 Okay, well welcome to the June webinar of the NASA night sky network this month We welcome Sarah Noble to our webinar who will share with us some of the history of the Apollo program and look forward The future missions to the moon Dr. Sarah Noble is currently a program scientist at NASA headquarters Working on a variety of missions to explore the solar system. Please welcome Sarah Noble Everybody I am happy to be here. I'm gonna share some slides Can y'all see the slides? Yep, they look great. Isn't it? Great, so I'm gonna start out here. Just a just a quick note about who I am Born and raised in Minnesota. I went to the University of Minnesota. I got a degree in geology I got graduate degrees from Brown and then I worked briefly for Congress actually doing some space policy And then I started wandering around NASA and what I'd like to refer to as my NASA nomad phase Spent some time at JSC came to headquarters and then down to Alabama and then to Maryland and then finally Stuck around at headquarters. I'm sorry. That's my that's my cat in the background. I apologize Luna's very excited about the moon And now I've been at NASA headquarters for about eight years now and Doing a lot of fun stuff Including working a lot on the moon So I want to talk to you a little bit today about Apollo and what we've learned about the moon from Apollo And also what we've learned since and why it is time to go back and what we're gonna learn when we when we do go back So I think Apollo is is interesting in a way because it's a different It's a different we started out different than we do with most of our robotic exploration Usually we start with a lot of robots first In samples is something that happens way down the road, but but with Apollo we had two big advantages We had humans on the surface with their human brains Which allowed us to do some greats on the ground geology and we brought back samples a lot of samples so many samples We brought back 850 pounds of samples And that allowed us to give them out to people not just a handful of scientists But literally hundreds and hundreds of scientists over the years have had the opportunity to work with these samples Including including me. I did a lot of my graduate work on these samples So hopefully you guys are all pretty familiar with what this is This is this is the moon and at least the at least the near side should should look very familiar to you We don't actually see the far side very often And so I took a minute and take a look at that and think about how the near and far side are actually quite different from each other And namely in that you should notice that there are dark bits and bright bits Right, we call those the Mare in the Highland And actually the geology the moon is pretty simple because it really only can is made up of these two kinds of rocks So let's talk a little bit about these kinds of rocks So first of all Mare right is is just the salt right? It's very similar to the kinds of rocks that you would find in Hawaii coming out of volcanoes I put the chemical formulas in here not because I think they're that exciting But because they show you that the piece of rocks are made out of basically the same stuff as rocks here on earth Iron and magnesium and silica and oxygen calcium. It's not that exotic right? The moon is made out of the same kinds of things that the earth is made out of Occasionally you do get some weird stuff and I made note here of two strange minerals that we actually found in Apollo samples Tranquillite in our Melcolytes These are were minerals that were first discovered at the on the moon But actually since then we have found them on earth as well So they are not they are not so exotic that they don't exist other places But we found them a first of the minutes We got to name them and they got great names right tranquillitites named after a first tranquillity base where Apollo 11 landed Our mouth lights a little a little bit more difficult. Has anybody guessed what that stands for? Think about the Apollo 11 crew Armstrong Aldrin and Collins They got to name their own and their own mineral the highlands the bright parts of the moon are actually even simpler It's all basically one mineral. It's a mineral called plagioclase feldspar calcium silicate aluminum And it and it's basically one of the most common minerals on earth as well In fact, if you all go home tonight and look at your granite countertops, right? If you can find the white mineral in granite that is plagioclase feldspar The same mineral that it makes up a large chunk of the moon Okay, so the question is how did we end up with this Mari and Highland mix and The basic idea the basic philosophy we have for how the moon was formed is that Somewhere around four and a half billion years ago something really big slammed into the earth something about the size of Mars Hit the earth and it kicked off a lot of material Right and that material sort of came together and coalesced to form what we think of as as the moon So it formed mostly out of the crust and upper mantle not the cores of these of the earth and this and the impactor And it was very very hot, right? And so it was formed probably mostly molten and a lot of the volatiles a lot of volatile elements The things that burn off really easily like water were lost Right and so that gives us our basic sort of framework for how the moon formed then right the boom was basically entirely molten And then the plagioclase started floating right so plagioclase right that that mineral that white mineral in granite is Actually very light and it will float as it starts as it starts crystallize Whereas the other minerals are heavy and so they'll sink and so it happens as you form the sort of crust of this bright Plagic material while the other minerals sank and then eventually Later on there were impacts that came and broke apart that crust and and then those impacts later on were filled with with volcanoes With lava coming out of volcanoes And so that cartoon is not the greatest to give you a picture of inside the moon But we actually do know a fair amount about the inside of the moon Because we had seismometers several of the Apollo missions 12 14 15 and 16 had seismometers on them. We actually had a seismic network active on the moon for about five years during Apollo We got great data from it and even today we're still looking at that data So this is a recent paper a paper from just a few years ago Where we finally were