was around 900 pounds of rock so the the soviet union brought back a very small amount but if you actually if you go online and try to buy moon dust so you can't buy and you can't sell apollo moon rocks and dust it's illegal but you can buy the uh the soviet collected moon dust and rocks on the web somewhere russian right of course if you have enough money you can also buy a nuclear warhead from russia [Laughter] so okay that's interesting so i had a sample return mission i didn't know that now for the first question what was it was what was the most surprising and interesting studying moon rocks and samples what did we learn that was absolutely shocking so we had no idea how the moon formed at the time uh this there's a famous scientist yuri he believed that the moon was a very ancient like it was made up of primordial dust and rock from the beginning of the solar system so he thought that just these rocks had kind of stuck together and ended up here on the moon so that nothing had ever happened to the moon it just bunched a pile of rock from beginning of the solar system stuck together um and but this was actually kind of good because people wanted to go to the moon to collect a sample of of what the solar system started out to be um why can't we just do that on earth oh because it has been processed at the same time we did but what has happened is we have melted we have we have been completely reprocessed our surface of the earth has been completely reprocessed so that's why when we when we collect certain types of meteorites uh they're called chondrites we're very excited because that is made up of the the primordial dust and and particles from the beginning of the solar system so we can learn about what what it looked like when it when this all started out because earth is geologically active that's right contaminates your the purity of what you see you change it it becomes different minerals it becomes yeah completely different and so we thought that the moon was just this gigantic piece of primordial dust and rock and when we the apollo astronauts went their collective rocks it turned out that the moon has had an incredible geologic history it has melted the the moon was at some point completely melted it was covered in in magma magma ocean that's what we call it and come differentiate and ended up differentiated so the the heavy stuff sunk to the bottom forming the an iron core and then the light material the light minerals and rocks floated to the surface and that's what you see what's the difference between magma and lava okay so magma is lava that hasn't erupted out of of of its source so you have a different word for where you find the stuff right so if it if it comes out of of the of the surface and becomes lava uh if it's still trapped underneath and melted then it's it's magma that's what we call it so whatever whatever geological thing it is once it gives birth now it's it gives birth to lava yes so it goes from being a fetus that's right that's right um keeping with the maternity theme i i just had a baby a month and a half ago so i got baby how many kids you have how many kids three that was my third three little lavas that's so lovely and they're spilling all over the house everywhere everywhere shirts everywhere um yeah so so we learned that the the moon has has had an incredible geologic history it had been processed it had been melted and minerals different types of minerals formed um and yeah it it made us think it made us think about okay so it didn't form the way we thought it did so how did it form okay so that's so so so your biggest surprise was not a question that it answered it was a question that it left you not knowing the answer to that's right and i think that's the most exciting thing is when you have more questions when things don't lead to the answer and you have more more things to explore so what are the questions you got jack uh here's robert weaver also from patreon and robert says my daughters lila and peyton would like to know how come the moon has so many craters and the earth doesn't have any um and i'm going to say robert you tell lila and peyton to go look it up we're not here to do their homework go google it next question all right i i love that question um so actually the earth does have craters so we have about i think it's about 150 recognized craters on the surface of the earth but because like i said the earth is very geologically active we have plate tectonics that's causing the plates to subduct underneath each other you essentially erase the history of what has happened in the past on earth and the other thing we have we have an atmosphere so certain rocks if they're small enough they just burn up in the atmosphere they never enter they never hit the ground whereas on the moon anything that hits it if it's a large enough size it's going to create a crater and then we also have wind which erodes any evidence of past craters we have water that also erases evidence and even life little critters making their homes underground collapse uh crater features here on earth so that's why we don't see them we've had them and we have them there's actually a beautiful crater in arizona called meteor crater that formed about 50 000 years ago and it's one of the best i think it might be one of the best preserved crater on earth and you can really you can see it and it's cool yeah it preserved not because there was a preservation society but because it was in the desert right that's right there's not much more rain exactly and it's a geologically dead area right exactly okay yeah oh that's super cool so so the earth is basically a contaminated crime scene you can never you never know what's going on constantly being bleached okay you just made me nervous i'm sad i'm i'm serious i'm like wait a minute you know what i know a lot about cleaning up a crime scene okay i used to be in the military and i was i worked i went i worked in a medical laboratory so i i know about cleaning cleaning