 Okay, we're back. We're live one o'clock rock. I'm Jay Fidel here on think-tek and more specifically on research in Manoa and our ongoing inquiry into the All the things in the universe we don't limit our inquiry We have with us Jeff Taylor Researcher Hawaii Institute of Geophysics and Planetology in so as the School of Ocean and Earth Science and Technology At the University of Hawaii Manoa and they have Linda Martel academic Academic support in Hawaii Institute of Geophysics and Planetology. Thank you again for being here you guys Nice to be here. It's good to be here. Mainstays to teach us and make us curious about the universe and and today's show is the origin of the earth and The moon Comma inseparable wow, that's provocative. We need to know about that who wants to start We're gonna talk about some of the older theories that people had about the origin of the moon because We've seen that moon up in the sky ever, you know ever since mankind's been looking up there So how did it get there? And then we're gonna talk about Breakthrough in the 1980s that kind of changed a lot of erasically changed the way we look interesting Yeah, and how come they're not advised of this earlier? Yeah, yeah, you didn't ask Okay, today people are still thinking about these theories and coming up with ways to test them So we'll get into a little bit of that. Okay, but this whole idea of inseparable, you know It's been since the space age These pictures of the earth and moon in Apollo it was beautiful pictures of the moon in the foreground and earth in the background and Then satellites going out of the planet started taking pictures of the earth and moon from a distance Yeah, and one of the coolest recent one taken it was taken about actually 18 months ago I think the satellite called it's a climate deep space climate Explorer and They have a camera on it that has an acronym, but the acronym spells out epic And so it's settle it's a million miles from earth The satellite and it's in a place where the all the gravity balances that we call them Lagrange points and they So that it's easy to aim it and keep it aimed at the earth and just looks at the earth and takes a picture every couple of hours This is further than the moon further than the moon. Yeah, yeah far as the moon a quarter of a million miles And this is the million miles those four times for their shot then from them. Yes, and we have you can see a film They made of looking at the earth a million miles and the moon Goes in front of it and it gets a picture of it But what you get a picture of is the far side of the moon that you don't see from the earth It's it's always locked in gravitation laser always the same side Looking at the can we see that now? I think we could The first slide which is here. Here's the moon creeping in. Oh, wow Look at that and that's the all the far side of the moon dark. It's not it's dark But not now otherwise we couldn't see it. Yeah, the dark side of the moon was a great album though Let's do it one more time One more time get some more detail on it And so the moon doesn't always intersect this view of the earth from the satellite and so But it's it's neat and the whole idea of the mission is to look at the earth Just look at it and to try to understand it has some other sensors on board But the camera seems to be so cool. So this is the far side looks quite different You know knows much of the dark areas that we have on the near side Right, we would never see that So but but here they are close together it must have their formation Must have something to do with each other. Yes, they must rather than just some accidental thing you would think yes and certainly however the moon formed we think we know sort of and But however formed it must be informative about the very beginnings of the earth to yes That's what's so neat about that. So I would call them inseparable. Yes. I love this discussion In contrast to like Jay and me as you were to test to insufferable So It's not just logic that makes us believe that the moon and the earth, you know Had a relationship or have a relationship. It's got to be science too, right? It's not just logic What is the science? Well, the science refers this go through the ideas that we had Until 1984 literally And so we have we have three pictures here that we're going to describe Okay, three major theories. They were all in such disfavor That Harold Yuri who is kind of the founder of space chemistry He said that well these theories are all wrong. So the moon mustn't exist So anyway, if you could put up them the second slide Looks like a bowling. I was mine. It's a bowling pin. It's a bowling pin The idea was that the earth was spinning so fast early on That a blob of it Spun off the form of the moon. It's perfectly logical for the something like that to happen But would there be a time when it was all hot like that and molten like that? Yeah It was in order for this to work It has to have been that way another question is Were there data that would say that and the moon and earth both form very early and if they form really hot Then that could actually happen. You don't sound convinced No, no one was convinced about that because it was you couldn't figure out two things One was how to get it spinning fast enough for this blob to come flying on and the second thing was How to If you get it spinning fast enough, it's too much spin and you have to get rid of a while We call it angular momentum. Okay, really spinning of the earth spinning of the moon and spinning of them In its orbit, it's too much out of the moon would be whipping around the earth and you have to get rid of it Well, it turns out recently someone has figured that out But nevertheless the other problem is it's testable in principle if the moon and earth have the same chemical composition Okay, so wasn't that that idea that the the moon spins off the earth wasn't Darwin somehow Son of grandson of Charles Darwin had this idea that is spun off knowing spun off spun off in In the Pacific which is why there's not no continents