able to confirm from that data that the moon does in fact have a core It's a small core, but like our core it is solid inner core fluid outer core So we actually have a lot in common with the internal structure of moon But you can see in this cutaway that it's actually quite small compared to the radius of the moon But you know, it's great. We're still learning about the moon. The thing with seismic network though is that all of these Seismometers were pretty close together, right? They're all on the near side They're all sort of in the same part of the moon and if we really want to understand the internal structure of the moon What we really want is a seismic network that covers the whole moon where you have one Size on seismometers that are far apart so you can see deep down into the into the deep interiors of the moon more easily And so that's actually that is something that is very high on planetary scientists lists of things to do on the moon And hopefully this new era of lunar exploration will give us the opportunity to do that Okay, so we're back to the moon again the front and back of the moon and these images look a little bit different than that Then the set I showed you earlier. These are actually compilation of images from the lunar reconnaissance orbiter and they're Together so that they're all at at low Sun angles that really emphasizes craters So if you look at the surface of the moon here, you can really see particularly on the backside on the highlands all of the craters And that's sort of amazing when you look at that and see just so many craters there, right? There are craters on top of craters on top of craters And it's interesting to think about how that the moon and the earth are in the same neighborhood We've been exposed to the same environment over time, right? So everything that's been hitting the moon has also been hitting their earth earth is not covered with craters Of course because our rocks get recycled, right? We have a lot of wind and water and we have plate tectonics and so the rocks on the earth tend to be much much younger If we only have a handful of impact crater in our record here on earth But it's it's clear that we get hit by stuff all the time well unnerving enough to keep you up at night You can also see the difference just between the the craters in the highland and the craterings in the marae, right? There are craters in the marae, but there are so many fewer than there are in the highlands And this is actually something that geologists use not just at the moon But across the solar system to help us understand the ages of different surfaces The longer something's been sitting out the more craters it has You can get a sort of relative sense for how old something is by counting the number of craters you see And it's important to think about impact events that they really happen at at all scales, right? So from planets planetary scales, right like the one I'm showing in the upper right here at the South Pole aching basin Which is that giant purple splotch on the south towards the south of the moon, right? That's one impact crater. It was enormous Cut so deep it probably cut down through the crust and into the mantle. That's incredible But you can also get craters that are sort of more on a human scale like at the bottom of the screen there Right and standing next to an astronaut, right? There's a crater maybe the size of a house or a city block, right? But then you could also get craters that are ridiculously tiny right on the right there I show a crater so you can see the scale bar is five microns for those of you not used to thinking in microns Think about us a single strand of your hair is about 30 or 40 microns across So you could fit, you know, like eight of those impacts across the single strand of hair So that's that's very very very tiny. These are the sort of impacts that I study actually We'll get back to that in a minute And here again, I was talking about how we can use crater counts to sort of age date different trains Here's a great example of this. This is a map that even even You know if you look at different parts of the Mare they have different numbers of craters on it So you can divide it up and get a sort of record through time of the volcanoes on the moon And where the old ones are the ones in purple and blue and the youngest volcanism on the moon Which is only about a billion years old. I know that sounds old, but to geologists That's like a blink of the eye, right? So we can see where the youngest volcanism is and this is a this is a great Sort of map to tell us where if we want to look at how the the chemistry of Of the volcanoes on the moon changed over time. We can go and sample some of the older ones We can sample some of the younger ones And we can also, you know, use this the moon is the one place in the solar system where we actually have actual dates, right? So credit counting only gives you a relative age You can say, you know, this has more craters than that It's it's older than that But if we want to tie that to an actual age and go, oh, that's a billion years old Then we need to have samples and the moon is the one place where we can tie those things together Because we have the samples that the Apollo astronauts brought back and we know how old those trains were And so we use that to sort of calibrate our time scales for all of the other Rocky bodies in the solar system and so Which is great, but it's imperfect and the more dates we can get on different units the better we can we can refine that scale So what's with the rays? You guys look through telescopes a lot You've probably noticed that the moon has these gorgeous ray systems But not all the craters have rays right only some of them do And it's the youngest ones right so again young here is you know less than a billion years or less But still these young craters have these gorgeous ray systems. Everybody's got their favorite mine is is propolis which is Crater there on the left hand of the screen up near my Ecrissium It's got it's got a really cool ray pattern because that that was an impact that actually came in at a Lansing angle it didn't it didn't come straight down It came in sideways and it created this asymmetric Injective pattern, which I think is really cool. It's also easy to find because it's right next to my So actually what I studied what my my PhD thesis was about was understanding How these grays form and how they disappear? So what happens is