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tv   Geoscience Lessons from Apollo 11  CSPAN  August 28, 2019 4:52pm-6:27pm EDT

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and the conflict surrounding an opinion piece she co-authored in the philadelphia enquirer. >> i think this is what roughled a lot of people, that not all cultures are alike. we were trying to tout this code of behavior as one that was particularly functional and suited to our current technological democratic capitalist society and comparing it to other cultures which, you know, aren't as functional. we gave some examples. and that madelene caused a fire storm. >> sunday night at 8:00 p.m. eastern on cspan's q & a. >> up next, a discussion about geoscience and how lunar samples from the apollo missions helped scientisting understand our moon and solar system. the national archives and geophysical union could hoefted the event. >> good evening. i'm david ferriero, the
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archivist of the united states and a pleasure to welcome you here to the william g. mcgowan theater at the national iraq ives. whether in the room or participating through facebook or youtuben a special welcome to our cspan audience. i'm pleased you could join us for tonight's program small steps pan giant leaps how apollo 11 shaped our understanding of earth and beyond. tonight's program is presented in partnership with the american geophysical union, swrating its 100th anniversary this year and made possible in part by the national archives foundation through the generous support of the boeing company. we thank them for support. starting tonight a and the next four days we commemorate the 50th anniversary of the historic flight of apollo 11 and the first moon landing. tomorrow night, july 18th we'll screen the recently -- recent celebrated documentary, apollo
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11, crafted from newly discovered video and audio recording here at the national archives. following the film, the nasa chief historian bill berry will moderate a discussion. with thomas pederson, the national archives motion picture archivist daniel rooney. and friday july 19th we will show two films in the afternoon. at noon we will have mayor tranquility, the 1998 hbo series from the earth to the moon. at 3:00 p.m. moon walk one, a 1970 nasa documentary. and finally on saturday, july 20th at 2:00 p.m. we'll screen the 2018 feature film, first man starring ryan gosseling as kneel armstrong. upstairs in the east rotunda gallery be sure to see our display of four documents that show the multitude of smaller steps and details necessary to the success of the apollo 11
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mission. the records include the flight profile, the entire eight days of the mission, the plan for the hour that the lunar module landed on the moon. panls of moon landing transcript and a card details the itinerary, the astronauts were to follow during their moon walk. those documents are be on display through august 7th. to keep informed about the events throughout the year, check our website, archives.gov or sign up at the table outside the theater to get email updates. and you'll find information about other national archives programs and activities. and another way to get more involved with the national archives is to become a member of the national archives foundation. the foundation supports all of our education outreach activities. and now it's my pleasure to turn the program over to kristine mcentee, the executive director of the ceo of the american geophysical union. it's a worldwide scientific community that advances the understanding of earth and space
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through cooperation and research. she is the third executive in agu's 100 year history. for over 25 years she has made her mark as a leader and innovator. in 2011 she was chosen for america's tom women mentoring leaders and in 2012 featured in the 100 women leaders in s.t.e.m. ladies and gentlemen, please welcome kristine mcentee. [ applause ] >> okay. thank you, david. on behalf of the agu and our 100,000 scientists that reside in 130 countries around the world, welcome to tonight's special event, small steps and giant leaps, how apollo 11 shaped our understanding of earth and beyond. we support earth and space scientists and their collaborates so they can advance
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and communicate science to ensure a sustainable future. we're proud to copresent this event this year in our centennial year as o organization. in 1919 when agu was founded, the world was a very different place. however, despite the century's worth of change, the analyst of earth and space science to improve our society and the desire of scientisting to provide the benefit to humanity has remained the same. as has the awe of discovery that all of us witnessed if we had a chance as i did as a 14-year-old girl in a small town in western pennsylvania watch the lunar landing on black and white tv. earlier in the year i was honored to interview geophysicalist and nasa astronauts dr. drew feistel who recently commanded space station 5 a appear 56.
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on the iss. he spoke about the apollo 11 mission for himself personal and and frmts she he also shared that the first science was geoscience. the deployment of scientific instruments and the collection of core samples on the lunar surface. geoscience, he said, will continue to play a pivot alin the future lunar or other plan tear missions. he also spoke about how over the course of his 197 days in space on his latest mission he saw the changes that the earth is having in its climate, how floods affect our planet and other geophysical phenomena are impacting the earth's surface. he also experienced what astronauts have dubbed the overview effect. when viewing the earth from space many astronauts see firsthand the fragility of our global environment and how we
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all are protected and in our i should by our planet's thin atmosphere. from this vantage point boundaries between mediations disappear and the issues that separate people are viewed as less important. what does become clear is the need to create a more unified global society. one that works to protect all of the inhabitants of this pale blue dot we call our home. during times of uncertainty and change to earth's climate and the scientific enterprise, all of us, particularly the scientific community, must join together to address the concerns. like all of us and those who were part of either witnessing or being on the apollo 11 mission, we have to be creative and passionate, committed and determined. we must advance research and to so with the integrity and transparency that is the foundation of scientific discovery. i am now proud to introduce
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agu's president dr. robin bell. robin has been a member of agu more than 30 years and became president-elect in 2017. she was appear past president of our cryosphere section and elected as a fellow in 2011. she received her undergraduate degree in geology from middle bury college vermont and ph.d. it from column yeah university. since completing her doctorate she led raefrp at the lament dourty earth observe on ice sheets, tech tonic and rivers and mid-ocean ridges. please join me in welcoming dr. robin bell. [ applause ] >> well welcome, i'm very excited. anybody has ever come within about 10 feet of me realizing i'm a natural geek.
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and when i realized we were going to have this wonderful event, first you thought i could just like -- i began to think where was i? it's one of my favorite questions to ask anybody. where were you when the apollo 11 landed. i was on aunt maybele coach, the same color as these chairs, red but gnawing a hyde and everybody in the little community was jammed into the room because she had the only tv in the community. so we had about the 45 people jammed into the room. but i decided that i should look a little deeper than just the couch. into what i consider sort of my lunar legacy. so i began to poke around at my institution, because it turns out lament columbia university had a lot to do with the geophysics of the apollo mission. and i knew there was a gravity meeter i had been tripping over my entire life.
