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tv   Geoscience Lessons from Apollo 11  CSPAN  August 28, 2019 11:27am-1:02pm EDT

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of riding." then at 9:00 p.m. eastern on "afterwards" in his latest book "the immoral majority" ben howe. >> i think the lesser argument is tempting but dangerous. i think it contributes to keeping a system in place that takes accountability out of the system. and i think it alsoal is an easy way to bring in something like evangelicalism or any other faith and then use that as a way to get votes which seems like about the worse possible way you could use faith. >> watch book tv every weekend on c-span2. >> up next, a discussion about geoscience and how lunar samples from the missions helped us understand the moon and solar system. the national archives and
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geophysical association cohosted this event. >> good evening. i'm david ferriero. it's a thrill to welcome you here. whether you're here in the room with us or participating through facebook or youtube. and a special welcome to our c-span audience. i'm pleased you could join us for tonight's program "small steps and giant leaps: how apollo 11 shaped our understanding of earth and beyond." tonight's program is presented in parer inship with the american geophysical union. it's made possible in part by the national archives foundation through the generous support of the boeing company. we thank them for our support. for the next four days we are commemorating the 50th anniversary of the historic
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flight of apollo 11 and the first moon landing. tomorrow night, we'll screen the recent celebrated documentary apollo 11 draft frd newly discovered video and audio recordings here at the national archives. following the film, bill barry will moderate a discussion with director todd douglas miller, thomas peterson, the national ark vis daniel rooney. we will have episode six of the hbo series "from the earth to the moon" and at 3:00, the show "moon walk 1" a 1970 nasa documentary. on saturday july 20th at 2:00, we'll screen the 2018 feature film "first man" starring ryan gosling as neil armstrong. upstairs in the east rotunda gallery, be sure to see our
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special display of four documents that show the multitude of smaller steps and details that were necessary to the success of the apollo 11 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, pages of moon landing transcript and a card that details the itinerary. the astronauts words were followed during the moon walk. those documents will be on display through august 7th. to keep informed about these events throughout the year, check our website archives.gov. you'll find information about other programs and activities. 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 and outreach activities. now it's my pleasure to turn the program over to christine
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mcentee, the executive director. advances the understanding of earth and space through cooperation and research. she is the third executive director in agu's 100-year history. for over 25 years she's made her mark as an association leader and innovator. in 2011 she was chosen for america's top women mentoring leaders. and in 2012 she was featured in the 100 women leaders in s.t.e.m. please welcome kristichristine mcentee. [ applause ] >> thank you david. on behalf of 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
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understanding of earth and beyond. we support earth and space scientists and their collaborators so they can advance and communicate science and its power to ensure a sustainable future. we're proud to co-present this event this year in our s cincinna y'all year. despate the centuries worth of change, the ability of earth and space science to improve our society and the desire of scientists to provide that 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 to watch the lunar landing on black and white tv. earlier in the year, i was honored to interview
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geophysicists and nasa astronaut dr. drew. during our conversation, he spoke about the resonance of the apollo mission for him personally and for humanity. he drove home the point that the lion's share of the research done on the first lunar landing was geoscience including the collection of lunar samples, the deployment of scientific instruments, and the collection of core samples on the lunar surface. geoscience, he said, will continue to play a pivotal role in the future lunar, or other planetary 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 a
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astronauts have dubbed the overview effect. many astronauts see firsthand the fragility of our global environment and how we are approximate all protected and nourished by our planet's thin atmosphere. from this point boundaries between nations 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 the inhabitants of the pale blue dot that we call our home. during times of uncertainty and change to the earth's climate and the scientific enterprise, all of us, particularity the scientific community, must join together to address those concerns like all of us and those who were part of witnessing or being on the apollo 11 mission, we have to be creative, and passionate, committed, and determined. we must advance research and do