okay all right cleaning the evidence yes yes but what you're meaning to just to summarize i think is if we didn't have these cleansing pro these evidence removing uh processes we would look just like the moon that's right just like it ever everything that this is what i meant by the moon being at witness plate is everything that's the same part of the absolutely exactly exactly exactly yeah all right all right chuck give me some more all right um let's see here this is uh canadian nope canadian very funny the way they spelled it this is canadian from patreon hello neil chuck stop blaming how people spell things on the fact that you can't pronounce their names what else am i going to blame it on oh this as much as i put your names i'm telling you i gotta find a way to you know i gotta have some excuse all right hello neil chuck and raquel uh if future immune missions end up drilling into the surface and extracting a core sample like we do on earth what do you think we might find how far down do you believe the rock layer extends before we start hitting cheese or oil yeah one of the other yeah yeah right they both have value with yes right right right very cool yeah that's i wonder that too raquel oh man as much as i love cheese and wish i could eat some moon cheese uh i i think we'd have to go pretty far down to not find it nice job i like the misdirection i like that mr brexit yeah what makes you think the surface isn't cheesed there you go but but it turns out there are layers there are layers what we find if we actually pull the core out yes well it depends on how far you go but the moon is a differentiated body so like i said before it's melted and it's it's been separated the heavy stuff sank to the bottom and the light stuff's at the top so what you have you have a core in the center you have your mantle and then you have your crust like here on earth just to be clear when people you know we think of rocks as heavy things because they go to the bottom of a pool but when you think of rocks you think of light things because metal things are heavier than rocks are that's right or density right that's there they're more dense so they yeah you see the light things floated to the top they're rocks what they're boulders what the hell are you talking about you're right yeah i know that's i have a very different perspective because you're a geologist from another species of person okay uh but on on top of the crust we have what's called the regolith so because the moon has been bombarded by you know billions of years of rocks hitting its surface it's broken up the rocks that were there before and so there's this powder uh of dust on the surface that that it i think it's between five and ten meters on top so so it's not a matter of uh breaking apart the rocks it's like completely pulverized pulverizing them yes yes powder that's right is this the same stuff they were trying to get they couldn't get off their spacesuits that's right so it ends up being very sharp because there's no water or anything to round out the corners the these fragments are so sharp that when they stick to you it's like impossible to get them off um and we we actually we have samples in our lab there's people in our lab that studied optical properties of the regolith and um and you can you can the samples that we got were removed from the astronauts spacesuits so they brushed they were trying to save everything they can it's such precious material to get to the moon that's right anything in the trash can so when they brought you know the astronauts came back they got their suits and and brushed off their dust and and we actually used that for scientific research and you can find little fibers in there and it's not mixed with their dandruff or anything oh man that'd be an interesting thing it's like oh you don't use head and shoulders we're gonna take a quick break when we come back more star talk cosmic queries with raquel nuno we're back star talk cosmic queries this episode on the moon the moon is a geological object not just a pretty thing in the night time sky check but we don't mind that we don't mind that it's a pretty thing in the united states that's right that works that works and we have raquel nuno who's a doctoral candidate at ucla studying the moon coming to it as a geologist and that's a whole other species of scientists as far as i'm concerned because you all see the world very differently from the astrophysicist you look at the moon you see rocks on the moon i look at the moon i just see a beautiful orb in the sky that's all i that's that that's where it ends for me and then i go to and then i go to mars to look for life see so chuck you got more questions you just made that up you just made that up nailed it i don't know what it is man he said i mean it says it says kevin kala kikamaka i think okay and and if it is kevin kawakimaka then i say uh aloha okay he says um uh what is it when the moon hits your eye like a big pizza pie no i'm joking he does not say that he did not say that okay here's what he says can the can the moon have a moon and can that moon have a moon as well i think this is a question more for neil but maybe you know too raquel do are there any because this is really kind of a really interesting question are there any instances that we find in the cosmos where a moon also has its own satellite so we i don't think we found one yet at least definitely not in our solar system but it is theoretically possible to have a moon of a moon and there's a paper that came out i think they called it a sub moon or moon moon depends on i think there's a thing on twitter where people on twitter were like no we want moon moon because it hasn't been named officially yet uh so um but yeah so theoretically you can have a moon of a moon but i think what the problem is is that you have to have the right conditions because if for example i think if it's the moon is too close to the parent body like the planet you can just just just stabilize its