 Hello, everyone, and welcome to the April NASA Nights Network member webinar. We're hosting tonight's webinar from the offices of the Astronomical Society of the Pacific in San Francisco, California. We're very excited to finally get him audible and visible, present this webinar with our guest speaker, Brian Day, from NASA Ames Research Center. And we also want to welcome everyone who is joining us on the live stream. We're very happy to have you with us. These webinars are monthly events for members of the NASA Nights Sky Network. But we look forward to live streaming these into the future for more information about the NASA Nights Sky Network and the Astronomical Society of the Pacific. Please check the links in the chat. And I think that Dave Prosper will put some things in there. And so before we get to Brian Day, Dave Prosper had, I think, one announcement. So Dave, unmute. That helps. OK, I've got several quick announcements here. A few of you have asked if you did the work to get the handouts sent your way around March. They may be wondering, where are the handouts? Handouts are in our office, and we are waiting so we can get back to our office to ship them your way. It's looking like it might be around early to mid-May, hopefully. So we will hopefully get your awesome handouts your way soon. This also includes new tool kits and stuff like that. So yeah, everything is pending, as with everything else right now. We also have, I just want to let you all know, too, if you want to add some events to the calendars, if you're doing a hosting an online event or a virtual event like a virtual star party, a presentation, add them to the calendar. Just go right ahead and add it to the Nights Sky Network calendar, that'd be awesome. And if you want to just do it locally, select your own club's usual location, or you can uncheck the option and have selected location as a no location online or regional event. And it will also show up just to everyone on the Nights Sky Network calendar, if that's something you're comfortable with. So yeah, you can still add events to the calendar if they're virtual or not. What's the other thing? Oh, and we will be hosting an online webinar about basically kind of doing some online outreach in webinars as well. And that's going to come out, I believe, was it May 12th, Brian? I think so. OK. Link will be in the chat. And it will also be way more informational be in our newsletter, which will be out in about a week. So you have plenty of time once that newsletter comes out to get prepared for that. And that's all I've got. So let's get started on checking out the moon. All right, thanks, Dave. So for those of you who are on Zoom, you can find the chat window. Please feel free to greet each other in the chat window. When you're in there, please make sure you go down. There's a little pull down menu usually down at the bottom on my computer anyway. It's blue, apparently. It's other colors on other computers. If you click on that, select the one that says All Panelists and Attendees. It defaults to just panelists. And the only people that can see your comments are me, Dave, Vivian, and Brian. So if you want to greet some of your friends, make sure that you select All Panelists and Attendees. There's also a Q&A window. Any questions that you have for Brian this evening, please put your questions into the Q&A. If they end up in the chat, we're going to lose them. And there's a few people that sent questions earlier. The questions that we asked for in that are more logistical questions having to do with the webinar itself. And so if you happen to have sent a content question in earlier, hopefully you can find that and add it to the Q&A window so that we can ask Brian at some point during the webinar. And I think that that got us. So we're very happy to welcome Brian Day to our webinar, who's going to share with us a little bit about the geography of the moon, lunar landings past and future, and a really cool tool that you can use to share the moon with visitors to your events. Brian Day currently serves as the lead for the Lunar and Planetary Mapping and Modeling of NASA's Solar System Exploration Research Virtual Institute. Or serving. Serving. He oversees the development of the solar system treks, one of which you're going to see in a little bit. It's a suite of really great online tools, facilitating data visualization and analysis. Brian and I have been working together off and on for since right around 2004 there are belts, and where he used to develop a whole lot of online resources and basically game type resources for schools and other educators. And so it's been an absolute delight to work with Brian for such a long time. So without further ado, please welcome Brian Day. All right, so with any luck, you are now seeing my title slide. Is that correct? Lunar landings past and future. OK, so we are at the 50th anniversary of the Apollo missions. We already had the 50th of 11 and 12 last year. We've got we just had the 50th of 13. And so it seems like a good time to look back at where we have been on the moon and why we went to those particular places and then look ahead to where we are planning to go in the future. As we look at Apollo and the landing sites there, we see that we went to a number of diverse locations for a number of diverse regions or reasons. So we can see we started out in Bari areas and then progressed to more and more challenging areas and into the lunar highlands. And one thing you will notice, though, is that all of the sites that we landed on are on the nearest site of the moon and they tend to be low latitude sites. So keep that limitation in mind, even though there was some diversity, there were also some significant limitations. Our first Apollo mission to land on the surface of the moon was Apollo 11 with Neil Armstrong, Buzz Aldrin and Michael Collins. And they went to the Sea of Tranquility, specifically along the southwest shore of the Sea of Tranquility. As we zoom in using the moon track tool, you can see that the lunar highlands are very rough and rugged