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it's -- i shouldn't tell you. i went looking for it i went first to the attic of lament hall, the same place they mapped the bottom of the ocean floor. then i -- wasn't there. i found apoll of 11 slides and pictures but no gravity meeter. next i checked all the closets in the mansion. no gravity meter meeter then i got brave and went to the cellar of the oceanography building. yes there was jars of jelly fish in the cellar. i knew those were not from the moon. i knew it. but i kept looking and finally opened the door. and there it was, under a yet tp i don't know why it was under a net. but there was the mock gravity meeter that you can find pictures of astronauts change on it went on the back of the vehicle. but then i remember -- that's out on the table if you want to see it i brought it down on amtrak i think the first time a lunar fwrafty meter has had a
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trim on ac tram track. but i decide the not to give up. because i remembered mark lange setting on my committee had conveyed one of these important lessons in science is you don't give up. pause he wanted to make heat cell measurements on the moon when he first tried something happened to the flight. it was apollo 13. okay. apollo 14 the drill stuck and they got one measurement. apollo 6, the first time there was a i swear an apology from the astronauts back to a scientist because something bad happened in mark us's obituary well, they tripped over it and pulled the wire. marcus stuck with it by apollo 17 the astronauts are on the moon and they're talking about joking about how not to trip over the heat flow measurement. when i walked away from the
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marcus's lesson is don't give up. you can be patient and you can get what you want. we went to the cellar again. this time i took colleagues. i wouldn't want to be down in the jelly fish by myself. what did we find, high up in the piles of boxes we found the heat flow instruments. so it's just been wonderful. i also learned the stories of the measurements they made of how the velocity of moon rocks isn't that different from cheese. published in science magazine in 197037 it shows scientists can be very patient, recover from disasters and have a sense of humor. so i hope you're going to enjoy the program as much as i'm looking forward to tonight. we're going to learn a lot. there are some amazing people back there we're going to learn from. and in my hole are role as president of a fwchlt u i realize now having watched the eyes of my cohorts when i went
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on the tip to the cellar number two how inspiring all this work is to the next generation. being able to hear the stories, hear where their parents were when the moon handing happened actually just lights up their eyes and gets people inspired to work on science on this planet and on other planets. so now i'm very pleased to introduce dr. jim green, who is nasa's chief scientist. he received his ph.d. in space physics from the university of iowa. and then worked at nasa's marshall space flight center where he developed and managed space physics analysis network. before becoming the nasa's chief scientist he was a director of the plan tear science at nasa. headquarters where he saw missions including the new horizon fly by of pollute o, the juneau space flight to jupiter, and one of people's favorites, the landing of the cursety rover
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on mars. we are you canny to have him as moderator of the panel tonight. please join me in welcoming dr. jim green. [ applause ] >> thank you. good evening. wow. i'm glad the rain didn't stop you from coming. because we're going to have an exciting time tonight. we're going to talk about apollo 11. we're going to talk about its legacy. we're gug to talk about the science that we learned and how it sprung board us forward into discovering many more things about the moon and the origin and evolution of the sole par system. it's going to be a really exciting time. we'll also talk about the future of lunar exploration. so without further ado i want to mention a couple of important things. everyone should have some cards. if you have cards in the audience, these are important
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because you can write questions down. please write your questions. as they come up, i find that's usually the best way to go. hang on to them and then what we'll do at the end is we will pass them down to -- to the end and go through as many as we can. now, in addition to the audience that's here we also have our remote viewers. and so for them let me read on twitter what hashtag they should send the questions to. hashtag apollo qa and hashtag agu 100. okay. so for those online, please get ready get your questions. and then we will try to get to as many of them as possible. so tonight we're going to have a moderated panel. i am just drieted to have been asked to moderate the panel. we have some of the best plan tear scientists in the world,
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okay, those that have worked with even apollo 11 data and many- and all the way to ellaro the lunar reconnaissance that's there now. the without further you a ado let me begin voukss. first i would like to invite sonia tikoo. the associate professor of geophysics at stanford, university. sonia [ applause ] >> next dr. sean solomon, the director of lament university earth observatory. sean. [ applause ] >> we also have heather meyer. hether is a post doc fellow at the lunar and plan tear institute in houston, texas.
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heather. [ applause ] >> and last but not least, steven hauck. and steven is the professor and chair of earth, environmental and plan tear sciences at case western reserve university. steven. [ applause ] >> so we're going to start out by talking about the legacy of apollo and what it meant to the country going back now 50 years. we're going back to the way back machine and out of this panel two people actually observed the landing. that was sean, much more as a working scientist and then as a high school skunt, jim green here. there are some fond memories i'm sure. i'm going to ask sean, take us back to the lunar landing.