here. That's what the idea was came from the earth came from the earth right specifically from the Pacific that can't Can't possibly because there's sepals too young and the moon's been there for too long, but that's but the idea was was Very popular, but everyone recognized even when in discarding the theory that it had to be early on When the moon's what as you pointed out when the earth is just molten. Yeah, well, there's another idea Okay, that's our third picture a third picture. Well, this is interesting So this is an idea that the earth is in the middle there, it's still hot and then the moon Created came together at the same time. They sort of see that ring of rocky stuff It coalesced into a moon and so they they sort of grew up together side-by-side, but independently But that doesn't really work as an idea because the earth has a very large Metallic core and the moon doesn't so if they they grew up sort of at the same time from the same building blocks Why didn't they sort of come out the same? Yeah, the other thing is is there a physical principle about the that that belt of space junk out there Can we see that picture again for a minute? You know that belt I mean is there a principle in physics that would say well if this stuff is spinning around the earth as it was then That that it could come together. Yeah, there is a principle that works out and in fact our new ideas have some elements of that in it and But if they do get pulled apart as well Saturn's rings there's not one there's not a single big moon out there. It's a whole bunch of rings and So the real problem was this iron problem that people tried to work around But no even they were not that enthusiastic about how you have so much more metallic iron in the earth then in The ring of debris and how the ring gets started Something of a mystery, you know, it wasn't clear. Why not just form one planet? Why is this ring? Another mechanism you also talked about the angular momentum So if these two things just form together then why do we have this high? Angular momentum right now between the system with the way that the moon is orbiting us So it doesn't quite it doesn't quite work So then there was another idea. Okay. Wow. This is the next slide This one is called capture this this is an idea that the moon fully formed somewhere else and happened to be in the Neighborhood of Earth and Earth's gravity pulled it in and just got it into orbit around us and people are thinking that the Probability of this is very low and why didn't this moon just hit the earth like everything of the other debris? Yeah, so this is and he was going very fast And it went beyond Earth's and then the gravitational force of Earth came back pulled it back And then it wound up in you know in a trajectory of some kind if it comes too fast It just keeps going or maybe skip. I'm keeping yeah, and there were really Exactly Yeah, that's right me though is that you don't have a lot of Debris floating around the size of the moon. That's a pretty big piece of space junk From nowhere. Yeah, it doesn't happen. Well, it doesn't happen on the other hand the earth formed by Coming together a big piece of the space junk a moon size to even up to okay bigger and bigger So this you saw it's the rarity of the event of capturing that's so hard without Smashing into the earth. Yeah, that is a more effective way of capturing things Yeah, so none of these ideas are working and where are we now in the timeline? What was this last that theory advanced the last that all of these were around for quite a while through the 60s and of course Darwin's idea of the spinoff Was in the 1800s or something like that I think but they these were the things Discussed up into there were new ideas in the mid 70s, but the this was discussed right up into the 80s and in 1983 I was on this committee that Gave out lunar samples that's two people who requested them, you know and made recommendations to NASA on The nature of them, but we also ran a series of conferences about the moon Just to to continue the interest in it and make it multidisciplinary So we'd have good use of the samples and one day we were sitting around And one of the guys said the guy named good Gunter Lugmeyer who is retired now from UC San Diego He said it's that one on the origin of the moon Everyone said well, that's a good idea. That would seem to be about time We should just focus on that and he said and then we said well, where should we have it? And then we could tie it to another conference that makes it economical for people to come And so he said where's this next is an astronomy conference called the DPS meeting to the vision of planetary sciences Where's the next meeting? I mean someone said Hawaii I was not living in Hawaii then so we all said who this is the obviously the choice and And and so it was held in Hawaii in Kona in 1984 and And at that conference a whole new idea emerged you were there. Yeah I in fact, I was one of the three organizers Linda wasn't born yet I Anyway, it's There was two papers published One was abstract only in 1975 and they just language for the idea was the moon formed by a big impact a Real but with our like a Mars-sized object. Yeah, in fact if you can show Number six No, no wait show number five. We'll go back to forget six. There we go. I just want to show this this is that was held the King Kamehameha Hotel in downtown Kona and This is the hallway. It was held in I took this picture in April of this year when I went my daughter was This is an American youth soccer organization meeting It was at the same hotel So I took a picture of the hallway and the meeting rooms are off to the left and I just thought I would show that It's kind of an interesting concept, but the place is still going strongly the great place for meetings It's called B-roll It's you know, it's kind of leading up to the big story Yeah, and the story would be when you had the conference and you were there as one of what three Presenters yep. Well, I'm organizing and found this this Found this theory that