compared to the smooth texture of the lowland Mare Plains. And this is exactly why Mare Tranquilitatus was chosen as a site, not because it is particularly scientifically interesting because it is flat and safe. This was a technology demonstration mission primarily and they wanted to make the landing safely. Zooming down closer again, you can see the fairly smooth nature of the terrain. But the flight computer of the lunar module, as it was coming down, well, it brought them in a little bit long, a fair bit long as a matter of fact. And so the flight computer actually ended up bringing them down toward this crater, West Crater with boulders in it and surrounding it. These boulders are about the size of cars. And Neil Armstrong looked out the window of the landing module and he saw what they were descending toward and realized very quickly that they could not land there. And so he took manual control and continued to fly. I'm hoping you can see my cursor here. Continue to fly onto the West and with only seconds remaining, landed here just to the West of what has been called Little West Crater. You can actually still to this day see the descent stage of the lunar module. Looking a little more closely, this is a view from the Lunar Reconnaissance Orbiter. You can see the descent stage here. You can see some of the equipment left out including a Lunar Laser Ranging Retro Reflector. And if you look very closely, you may see some dark lines across the surface. And these are actually the footprints of the astronauts. This one path going here to the edge of Little West Crater, these are actually the footprints of Neil Armstrong. Only he walked actually out to the edge of that crater. Apollo 12 got a little more ambitious. This is with Pete Conrad, Alan Bean and Charles Gordon toward the end of 1969. And they went to the region of Oceanus Procellarum. Again, a nice flat area, but one of the key things to note was this crater here, the crater Copernicus. And their landing site was to the south of Copernicus. One of the goals of this mission was to actually measure material, sample material that had been excavated from Copernicus so that we could get a good handle on the actual age of Copernicus. Copernicus is one of the key mile posts in our estimation of lunar chronology. Now Copernicus itself was too rough a place to land, but it sent ejecta streaming out across the surface. And if you land in one of these flat Mare areas here in Oceanus Procellarum that has material from Copernicus draped over it, it was reason that we could safely sample and determine the age of Copernicus. So here's the landing site. And you can see again, the lunar module. Now with Apollo 11, they deliberately tried to avoid craters. This time, they deliberately tried to target craters. And the astronauts actually walked around and sampled these craters. The craters were used as natural excavations to retrieve material from various layers of the lunar regolith. As we zoom in, we can also see the footprints of the astronauts as they were going along here. And here's the lunar descent stage, but we also see an area here that garnered their attention quite a bit. And this is actually the Surveyor III spacecraft that had landed on the moon over two years previously. And so they actually demonstrated that they could now pinpoint a landing, landing right next to Surveyor, and they were able to go and actually retrieve equipment off of Surveyor and bring it back so that we could see how electronic equipment fared under long exposure to the extreme environment of the moon. Apollo 14 was led by America's first astronaut, Alan Shepard. He went to the surface of the moon with Edgar Mitchell, with Stuart Ruzza remaining in orbit. And this time, the target was the promontal formation. And what we're looking for here, something similar to what we did in Apollo 12, here this is the Mare Imbrium, the Imbrium Impact Basin right here. And again, this is one of the major signposts we have in lunar chronology. We wanted to figure out how old this structure was. Now landing in Mare Imbrium wouldn't help because at some time after it was formed, it was flooded by this basaltic lava. So we would sample the age of the lava rather than the age of the impact basin. So instead, the idea was to go south to where a bunch of the ejecta from the impact was still lying on the surface. And this ejecta took the form of the promontal formation, this rolling hummocky terrain of material that had been blasted out of that large impact basin. So here is the actual landing site. You can see the lunar module down here in the lower left. And in the upper right, we have cone crater. And cone crater was gonna be one of their big objectives because again, it was going to excavate multiple layers of material. But from their landing spot, they were not able to see cone crater because it's actually up on a ridge above them. So as they set out, they were unable to see the crater and they ended up going a little too far south. They got up to the top of the ridge, were unable to see the crater, wandered around for a bit, finally made the assumption that they were too far south, continued north for a bit, but their oxygen was running low so they had to turn back without ever standing on the edge of the crater. Fortunately, they got close enough that even though they were denied that spectacular view down into the crater, they were able to collect material that had been excavated from the crater. One of the samples they excavated or that they retrieved was this, a rock about the size and shape of a football that got nicknamed Big Bertha. And recently, Big Bertha has been in the news because last year it was studied in some detail, actually a little over a year ago. And this is a lunar breccia, different types of rock that have been fused together by the heat of a meteorite impact. But one of those clasts within Big Bertha, one of those rocks in Big Bertha really stood out for being very, very different. Different than any moon rock we had ever seen. And as they analyzed it carefully, it started telling them