when you get a fresh impact in it exposes fresh material right like this L Rock image of a young of a small young crater right it exposes that fresh material the fresh material is very bright But then over time It starts to get darker and I study the process by how that starts to get darker And it mostly has to do with those very very tiny impacts the little tiny, you know microns across impacts Every time one of those comes in and hits it melts and vaporizes a little tiny bit of the moon And you can see that the lunar soil there is full of all this like melt Products that you that get sort of draped over over the outsides of the grains and at the bottom of the screen You see a TEM image. It's a transmission electron microscope image of a grain of lunar soil and you can see around it It's got this sort of ring around the outside full of freckles Those freckles are actually tiny little blebs of metallic iron that happen in these tiny little impacts the vapor in these impacts It's so hot that the iron and the mineral separates from the oxygen and you end up with metal iron metal Coating the outside of these grains and that's sort of opaque and so it changes the optical properties of surface And that's what makes the surface dark over time Okay, so let's talk about some other craters, right? So the craters at the poles Are a really interesting case on the moon because the moon isn't tilted like the earth It's basically straight up and down. It's tilt is about like one and a half degrees So it's pretty much straight up and down which means that there are places where the Sun can't get in right? It can't get down into the bottoms of these craters and there are places that just don't get sunlight that haven't seen sunlight in billions of years Just kind of incredible So we've done with the lunar reconnaissance server It's been an orbit around the moon now for about a decade has spent a lot of time mapping the illumination at the poles And this is sort of a buildup of that illumination map over six months period So you can see the places here that are dark places that didn't see sunlight Places that are bright up on the rims are places that that see sunlight most or all the time It turns out there's not quite any places that see sunlight all the time. They get pretty close, but not quite and these are places actually that we are looking at to to want to land and build and build some infrastructure a Lunar base because you have a resource there of sunlight Right, but then there's another resource that you've probably heard us talking a lot about which is which is water right when we think that these Dark places on the moon are also incredibly cold incredibly cold. So here's a temperature map from one of the instruments on LRO And you can see the scale there and it's a little small, but you can see that this those purple and blue colors That's a Kelvin scale. So the purple and blue colors there are down in the like 25 30 degrees Kelvin 30 degrees above absolute zero So this is some of the coldest places in the solar system This is colder than Pluto right these places haven't seen sunlight in billions of years They're just incredibly cold and what happens is if there are molecules bouncing around the surface And they end up in one of these cold places They get trapped there they get stuck and they they have no more not enough energy to move out So they stay there and so we've thought about this for a long time And we thought what you know what might be hiding in these cold tracks So back in the late 90s we sent a mission called the lunar prospector mission to tell us a little bit about that to see if we could find anything in these cold traps and and the Instrument on lunar prospector can't see water But what it can see is hydrogen and so it mapped out and it found that over the poles There's a lot of extra hydrogen Which could have been water it could have been just hydrogen. There's no way to know for sure At the time, but we thought well, you know, this sort of fits our story that there might be water there So we actually send another mission This is like this is a great little mission that's launched with with LRO Submission called L cross you can see the cutout of the rocket there with the LRO spacecraft And then there's the L cross based couple which was actually the ring that attached LRO to the rocket And they built the spacecraft out of the ring was very ingenious What they did was they actually took the the empty rocket with them to the moon and crash the empty rocket into the Surface of the moon and then flew through the plume with the little spacecraft And and used a number of sensors on that spacecraft to actually find water And so that was our first real evidence that for sure We are certain that there is in fact water in these cold traps We found a lot of other stuff in the cold traps too and in particular we found a lot of mercury So for those of you who are thinking you can just you know go up and take a drink of that water You might want to you might want to hold your horses a little bit. You'll all be mad as headers on the moon But it's still still a very useful resource that we can use for fuel and other things More recently, we are continuing to sort of explore Water at the surface of the moon and this is that this is a paper that actually just came out last year Looking at at some more recent orbital data from mCube as well as some LRO data Where they've actually now been able to convince themselves that there's water ice sitting at the surface We sort of frost or ice directly at the surface All these places where there are these little blue dots and so pretty widespread Across a lot of these permanently shadowed regions. It looks like you have water at least at the surface Now we don't know how deep that is. We don't know how much is there There are a lot of questions we still have about the distribution of this water, but we do know that it exists so let's talk a little bit about where we're going from here and then Finally the moon to Mars, right? So so we think about Apollo. Apollo actually visited again a very narrow Piece of the moon, right? It's about the same amount of the moon as as North America So you were an alien and you came to earth and the only place you ever visited was North America Yes, you would learn a lot about the earth, but you would really miss a lot of stuff too, right? You would miss out on Antarctica, right? No polar bears You've missed out on on the