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you know, what was the feeling of the science community at that time snt what were they excited about? >> i hope some of you will remember the apoll p.o. 11 landing. but i was a graduate student at fwooe physics at m.i.t. and the world had been following the apollo program and lead-up to it. we had the anniversary of the law firm of apollo yesterday, the ail polo 11 i should say. and this saturday the anniversary of the landing. that evening, july 20th, 1969, late afternoon, was the -- was the landing. and i would say that there were problem billions of people around the world watching that event all over the globe. and it brought humanity together to look at a technological achievement and a very -- and
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largely in an afflictle way. it was a marvel of technology that eight years, less than eight years after president kennedy announced in his speech in houston in early 1961, challenging the country to go to the moon before the end of the decade to send humans to the moon and bring them back safely, that we did that. and 1961 was such an early phase of the space program. the first team had orbited the planet only four years after sput nick. and within eight years we carried out apollo 11. ral extraordinary. it took an agency that had -- had the backing of the country, had resources and some some really amazing engineers who figured out some very challenging problems. so one of the things that the scientific community realized
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was they were witnessing a remarkable event in history and a remarkable technical achievement. but scientifically the apollo 11 mission was enormously important to our perspective of our our planet fits into the solar system, and what the early history of the solar system was like. and i can't understate the importance the apollo mission in particular for bringing back lunar rocks, lunar soils, core samples into the best earth laboratories where the most sophisticated instrumentation may have -- many of the instruments purchased by nasa specifically for the apollo program were ready to lack at the lunar samples. and we immediately learned that the moon is very ancient. we immediately learned that all the mineral on the moon are volcanic and we learned threw a great leap of logic that the
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high areas of the moon were an early part of the planet when the entire planet was magna and volcanic. it came from the lunar apollo mission. it came to an early understanding of the history of the plan tear system, a part of the system of our planet that's not preserved in our rock record. so i'm not sure i realized all that as a graduate student sitting in front of the television and listening. but that's what happened. en and it didn't take long before the scientific community realized what a water shed annett it was. >> indeed. we are celebrating the 50th anniversary. and i think a lot of people in the general public think of it as human exploration. but science was there from the very beginning. when i watched it one of the startling things i saw when neil
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outside of the capsule before he said the famous lines he looked around how the lunar lem was sitting on the surface and how deep the legs might have been crushing in. there was debates how thick it might be. although we landed on the money by the surveyor you don't know if it's piling up in certain areas. he was right off the bat talking science. and that was just -- to me justo was just spectacular. what science experiments did- sean you get involved in what did we put down on the moon for apollo 11? >> apollo 11 was the first of course of the landings space craft. and there were a total of 6 that landed successfully. and it wasn't the most ambitious by far in the experiments that it brought to the surface. but one of the opportunities
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provided by the apollo missions was the opportunity to do seismology, to study natural tech tonic events and the impact of meteorites on the moon. now i guess what treftial geophysicalists had been doing a quarter of a century. using the earthquake waves to learn about the interior structure of the earth. scientists at my institution and a few other- my current institution and a few other institutions got together and sent a seismic system on apollo, including apollo 11 but for reasons of the cost, for reasons of schedule, the very first passive seismic experiment carried by apollo 11 did not have a long enough power source
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so only lasted three weeks. and it produced signals that the very best seismologists in the world could not understand. so for three weeks there were seismic signals being recorded by the seismic system on the lunar surface then the power ran out and the signals stopped. and really distinguished seismologist, morris ewing. frank press, gary lathe am, others who had been working on lunar seismology and thinking about it for years prior to the mission. didn't know what they had in the way of the signals. and sean on the screen there is really an explanation, the top four traces are lunar seismic grams. and the bottom trace in red is a earth seismic gram. >> they had taken this to the moon with the mindset that you
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would see signals like on earth. but they saw them very different full of high frequency energies. didn't have distinct riveting phases and that rung on for tens of minutes or an hour. it was said that the room rank like a bell. and the apollo 11 signals nobody figured what they were. it took apollo 12. the difference was the apollo 12 astronauts landed in a different place, took another system with longer power sources then left the moon again. but the seismologists had asked nasa for permission when the astronauts docked with the command module in lunar orbit and didn't need the ascent vehicle anymore to send the assent vehicle back to the moon where it was li it would crash but it would crash and create
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seismic waves and crash in a known place at a known times. for the first time ned a seismic source, the characteristics of which any knew, they knew the energy, time, location. and it produced size mow grams like on apollo 11. it was an ah-ha moment. this is what seismic grams looks like on the moon but it took another experiment, cooperation of the flight folks at nasa to recreate an event so that we could understand how different the moon is from the earth. it's different for a the variety of technical reasonsle. it's different because the outer tens of kilometers are fractured and broken up and the moon is extraordinarily dry. so seismic waves go on for hours instead of minutes. and none of that had been anticipated before the apollo mission. so the lesson was if you take a
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treftial experiment to a new planetary body you have to think out of the box to interpret what you find. >> indeed. these are fabulous sets of data. we call them wiggle plats. if you are excited about these you have pennsylvania scientific career please see me after the lecture. well, you know, they also collected a variety of samples. they did a fabulous job. they had about 50 pounds worth of sample that is apollo 11 crew brought back. sonia why do we need the samples? what can we learn from those. >> the apollo samples are not just a bunch of souvenirs eep though they are really cool. but they represent the incredible treasure trove of knowledge about processes occurring in the early solar system, not just how the earth and moon formed but also the incredible bombardment of giant impacts that were occurring in the first billion years or so
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after the solar system initially formed. so what's great about getting whole rock samples from the moon on the crude missions is that we can bring them back to earth and cut them up into 10 oh pieces and send them to 10 oh different lance labs and do 10 oh different experiments on the best equipment possible as sean pointed out earlier. it's because of in we can address a much wider diversity of science questions than you can with, say, a few instruments that you could put on a revolver. and you request have a mier diversity of viewpointing, different scientists with different perspectives addressing the questions. and from that perspective, getting actual rock samples from the moon is integral. and we have lunar meteorites. moon rocks fall to earth all the time. what's great about the apollo safrmts is we know exactly where they came from and what geology they represent.