a rather amazing story. It told them a story how it was not actually a moon rock at all, but apparently it is a rock from Earth. And it was a rock from Earth that formed several miles down beneath the surface between four and 4.1 billion years ago. Back then, the solar system was a very violent place with lots of impacts happening. And a large impact happened, the asteroid struck the Earth, excavated a lot of material, including this rock, and blasted it into space. It landed on the surface of the moon, but did not get to rest there very long. Just 3.9 billion years ago, another asteroid slammed into the moon forming the embryom impact basin. And from the standpoint of our rock, it saw this giant tsunami of hot molten material come roaring over the Northern horizon and bury it and fuse it to the local moon rock. And there it should have remained buried for the rest of time, except for 26 million years ago, a smaller asteroid came, slammed into the ground, formed cone crater, excavated the rock again, and left it lying on the surface for Alan Shepard to come along, pick up, put in his bag, and bring back to the Earth. As a result, we now apparently have the oldest Earth rock we have ever seen, and it was kept and preserved for us on the moon. A neat story. Apollo 15, commanded by David Scott, the journey to the surface of the moon with James Irwin and Alfred Warden remained in orbit in the command module. And this time, well, Murray Embryom was again this center of interest, and it was actually the destination, actually the edge of Murray Embryom. And as we look at the edge of Murray Embryom, we see that at least on the southeastern section, that border, that rim of Murray Embryom, is formed by the Apennine Mountains, a mountain range that is about as tall as the Alps here on Earth. As we look at the northern extent of the Apennine Mountains, we see this interesting embayment and a singuous rill, a feature that looks like a river valley, but no water ever flowed here. This is carved by flowing lava, erupting from the elongated vents you see down at the lower left end of the rill. And then this flowing lava carved this singuous pattern, stretching for about 130 kilometers. Apollo 15 was notable for taking the first of the lunar rovers, greatly extending the range that they were able to explore. They of course explored Hadley Rill, this wonderful channel that had been carved by flowing lava, and they also drove up toward the lower slopes and onto the lower slopes of Mount Hadley Delta, you see there in the distance. The idea here was to be able to now actually collect some of that light highland rock that was believed to be far older than the lunar basalt. And so this would be their first chance to actually get some of this apparently much older rock, and they actually succeeded, retreating being a rock called the Genesis Rock that until that time was the oldest rock yet recovered. But another rock kind of stole the show. And this is a wonderful piece of the circulated basalt that they picked up on their way back from Mount Hadley Delta. Now on their way back, they were informed as they were driving back that they were informed by mission control that they were behind schedule and they were gonna have to skip their last remaining collection stops in order to get back to the lunar module in time and have plenty of oxygen to spare. Well, Dave Scott realized that there was plenty of margin built into this, so he wasn't really worried. And as they were driving along, all of a sudden he saw this rock off to his right. And he realized he really wanted this rock, but he also realized if he called mission control and asked for permission to stop, they tell him no to keep on going. So instead he called mission control and said, hey, I'm having a problem with my seatbelt here. At which point they told him, well, then stop. That's a safety issue, stop and fix it. So he stopped, unclipped, jumped out, ran, got the rock, put it back in his bag, jumped in, clipped in and said, okay, all good, drove back to the lunar module. And so that is why this rock is now known as seatbelt rock. Apollo 16 finally took us to the actual highlands themselves. We'd gotten good enough at precision target landings that we were reasonably certain we could risk landing in the far more rugged terrain of the lunar highlands. And so Apollo 16 did that with the idea that we wanted to better understand the highlands. We knew that there were very rugged areas, but then there are these smooth areas in between. And it was thought perhaps this was some kind of different type of volcanism, some sort of highland volcanic deposit. And we wanted to sample that. But landing there, and you see this wonderful, bright and orthocytic terrain. As they started exploring, they realized that in fact, this was not at all volcanic, but it was crustal breccia, broken up rock. It was a regolith of, again, just the highland terrain that had been battered. There was no sign of volcanism here at all. And they were able to sample number of strata by looking at material that had been excavated from North Ray crater, which they drove right up to the Etcho. Apollo 17 was the last of the missions to go to the surface of the moon and the Apollo program. And with Eugene Cernan as commander and taking along to the surface of the moon, Harrison Schmidt, the first and so far only scientist to actually walk on the surface of the moon, Dr. Schmidt has a doctorate in geology and it turned out to be very useful. In this case, the destination was on the edge of the Sea of Serenity. And this is the Taurus Litro Valley. And we can see it right here sticking out as this embayment going into the lunar highlands out of the Sea of Serenity here. It's really a pretty remarkable location. This valley is deeper than the Grand Canyon here on Earth. It has these marvelous mountains to the south here. This is South Messief. Here you have North Messief. And well, I'm gonna back up a little bit as we look here at the landing site. One of the really interesting ideas that went along. Here you can see where