orbit and it will either spiral out of orbit or into the planet so neil do do you have any more insights about it yeah i agree entirely yeah it's a matter of uh i mean just just think it through so let's say our moon had a moon right and so it's going around our moon i think as it comes to this side earth's gravity on it will be stronger much stronger than it is on the other side so here's this satellite that's getting tugged asymmetrically as it's trying to orbit the moon and this creates conditions for very unstable orbits when you have an unstable orbit your your future is doomed either as racquel said to fall into the earth or to spiral off into infinity so you need in order to have one of these three body systems what you would need is a very big separation between the planet and the moon so that an object can go around that moon and not have the difference in gravity be so great that's what the moon and earth is relative to the sun right okay if if earth is a moon of the sun then the moon is a moon moon of the sun okay but that's okay because we're really far away from the sun so so so you can do the math on the the fabric of the of the stable orbits and you can see where you can put objects where they can stay and where you can put objects where they're unstable so see and now i am really not that i could do the math because i couldn't but now i'm just thinking how cool would it be to create a solar system mathematically where you could actually have a planet a planet the moon its moon and they all are in orbit so that the gravity pulls just at the right time to keep everything in balance like like those plate spinners on the you know like dude it's on the right path though i like these ideas but it is fun chuck there are these orbit programs where you try to create a solar system and you you might be surprised how hard it is yeah because you i want to put a planet here at this speed nope that's going to fall into the sun so there's only a speed that works at a distance in in whatever is the shape of the orbit that it has so uh in fact the solar system uh correct me if i'm wrong raquel uh recent models suggest that we might have started out with as many as 30 planets in the formation scenario most of which have spiraled off into interstellar space is that about the right number 30 is that a fair number to use that rings right and it seems reasonable but yes that i think the takeaway is there's more planets that we don't have that we can than we currently have right that are that have been ejected out ejected out yeah i've seen those i've seen some of those models where you ha and they were even closer to the sun and then once they they kind of jump places and they get knocked out everywhere yeah yeah it's quite quite the unstable place that's right we're so lucky we are so lucky it blows my mind every time i think about it wow okay all right that is super cool okay here we go um morgan tanji also from patreon um if there's no weather or atmosphere on the moon where does the ice come from oh because we learned about i there's ice on the moon so you all just thought you knew everything but you don't there's ice there's still so much to learn we think they're thunderstorms on the far side you just can't see them that means that's so cool that would be cool it would be cool so what's up with the water on the moon yeah so there's different um sources of water on the moon um they can come from comets and and meteorites that bring water to the surface of the moon um you also have what i think is really cool is the sun the so the sun is spewing this massive amount of charged particles called the solar wind and protons from the solar wind hit the surface of the moon so hit oxygen that that's on the rocks hit the rocks and and bond with oxygen forming water like hydrated minerals right the proton is the nucleus of a hydrogen atom yes so it's hydrogen hydrogen combining with the oxygen in the rocks forming hydrated minerals forming water at the surface of the moon um and there's actually so wait a minute is this like water out of thin space yes that's right yes yes yes yes yes the water just got conjured it's just like particles right it's like wow you're just looking for the moon to have a wand just like it's right water that's crazy yeah and there's actually one other place that we get water from and that's actually from the interior of the moon and we didn't know this until recently um they there they did there's these they call them glass beads they're just volcanic glasses that from the samples collected from the apollo by the apollo astronauts and when you slice them open and look inside you actually find trapped water molecules inside those those those glass beads so that tells you that there is water there at least in the past when these when the moon was geologically active there was water trapped within the mantle okay but it gets very hot during the day why doesn't all that just evaporate yeah right oh that's a good question so it does it does sublimate out chuck i asked a good question you know what i did a compliment i didn't want to break up the flow but i was about to say it better be a good question like could you imagine if neil asked a question and you were like what a crap ass question oh my god i'm glad i didn't do it wait did neil degrasse tyson just ask me that dumb ass what what [Laughter] all right i'm sorry bad question so um what ends up happening is there's these places at the poles these craters at the poles of the moon so at the top and at the bottom um that haven't seen sunlight they're so deep and they because of the way that the moon rotates they haven't seen sunlight for billions of years so it's very cold it actually turns out to be one of the coldest places in the solar system actually even colder than the surface of pluto and so if water ends up there it gets trapped essentially forever for for billions millions of years and that's where the ice is that's where where we think that the ice is is