outback in Australia. You've missed out on the desert You miss out on the Himalayas all sorts of things that you that we you would totally miss If you only went to North America and so we can think of the moon in the same way, right? All of the places we visited sort of central near side. They're actually all in the sort of weird part of the moon where the Mars is We have we there's still a lot of the moon left to explore and a lot. We don't know about it Now since Apollo right we have done we've done our due diligence and we have gone around So Apollo came and went and then there was a huge gap about, you know 20 years Before we went back to the moon at all there were a couple of little missions in the in the 90s We talked about prospector as well as Clementine, which was actually a Department of Defense mission It wasn't a it wasn't a NASA mission But Department of Defense wanted to test some sensors and they thought hey you guys want this data of the moon and we were like Yes, please please give us the data But then you know starting in about 2009 the last time that NASA got very excited about the moon We put in a real sort of concentrated effort to look at the moon So we sent LRO, L-Cross, the moon mineralogy mapper, rail, the gravity recovery, and interior laboratory Ladi which looked at the dust and atmosphere around the moon and and not to be confused with the new Artemis mission There's actually a mission around the moon right now called Artemis Which is a heliophysics mission to understand how the moon interacts with the solar wind That's an acronym for Acceleration, reconnection, turbulence, and electric dynamics from the moon's interaction with the Sun, which is a little bit of a crazy acronym But so you're not confused Artemis all caps Heliophysics mission, Artemis lowercase is the new plan to go to the moon So two decades now studying the moon from orbit has really sort of Revolutionized our understanding of the moon right we now have this this very global view of the moon We know where to go right we have a much better understanding of the questions we want to ask right for example We'd love to go to some of those young volcanics that I was showing you earlier We also really need to go to the surface to answer the next big questions We've done a lot of what we can I wouldn't say we've done everything but we've done a lot from orbit And the next big big move in lunar science We're gonna have to go to the surface in order to understand those things But we do have a lot of big science questions for the moon right so we talked a bit about the polar volatiles How did they get there? How are they distributed? What are their isotopic and chemical compositions? How did the moon form and evolve can we better characterize the lunar interior? I was talking about putting in a seismic network. That's very high on our list as well as other geophysical measurements Are there rock types? We didn't sample in Apollo and what can they tell us about the moon's evolution? Yes, there absolutely are we know from our remote sensing in fact that there are there are a number of rock types That we just didn't sample in Apollo they weren't they didn't exist in the places where we went But we know where to go now and we can go and find them But more than that as much as I love the moon and as a lunar scientist I'm very excited about the science of the moon But the great thing about the moon is that we can actually really use it to understand the whole solar system and even beyond Right so we can use the moon to understand the distribution and timescale of impacts and volcanism We can use it to provide an absolute chronology. I was talking about how we count craters We can use it to try and understand how and when the giant planets migrated We think that the solar system was very active earlier on and things were moving around and we can use our understanding of the Of the moon and when things impacted to try to understand what the timing of those migrations were We can explore craters to understand the physics and impact cratering That is the most prominent prevalent geologic process across the solar system and the moon is a great laboratory to study that We can use the radio quiet of the lunar far side, right? We'd like to we'd like to put a radio telescope on the far side It's the one place where we won't have to worry about interference from radio waves here on earth And that will allow us to actually see back to the to the cosmic dawn to the very beginning the big bang earliest moments of our solar system And and that's the only place we can do it is on the far side of the moon And we'd like to try to understand our Sun better, right? There are a number of things you can do On the moon to help us understand better our Sun and the way that the Sun interacts with the moon So as much as I like to think it's all about the moon It's not just about the moon the moon is is sort of a cornerstone for understanding the whole solar system So and of course, it's it's also not just about the moon this campaign That we are on now is about is about using the moon as well to help us eventually move on to Mars And so there's a whole on number of things. I'm like Don't dwell too much on that Here's sort of the the giant plan right of Artemis to get humans to the moon very soon 2024 We've also got Mars 2020 launching that is the first step towards Mars sample return My part in this actually those that is the bit on the bottom there the commercial lunar payload services I'm very excited about this. This is a this is a new thing for NASA You guys remember the Google lunar X Prize There were a number of teams out there nobody nobody won But there were a number of teams that tried very hard to get to the moon For the Google lunar X Prize and a lot of them got very close and a number of those teams now Are on contract with NASA to provide commercial lunar payload services by which we mean We will provide them a payload whatever instruments we want to send to the moon And they are like FedEx that they will deliver those payloads for us and send us back our data And so we've been working really hard on this. Um, we've got actually just announced Last month we've selected three of these of these teams to actually fly to the moon over the next two years One as early as as as september 2020 and just over a year from now the other two two years from now And this is just the beginning our plan is to is to keep sending these like one