they landed. Way down here you can see in the lower left, you can see Tycho Crater. And if you've looked at Tycho Crater through your binoculars or telescopes, you'll see the bright rays streaking across much of the surface of the moon. And it had been noticed earlier that there was ejecta within this area that was aligned with Tycho Crater. So apparently material from Tycho Crater had been blasted all the way up here. And as people looked at South Messief Mountain here, they saw this white area extending out onto the floor of the valley. And this appeared to be a landslide coming down from the face of South Messief. And so what people reasoned was that ejecta from Tycho Crater slammed into South Messief and caused this landslide to come down the face of the mountain here. And so it was reasoned that for a number of reasons we'd want to go to this valley. I mean, you've got again, a mixture of highland terrain, barry terrain. You have a wonderful, beautiful fault scarf here, the Lee Lincoln Fault. And you have this landslide. And if you collect material from the landslide and date it, then you could get a good handle on how old Tycho Crater was. So lots of good reasons to take a geologist to this fascinating area. But even more so when you look at this puted landslide area, people had noticed in earlier Apollo missions looking down, they saw these dark haloed craters. And we'd seen dark haloed craters on the moon before as volcanic craters that had sent out clouds of pyroclastic ash, volcanic ash. And seeing a potential volcanic crater with an ash deposit that was overlying this landslide that apparently came from a very, very young crater, Tycho is one of the younger craters on the moon, then that led people to believe that this could be very young, fresh volcanism. My God, we've got to send a geologist there. So imagine if you will, descending into this incredible canyon, we've gotten pretty good at bullseye landings now, and landing here toward the foot of North Massif. So here's the actual site of the lunar module. You can see the tracks extending out in either direction. And from this vantage point looking forward at North Massif, we can see something really amazing. We see boulder tracks. We see tracks of boulders that have rolled down from the heights here. So this could be that, again, that wonderful highland ancient or North acidic material. Now we're not gonna be able to drive all the way up the mountain to get to these patches, but they're rolling down to us. And the beautiful thing is, is if you can drive up to one of these boulders, you can by tracing its path back, you can see exactly where it came from. So you know its context, but you can get to it easily. And so this particular boulder right here, they actually drove up to and sampled. They then, of course, drove out across the Lee Lincoln Fault and onto the landslide and up to the base of South Massif mountain. And they then drove here to Shorty Crater, that crater with the dark deposit around it. People had believed to be a fresh volcanic crater. And when they got there, Jack Schmidt realized right away that this was not a volcanic crater, it was in fact, just an impact crater. An impact crater that had excavated the dark Mari material beneath the landslide and overlaid it on top of that lighter landslide material. So that at first seemed like a great disappointment. Until they started ticking around in that material that had been excavated, and they saw beneath their feet this wonderful orange soil. And this orange soil is in fact, beads of volcanic glass that had been erupted long ago in an ancient fire fountain and had then been excavated by this impact that formed Shorty Crater. Looking out from South Massif, this is a view they never had, but with our Moontrek portal, we can place ourselves in a location that they would have loved to have observed from and went from the top of the mountain, we can see the landslide going out. But we see something interesting. There appear to be actually two separate units here. A lighter, younger unit and a older, more faded unit. There seem to be two different landslides separated by a large amount of time. And that right there is inconsistent with this having come from Tycho. Tycho would have formed one event in time. And so the question is, what would have caused these landslides if it wasn't the impact of Tycho? And the answer goes back to this Lee Lincoln Fault here. And this is an example of what we would call a lobate scarf. And many of these types of scarps can be found across the surface of the moon. They are formed by the fact that the moon over time is shrinking as it cools. And as it shrinks, that rigid crust buckles and forms these faults. And this is going on today with seismometers left behind on the surface of the moon by the Apollo astronauts. We were able to see earthquake activity continuing along these faults, including this area here of the Lee Lincoln Fault. So we got a pretty good picture of the moon from Apollo. But after Apollo, we had a series of robotic missions that radically changed our view of the moon. Apollo gave us this view of the moon as being an utterly dry arid location. But in the 1990s, two probes, Clementine and Lunar Prospector, gave us hints that, in fact, there might be water ice at the lunar poles. The evidence was equivocal, though. And it was interpreted in different ways. But how could there be water ice at the moon? Well, at the lunar poles, the sunlight comes in at a very, very, very low angle, giving the surface. And as a result, the rims of craters near the poles can be permanently shadowed. There are craters near the poles of the moon, whose floors have not seen sunlight in well over a billion years. And because of that, they've remained very, very dark and very, very cold for a long time. And so is the reason that this could be great places for water ice to accumulate. So to test this hypothesis out, the Lunar Reconnaissance Orbiter and the Lunar Crater Observation and Sensing Satellite L-Cross were both launched to the moon. In 2009, they launched together