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thanks to the samples we learned some incredible things. we learned the earth and moon are geochemicalically very similar to each other. and that in some sense we have a common origin and this led to the giant impact hypothesize that you may have herd of that the moon formed by the impact of a mars size body into the earth. and we wouldn't know this without the samples. we can do are date rock samples that are basically glasses from impact hitting the lunar surface and melting crocks and recrystal azing we could radio metrically and date them and figure out when the impact happened. we can figure out the first billion years of our solar system history was chaotic. we go back to the impact that killed the dane saurs, in the first 2 billion years of earth's
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history. stuff like that happened three hundred time based on the scaling laws we developed from studies the moon. that's the power of lunars samples from the apollo missions. it's fantastic we get to work with them. >> yeah, in fact over all the six apollo missions we brought back about 840 poisoned worth of lunar material. and as it came back the first thing we did is we set aside about 25%, not to be looked at. and it's done that way because as we learn things about how we analyze the current material in our hands we can appreciated the new teerm that way. but over the last 50 years our ability in the laboratory to look inside the rocks, with c.t. and scans and the individual atoms and getting the isotoeps and all the complexity the samples provide us is now becoming well in hand. this year we're opening brand-new samples we have never
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opened before. well, we had the panelists think about many so of the great images from the apollo program. and we have asked them to give us those. and let's talk about these. so here is our first one. and this comes from apollo. >> eight. >> eight. this was yours, sean. what did you see? what did you feel like when you saw that. >> those of you who read the "washington post", should have seen the story yesterday on this very image. i think it's one of the most compelling images to come out of the apollo program. apollo 8, you may remember, was before any lunar landing but sent the first astronauts to loop around the moon before they came back. the astronauts were james lovell, frank boreman and william anders. and when the space craft came
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from out of the shadow side of the moon to view the earth rising above the horizon, anders took this famous image, earth rise. and boreman was quoted in the post yesterday as saying, all three of the astronauts just were awe struck by the image. and because of the beauty of the home planet, because it was almost the only color in the sky, because you could see the fragility of earth's atmosphere. and yet we really on that with every breath we take. you could see land. you could see the oceans. from space there are no political boundaries. and the contrast with the excrete liar i had and dislit
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though beautiful moon was more striking than really had been appreciated up to that moment. and in the 50 years since then the magnificentens of the space view from earth and the realization of the changes that mankind has imparted to our atmosphere and our oceans have made it less habitable place than it was 50 years ago, just underscores how precious this -- and in our solar system, the fully unique this planet is. so it took the ventures of humans into space to look back from another airless ancient surface and give new appreciation to our home. >> yeah, to me when -- walking
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around the news stands just about every merchandising that could grab ahold of this. i remember life, a huge magazine, very popular had it front and center. and it was you a inspiring they weren't the oem three inspired. iconic image. one of the great images of the last century. next slide, please. >> oh, okay. all right. this is one of my favorite photos. it's from apollo 15 actually. and it's a picture of command dave scott, kind of collecting samples on the lunar surface. and i'm a sample scientist. this is like my bread and butter. and so you really get a sense of how they were going about it in this photo. so you see that he has a bag in his left-hand that has a rock in
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it. so there is a sample bag and they put the little tiny rocks they picked up off the ground into them. he is messing around with in larger rock in the center of the image on top of it is this funny stick looking tripod thing it's creating a shadow. and what was cool about it when you're on the moon you don't have a compass that can it tell you which way is north, south, east or west. if people on earth wanted to reconstruct the direction they were studying they had had to use the sunlight cast on the strike on the ground. the sunlight angle figured with the time this could tell you the direction. it gives you a sense how they went about the business on the surface. you have the footprints in the soil, you have the sample bags, the whole thing. but i have to say my favorite
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part of the image unfortunately got cut off, because if you actually were to tilt upward at the top and dave scott's helmet you have the best selfie of all time. because there is a reflection of the other astronaut's space suit and camera in the image. and, yeah, it just goes to show that you instagram is not a modern phenomenon. they totally rulers at selfie taking even during the apollo era. >> these were really bulky suits. and it's very hard to be able to in the bulky suits to be able to pick up the material on the ground. they had a variety of implements things they would use. one of the astronauts wanted to pick up a very heavy rock and knew it might take him down if he picked it up. he put his leg against it and
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with one of the rods that they had with a fence on the finishing that picked up rocks he just rolled it up his legs and threw it in the box. but indeed we have to -- when we look -- look at our rocks in the archive today we have a little orientation cube which talks about where the sun was during the time period when the rock was collected. we try to maintain all that data, yeah. next slide, please. >> this one was mine. >> yes. >> this is an image i think captures a lot of what apollo 11 astronauts armstrong and aldrin were doing when they were on the surface. so in the foreground we see -- that's actually the seismometer that sean was talking about that was solar powered even back in 1969. and they were able to install
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quite quickly whereas the ones that came on later missions took them longer and also lasted a lot lurng on the top of it you see the white stick that's actually the antennae that allowed us to get data back from the moon to the earth. behind that you can see sort of where that white stick is you can see sort of like a triangle. this is an experiment still operating today from apollo on the surface of the moon. it's a lunar laser retroreflector and its purpose is to do a better job of reflecting lays are light back from the surface of the poon. and this was an ingenious experiment because it required no power. it just had to sit there. and then all of the technological advances happened here on earth. as our laser got bettor, our
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telescopes got bettor. and we use this -- scientists use this to measure the rotation of the moon, the distance of the moon, and the major thing we learned about it is what does the inside of the moon look like? how does it respond to the tidal stresses is receives from the earth? that tells you about what the deep interior of the moon is like. this an experiment that has been going on for 50 years. and then on the background we can see other iconic parts of this apollo 11 image, we can see the flag that was in place. we see the lander. then in the far distance we can see the television camera any used to provide the first interplanetary television show. >> yeah, that's right. next one, please. >> that's me. okay. so sean took my favorite image.