or two of them a year every year Mostly for science reasons, but also as a way to support the humans To you know deliver cargo and whatnot and the idea is that many of these companies Are are designed to not just be a delivery service for NASA, but they are actually building A plan to to use To to bring in other customers Astrobotic in particular has has like more than a dozen other customers other other countries universities All sorts of things that want to send their stuff to the moon And and if you do it in bulk right it becomes cheap enough that that You know it becomes a viable business And so the idea is these guys will grow and evolve and and their capabilities will mature and we can use them We can use them for science, but they will also You know make money on their own as well. And so we wish them all well, and I think this is a really great beginning for for Partnership between us and and the commercial industry to to sort of build on each other And expand our capabilities on the moon Rather than NASA just paying for everything Okay, that's that's the end. I'm happy to take questions All right, and it looks like we've got quite a few questions here already and we'll probably end up having some more Coming up here And so I just want to remind everyone that if you do have a question to please put it in the Q and a window that will Help us keep track of it And things tend to get lost in the chat window. So if you could please put that in the Q and a window That'll make life easier for all of us So a long time ago way back at the beginning bill asked the question and you you talked about this A little bit, but maybe not some of the differences He was wondering about the difference between the near and the far side crust Yeah, that's it. That's a fascinating question And it's one we have spent a lot of time thinking about and don't actually have Answers we can tell you that the crust is thicker on the far side Then it is on the near side and that's why most of the volcanism happened on the near side Because if you can have it's hard to go to get through the crust We don't really know why the far side is bigger than the near side. There are a number of Theories about this. There's there's one theory that suggests I love this theory. I don't think it's right, but I think it's really cool Yeah, that suggests that that actually when the when the moon first formed there were two Um and a big one the small one and the small one sort of collided and stuck on the far side And that's why we have it's thicker on that side There's another theory that suggests that the earth was so hot That it was radiating enough heat the earth in the middle much closer than and the earth was radiating enough heat that it kept the Near side warmer and so the crust there just didn't get as thick There are nobody nobody has coalesced on a on a theory yet, but there are a number of good ideas out there So, you know, that's still a real open question All right Adrienne asked the question and and I know that you alluded to the seismic network and hope to have that How much risk to future moon missions would there be without A moon wide size seismometry data? Yeah, that's a good question. We do know that we get moon quakes. Um that are up to about Fives or so on the Richter scale. So um that would be something that might be a little scary for for astronauts um We do actually know that the that the moon is shrinking and so we can actually see New ridges and things being formed. So there is sort of tectonic activity happening on the moon. Um We do know from this from the apologizing network that there are sort of nests of where These earthquakes are sort of clustered So there's probably not great places to build up infrastructure. So we can probably sort of will avoid those But it is something it is something to be to to think about When you when you're planning for where you're going to put your habitat down. Yeah So, uh, you know kind of going along with the idea about habitats and so jeremy asked about the potential of cave systems on the moon as potential sites to protect the explorers Yeah, this is an idea that's been around for a while. Uh, we do know that there are Pits and probably lava tubes on the maria parts Is there volcanic structures and what happens is you get a sort of crust crust on the top that that cools But there's still lava flowing underneath and it sort of flows out and leaves behind an empty tube Cave and those are protected from radiation that there are some pluses there But if you've ever gone Caving if you've ever tried to wander around in these things, it's not easy It's not easy to get into and out of you remember you'll have people in spacesuits spacesuit designers Put up conniption fits because they think you might tear So for safety reasons, I think that we're at very least a long way off from considering those as habitats But scientifically they're they're probably really interesting places to explore So I'm hoping at least robotically we will be able to Get in and explore some of those lava tubes and caves. I think they're very cool all right so cook asked a question and So you you related some of the mineralogy differences between the different Areas on the moon and so cook was wondering about the isotopic similarities between the earth and moon and what how the The impact I guess impact hypothesis for the formation how that might have affected the Those similarities Yeah, so the the moon and the earth are are incredibly similar in their isotopic signatures, which is one of the evidence For the idea that they they must have formed in the same part of the solar system Because if we look at you know mars if we look at the asteroids other planets, they have very different isotopic signatures and so It sort of cuts both ways There are those who say that that in fact the the isotopic signatures are are too exact To map matching that it can't be a A giant impact hypothesis because you would have had some fractionation between them it wouldn't have Mixed so well On the other hand if you're made out of the same stuff, right? It's all the same material presumably the impactor must have been Made of similar material as well. You can see how it would all be the same We actually have Recent years there have been Some evidence that in fact there are some subtle differences that we didn't used to have the resolution to see but now we do actually see Some subtle differences in their isotopic