aboard an Atlas V rocket. And I'll talk first about the L-Cross mission. It was designed to actually excavate one of those permanently shadowed craters near the south pole of the moon. The shepherding spacecraft held all the instrumentation and it carried with it the upper stage of the Atlas V rocket, the Centaur upper stage, something about the size of a school bus weighing two metric tons. And the idea was as we were approaching the south pole of the moon to let go of that upper stage, send it flying down into the shadows of that crater, slamming to the ground at 5,600 miles an hour, blasting hundreds of tons of materials up out of the shadows into the sunlight, high into the sky of the moon. And our little spacecraft would dive down through that debris, sense it, sniff it, analyze it and see if in fact there was any water ice there. And in fact, there was. The Lunar Reconnaissance Orbiter, or LRO, remained in orbit around the moon and mapped the moon in great detail and was able to sample through remote sensing and using neutron spectrometry where looking for deposits of hydrogen that Elkross told us now were in many cases in the form of water ice. And one of the things that LRO was also able to do is tell us that these permanently shadowed creators are indeed really cold. They are the coldest places we've yet found in the solar system, even colder than the surface of Pluto. And we have found good indication that there are hundreds of millions of tons of water ice at the poles of the moon. That could be an incredibly valuable resource for us in the future. And there could even be a water cycle on the moon thanks to the moon's tenuous atmosphere and our understanding of the lunar atmosphere came about through the LADI mission, the Lunar Atmosphere and Dust Environment Explorer that was developed at NASA Ames, launched in 2013, a very successful mission. So with a new understanding of the moon, the moon having an active atmosphere, having abundant water ice and actually being geologically active, in 2018 that's a plan, a workshop to look at where do we want to go as we return to the moon in future missions. Report from that meeting is available to you. You can download it from the URL that you see here. But what we'll do is we'll take a look, a brief look at some of these really exciting sites. We'll start out with the lunar swirls that are best characterized by the object, Reiner Gamma. So as you look at the face of the moon that we see here from Earth, Reiner Gamma is off toward the western limb. It is best seen during the full moon phase with flat lighting. It's an albedo feature and you get this tadpole shaped object here. Looking more closely at it, we see it has a very intricate pattern of swirls. And this actually corresponds to an area of a localized magnetic field on the moon. The moon no longer has a global magnetic field like the Earth does, but it does have areas with relic localized magnetic fields. And so what we think is happening here is that the localized magnetic field is diverting incoming particle radiation. And the particle radiation then flows along the field lines of this localized area and causes differential space weathering of the material on the ground here. Now, this is actually a very flat area. There's no relief here. And if you look at this under low lighting, the albedo features go away and you see this is flat. What we're seeing here is just the difference in reflectivity. And again, apparently related to this localized magnetic field. What caused that magnetic field? We don't know. That's one of the reasons why we wanna go there. Nearby we have the Marius Hills. And so again, looking at the moon as we see it from here on Earth, the Marius Hills are essentially right next door to Reiner Gamma. As a matter of fact, here you can see Reiner or Gamma right here. Again, if you go to the end of the tail of the tadpole and here's the crater Marius, right here at the Marius Hills. This is one of the most spectacular collections of volcanic peaks and cones you will find anywhere on the moon. Except for it doesn't look very spectacular here. The only time you'll really see it through your telescopes to any advantage is when it is right on the terminator and you've got very, very low angles of sun coming in along the horizon there. And we can simulate that here by changing in moon track to a laser altimetry view. And we can see all these peaks and cones stand out very readily. Zooming in, we can see there are several hundred, or well over 100, close to 200, perhaps of these cones and peaks. And this erupted over a long period of time. And so this will help us understand the chemical and internal evolution of them. We can see a variety of flow features across here. Now the reason that these peaks are so hard to see is again, they are very low relief. Lunar basalt typically when it erupts has about the viscosity of olive oil at room temperature. It is a very low silica content and therefore it has a very low viscosity. And it's pretty hard to build mountains out of this very low viscosity material. Even so, the Marius Hills are actually steeper than your typical lunar volcano. So you can see evidence of flowing lava across the surface here amongst these cones and peaks. Continuing north from there, we have the Aristarchus Plateau and the P60 basalticium. So here we have the Marius Hills in the foreground where we just were, but looking north, we have this wonderful area showing up on the horizon. We'll zoom in a little closer to it. We'll see that here it is in our typical Earth view. Zooming in, we see the craters, Aristarchus and Herodotus and this wonderful plateau around them. The plateau has dark stains of lunar ash deposits and it has this magnificent feature here, Schroder's Valley, the largest sinuous rail on the surface of the moon. 10 kilometers across at its widest. It is magnificent close, 180 kilometers long. As we look to the south and west of the Aristarchus Plateau, we have this very smooth, bland, volcanic basaltic plane. This is the P60 unit and this apparently represents the