trapped inside these we call them permanently shattered regions because they're so cold essentially nothing can escape rachel you can say it the water is where the sun don't shine for that i think so i guess if you're on the poles the sun never gets very high in the sky that's right and so you can have a crater lip that permanently shadows because the shadows are very long by the low sun that's right and that those pockets are where you're talking about that's right so if we're going to have colonies on the moon and want to use in situ resources we've got to have some access to these to these craters at the poles in order to get the water and that's a lot of a lot of mission concept designs have been to go to these crater rims so you can you still have access to sunlight to power your equipment and also now you have these permanently shattered regions where you can go and collect the ice that we think is there okay the moon is sounding a little more interesting right i'm not there yet i'm gonna give it a few more minutes so now when let's i just have a question so when you the water that we're talking about that uh in the form of ice whether it's deposited there or it it it uh just forms is it is it is it potable is i mean is it like is it like is it just water can we drink it or is it you know something else so it is water but it's probably mixed in with the that regolith that that's right so you might need to uh bring some some filters with you if you're gonna need some machine to to scoop up the regolith and have some you know a spigot at the end but something's to have to process it together that's right because a lot of these is it true a lot of these are just sort of isolated or just a few water molecules yeah it at the surface yes yes it's it's pretty much just like a coating on these minerals that you have some coating of water so you need to go to these permanently shattered regions where we think there's large amounts of water eyes but we don't know how much and and that's actually a really exciting field of research is is sending away sending more spacecraft or you know people try to figure out what what is happening in these regions so if i went back to the moon i'd want to go to near one of those coal traps and start around i [Laughter] here we go this is bryce sondag and bryce uh is coming to us from instagram and i should bring this over here i'm talking away from the microphone um bryce would like to know how are the rocks and minerals on the moon any different than the rocks and the minerals here on earth and can i can i add a dimension to that question so you as a geologist have full expectations that minerals repeat right quartz or do whatever you know whatever your fundamental minerals are you're pretty sure it's something that happens universally at whatever temperature and pressures that you'd expect does the biologist should the biologists have the same confidence you do that if you find life anywhere it's going to have dna naturally because that's how nature makes life just the same way your quartz has sio2 because that's how nature makes quartz do you have any insight there or do you just privilege that your geology repeats every place you go that's an interesting question um good job again okay just kidding um so i would i would expect the the quartz would form the same anywhere and if it doesn't then we probably end up calling it something else it would probably be right but it turns out so warts it's warts it's faux quartz okay um but when you look at the rocks on the moon that the apollo astronauts brought back or even from meteorites that we know came from the moon um the moon is actually so similar to the earth and that's that was one of the that was a big question like why why would the moon why would you expect the moon to to be so similar to the earth you wouldn't you wouldn't at all and so because they are it has um it it adds this element of of curiosity of like what happened how did the moon form to to cause that to happen because you would not expect that at all because if some some object came and hit the earth and you would expect that the moon would be part of that other object as well but it's it's not it's essentially made up of the earth's mantle uh which is kind of mind-blowing so our theories of how the moon form need to take that into account but don't they the modern ones some of them do but they don't account for everything yeah it's hard and so now there's these things that's hard it is it's really hard there's all these questions that we still don't know about the moon and that's i feel i think that's why it's so exciting scientifically okay all right all right uh this is evan wells from patreon who sees this dr tyson and dr soon to be nuno i've been waiting for this talk for a very long time as i'm a big fan of the moon as well as planetary geology do you two personally believe in thea is that correct am i saying it right thia thea t-h-e-i-a the most logical theory of the moon's origin are there any other examples that you can recall of the moons that that are exceptionally close to their planet such as our moon uh looking at different other moons in the in the solar system uh thanks and so much respect uh from the space coast oh so down in florida yes uh very excellent uh that's a really great question which we don't have time to answer until we come back from this break see what i did there i teased that that's what the pros do that right sit through the commercial uh but of course commercials are what drives the finances of everything so anyhow we're going to be right back star talk cosmic queries the movement with soon to be dr raquel nuno back with chuck nice my goodness jack yes yes and our special guest today raquel nuno nuno i feel i have hispanic background and so to say nuno feels wrong i know i hear you struggling with it too yeah it's so funny it's so funny because when we went to break you went and raquel you heard that damn i thought i covered that up no no so you