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so with the integrity and transparency that is the foundation of scientific discovery. i am now proud to introduce agus president dr. robin bell. robin has been a member of agu for more than 30 years and became president elect in 2017. she is a past president of our cryo sphere section and was elected agu fellow in 2007. she received her phd in geophysics from columbia university. since completing her doctorate, robin led research at the lamont doherty on ice sheets, tectonics, rivers, and mid-ocean ridges. please join me in welcoming dr. robin bell. [ applause ]
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>> well, welcome. i'm very excited. anybody who's ever come within about ten feet of me realizes i'm a natural geek. and when i realized we were going to have this wonderful event, first i thought i could just -- 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 -- the coach couch was kind of the color. it was red. everybody in the little community was jammed into the room because she had the only tv in the community. so, we had about 45 people jammed into the room. i decided i should actually 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 lamont columbia university had a
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lot to do with the geophysics of the apollo mission. i knew there was a gravity meter i had been tripping over my entire life. it's -- i shouldn't tell you. i went looking for it. i went first to the at atick of lamont hall, the same place they mapped the bottom of the ocean floor. i found apollo 11 slides and pictures but no gravity meter. so, i checked all the closets in the mansion. no gravity meter. then i got really brave and went to the cellar of the oceanography building. there were jars of jelly fish in the cellar. i knew those were not from the moon. but i kept on looking. i finally opened the door and there it was. under a net -- i don't know why it was under a net -- there was the mock gravity meter that they -- you can actually find pictures of astronauts training on it. it went on the back of the vehicle.
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but then i remember the -- so, that's on the table if you want to see it. i brought it down on amtrak. i think it's the first time a lunar gravity meter has had a trip on an amtrak. but then i decided i wasn't going to give up because i remember that mark lineseth on my committee had conveyed one of these important lessons in science, you don't give up. he wanted to make heat measurements on the moon. when he first tried, something happened to the flight. it was apollo 13, okay? apollo 14, the drill stuck. they only got one measurement. apollo 16, it's the first time there was a swear and apology from the astronauts back to the scientists. something bad happened. it was a misstep. they tripped over a wire. but they stuck with it.
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by apollo 17 they're on the moon and joking about how not to trip over the heat flow measurement. what i walked away with, don't give up. you can be really patient and get what you want. we wouldn't the the cellar again. this time i took colleagues. i didn't want to be down there with the jelly fish by myself. high up in some of the boxes we actually found the heat flow instruments. it's been wonderful. i also learned the stories of the measurements they made of how the velocity of moon rocks isn't that much different than the velocity of cheese, published in science magazine, 1970. so, it just shows that 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's some amazing people back there we're going to learn from. and in my role as president of
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agu, i realize now having watched the eyes of my cohorts when i went back to the trip to cellar number two, just how inspiring this work is to the next generation, just being able to hear the stories, hear where their parents were when the moon landing 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's nasa's chief scientist. he received his phd in space physics from the university of iowa and worked at nasa's marshall space flight center. before becoming nasa's chief scientist, he was a director of the planetary science at nasa head quarters where he saw missions including the new
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horizons fly by of flpluto, and the juneau to jupiter, and the landing of the curiosity on mars. we're very lucky to have him as the moderator of the panel tonight. join me in welcoming dr. jim green. [ applause ] >> 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 going to talk about the science that we learned and how it sprung forward into discovering many more things about the moon and the origin and evolution of the solar system. this is 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
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ink this i things. everyone should have some cards. if you have cards in the audience, these are important 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 at the end is we will pass them down 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. so, for them, let me read on twitter what hash tag they should send their questions to. so, that's #apolloqa an and #agu100. 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 delighted to have been
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asked to moderate the panel. we have some of the best planetary scientists in the world, okay? those that have worked with even apollo 11 data and all the way to lro which is the lunar reconnaissance orbiter which is there now. i would like to invite sonia tikoo on to the stage from stanford university. sonia. next is dr. sean solomon. sean is the director of lamont doherty earth observatory. sean. we also have heather meyer.