youngest Maori basaltic flow that we find anywhere on the moon. About only about a billion years we estimate from the rate of impact craters, but we'd love to actually retrieve some sample material and precisely date it. Because again, this appears to be the youngest of the moon's basaltic flows. Looking for the north end of the Aristarchus Plateau, again, you can see plenty of evidence of flows and other sinuous rills besides Schroder's Valley. There's a lot here to explore. But then as we look north across the plains of Oceanus Propholarum, on the far limb of the moon, we see something interesting catching our eye. And those would be the Gurthos and Domes. So looking again at our earth view of the moon, the Gurthos and Domes occur on the western edge of the embryum impact basin. They're located here at the bottom of this promitorium or beneath sinus iridium here. You can see these features right here. These also are lunar volcanoes, but we don't need laser altimetry or low light angles to see them. These are big steep mountains. They differ from your typical lunar volcano in that these are highly solistic in comparison to the other volcanoes. Sick, pasty lava, able to build up these large mountain edifices here, close to 2,000 meters. So significantly different than typical lunar volcanism. Why would the lava here be so much richer in silica? We don't know, but we'd like to find out. Another really intriguing volcanic area is the Aina de Caldera. And we'll zoom in here on it. We can see this small feature right here. Looking more closely, we see this, it is a basaltic volcanic material, but this caldera has a very strange morphology. You have these pillow-like features that are lightly cratered, but then you have this strange terrain between them that you will find no impact craters or virtually no impact craters in at all, which indicates that this is really young material. And based on crater counts, we're seeing that this would be less than 100 million years old. That's hard to reconcile with our understanding of the thermal model of the moon. We can't see how volcanism could have continued that late. So is our understanding of the lunar interior that wrong? Or is there perhaps something different about this material that causes crater counting here to misrepresent the age? We don't really know what's going on in Aina. And Aina is just one of a number of these, what we call irregular Mari patches across the surface of the moon. So again, this is an area that really calls. Rima bode is this very, what an example of a very dark patch here. This is again, a pyroclastic deposit, a positive ash from fire fountains that erupted across rifts and some indications from orbit are that the ash here could be uniquely or especially enriched in water content. There is a possibility that perhaps this kind of ash could also be a resource for us. So we might not be limited to the very high latitude locations to retrieve water. Is this an ore grade deposit? Is this water that could be used? Is that water really there? We don't know, but it's certainly worth exploring. Across the surface of the seas, the basaltic seas, the Mari patches, we have a number of features like these, pits, that seem to be holes in the ground that open up into voids beneath. These appear to be skylights into subterranean lava tubes. And so, the area that we're going to be looking at and so, some people have even proposed that these could be good areas for us to establish habitats that would be protected from micrometeorite impacts, that would be protected from the harsh radiation and that would be protected from the extreme thermal swings going from day to night. Now, we're going to take just a quick time check I know that we lost a little bit of time at the beginning, we're at about 10 till and we're accumulating quite a few questions too. Okay, I'll speed up here. So, Compton Belkovich, just on the far side of the moon is actually an area where we have, again, solicic volcanism and high enrichment of thorium. Mari Moskovienza is one of the very rare examples of Mari terrain on the far side of the moon. It includes pyroclastic ash deposits and even some of those enigmatic swirls. The South Pole-Aitken basin is an actual, is the largest impact basin on the surface of the moon, 2,500 kilometers across, it's very ancient and it's been battered, but it may excavate all the way down into the lunar mantle. The Schrodinger basin on the edge of the South Pole-Aitken basin, seen here has wonderful rock outcrops, has permanently shadowed areas and has volcanic pits. The South Pole of the moon, where we plan to go with Artemis, again, very thick shadows, but with the moon track portal, we can pierce those shadows by switching to laser altimetry. We can generate slope maps. We can overlay the permanently shadowed areas. We can look at average temperatures, maximum temperatures. This is Lamp Albedo, actually perhaps showing us frost deposits. Hydrogen abundance and even, this is looking at ice stability at depth, how deep would you have to dig in order to get the ice? So this is the site, this is the area where we are planning to send astronauts. Right now we're targeting 2024 with the Artemis mission. So I think we'll call it quits from there, except for I will just actually encourage you to go to trek.nasa.gov where you can use the moon track portal that I've been generating these images with tonight. And you can do so much more and you can also use our portals for a number of other worlds. So with that, I'll bail out and let's take some questions. All right, well, thank you so much, Brian. This is fantastic. And Don did ask, and I'm glad that you brought that up right there, that where can you get these lunar images? And it looks like the other than the ones on the surface from the missions, you too can generate these images, whichever ones you want. Yes, and you're not limited to stills. You can actually take, normally if I was in a higher bandwidth, if I had a little bit of a higher bandwidth environment, like doing this out of the office rather than my