have a portuguese root i do yeah that's born raised my whole family's been there forever so they don't have an a in portugal no we don't so if you want to make that sound it would be an n and then an h afterwards that's how we make the sound yeah yeah but my my name is just nuno with just an n and it's weird my this is nuno is of portuguese first name that my family somehow ends up ended up with the last name no idea how that happened it's like mary mary would be all right all right when we left off chuck you there was a question about uh the hypothetical object thea yeah is that correct so evan wells wants to know this do you two personally believe in thea and the other thing is are there moons in the solar system that are like our moon so um can pro so the whole idea of thea can we can you let me in on that yeah sure so the idea was that a mars-sized object then which we're calling thea impacted an early earth and it was such a massive impact that sprayed all this material out into space and that it condensed out and formed our moon so that's the idea so marseille's object called thea hit the earth and formed the moon but just to be clear thea is gone yes yes and so some became earth and the rest became the moon and some scattered wherever else right that's right that's not wait a minute for this to happen these that thing would have to be super super hot like you know what i mean no chuck you'll get hot just from the collection it gets hot yeah it gets loud oh yeah you get that for free oh that's super cool you don't have to order that okay great oh okay okay and that's actually that's what would cause all that impact so then when the moon formed and all these pieces came together um it heated up the surface of the moon and that's how we got that magma ocean it completely melted so yeah you get energy just from things he get heat from things hitting each other wow all right so what's the status of that hypothesis is it embraced so yeah i mean it's the best we got yeah i read it i read it was like yeah that i'll go with that it's fun to talk about and on multiple occasions people said if i could go anywhere in the universe where would i go and i said does that include time and they said sure i said i want to go back and watch thea hit the earth yeah yeah that's cool man so you say it's got good support by your people it definitely has good support so we know that early in the solar system giant impacts like this were very common so it makes sense that this would have happened to us um and they would produce moons and and discs and the there's other pieces of evidence in the geological record so um the moon actually lacks iron in bulk so what we think happened is when thea hit the earth the its core the core of thea kind of sank into our earth and what you ended up having is the the mantle stuff so the stuff without the the iron to to form the moon um and uh and then the elemental so then there's the evidence for against it is the fact that the moon rocks are so similar to the ones here on earth um you would expect that you would see some evidence of thea somewhere and we don't so there we do not have any evidence of thea um material here on the here on earth or on the moon so we'd have to we have to figure out and we need an explanation as to why that is and how if you found an asteroid stream around the sun and you looked at its ingredients and they matched some combination of earth and the moon that could be the remains of thea that's right orbits still orbiting the sun that is right but how do you form two objects that are essentially identical so that would mean that the moon that the thea and the earth were very similar to begin with and we we have a very hard time with models making that happen it's very hard because when we look at at other objects other planets asteroids everything is really different you can you can find the fingerprint for each of these bodies and we really can't with the earth and the moon so so are what other moon in the solar system comes closest to matching our own well i guess it depends on what you're trying what do you mean by closest so uh if if you're talking about size so the moon is very big compared to the earth because when you look at other moons in the solar system the planets are huge compared to the size of of um of their moons well it's not only big compared to earth it's big compared to anything and anything that's right all the other if you lined up all the moons our moon is like in the top side of that it's huge absolutely yeah it's it's very it's a weird moon is weird yeah but um pluto i know it's not a planet uh it has a moon that's back [Laughter] uh but it has a moon that is very large compared to pluto itself so in that sense it is similar to our system our earth moon system is similar to the pluto sharon system because of the size the size ratios between the planet and the moon yeah okay and how about composition wise is it are there any moons that are made up of like you said basically like the mantle like you said what is there any any do we have any evidence of anything like that anywhere else yeah there's definitely um so io is a is a rocky moon um and it it has it it has rocks on it so but everything is very different and when you go out into the solar system you have more icy bodies whereas here in the inner solar system you have more of the rocky uh moons and planets of course io is around jupiter yeah okay all right all right chuck keep going here we go this is will uh from twitter he says do you think there is bacteria still alive in the apollo missions oh god leavings i will say uh the bags that they had to leave uh if there is none that have survived what would that mean for future deep space travel so i'm guessing oh i think i know okay i think i think i know the question okay yes yes yes so it they did do that they did leave bags yeah yes see because you can say that neil when i say poop bags people go chuck chuck okay these poop bags describe for me the