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so we'll have to do with this boot print. many of you have probably seen this image before. but just for context i'm a remote sensing specialist. i work on data from orbit. and most of what we do from orbit depends -- dsh what we interpret and how we see it depends entirely on the properties of the surface. one of the things apollo did was teach us about the properties of the top soil. and the properties so werkd we could derive meaningle information from orbit. if you are a sherlock holmes fan there is a lot of money. rregalith is the upper most part of the surface. the fact that you have this large imprint on the surface indicates this there had to be space between grains of the dirt for it to compress. porosity is the changes depending where you you are but
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in in situation it's at least swla porous. that's the reflecting the the way we see light reflected back from the surface. that's important to make sure we are interpreting things correctly when we look back down. >> indeed. >> this is the same -- i had to go for two because he took my favorite. >> that's what neil was looking at. >> as jim mentioned, the foot pads touched down and they had the rods that stuck down. they didn't sink too much. it was telling us the upper most part of the soil was not as pour porous as we expected but still fairly por pous such as the lup ar mod pul could sink a bit. but perfectly support the weight of the astronauts. nobody got stuck. this is important for ground operations. you need to know you can move on the surface. we wouldn't send revolvers if we thought it would get stuck in the sand. things like this are critical
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considerations that were beautifully demonstrated by apollo 11. we got a surprise that it was not as porous as we thought. they didn't sink as far asthy we thought they would. >> well, you know, a scientist -- as we delve into things and get excited about a variety of things that maybe people think are minutia. what sore many of the things that you think the general public would be interested in knowing that you really got excited about? so let me open it up to the panel. >> well, i could talk about magnetism now. >> sure. >> is a moon a magnetic field. >> the moon used to be magnetic. we all -- you probably know that the earth has a mat nettic field. it's visible but we're sitting
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in it. and it tell us where north is if we use a compass. but the moon used to have a magnetic field too and you're probably wondering why does it matter at all. that's what i'm going to explain. if we go to the image of the moon and its magnetic field. there it is. yeah. this is an artists conception of the magnetic field that used to be on the moon billions of years ago. it has to be artist conception for one because it's invisible. and we can't see inside the moon. magnetic field -- the way i think of them they're almost like the heart beat of a planetary body. they are this invisible by detectible signal that tells you that there is some activity going on inside at the core.
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and so -- in the case of magnetism, the process that is occurring is organized motion of molten metal, hot liquid iron at the center of the planetary body. and it's moving around in such an organized way it can generate a magnetic field. and so it tells that you the planet is alive and that it's cooling down. the motion is driven by thermal convex inside the core of the planetary body. and in some sense it's a signal that the mean was active. what's funny about lunar magnetism is we did not learn much about it from the initial landing at the apollo 11 site because they neglected to bring a magnet meter on the mission. but we fixed that in apollo 12. all right. so if you go to the next
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image -- sorry there were two -- there is one of the -- yeah, that one. so the image on the left that you see at the end of that rope or cord is this the little box looking thing with three prongs coming out of it by the astronaut. and that is a magnet meter that they took to the moon upon apollo 12. you have a magnet meter in the cell phone now all smartphones have them. this is a testament how the technology changed over time. but what they were able to do is they were able to measure the surface of the field at the phenoand was 1,000 times weaker than theering's magnetic field. but also not zero. why is it significant? it tell us it was magnetized at some point. there was something there. which means there probably was a
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core inside the moon that might have had a magnetic field generated from it at some point in the past. magnetism was sort of like a circumexpect way of looking of the problem. from laser ranging data that wasn't obvious that the mine moon has a core. but if you can detect a magnetic field on the moon or show it had one in the past you can say oh this is the internal structure of the moon and we know for sure it had one. surface measurements were a hint of that. but what nailed it was studying the magnetism that recorded in the apollo samples from the time they initially formed billions of years ago. that's the picture on the roo, apollo 12. this is the astronaut about to pick up a moon rock with tongs. and so what they were abled to is once they were brought back to earth, these were send to lab that is study pal owe magnetism.
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usually when i say that people are like what dinosaurs are magnetic. >> no pal ontology. >> at least the personalities are. >> yes. paleo means old and magnetism is magnetism. we stick the rock in a magnet meter. whether or not it was magnetized. they' choir the magnetism when it's formed and preserves it for pretty much its history. what the apollo era pal owe magnetists found was the moon -- it seemed the moon had a magnetic field that imprinted magnetism in the rocks prior to 3.5 billion years ago and that it was at that time time period it was as strong as the earth's magnetism is today. which is a surprising for the a small body like the moon because small body, small core, farther away from the core, it's not
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such a big field. but it did. that was a huge mystery. and what actually persisted tepd of the apollo era was people weren't sure whether the field was actually from the inside of the moon or not. there were other hypotheses that giant impact can create plasma and that moving parnd generates magnetic fields and all the rocks. we kept ourselves busy for all the years. we tame came up a way to show whether the rocks recorded the magnetic field from the moon or other sources. what we found is the moon generate add field. it lasted 2 the.5 billion years aigt. we had a field on the moon for at least 2 billion years, much longer than people conceived of at the time. it tells us the moon was alive and active. >> very surprising. you learn that planets evolve
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over time. >> yes. >> we go back on two or three different years look petition moon it's a different october. >> yes very different. >> very exciting what else. >> with brenda's help we have gone past the slide i inserted in the group twice now. >> you better talk about it. >> i better talk about it. it's a little bit by the case of the dog that didn't bark in the night. during and shortly after the apollo mission, it should be said, nasa was very active. at sending robotic space craft to he other planetary bodies in the is solar system and in very rapid succession we had been sending space craft to mars and venus and markerry and jupiter and saturn in the early 70s. and it was 16 months after the last apollo mission gnat very first space craft viewed the
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planet mercury at a close range the first time, mariner 10. and mariner 10 showed that mercury outwardly looks a lot like the moon. a heavily cratered surface like the moon. airless body like the moon. and it has planes since we learned are volcanic. but what mercury has the moon did not illustrated by the images from a later mission, is that mercury is crisscrossed by huge faults that accommodate horizontal shortening of the crust. they are the like those underlying the mountain ranges on earth, also the kinds of faults that accommodate subducks on earth and give rise to the large earthquakes on the planet, large tsunamis and these faults are seen throughout the planet mercury. and the interpretation of the