home, I'd show you how you can actually interactively fly across the surface of the moon, down into the craters, up over the mountains. You can create your own virtual reality experiences. You can measure the heights of mountains, the depths of valleys. You can draw bounding boxes over terrain that you find interesting and generate 3D print fun. So there's a whole lot you can do with it. I know it's a really powerful program and we might have to have you back just to do something with the in and out summit. I think that people would be really interested in that. Very good. Well, we're going to ask some. All right, so Barry asked a question back when we had the orange soil. He said that it looked like there was a three legged device with a multicolored strip. Do you know what the strip was? Yeah, that's actually that multicolored strip is actually for color calibration and the photography there. So basically, as you know, this was all that was taken with a Huffleblad camera using, I forget just the way if it was a variant of ectochrome, I believe, that was used. But if you remember back to film, you could always get interesting casts and so in terms of color balance. So that was a set of known colors that we could use then to calibrate the photograph and so we could accurately reproduce that the true color of that orange soil. OK, so Coco was wondering when the water ice was ejected, presumably with the all-crossing factor, would it sublimate similar to what it does on Mars? So yes, over time it certainly would. So as that ice got out into the sunlight, then it would turn to water vapor. Now fortunately, as we came down, as all-cross shepherding spacecraft came down through that cloud of debris, we were able to see both water vapor as well as still water ice in material that had not yet sublimated. Gregory asked, what's the significance of creep on the moon and has creep rock ever been found on the earth? So the creep rock is enriched in a number of elements. The thing that really catches people's attention with the creep rock is that the RE stands for rare earth and this is apparently enriched in rare earth elements. And as you know, here on earth, the rare earth elements are in very high demand. These are used for creating the strong magnets that are used well in your phone and all kinds of electronics. And this could be potentially a valuable source. Now, we do have rare earth deposits here on earth. Is it yet economically feasible to go mine them on the moon? That's probably to be determined, but it is fascinating that we do see these deposits there on the moon. John asked a question and sites such as the Marius Hills were once considered for Apollo landings, given all the survey data collected since then, are any of the old landing site candidates still valid? And I know that that certainly one of the plans was one of the finalists for going Mars 2020 was where Spirit had been. Right. So the question is, is there a desire to go back to some of the previous landing sites? Is that what you meant? That's how I read it. Not right now. No. At this point, we're looking at really expanding to two other areas. We want to see some terrain that is fairly diverse from what we have already experienced. The thing that makes the pole so especially attractive is, again, the potential for in situ resource utilization, a resource that could make the pole of the moon a place that we could live sustainably. If there's an abundance of water ice that is accessible, and we've yet to determine that. We know there's ice there. How accessible is it? Well, that's yet to be determined. But if it is, in fact, accessible and usable, then that becomes not only water for us to drink, but that can be used to make hydrogen for fuel, oxygen for breathing. It can be used mixing with the regolith to make essentially a lunar concrete that we could use as a building material. There are lots of really good reasons to do that. Plus, at the poles, you don't have necessarily that nasty problem of the two-week-long lunar night. That's a real logistical issue. Surviving the lunar night is a challenge. But at the poles of the moon, especially the south pole, which is relatively rugged compared to the north, you have peaks that stick up into almost constant sunlight. So imagine having areas with near constant sunlight right next to areas that are in permanent shadow. So you have the resources of water plus the resources of solar energy. Wow, that makes especially the south pole look pretty irresistible to us right now. So David Evans asked, how did they determine that big bertha originally came from Earth, or at least the class in it? And that was a pretty complicated history. It's been rather eventful. And so how did they determine those various events? Very good. So basically, the mineralogy of the class within big bertha is distinctly non-lunar. But it does in terms of some of the mineralogical components in quartz and the zircons, and also the oxidizing environment that it formed in. Again, distinctly non-lunar. And so you can come up with ways to maybe make that happen at a great depth in that early lunar environment. But there's no evidence that this could have been excavated from that great depth. Whereas it would be a relatively shallow and accessible depth here on Earth, and it represents mineralogy and an oxidation state that would be entirely consistent with terrestrial origin. Can, and thinking about the evidence within the rocks there, so Mike asked the question, is the captioned fission or accretion theory still held as the top theories for how the moon was formed? Or is there a new leading theory? Did any of the lunar samples give us a better understanding of how the moon came to be? Yeah, we still, our best candidate is still an impact and then accretion of ejected material. That still is by far the best model that we have for the formation of the moon. OK, so we have a couple of questions, and we're going to apologize right up front that we're not going to get to all of these. At some point, Brian's going to need to go home. But kind of combining