compositions, which which actually gives more credibility to the giant impact I thought it's this but there are still these these arguments Still go on between the isotopic folks. I I kept to admit that I don't get too deeply involved in this Down at the you know like fourth and fifth decimal point, but they're very important to those guys Yeah, it's really amazing how the the the ratios between different isotopes Really can you know provide an awful lot of information? Yes, once again right samples are a gift that keeps on giving right because as as our technology improves Right, we can go back and relook at samples and we find new things because we have Higher resolution higher power new techniques So that's one of the the best things about having samples is that is that we can keep using them And keep learning from them And that's and that's one of the reasons why we take such good care of them We curate them so carefully is so that future generations will still have access to them Although I guess there's a there's a few stray samples that were given away that no one's quite sure where they are to So Yeah, it happens. We actually keep a pretty we We keep a very close eye on on the on the samples But there are the ones you're talking about are when when uh, when a paul came back back They had these goodwill samples that they they gave out very small Rock samples that they they gave out to heads of states around the world Um, and some of those heads of states, you know, we're later deposed or whatever like Unstable countries and a few a few of those have gone missing over the years. So Um, yeah, there are a few floating arounds that we don't know where they are We have Mike Zolinski from the astro materials lab With us in earlier this spring and he gave a really fascinating presentation about All the different materials they have down at johnson space center And so for those of you that are interested go to the nsn website or youtube channel. You can check that out so um So back to this so hailing us a really interesting question Seen as how we uh, you use the moon's craters as a way of age dating. Is that similar to age dating? uh trees with their rings um Yes and no the the nice thing about age dating trees with their rings is that it's an exact science you can you can count them Right and you have an exact date whereas whereas crater counting is again. It's about relative, right? It's about this this surface is younger than that surface, but I don't know how old this surface is um So, uh, it's it's not it's more of an art What's probably more of the uh, you know back in when you take the geology classes and probably has more to do with, uh, you know relative dating and and what crosses what And and things like that. So Ron asked the question. How many new craters have we found on the moon since Apollo? That is a great question. We have found um Since uh, since allero has been up there 10 years this month actually, um, we have found uh, a lot hundreds of new craters that have occurred that we that we see in allero images because allero Um repeatedly images the same areas over and over again We've tried to go back and do some comparison with Apollo imagery Imagery, but it's it's harder because it's a different camera and whatever it's it's not quite as easy to to find them But uh, the the lro ones you can do different images and actually if you go to the lrock website Um, you'll find some you can find some of these where where they you can see the before and after And you can actually see the the craters. Um, and and we've seen the craters that we've made, right? So we've impacted Um, a couple of spacecraft the laddie spacecraft the grail spacecrafts Um, unfortunately the the bear sheet the israeli spacecraft that that attempted landing a couple months ago um And and some of the apollo Um rockets and whatnot. And so we've been able to find those over the year We can we can see those impacts as well. So even even the ones we've made Which is fascinating and so you can see these very very young ones in there and how they they even they weather so quickly He's kind of staying with uh with mineralogy here. We've got a couple of terminology questions that uh, so greg gregory notes That he here's the terms mafic and creep. I think kre is an acronym actually for something when referred to moon rocks What exactly do those mean? Yeah, so creep, right? So you ever hear your lunar geologists talk about their creepy rocks It's not that they're like haunted or anything creep stands for a potassium rare earth elements and phosphorus Uh, and these are sort of the last rags of things These are the the incompatible elements that don't like to go into minerals So as the as the moon is forming, right and all the pleasure places coming to the top and all the all being Appearance being exploited to the bottom the creep is the last stuff is the last seen which of stuff That doesn't want to go into anything that gets sort of left over. It's the very last things to form minerals um mafic is uh is a term for um, how how much Iron rich minerals are in your rocks. So so basalt is a is a very mafic rock. That's the the darker rocks All right, you know for those geologists out there, uh, if you understand a little about about bolin's reaction series That would help understand that So, you know what I mean sarah Okay, so uh, lori asked a question is lunar and north of site now called plagi clays feldspar for highland rocks Uh, those are the those are the same thing. So north of site is the is the so plagi clays Feldspar is the feldspar is the general class of minerals and north of site is the Specific name for that end member that's the calcium and member of that. There's a series Um, you can substitute sodium instead of calcium in that in that feldspar series But the moon right because it was violent and hot whatever it lost most of its sodium That's a very volatile material. So it's mostly calcium. And so it's mostly the end member, which is the north of site Okay, well back to uh, human exploration here lane asks Is there enough water on the moon to actually support life there such as a long-term space space? Uh, that is uh precisely the question that that we are trying to answer right now, right? So, um, we don't know Um, I showed you the evidence we have that there is at least some water there But we don't know how much it is We don't know how thick those ice deposits are how extensive they are whether they're renewable