sounds pretty good, but but we can't talk about it right now Because now We have to take a break When we come back sure, yeah Be better be better after we'll be better watch this Thank you for watching think tech I'm Grace Chang the new host for global connections You can find me here live every Thursday at 1 p.m We'll be talking to people around the islands or visiting the islands who are connected in various aspects of global affairs So please tune in and aloha and thanks for watching I'm Ethan Ellen host of likable science here on think tech Hawaii every Friday afternoon at 2 p.m You'll have a chance to come and listen and learn from scientists around the world Scientists who talk about their work in meaningful easy to understand ways And you'll come to appreciate science as a wonderful way of thinking way of knowing about the world You'll learn interesting facts interesting ideas. You'll be stimulated to think more Please come join us every Friday afternoon at 2 p.m. Here on think tech Hawaii for a likable science with me your host Ethan Allen Bingo, we're back think tech on research in Manoa with Jeff Taylor and Linda Martel talking about the origin of Earth and the moon comma in separable Okay, we got a new theory on the whole thing that's gonna happen now watch this pops out in 1984 And this painting is a very famous painting number six this painting is By William K. Hartman who is the inventor of the whole big impact theory and one of the Co-organizers of this conference that third one was a guy named Roger Phillips who recently retired from Southwest Research Institute, so Hartman is a painter as well as a scientist Which is a great gift to be able to illustrate your idea really great So he and a guy named on Davis came up with this idea that there's a lot of things kind of tell you like You were talking about before about these things flying around They like moon-sized objects and even bigger. Well, they thought maybe a Mars-sized object hit the earth and Sent debris into orbit So dug a dug a hole and through that a hole but it sets a violent event because they're coming in at 15 What's it coming in big bigger than 25,000 miles an hour because that's the Earth's escape velocity and This is a tremendous amount of energy involved and so it ends up making kind of a ring around the earth and we'll show up a movie of that in a bit, but it's it really is a a profoundly important event and Hartman was able to picture it so that that that Goes to the whole thing about gravity drawing Objects of space into the earth because it's bigger and it has a gravity and it grows fast and once it grows fast But then Jupiter too plays a role in all this because it changes the orbits of things and so Because it's big and so this object might have come from the vicinity of Mars even we don't know this for sure But it comes whip it in and it hits the earth The question is did it happen with Venus? Maybe it did but it hit it head on so he didn't have to spin to send stuff into orbit and keep it there But I have a question earlier we We debunked one of the theories because the moon doesn't have the metallic that earth has No metallic on the moon and therefore there's a real question about whether one of this came out of the Pacific basis One of the selling points of this idea is that the big impactor that's the size of Mars It's a tenth the diameter of the earth the Hartman actually has smaller in his picture, but It's already molten informed to core And when you do computer simulations of these things when actually certain people do the other I don't other people we have a tactical staff that They don't want to be called Anyway, it the metal big core That is way bigger than the moon itself actually ends up sinking through the earth into its core and the stuff that goes into orbit is from the rocky Outsides of the two objects Okay, and that's not metal and that solves the problem of the metal core and then to solve the problem to have spinning everything up so that you keep things in orbit and And so it's kind of a satisfying idea and everyone at this conference except for three people Barton to the idea to a woman's a captive guy woman's a fishing guy You know those people you can't think about and But the other guy was a really great lunar scientist and still is a great lunar scientist named Paul Warren He's that used to LA and he He on the field we had a field trip in between this first meeting and the origin of moon meeting to kill a whale and At the you know the volcano arts center. I'm sure Hartman has painting there for sale This guy Paul Warren buys the painting perfect and at the end of the conference He was one of the people who didn't buy into the idea yet What the painting but not the idea the idea. Yeah, it's still honest the painting You wanted to get it off the market Still still honest the painting it has it on display Beautifully in his house and taking care of special lights because he knows it's a nose It's important thing in his heart. He knows well. He actually he's Almost everyone has part into aspects of this whole thing now. Okay, let's look at the simulation now, okay? Or you will one more one more one more. Oh, here it is. Yeah, there it is. Okay this is done by Robin can up who's at Southwest research Institute in Boulder and There there are two objects come smashing into each other and it'll it'll play again We just have to have time It'll play it again when the two objects hit there. There's a color coding for a temperature The redder it's hotter the the temperatures of the really hot things get up to 7,000 kelvin and and and then you can see all the debris around the moon the little circles are actually a little Analytical grid points in the calculations. These are called 3d hydrodynamic codes. Of course. They are Really, you can't I don't go a day. Do I without saying 3d hydrodynamic code now? So that those codes are driven by though the real chemical evidence that we have from the rocks that the Apollo Interesting things about a vacuum so to speak no and and computer power