bacterial composition of these thank you neil so so the question was there do i think there's any bacteria still alive bacteria still wait just to be clear they left it on the surface of the moon they did wait you have to carry your poop out of our national parks or something what's this some place there's some places that are so preserved you can't you can barely pee on a tree without scraping it off and taking it out of the park with you and we can leave poop on the moon i don't know these astronauts are like the neighbors that i have because i live next door to a doggone dog park okay they're worse than my neighbors rachel i i didn't know that okay yeah yeah yeah so i if you had a choice would you want to bring poop back to earth or rocks back to the air that is true it's a trade-off isn't it so you want to bring i'm bringing the rocks you bring in the rocks so weight is very important thing when it comes to space travel and space exploration so you're gonna try to maximize the quality of the weight that you're actually transporting um i don't think that there's bacteria alive so i know that um the the poop back bags um had germicidal in in them to actually kill bacteria so the the bags themselves i think they had to tear these pouches and and pour it into the uh and mix mix the stuff and and there's but there's other other reasons why i don't think it's alive nothing's alive in there you radiation is a really big challenge in in space so it's probably been completely irradiated from out there although this is a radiation because it has no atmosphere to protect it that's right anything coming hits the surface it hits it yeah and also the heat so the surface of the moon can get as hot as i think 260 degrees fahrenheit so you essentially have probably cooked everything that's baked in the bag yes a specialty in some parts getting a feeling that after this conversation there'll be several young people who are like yeah i don't think i'm going to be an astronaut oh that's sad no no no we need we need astronauts yeah all right um let's see here this is whoopsie doodle um you could pronounce that one chuck good yes you're damn right finally somebody likes me uh whoopsie doodle says dr tyson and raquel and hi chuck my question is can you explain what is the dark side of the moon so there is no dark side of the moon next question but a lot of people don't know that a lot so we don't have a dark side it's only a side that we never see because the moon is tidally locked to the earth so but it's not dark it gets it gets sunlight um and so gary larson did it right with the name of his column was the far side that's right pink floyd got it wrong where the name of the album was the dark side that's right this is the measure of science literacy here yeah we call it the far side that's what we call the what a lot of people know as the dark side there you go yeah it's dark to us all right so uh manuel uh delgado and it's actually del ghetto wow delegato there it is manuel delegato from instagram says in the film time traveler the moon breaks apart due to mining what would happen to the earth if the moon broke apart by the way that's that's uh i think the umbrella academy that that's the destruction of the earth too the piece of the moon breaks off and destroys the earth but what what what what what would we be it's also true in the movie melancholia the the moon approaches earth and then they collide and everyone dies my my favorite book called seven eves that happens in the first page as well in the first page of the first page the moon breaks up and it picks up from there and they lived happily ever right exactly all right so but what would we what are we without the moon it would be a very bad time on earth if if the moon broke up so the energy between the pieces breaking up and hitting each other would destabilize their orbits and they would end up crashing into the earth and that would be bad very very bad as we know happened to the dinosaurs um with much smaller pieces with much smaller p that yeah so it would the earth we wouldn't survive life might not even survive if that were to happen um but if you don't even take that into account so let's we don't worry about pieces falling into into earth the the moon provides the earth with a very stable orbit so um we don't tilt the earth doesn't tilt very much because it has the the moon there to stabilize its orbit so that's why we have very mild seasons so if we didn't have the moon there our seasons would we would have years thousands of years of ice ages and then and life would not survive the same thing actually happens on on in mars because mars has small moons they don't stabilize their orbits so mars is always tilting over periods of millions of years and um yeah so bad bad thing but but but to be clear this would not happen if you're just with normal mining techniques you don't have enough energy to actually break up the moon so we don't have to worry about that unless they find roku for cheese and they pull it all out that's half the mass of the moon that'll totally just that'll totally mess up the moon we confessed earlier in the show you have to dig very deep to not find cheese i think you said that in the beginning of this program did you what do you think neil if the moon broke apart like that's terrible right yeah but i i think that our access would go unstable on a period of time longer than civilization i mean yeah yeah tens of thousands of years not just a few thousand so i think the astronomers would love it because the moon completely messes up our night sky we can't see anything when the full moon is out so i would love it for the time until we all died it would be great that's so funny all right that's funny yeah well all right chuck what do you have next here it is um this is destin uh destiny from twitter says what color is the moon really is it is it all really gray are there features in different colors and and why why okay so uh and then he says chuck's chuck you