or if it's a one time Deal, uh, there's a lot of questions. We don't really still understand about that It's one of our our first targets When we go back to the moon that is one of the reasons we're going to the south pole is that we can sort of investigate that and find out It's always easier to to bring uh to to live off the land that it is to bring all of your own supplies and so Hopefully we'll find that there's enough water that's usable. It's not the only reason we're going to the south pole though the actual Main reason we want to go to the south pole is the is the other resources there and that's the sunlight right next to all these permanently shadowed regions are the regions that have almost permanent sunlight and so That is the energy source that we're actually going to the south pole to find water would certainly be a bonus and would definitely help us with our long-term plans, uh, both for the moon and and Uh, moving moving off the planet moving moving to mars, uh, because if you you can you know If there's enough water that you can have fuel depot and you can you know Produce water that you don't have to get off of the earth's gravity well Then that will help us explore other places in the solar system too All right Okay, gloria asked a question and back to uh, you know sticking with the idea of humans going to the moon According to nasa press releases nasa will send the first woman to the moon by 2024 Do you know the name of the female astronaut or maybe some of the ones that are in training? Who's uh going to be chosen for this? Yeah, it hasn't been announced. Um, I heard or I heard a hint That that that bryan stank gave something away the other day that he said it was somebody who had already flown So that narrows it down to a to a few dozen or a couple dozen, uh options um I don't think it's been I I don't know that it's actually been decided yet so I I I I If I knew I couldn't tell you but I don't actually know Um, I do know that we're working uh working very hard to to train them right one of the One of the key things about apollo right was not just that we had humans with their human brains, but that we had really well trained Um geologists right only one of the apollo astronauts was had a geology background But by the time they were done with their training course They all had about the equivalent to a master's degree in geology. They were really really well trained They spent a lot of time out in the field Learning how to you know, how to be a field geologist how to ask the right questions How to pick up the right rocks and it really made a difference Uh in the rocks that they found and the geology that they did in the field And so we're in the midst of sort of ramping that up And trying to figure out how to how to train this next generation They already have a slight advantage because we've we've been training them um, at least a bit on geology for the last decade or so um, and so Uh, you know, we're working on on ramping that up and making sure that that we have really well trained Field geologists out there when they do land probably at this point one of the main constraints for training is the lack of a Vehicle to train with so, you know, that's kind of a something that has to happen So you can get there to do the geology I sure We're working on that too. That's oh, I know my apartment I know I know They all fit together somehow so Okay, carol asks, uh, if you could recommend a location on the moon for the astronauts to land and explore Where would it be? Oh, if I could pick If I could I mean personally if I could pick I would like to go to a swirl I don't know if you guys have ever heard of the lunar swirls, but there are these places on the moon Um, which I had a picture to pull up right now and I don't Uh, there are the places on the moon where, um, where there are some wonky magnetic field things happening that causes Um, just really incredible swirly patterns in the in the soils That we don't understand It has to do with with again the space weathering that I was talking about how you make surfaces darker But not uniformly it has to do with the magnetic field. Perhaps Uh, blocking the sun, uh, the solar wind in those places We're not we don't really know for sure, but and I think it would be a really fantastic mission to go and find that out that's uh as a personal One that in more more generally, I talked about visiting the some of the youngest Mechanics, I think if you asked your average lunar geologist, that's that's high on their list, too Um, there's a couple other spots. There's the the Aristarchus Plateau Sort of that bright spot on the on the left side of the moon and in the In the midst of the big dark swirl there There's one very bright spot and that's there's some really cool geology to be found there Um, again, there are there are places where I talked about where we know that there are new minerals that that we didn't sample During Apollo. I would love to go to one of those spots. They're mostly hard to get to they're like in the sides of crater rims Or central peaks of craters, which make them a little challenging for landing But eventually I hope that we are have the capabilities to explore some of those more difficult spots Um, and then you know the poles we talked about the poles But that's where that is where we're going and it is one of the places that I think Lunar scientists are very excited about visiting Yeah, we've had quite a few questions regarding Meteor impacts from A question about how great would the threat be? to the astronauts there to What's the rate of micro meteorite impacts on the moon because you know they Don't get burned up and and we don't see them as pretty streaks across the sky and in the moon Um to You know some of the other ideas about uh, you know, how can they protect themselves? And so any comment about? Any of these meteorite things um Yeah, so it's certainly something that that you know, especially if you're building a long-term habitat It's something you have to think about. Um, I you know, I wouldn't worry too I think the statistical odds of like a random micro meteorite hitting you as you're walking around the surface are probably Uh, really incredibly low. They're not zero, but they're they're probably not something that would that would be a showstopper Um, but I think if you have a habitat that that is, you know, permanent that you want to have there for A long period of time you better be prepared Um to