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now, heather is a post-doc fellow at the lunar and planetary institute in houston, texas. heather. and last but not least, steven hauck. and steven is the professor and chair of earth, environmental, and planetary sciences at case western reserve university. steven. 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 in 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
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young high school student, jim green here. so, there are some fond memories i'm sure. so, i'm going to ask sean, take us back to that lunar landing. you know, what was the feeling of the science community at that time? what were they excited about? >> i hope some of you will remember the apollo 11 landing. i was a graduate student in geophysics at m.i.t. and the world had been following the apollo program and the lead-up to it. so, we had the anniversary of the launch of apollo yesterday, apollo 11, i should say. and this saturday we'll have the anniversary of the landing. that evening, july 20th, 1969, late afternoon was the landing. and i would say that there were probably billions of people around the world who were watching that event all over the
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globe. and it brought humanity together to look at a technological achievement in a very apolitical way. it was a love of technology. less than 8 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 safety, that we did that. and 1961 was such an early phase of the space program. the first humans had orbited the planet. it was only four years after sputnik. and yet within eight years, we could carry out apollo 11. really extraordinary. it took an agency that had the backing of the country, had resources, and had really
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amazing engineers who figured out some very challenging problems. so, one of the things that the scientific community realized, what 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 how 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 of the apollo 11 mission, in particular for bringing back lunar rocks, lunar soils, lunar core samples into the best earth laboratories where the most sophisticated instrumentation specifically for the apollo program were ready to look at the lunar samples. and we immediately learned that the moon is very ancient. we immediately learned that the
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moon is volcanic. and we learned through a great leap of logic that the bright areas of the moon were the product of an early stage in lunar history when the entire outer part of the planet was molten and the crust formed as a result of a cooling ocean. all that came from the apollo 11 mission. it led to understanding of the early history of the planetary system, the part of the system of our planet, that it'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 listening to walker kr kronkite. >> we're celebrating the 50th anniversary and i think a lot of people in the general public think of it as human
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exploration. but science was there from the beginning whch beginning. when i watched it, one of the startling things i saw was when neil walked out of the capsule before his famous lines, he looked around and saw how the lunar limb was sitting on the surface and how deep the legs might have been crushing into the regular. and there was some debates on how thick that might have been. although we had landed on the moon by certain surveyors, you don't know if it was that deep. he was right off the bat talking about science. that was spectacular. what science experiments -- what did we put down on the moon for apollo 11? >> apollo 11 was the first of course of the landed spacecraft, and there were a total of 6 that landed successfully. and it wasn't the most ambitious
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by far in the experiments that are brought to the surface. but one of the opportunities provided by the apollo missions was the opportunity to do seismology. to study natural techtonic events. using seismometers. studying earthquakes all around the world and using the earthquake waves to learn about the interior structure of the earth. scientists got together and sent a seismic system on apollo. for reasons of coast, for reasos
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of schedule, the very first seismic experiment didn't have enough power source. i only lasted three weeks. it produced signals that the best seismologist in the world could not understand. really distinguished seismologists who had been working and thinking about it for years prior to the mission didn't know what they had in the way of the signals.