get 10 cosmic points if you say my name correctly well guess what keep your points [Laughter] because you know damn well uh let's see uh okay that's all i can say maybe that that might be your name okay okay so what do you have ratel well it's really interesting is that how many people think that the moon is white or this very light gray color you know when i do outreach events people and i bring moon dust with me people i like whoa it's so dark i thought it was white and it's not it's actually very dark thing in the sky um when you look up at the night sky you see these different regions so you have the dark and the light regions and in the dark regions those are ancient volcanic plains so those rocks are are like black lava rocks that you see in hawaii or in iceland they're they're almost as dark as a newly paved road so it's it's very very dark those rocks are very dark um and then the the lighter region of the moon um those are the highlands so those are made up of certain minerals that are lighter but it's still a a dark gray color so the fact that the moon is so bright just means the sun is really bright on them that's right that's the only reason and the other reason is is a relative thing it when it's in our night sky we look at it compared to a dark background so it looks even brighter to us so what's around it is darker and that makes it look brighter so i i heard that it's uh the moon is a is basically as dark as the sidewall of your black tires i heard that reflecting just a few percent of the total sunlight that hits it yeah and um i think overall i think it's about like 13 maybe or twenty percent better even that high i was thinking overall overall so because but if you look at just the dark regions so the the the lava fields uh those are yeah as dark as a paved road yeah yeah it's kind of crazy wow that is that's really fascinating but just to be clear so so the they'll reflect some light some of the light the rest of the light it absorbs absorbs so that would heat up the surface which is why you get so hot in the daytime there that's right it's got to contribute to that somehow yeah okay that is so cool that's so cool so now uh i'm i'm gonna use the saying black as a moon is the moon all right i like it okay all right here we go um this is pratik kotari um pratik wants to know this uh what would it take to make the moon habitable uh is it possible for a um colony in the near future uh yes you can have colonies uh on the surface but you have to uh to mitigate all kinds of issues like the heat and the radiation um but there are there's there's actually lava tubes on the on the moon that you can you can see you can go underground with colonies which is really exciting but you cannot terraform so you cannot change the moon to give it an atmosphere to have running water because there's just not enough gravity to hold an atmosphere on the moon yeah i don't think people think actively about that you know we take it for granted that there's air here available for us to breathe without thinking that the gravity of earth is keeping the atmosphere on its surface that's right and so on the moon the molecules will just escape absolutely so you can have maybe very a very short time where you might have an atmosphere but the solar wind and the will just blow it out of the way just blow it out and the gravity won't hold it in place so what you're saying apart from the dozen things that will kill you you can easily just have a colony on the moon yeah not a problem ignoring those other complications that's fine all right all right chuck barely time for one more give it to me okay this is cremav raval who says this if you were granted full authority and unlimited resources what is the one scientific instrument you would choose to land or send to the moon to broaden our understanding go i love it i would not send anything there i would bring back the samples to the earth we can have make much better uh instruments here more sensitive instruments then it would cost too much take too much time to build instruments to take to the moon so bring the samples back that's what i would say answer good answer i gotta agree with that how could i not agree with that yeah we gotta call it quits there and raquel thank you for being on the show thank you for having me i love talking about the moon so yes i guess so that's why we picked you out of the that's why we did this so we'd be delighted to have you back on when you get your phd and we can you can tell us about what your discoveries were sounds good in in that effort very good so good luck with that sometimes you need a little bit of that too and and we loved your background it looks like a showroom from a catalog and um chuck you know that plant is fake you just know it just looks fake like yes it is it is yeah yeah it has to be it's a completely fake plant right all the other pants plants are just like don't talk to that plant that's not what i meant chuck but all right we got to call it quits there chuck always good to have you oh it's a pleasure tweeting at chuck nice comic thank you sir and and raquel you you do public stuff are you do you have active social media i mostly use instagram to do my science outreach it's this space geologist but you know very on the nose when we come back i want a better instagram handle than that okay all right great to have you good luck thanks this has been star talk cosmic queries edition i'm neil degrasse tyson your personal astrophysicist as always [Music]

Channel: StarTalk

Views: 209,609

Rating: 4.9026275 out of 5

Keywords: startalk, star talk, startalk radio, neil degrasse tyson, neil tyson, science, space, astrophysics, astronomy, podcast, space podcast, science podcast, astronomy podcast, niel degrasse tyson, physics, chuck nice, raquel nuno, Moon, luner geology, Earth, moon craters, apollo missions, theia, giant impact hypothesis explained, dark side of the moon

Id: y0_JvaREOVQ

Length: 57min 10sec (3430 seconds)

Published: Thu Jan 14 2021