you know for it to occasionally get hit with things. Um And so, you know, I think that is something that they are are thinking about. I think Um in the scheme of things I would be much more concerned about radiation than micro meteorite impacts I think that is a harder harder problem to solve in a more immediate danger for astronauts Okay, going back in in Time back, I guess to the beginning of the moon mark Ask if a Mara size object, you know, if we're if we're thinking of the big impact or hypothesis of a Mara size Object struck a glancing below to the earth. Where did the object go? So how did that kind of work? It yeah, sure it became it became part it became part of the earth and part of the moon, right? It sort of got absorbed By by the the earth moon system, right? And so it's it's in both of us. I think Uh, I think they think mean you can make your models do a lot of things But I think they think that more of the impactor went into the moon than the earth but the core of of the impactor would have stayed with the earth And so we got more of the mantle of the impactor. I think it's how they they currently think that that it sort of Worked itself out okay D ask a question Is one lunar pole more favorable to a base than the other? um Yes, uh, I think mostly because um, I showed you all those pictures of the south pole and that is where we're planning to go Uh, and I think that has largely to do with um, the fact that LRO Um, was in a it's a very elliptical orbit Um, and so it was always at its closest approach around the south pole And so we have the best data there our data for the north pole is is much lower resolution um, and so I think that's part of what's driving, uh our Preference for the south pole. I think the reason that we picked that orbit for LRO is because the the south pole has more permanently shadowed Area than the north pole. I think that's that might be true Uh, but regardless that is now where we have the good data that we're going to need In order to to navigate and choose landing sites. So that's why we're going to the south pole Okay, so, uh, we're going to go for just a couple more questions here. And so we had two people dug and um, I don't remember who know Um, noted about that there was an announcement of an impactor that was perhaps discovered below the south pole Do we have any idea of what that is? And I'm not I don't recall having read that so I can't elaborate on the questions I don't recall. I'm not sure what they're referring to either So let's see if they Yeah, they just said that there was a mass apparently, you know Two people noted that there was a mass that was recently reported under the moon south pole. And so Oh, I know what they're talking about. So not under the south pole, but under the south pole acan basin Um, so that giant that giant crater, right that covers like a third of the moon, right? um, they recently have Some done some modeling that shows that there's like a big mass concentration underneath it. Um, There's one theory that suggests maybe that has to do with the impact Or maybe it was a big metal impactor and that's the big massive metal that it's underneath it more likely than that That might that is a possibility, but more likely than that. Uh, what happened to us that that that impactor Broke through the crust and and has um, hold some of the mantle up Um, and then that mantle material is denser than the crust material, right? That's the that's the stuff that's sank, right? so it's denser and so that's that the The impact has sort of pushed that stuff up closer to the surface And so there's more mass concentrated the other surface Where the south pole acan basin is than than other parts of the moon and so I think that's the the mass concentration Or possibly it's the giant metal impactor underneath. I'm not But the paper put out both hypotheses. I think what I think one is more logical than the other, but I'm not I'm not gonna discount the All right, well, let's go for one more and we apologize to everyone who have Some really great questions. We are just running out of time to Get to them all So adrian asked what has surprised you and maybe scientists in general researchers in general What has surprised you most about the moon? Uh, so about a decade ago So for 40 years We had these lunar samples in our collections and we were studying them and we thought they were bone drive, right? We talked about how you know It was big violent collision and all the volatiles all the water disappeared and the samples that we brought back from the moon were completely dry Moon doesn't have any water in it. And then about 10 years ago um, a scientist at at brown university actually Um, found water in the samples Um, and he was uh, he was an earth scientist He came at this from from a different perspective You know, all of the planetary geologists were like, why are you bothering to look at this? We all know we all know that the moon is dry. Why would you even bother to look? But he's coming at it from a different perspective Uh, and he actually had Again the capability the resolution to to look inside some of these samples that a finer scale than others had And he actually found out that that he looked closely enough. There actually is water in some of these lunar samples Native water water that that you know erupted in these volcanoes When when they when the volcanoes originally erupted And it's sort of revolutionized or thinking about the moon Which is really incredible. And it's again a great statement for why samples are important But also a great statement for why it's always good to hang a question mark on things that you have long taken for granted Yeah All right What would it be exciting to uh go back and to discover more things that we have no idea about that's uh That's kind of the nature of those small ones That's the one thing I can guarantee is that we will find surprises and and things that we weren't thinking about. Yes all right, well Lots of interesting days ahead and so And that's all for tonight You'll be able to find this webinar along with many others on the night sky network website in the outreach resources section Each webinars page also features additional resources and activities We will post tonight's presentation on the night sky network youtube channel within the next few days Also, check out the resources and activities from the new lunar toolkit including a set of slides about human exploration Thank you everybody