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they had taken them to the moon with the mind set they would see signals like you see on earth. they saw signals that look very different. that were full of high frequency energy that didn't have distinct or rising phases and rang on for tens of minutes or an hour. it was said the moon rang like a bell. the aploel 11 signals nobody figured out what they were. it took apollo 12. the apollo 12 astronauts landed in different places. they took another system and left the moon again. the seismologists asked nasa for permission when the astronauts docked in the orbit and didn't need the assent vehicle anymore
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to send the vehicle back down to the moon where it would crash. it would crash and create seismic waves and crash at a known place at a known time. for the first time they had a seismic source. the characteristics of which they knew and produced seismograms like the ones they seen on aploollo 11. it was an ah-ha moment. it took cooperation of flight folks at nasa to recreate an vent so we could understand how different the moon is from the earth. it's different because they are fractured and broken up. seismic waves go on for hours
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instead of minutes and none of that had been anticipated before the apollo mission. the lesson was if you take a terres terresitial experiment to planetary body, you have to really think out of the box. >> these are fabulous sets of data. if you're really excited about these, you have a scientific career, please see me after the lecture. they also collected a variety of samples. they did a fabulous job. they had about 50 pounds worth of samples the aploollo 11 crew brought back. why do we need the samples? what can we learn them? >> they aren't just a bunch of souvenirs even though they are cool. they represent this treasure-trove of knowledge. not just about how the earth and
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moon formed but also the incredible bombardment of giant impacts that were occurring in the first billion years or so after the solar system is initially formed. what's great about getting whole rock samples from the moon on these cruide missions is we can bring them back to earth and cut them up and send them to a hundred different labs and do a hundred different experiments on the best equipment possible. it's because of this that we can address a much wider diversity of science questions than you can with say a few instruments that you could put on a rover. you can have a higher diversity of viewpoints with different scientists and perspectives addressing those questions. from that perspective getting actual rock samples from the moon is integral. we have lunar meteorites.
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what's great about the apollo samples is we know exactly where they came from. we know exactly what geology they represent. we learn some really incredible things. we learn the earth and moon are very similar to each other and that in some sense we have a common origin and this led to this giant impact hypothesis that the moon formed by the impact of a mars size body into the proto earth and all this debris created the moon. we wouldn't know any of this without the samples. we can date rock samples that are glasses from impacts hitting the lunar surface and melting rocks. we can date them and figure out when those impacts happened. we can learn that the first billion years of our solar system's history was chaotic.
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in the first two billion years of earth history, stuff that big happened 300 times based on the scaling laws that we developed from studyin lunar samples from the apollo missions. it's fantastic that we get to work with them. >> we brought back about 840 pounds worth of lunar material. as it came back, the first thing we did was set aside about 25%.. it's done that way because as we learn things about how we analyze the current material we have in our hands we can approach the new material that way. over these last 50 years, our ability in the laboratory to look inside these rocks with ct scans and the individual adams and getting the isotauopes and e
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complex has become in hd. sampl never opened before. we had the panelists think about some of their great images from the apollo program and we've asked them to give us those and let's talk about these. here is our first one. this comes from apollo. >> 8. >> this was yours. what did you feel like when you saw that? >> those of you that 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 alpollo program. apollo 8 sent the first
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moon before they came back. when the spacecraft came from out of the shadow side of the moon to view the earth rising above the horizon anders took the famous image, earth rise. it was almost the only color in the sky. you could see the fearth's atmosphere. you could see land. you could see the oceans. you could see from space there
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are no political boundaries and the contrast with completely arrid and desolate, though beautiful moon had been appreciated up to that moment. in the 50 years since then, the magnificence of this view and the realization that the changes that man kind has imparted to our atmosphere and our oceans have made it less habitable place than it was 50 years ago just underscores how unique this planet is. it took the venturing of humans into space look back from
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another airless, ancient surface and give new appreciation to our home. >> to me walking around the newsstand just about every magazine that could grab a hold of this and i remember life which was this huge magazine, very popular, had it front and center and it was you really awe inspiring. they weren't the only three inspired. i conic ima iconic image. next one. >> okay. >> this is one of my favorite photos. it's a mirror of commander dave scott. kind of collecting samples on the lunar surface. i'm a sample scientist. it's like my bread and butter. you really get a sense of how they were going about it in this
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photo. you see he has a bag with a rock in it. there's a sample bag. they put these tiny rocks they picked up off the ground. he's messing around with this larger rock and on top of it is this funny stick looking tripod thing. it creates a shadow. what was cool is when you're on the moon, you don't have a compass that can tell you which way is north, south, east or west. if people on earth wanted to reconstruct what direction they were studying, they had to use the sunlight angle that was cast on the stick at the top of the tripod onto the ground and it's the sunlight angle coupled with the time and they could figure out what direction was what. this photo was amazing. it gives a sense of how they were going about their business