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mariner 10 team was that mercury shrank. the amount was visible and preserved in the surface. mercury is only a little large ner diameter than the moon. but the moon does not have the global pattern of great faults that accommodate horizontal shortening. the combination of the mariner 10 results and the lunar imaging got me interested in the question much why mercury contracted enough to produce all these faults and the moon over its history did not contract enough to produce a comparable pattern. and that speaks to the thermal history. speaks to the history of the core that sonia was talking about. so it -- this particular question got me actively involved. >> what else. >> that the public may not know
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about these discoveries. >> one of the things that may not be well understood that the astronauts in orbit were doing science. it wasn't just. >> science. >> i'm sure we'll talk about different aspects. onboard those -- the command modules in orbit there were scientific instruments. and so- dsh and some that became precursors of the things that became important later in space exploration and in some cases exploration of our own planet. for example on apollo 17 there was a radar which could see beneath the surface. and so we were using radar to understand what was the depth of the regalith, the depth of the rock from orbit. it's the same technology we use
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on earth to understand how deep are the ice sheets in greenland and antarctica. there was a laser altimeter that tells us the topography of the surface. i think one of the ones i come back to a lot because when i was in graduate school one of the scientists, larry haasken, a geochemist and worked in apollo missions. he was interested in the gamm ma ray spectrometer. the apollo command modules went around the equator pu but they collected data suggesting hot spots of thorough yum. but looking at the lunar samples they had a suggestion that it came from this large and one of the last large impacts imbre
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yum. and later when the klemen tien space craft, the lawn ar prokters was able to map the planet they were able to see the hypothesis, thes drkts of the element on the surface was largely attributed to a single impact happening early in the man planet history. >> throwing material all over the place. >> all over. >> massive impact. the moon took one for earth that day as it did. heather. >> kind of works that like, yeah. a big large impacts are my specialty. so amusing for me. he covered what i was going to talk about. but the important things -- one of the important things for what i do at least and sort of drilled into me is how important the samples were for orbiting sensing. the j missions and apollo 15,
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16, 17 because of the great instrument package where they could do orbital skoins and tie it directly to the areas samples meant we could extrap rate to other sites. we could say this looks like what we saw at the other apollo site. that's the crux of remote sensing even on earth. for every other planet you can only tie it to things you know. getting the samples, knows are the key. and for what i do, i mean the samples -- i don't know if you know this i'm sounding so cheesy i'm sorry. but the rocks are -- the moon is sort of our archive. the history is hidden in the rocks. we need to get the samples not just for the chemistry but for the ages. for the large impacts we use the replaces of the large impacts and their -- the amts that we know or think we know -- we use that determine the global strategiography and say i know that area is area is 3 billion
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years old. that system of collecting the ages. is connected to all the other planets and solid surfaces of the solarsome. the ffgs from apollo is the basis for that. it's tell relatively few data points. it's enough to get good information but we need more. it's a spectacular foundation. i think the tying the sensing is far more important than people tend to think. >> well, indeed, this brings up another little segment a i'd like to do quickly since we are running out of time. after the apollo program everybody thought we took a hiatus. we did from robotic instruments. but in the 90s we started getting back to the moon. we had a series of missions. we have learned an enormous amount by them. what are some of the favorite discoveries from some of our more recent lunar mission sns steven, let's start with you. >> so i think more exciting
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pieces of information that we have learned, particularly since apollo has to do with the discovery of ice at the lunar poles. so we have this -- as the astronauts saw and as sean was talking about the understanding of the lunar rocks. they are very dry. no evidence of water. at least not then on the surface. >> we thought the moon was bone dry. we called it bone dry a couple of decades. >> exactly. but then with later orbital missions we were able to start to peer into pieces of real estate near the north and south pole. and because of the way that the moon rotates these are places inside the holes that basically never see sunlight. >> yeah, therefore the water remains frozen. >> yes. >> heather quickly. >> ripe for the picking. i froth. >> hell, hello row, the gas. >> we had tantalizing hints from
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apollo based on orbital imagery that there were weird volcanic things on the surface. we call them irregular mari patches because similar to that they are similar to-- in terms of composition but they are weird looking and i wish i would have included a picture. now we know there are tons of them and it suggests the moons volcanic history lasted a lot longer than we thought it did. it seemed possible that many of these formed in the last billion years or less. no one thought it lasted that long and that it could because like i said, we thought it was dead. we have these hints that we can go and investigate and one of the ones we still don't know. >> this may anticipate another question you are going to ask but one of the surprising
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things we have continued to learn about is how incompletely we understand the origin of the moon. we went to the moon and we know three ideas. one is that it's a sister planet of the earth, it was ejected by a rapidly-- body, i've forgotten the third one. the lunar magma ocean. it doesn't matter. capture. the capture of another body early on. all of them were dynamically implausible but those were the best-- and it did not.
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these are all really bad ideas. >> but we have a top idea that we've hung on to for a couple of decades. post apollo. >> it took the scientific community more than 10 years to coalesce behind the hypothesis that the moon was born-- a giant impact or a mars -sized object to hit the earth. what has challenged us in 35 years since that hypothesis became generally accepted, the deeper we study the chemical and-- similarities of learner material, the more difficult it is to understand this. >> this is worked out several decades ago which were remarkably similar but
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different. martian meteorites, so if the earth was hit, certainly it would be a remarkable coincidence for that impact to have started out with the same competition composition. so why should the moon which is a mix end up with an isotopic system and our ability to measure? in the last few years we've gone down other systems and show in a similar remarkable coincidence. and we still don't understand it. the traditional models and accreting a portion of that into a satellite would produce a body from the earth in the way that the moon is not different.