The beauty of this 1984 conference is that computers had become cheaper And so you could have a little laboratory computer and run Simulation they were simpler than they are now But that came along and our knowledge of the impact process came along So these two things could be combined and and now all those things are much better than anything else And just as our chemical analyses are better than they were then yes So it's really is great and an interesting thing about the one of the interesting things about the big impact idea Is that it actually ties elements of all the other ideas together? Yes, and so the slide seven shows this Remember those other pictures we showed there they have those names fission capture and Coagulation growing together and and where they all intersect in ideas is that big impact theory now We call it the giant impact theory hypothesis, so we're still working on that That's what all of it has has some aspects You know the impact ships things off then quite chip it off It's not the right thing because it melts so much of it vaporizes even I mean this after this this cloud contains Rock vapor. I mean this is so hot rock vapor. Yeah. Wow, but it's so and it goes around so then it becomes There's a cloud of stuff like creating around the earth just like the coaguration But it captured it too because some of the materials coming from the big impactor and It does kind of fish in off a lot of material from the earth so it has elements of all of the ideas So it's like the Henry clay great compromiser theory of The origin of the moon, you know, it blends everything together. Can we look at that one more time just one? The rabbit okay, so I Understand the capture because the capture assumes that it's coming from space somewhere And the modifications instead of going around the earth it hits the earth I understand coaguration because well, I'm not sure I understand the the Implications of coaguration and big impact. I'm with fishing. I don't understand that because Because fishing assumes that it came from the earth and well it did. Yes. Yes, it isn't all of it It's some of them and the two things may merge and there is isotopic evidence that suggests that they merge Completely, I mean they got homogenized the whatever the composition of the big impactor and Came on sort of like that. Yeah. Yeah, what about the coaguration one the coaguration is once you do this And you remember at the end of the simulation which we should show again because it's so cool That's from the internet you hear about that and But once at the end of it you see this disc of stuff around it with the moon forms in that So in that sense, it's at that stage It's coagulating the earth is already formed. So that's a different but it accretes around the earth So what is this you know this theory here? Oh, there it is So this is what happened when it's something hit Something hit the earth and they do many there's a lot of variables the size of the object the velocity object in the angle With respect to the it should be consistent with geophysics geophysical. Yes. Yes. Yes. Yeah It's it's a it really is an interesting thing Well, yeah, I wanted to explore that so here we are and we've we found a theory that works that adopts Accidentally we're on purpose. You know all the theory all the three theories from before And now we have a better guess as to what happened how the moon okay But what does this teach us in the larger sense? What have we learned here that you know? That would be useful in space travel that be useful in understanding, you know the Formation of other Moons and places around other sun around other I mean it sounds like it would be it's a breakthrough of sorts, but but what is it? Conceptually, I think one of the most interesting things is that it tells us Planets there was a theory at first and then becomes a little more advanced or a hypothesis at first You know there you're making a guess and then it becomes firmer and firmer that the planets the interplanets Did formed by little things coming together starting with dust that became asteroid size than the asteroids became Moon to Mars size these things all kept whacking into each other until they were either ejected from the solar system by making a close pass to the Sun or something or made a bigger planet and There is hints that this is going on when we look at stars other stars and other The astronomers are looking for this kind of situation around other stars. Are there earth-like planets with moons? Similar to ours like a system like ours and we it could happen again And I may not hear not here. We're an older solar system about that But it could happen somewhere else and we could actually we in principle We may have we had a PSRD article that was written by one of our graduate students with a faculty member who is in Could have been in the Institute for Astronomy, but he's in geology and geophysics one of these broad multi-disciplinary people by Eric Guido's his name is I don't know if you've ever met him, but and David Trang was the student there would be it was part of a course project and There was a signal in the infrared around one of these very young stars that you can interpret as a big collision a collision like this would happen Instantaneously or it's for a slow motion well The event that ends up making the first ring around The earth, you know where there's a lot of debris and it's hot is a week a week And then the moon would form half the moon could form these are simulations done by Robin Canope who showed the one who made the one that we showed that It's a week to make half the moon and then a couple hundred years to finish the job You know this is instantaneous. I mean Yeah, well in the Bible they talk about what how it took So many days you do this and that so Maybe there's something we can learn You guys are great. This is terrific. This is a great examination So and it puts us there it puts us there in space watching these things happen So thank you very much Linda. You're great in great Martell Jeff Taylor