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on the surface. you have the footprints and the soil. you have the space suit. you have the sample bags. you have the whole thing. i have to say my favorite part of this image got cut off because if you were to tilt upward at the top and dave scott's helmet you have the best selfie of all time because there's a reflection of the other astronauts space suit and camera in the image. it just goes to show you that instagram is not a modern phenomen phenomenon. they were totally rulers at selfie taking during the apollo era. >> these were bulky suits. it's hard to pick up the materials on the ground. they had a variety of things they would use to pick them up. one of the astronauts wanted to pick up this very heavy rock and knew it might take him down if
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he picked it up. he put his leg up against it and with one of the rods that they had with a fence on the thing that picked up rocks, he just rolled it up his leg and then threw it in the box. we have a little orientation cube that talks about where the sun was when the rock was collected. next slide please. >> i think this one was mine. this is an image that i think captured a lot of what apollo 11 restaurants were doing. in the fore ground we see that's the seismometer that sean was
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talking about earlier. they were able to install quite quickly where as the ones that came on later missions took them a bit longer and those also lasted a lot longer. you see a white stick that's the antenna that allowed us to get data back. you can see a white trig angle. this is an experiment that's still operating today from apollo on the surface of the moon. its purpose is to do a better job of reflecting laser light back from the surface of the moon.
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all the advances happen here on earth. we use this, scientists use this to measure the rotation of the moon, the dance of the moon and the major things that we learn about it is what is the inside of the moon look like. what does it, how does it respond to title stresses that it receives from the earth. that tells us about what the deep interior of the moon is like. this has been going on for 50 years. in the background we can see other parts of the iconic image. on the farthest since we can see the television camera they used to provide the first interplanetary television show.
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>> that's right. next one, please. >> that's me. sean took my favorite image. we'll have to do with this boot print. many of you have probably seen this image before. just for context, i'm a remote sensing specialist. i work on data from orbit. most of what we do from orbit depends, what we interpret and how we see it depend ons ts on properties of the surface. apollo taught us about the properties of the red lift and those properties so we could derive meaningful information from orbit. this boot print may not look like much but if you're a sherlock holmes fan there's a lot of information here. the fact you have this imprint indicates there had to be some pace between the grains of dirt in order for it to compress.
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that affects the way we see light reflected back from the surface. it's important for making sure we're interpreting things correctly when looking back down. >> indeed. >> i had to go for two since he took my picture. the foot pads had these rods that stuck in. it was still fairly porous. it was sufficient to support the weight of the astronauts. nobody got stuck. properties like this are important not only for orbital
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stuff but round operations. you need to know you can move around on a surface. we would not send rovers if we thought it would get stuck in the sand. we got a surprise that it was not as porous as we thought. it didn't sink as far as we thought it would. >> us scientists delve into things. you think the general public would be interesting in knowing that you really got excited about. let me open it up to the panel. >> i could talk about magnetism now. >> the moon may have a magnetic
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field. >> the moon used to be magnetic. you probably know that the earth has a magnetic field. it's invisible basketball we'utg in it. the moon used to have a magnetic field too. you're probably wondering why does this matter at all. that's what i'm going to explain. if we go to the image of the moon and its magnetic field. this is an artist conception of the magnetic field that used to be on the moon billions of years ago. it had to be an artist conception because we can't see inside the planet and magnetic fields are invisible. they are almost like the heartbeat of a planetary body. they are this invisible but
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detectable signal that tells you that there is some activity going on inside at the core. the process that's occurring is organized motion of molten metal. hot iron at the center of the planetary body. it tells you that it's cooling down. we did not learn much about it from the initial landing at the apollo 11 site.
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if you go to the next slide. the image on the left that you see at tehe end of that rope is this little box looking thing with three prongs coming out of it by the astronaut and that is a magnatometer that they took the moon on apollo 12. you have them in your smartphones now. what they were able to do is they were able to measure the field at the surface of the moon. what they found is it was 1,000 times weaker than the earth's magnetic field but it also wasn't zero. why is that significant? it sells us that the moon was
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magnetized at some point. there was something there which means that they are probably a core inside the moon that might had a magnetic field generated from it. it wasn't obvious the moon has a score. the surface was a hint of that but what really nailed it was studying the magnetism in apollo samples from the time they formed billions of years ago. that's the picture on the right. this is also apollo 12. this is an astronaut picking up or about to pick up a moon rock with some tongs.