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so 50 years after we are chasing the question-- >> that's how science progresses and it allows us to take the next step of figuring out what next set of measurements we need. but i would like to have happen , most of the cards have come and please submit your questions. in the last minute before the questions come to me, they are already here. >> that was fast. >> we unfortunately cannot answer all of the questions but we will be able to answer many of them and have them online at the website. one question from the
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audience. should we challenge people who deny the moon landings ever to place? and what is the most effective way of doing that? >> let me go ahead and start. the lunar reconnaissance orbiter is orbiting the moon and launched 10 years ago and is doing a marvelous job mapping the moon to high resolution. if this table sat on the moon it would see it. so consequently when we see these, we see the lunar take off platform. we see where they deployed the- -. we saw the lunar rover vehicle. we can't usually is a
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leash show and authorize those and begin the dialogue of what happened during that period. there's our a number of people who question it. >> which has those. >> i work for the lunar reconnaissance orbiter camera team and had a slide deck with the images that did not make it into the slide deck. you can also google it for the direct images. there's also a good easy argument for samples. you can't make these on earth. some of the minerals are similar but the rocks themselves do not form here on earth. you can see that in the samples. >> if you look at a moon rock
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under the microscope you will see some minerals are different. in earth we have oxygen and that likes to react to iron so we always have iron oxide and on the moon there's none of that. it's just metal. immediately when you look at a moon rock you can say this is not from here. we don't have metallic iron and basaltic rival lava rocks on earth. it just doesn't happen. it's clear that they are not from earth no matter what looking at the samples. >> any others? okay from twitter. how has studying the moon and other planetary bodies help us understand the earth that we wouldn't have known otherwise? >> to me this is enormously important. we are so lucky to have venus
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and earth, plan is to compare. we know that our sources came together 4.6 years ago and have all evolved. what has happened on venus can happen on earth. what has happened on mars can happen on earth. so comparing other planets tells us a lot about how we have evolved and how potentially we will continue to evolve and what will happen to us. >> i think by studying other planets it's important for our ability to understand the earth and part of that comes from the same physics throughout the universe. clearly there are different outcomes when we look at the different planets in our solar system. this is a real opportunity because it allows us to understand how those processes
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work in different environments. for example, you were talking about how venus and earth have had different outcomes. venus is this extraordinarily hot greenhouse planet. it has undergone a massive amount of change at its surface and is a relatively young planet at its surface. one of the things that is really important and is one of the fundamental question is why do we have plate tech tonics? we can start to look at other planets to help us understand that question and what's interesting is that mercury doesn't have plate tectonics, mars doesn't, venus probably doesn't, so now we can start the question what is it that a special about here on earth? >> and systematically start
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answering it. >> my favorite angle is the bombardment record. the history of the forces were preserved on the lunar surface. we do have plate tectonics which destroys everything. mars has eroded, mercury is covered in like lava, venus is covered in lava and horrible atmosphere gets away in front of everything. so the bombardment record, what you can see with the naked eye are preserved where they are not otherwise preserved so this feeds into critically important questions about earth like when did life evolve? could it have evolved when we think it did? if you have a large flux of impactors, if you had all them going on you could not evolve life. it had to happen way before
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this influx or after. just on our own planet, what piece of history are we talking about? is it relatively new or way older? the moon is one of the keys to unlocking that question. >> the hypothesis that it was an impact that killed the dinosaurs would not have been accepted without the lunar program. geologists simply missed-- our critical geological process on this planet. as we've mentioned earlier, the earliest history of the solar system is not preserved. we have none that date-- to
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history. as well as we can study the earliest chapters of our planet are not available and it took the exploration of other planets to reveal to us how chaotic and disruptive the early solar system was. how impacts were common and how the growth of the planets themselves was a long drawn out process of interactions. how even the positions of the major planets around the sun which impacted all of the other planets as well.
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the dynamic of the solar system tells us something about the challenging environment of our planet and the cast between venus earth and mars in terms of conditions that are nearly comparable and yet outcomes today than the runaway greenhouse on venus and an atmosphere on mars that was lost after the planet lost its magnetic field leaving a cold, arid body. there is an important lesson for the sensitivity of the evolution of our own planet and climate to small differences in
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condition. differences in atmospheric composition and differences in the history of the magnetic field and how that can have profound consequences for surface outcome. sonia? >> because the moon is such a well-preserved body, the crust basically holds on to what was going on geologically so it's great for understanding what the earth was like early on and not just from an impact standpoint but from a printed-- planetary evolution standpoint. at some point they turned on but the earth may not have started right off the bat with plate tech tonics. a solid outer crust and a mantle underneath it was creating volcanism.
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a cool laboratory for understanding possible outcomes for bodies that have an outer shell. you have this crazy asymmetry. we are used to seeing what we look at with the crust and lava flows but what you may not know is if you look at the other side of the moon it doesn't look like that. there are a big impact basins but not as big as the nearside because they involved were filled with a different regime and so it tells you in these planetary bodies you may have some weird magnetism happening on the interior of the body and we see asymmetry another but planetary bodies as well. mars has one that may be from some internal process but i think the moon is a good example of that, of what may
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have happened before the earth . >> let's go to another question from the audience. who made the lunar laser light reflect reflector and what have we learned from laser lights coming back on the moon? >> i don't remember who. could be found. what are we learning from those? the reflectors were left by several of the apollo missions . what we learned is to extraordinary precision,
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precision between my fingers, the rotation rate in the distance to the moon. by measuring that over many years we can understand essentially, you imagine spinning an egg and that tells us about what the interior looks like. is it hard-boiled or is it not? that's one of the main questions, understanding what is it like so coming back to the question that sonja has talked about a lot, what does the core of the moon look like? is it liquid today? that's one of the fundamental questions. those are the kinds of things that the deepest interior-- today.
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>> the distance, we do it every year for 50 years. didn't we get it right the first time? >> that doesn't mean it's--. >> about an inch and a half a year. so that tells us about the title interaction between the earth and the moon so that's an important way of understanding that interaction between the earth and moon system. >> if the moon does not show signs of contraction as mercury did, is it possible the moon is hollow? >> [ laughter ] >> no. so let's tease this out a little bit. i saw the ringing of the moon and that is in the crust so there are seismic impacts and it just really rings across.
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are there traces from the seismic measurement that go down to the core? that's a dead giveaway. >> the apollos seismic experiment ran from apollo 12 until the end of fiscal year 1977. it collected about eight years of data, what quite shallow and deep with meteorite impacts during the period. as a preserved the data, and decades later in the late 1990s or early in this century, cosmologists returned with new techniques that have been developed since-- and able to see features they
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hadn't seen before. in particular they were able to see reflections for the core. they are able to see evidence that the core is divided into a cool outer part in solid inner part in to see a distinctive layer above that maybe--, they did that with ways that traveled to the center of the moon and reflective backup. >> that's the tough part. that rules out a hollow moon. >> you could have started out with that hypothesis. that's an important way to look at it. >> would earth exist without the moon? >> this is a good question. >> i can partially answer that.