a couple here, so we had one person inquire about whether or not there's any plans to explore on the far side. And then we had another one says, what would the far side offer that the near side doesn't, if we were to go to the far side? OK, so are there plans to explore the far side? Yes, as a matter of fact, it is being explored right now. The Chinese actually landed in the South Pole-Aitken basin recently with one of their Chang'e probes. And so they actually had deployed a rover into the South Pole-Aitken basin. Now, again, what does that have to offer? We would like to understand the geophysics, the structure of the moon very more intimately. And one of the things that here on Earth you do when you want to understand the interior structure in geophysics is you drill deep holes. We'd love to do that on the moon, too. But there are logistical challenges for doing that in the environment of the moon. But nature is already taking care of that for us in making this 13-kilometer deep hole on the far side of the moon in the South Pole-Aitken basin. So we can get down to certainly lower crust and perhaps into mantle material by exploring the South Pole-Aitken basin. Also, from an astronomy standpoint, since we're dealing with a lot of astronomers here, this is a really good point to make, is that the far side of the moon is the one place in the solar system that is always protected from the Earth by miles and miles and miles and miles and miles abroad. And the Earth has become annoyingly radio-loud. And some of the really, really sensitive radio astronomy programs that you would love to be able to do will be overwhelmed by the noise from the Earth. But if we were to put a radio array on the far side of the moon, we would have that protection of all that rock. We'd be in the shadow, the radio shadow, formed by the moon. And with that, we could do studies of the dark ages of the universe when the first stars started turning on. And so there are active plans afoot. Jack Burns out of University of Colorado at Boulder has put together intricate plans to put together a wonderful radio telescope installation on the far side of the moon to do really profound astrophysics. All right. So we have another, I'm gonna do two more questions here. So Andy asked a question, and I'm gonna kind of expand on that. She was wondering what do you think about mining on the moon and maybe, just maybe turn that into a more general question about any potential for commercial development or what it would take to do that if it's feasible, if it's even something that should be done. So one of the resources right now that has most caught our interest on the moon is that water ice. If it is accessible, if it is usable, if it is as abundant as it appears to be, and we can actually get it, if it is ore grade in nature, then that becomes an incredibly valuable resource because that could end up being used as fuel to take us throughout the rest of the solar system. Getting out of the earth's gravity well and through that thick atmosphere is a real encumbrance, but the moon with its almost complete lack of an atmosphere and with its relatively shallow gravity well, this could become a great launching spot to go throughout the rest of the solar system. And we could have the fuel right there rather than having to bring it expensively from the surface of the earth. Is that feasible? I mean, a lot of companies are looking at this as a business model. But are we ready for that yet? And the answer is we don't know how usable, how accessible that ice resource is. We have to go through the absolutely critical stage of prospecting. That's what you do with resources here on earth and that's what we'll have to do on the moon. And so there is a mission being planned right now by NASA called Viper. And Viper will be a robotic rover that will go to the south pole of the moon and it will prospect the lunar ice resource. It will map it out, it will see how it's distributed, how accessible it is, how usable a resource is this? Is this something that really could be done on an economical basis? And so until we have that information, we are right now just speculating. And the last question, I know that you're very enthusiastic about the moon and you're always excited about, but what excites you the most? What's your favorite thing? Oh my God, favorite thing about the moon. Oh, there are so many. You're asking me to like to choose among children. I am fascinated by lunar volcanism. I back as, you know, I first started doing amateur astronomy of the moon and hunting that there was a wonderful book that came out on lunar domes and searching for lunar domes is a wonderful, challenging thing to do as an amateur astronomer. You have to get the lighting just right, but then there are those really abnormal volcanoes too. So that for me is, that's always been something I have found really fascinating is the lunar volcanic environment. And you certainly have pointed out a number of those that I think that NASA in general is seems to be really interested in going and visiting those too. So that's very good. Very good. All right, well, that's all for tonight. Thank you very much for Brian. I'm sorry that we had some technical difficulties at the beginning, but I think that we managed to make up for it just a little bit. And thank you everyone for tuning in. You'll be able to find this webinar along with many others on the Night Sky Network website in the Outreach Resources section. Each webinar's page also features additional resources and activities. We will post tonight's presentation on the Night Sky Network YouTube channel. Probably, well, I think that YouTube since we're streaming it, it automatically puts it up there, but we will put an edited version of it by the end of the day tomorrow. We'll edit out some of the glitches. And you can also join us for our next webinar on May 27th. I believe that's also a Tuesday when we feature some of the science NASA is doing from the International Space Station. And so keep looking up and we will see you next month. Good night, everyone.