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what they were able to do is once the samples were brought back to earth they were sent to labs that study paleomagnetism. people are like dinosaurs were magnetic. no. >> at least their personalities are. >> paleo just means old. we can figure out whether a rock is magnetized. rocks acquire magnetism when they form. it reports it and preserves it for all of its history. what the apollo era paleo mag a magnetists found is in these rocks and it was at that time period it was as strong as the earth's magnetic field is today
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which is surprising for a small body like the moon because small body, small core. if you're further away from the core it's not going have such a big field but it did. that was a huge mystery. what persisted at the end of the apollo era is people weren't sure whether the field was from the inside of the moon or not. there's all these other hypotheses and it generates magnetic fields. we kept ourselves busy for 50 years. we came up with all these tests to show whether the rocks record an internal magnetic field generated by the moon or other exotic field sources. we found the moon did generate a field. it didn't just last till 3.5 billion years ago, it lasted past 2.5 billion years ago. it's much longer than people
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conceived of at the time. it tell us the moon was alive and active. s >> surprising. you learn planets evolve over time. you go back years and look at the moon it would be 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 bit like the case of the dog that didn't bark in the night. during and shortly after the apollo missions, it should be said nasa was very active as any robotic spacecraft to other planetary bodies in the solar system.
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it was only 16 months after the last apollo mission that the spacecraft viewed the planet mercury at close range for the first time. what mercury has and that is demonstrated by the images from the later mission, is that mercury is crisscrossed by huge faults. they underlie the great mountain ranges on earth and also with kinds of faults that accommodate and give rise to the largest
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earthquakes and these kinds of faults are seen throughout the planet mercury. the interpretation of the mariner ten team is that mercury shrank. it cooled so much that the amount of krcontraction was visible in the features that were preserved at the surface. mercury is only a little bit larger in diameter than the moon. the moon does not have this global pattern of great faults that accommodate horizontal shortin shortings. the accommodation of the lieu mar imaging got me interested in the question of why mercury contracted enough to produce all these faults and the moon over its history did not contract enough to produce a comparable pattern. that speaks to the thermal history, the history of the core that sonya was just talking
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about. >> what else the public may not know about these discoveries? >> i think one of the things that may not be well understood is the astronauts in orbit were doing science. there were scientific instruments and some that became p precursors of what we did later and in some cases exploration of our own planet. there was a radar which could see beneath the surface and we were using radar to underwhstan
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what was the depth of the rock from orbit. it's the same kind of technology that we use here on earth to understand how deeper the ice sheets in greenland and antarctica. when i was in graduate school one of the scientists larry haskin who worked in apollo missions was interested in the gamaspectrometer. there was this particular one seen. command models went around the equator. they collected data that suggested there was this hot
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spots. it went there and able to map the entire planet. they were able to see their hypothesis, the distribution was largely attributed to a single impact that happened early in the planet's history. >> throwing material all over the place. massive impact. the moon took one for earth that day. heather. >> kind of works like that. he covered what i was going to talk about. the important thing, one of the important things for what i do, at least, and that was sort of drilled into me is how important
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the samples were. the j missions and apollo so 15, 16, 17, because they had this package where they could do great orbital science and tie it directly to the areas we sampled meant we could extrapolate to other areas. that is the crux of remote sensing on earth and for every other planet is that you can only tie it to things you know. getting to sample, those are the key. i don't know if you know this. i'm going to sound so cheesy but the rocks -- the moon is our archive. the history is hidden in the rocks. we need to get those samples not just for the chemistry but the ages. for example, with the large impacts we use the relationships of the large impacts and they are the ages we know or think we
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know. we use that and say i know that area is approximately three billion years old. that whole system of connecting the sample ages to the stuff we see on the surface is extrapolated to all the other planets. all the solid surfaces of the solar system. the information is the basis for all of that. it's relatively few data points. it's enough to get some good information but we need more. it's a spectacular foundation. i think the tieing the remote sensing to samples is far more important than people tend to think. >> indeed. this really brings up another little segment i'd like to do quickly since we're running out of time. after the apollo program everybody thought we took a hiatus but in the '90s we started getting back to the moon. we learned an enormous amount by
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them. what are some of your favorite d discoverie discoveries. stephen. >> i think more excite iing pie of information we learned has to do with discovery of ice at the lunar polls. sean was talking about our understanding of the lunar rocks. they are dry and we don't see evidence of water, at least not then, on the surface. >> we thought the moon was bone dry. we call it bone dry for a couple of decades. then with later orbital missions, we were able to start to peer into pieces of real estate near the north and south pole. because of the way the moon rotates these are places inside these holes that basically never see sunlight. >> therefore the water remains frozen. >> heather, quickly. >> ripe for the picking.