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the direct answer is difficult but there's an interesting contrast between the earth and mars in the history of climate over millions of years. mars has two little moons that were captured, it doesn't have a major moon. -- changes drastically over time scales of millions of years. the ubiquity on mars varies all over the place. it has been known for several decades and as a result, the climate including the location of ice ice is left over near the equator since the axis was pointing way different
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perpendicular. the earth and the reasons we have seasons is because there's a fixed obliquity, and that obliquity is stabilized by our moon. the moon helps to keep the earth's orientation in space having the characteristics that it does today. >> one of the challenges would be very different without the moon. >> so right now it's 23.5 degrees and can be 22 degrees and 24 degrees. it hardly moves, and even that produces enormous changes in our climate. you can imagine 45 degrees the
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change in civilizations and migrations and everything else you have to do to survive that. that has really been an important stabilization for us. >> this is another i like. if you had a blank check scientists, what instruments would you send to the moon on the next mission? >> something that could draw the radiometric age of rocks so you could just wander around the surface and figure out the age of things. the sample return you are limited by mass because it's hard to get stuff back. if you had an instrument on site that could do that, and there are instruments like this underdevelopment, it's like trying to put a laboratory the size of this room into a tiny little box. it's very challenging but if you can do that you can do a
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lot with the chronology and the history of the solar system . >> i think we have to send back seismometers. >> they had some limitations and one of those was as sean dimension sean mentioned, the duration in which they were operated on the surface of the moon. another one had to do with locations. that limited the ability to understand where earthquakes were throughout the moon and limit our ability to understand the structure of the moon. understanding the deeper interior is difficult so we need more data in order to understand how big it is analyzing that archived data.
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there are questions about exactly how big it is and how big a solid portion of that is. dasher important to being able to understand the history of that core leading to the history of the magnetic field. also, it fits into the theories. when--, it lost its cord to the earth. it's only the remnants that came together so one would expect that to be smaller than if it had accreted on its own without an impact. >> and it is quite small. >> at least we initially think that. sean? >> if i had a blank check book i probably wouldn't go to the moon next. [ laughter ] but i would take advantage of the latest
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discoveries in the polls. i would want to go to the core of the ice. between 100-200 million tons of ice in those craters and that accumulated over time. when the moon had a magnetic field and when it didn't. we want to understand that and the only way to do it is to get a court and be able to look at it and that's going to be really tough going to a place that's dark. ice is there, and locate what you want. >> give me your blank check, i'll do it. >> sonia? >> i like the idea of drilling deeply into the moon. one thing that i would do is have devices that could drill more than a kilometer down into the surface and a big
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impact melted all of these rocks and they cool down again. what's cool about magnetic bodies is the sort of separate into layers and some layers are full of minerals and stuff like that and may be something similar happened. some of the powerful magnetic signatures, i'd like to figure out where is it coming from? that's what i would do. >> what are some of the exciting technological advances that you think will revolutionize space exploration over the next couple of decades? >> we can make everything
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smaller now. we can send 100 shoebox size probes crushing toward the moon and making every sort of measurement on the way down. just putting small instruments on a rover and dating moon rocks at the surface would be incredibly useful. the fact that we can do all of these on a rover, you can learn so much from that. >> enhancing our ability to communicate. when we are moving towards, instead of radio communication to laser communication, we can bring back an enormous amount of data. in planetary science we are very limited in terms of the amount of data we can get back because the further away you are the lower the data rate is.
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that's one of the physical laws we have to worry about unless you change the wavelength and up your game. those kinds of technologies are right around the corner. also, the ability to go from point a to point b like we did with a mission called gone. it's like star trek conventions. we were able to saddle up to a huge asteroid and get it right into orbit. when we approached it we ended up approaching it about the speed of an airplane landing on a runway and that's what that ion engine enabled us to do. we broke orbit and went out to another one, but those engines are getting better and better and that will open up many more objects to be able to get to and really study and analyze. any others?
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>> you looked like you are going to say something. one of the things that is exciting is drone tech knowledge he. nasa selected a mission that's going to use that technology to fly in the atmosphere and be able to lower its surface. the ability to take that technology and explore greater distances, to be able to choose where you are going to explore as you are exploring i think is exceptionally exciting. it's a great merger of arrow and space-- there are places we imagine doing things that are more-- whether it is at venus or someday with that blink check we will be able to do things and go to larger
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planets in our solar system. >> speaking of flight, we've already cashed this check, we have a helicopter on a mission going to mars. it's a rover. it looks like curiosity and is underneath the belly pan. the helicopter will drive away, we will started up and it will have a go pro camera looking at the path ahead of the rover and radio back that information to make decisions on how it will move forward. this i think is the start of how we might be able to use these. although it's a very thin atmosphere we are able to navigate in it and those planets that have atmospheres are next on the list. these are really exciting
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times. this will have to end our little overview. let me thank everyone. [ applause ] thank you so much for coming. i've been allowed a few minutes to wrap up so let me mention a couple of things about what is coming up. we are going to be going back to the moon, we call it going forward to the moon with many more landed systems. but also the plans are to have humans on the surface of the moon by 2024. by 2024, you will witness, and the youngsters in the audience who had not seen any of the
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landings, will have the opportunity to live what we lived in our young careers. and i've got to tell you, i don't think you will be prep paired to see what will happen. it will be so exciting. we are going to have the first woman and the next man stepping on the surface of the moon in the southern polar region. unlike what we see with the apollos, we are going to have some eerie views and a whole host of things we are going to do so this is a tremendously exciting era coming up. once again, thank you for allowing us to talk about our exciting first set of message missions that have gone to the moon. let me tell you, that is only the start of what we have planned for the next decade.
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in the late 1850s americans generally trust of their congressman but did not just congress as an institution, nor did congressman trust each other. by 1860 many were routinely armed not because they were eager to kill opponents but fear that their opponents may kill them.
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