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i forgot now. right. we had some tann tantalizing hi from apollo there were weird volcanic things on the surface. i wish i had included the picture. we know there are tons of them. the reason these are interesting is because it suggests the moon's volcanic history lasted a lot longer than we thought it did. it's possible some of these things formed in the last billion years or less. for a geologist that's like yesterday. we have these hint wes can now go and investigate.
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i would say one of the surprising things we have continued to learn about is how incompletely we understand the origin of the moon. with went to the moon 50 years ago saying we know three ideas for how the moon formed. it was a sister planet of the earth. it was ejected from the earth, a rapid lly spinning body. i've forgotten the third. >> the lunar magna ocean with the -- >> it doesn't matter. the third one at the time was capture of another body early on.
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all of them were implausible. those were the best ideas we had. we thought the apollo mission would allow us to have them and it did not. it said these are bad ideas. >> we have a top idea we have hung onto. post-apollo. >> it took the scientific community more than two years to colease behind the hypothesis that the moon was born as the material thrown out. wa h what has challenged us is the deeper we study, the more difficult it is to understand this giant impact hypothesis.
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this was worked out several decades ago but are different in most meteorites. they are different than martian meteorites. if the earth was hit by a mars size object it would be a remarkable coindense to stacide out. in the last few years we have gone down others that have shown remarkable coincidence. we still don't understand. it's creating a portion that would produce a body that is
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different from the earth in ways that the moon is not different. 50 years after the apollo mission we're still chasing the question. >> that's how science progresses and allows us to take the next step of figure out what the next set is we need. what i would like to have happen while we continue on discussing is the cards come to the end of the aisle. perhaps most of them have and start and collect. those online using the appropriate hashtags submit your questions. they're already here. that was fast. we can't answer all the questions but we will answer
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many of them and have them online at the ag website. question from the audience is should we directly challenge people who deny the moon landings ever took place? and what is the most effective way of doing that? let me go ahead and start. the lunar is orbiting the moon and is healthy spacecraft. it's doing a marvelous job to mapping the moon to high resolution. if this table sat on the moon, it would see it. we see these sites. we see where the astronauts walk. we see where they deploy the instruments. we see their backpacks before
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they walked in to levave the moon. we can't easily show those images, talk about those images and begin the dialogue then of what happened in that time period. that's how i've addressed that to a number of people that question it and you guys don't ever -- >> i work for the lunar reconnaissance camera team that takes those pictures. i had a slide deck that didn't make it into it and i can show it to you. you can't make these samples on earth. they just don't happen. some of the minerals are similar but the rocks themselves do not
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form here on earth in the same way. you can see that in the rock samples. >> if you look at a moon rock under the microscope, you will see there's some minerals that are different. on earth we have free oxygen floating around. oxygen likes to react with iron. on earth we always have iron oxides and on the moon there's none of that but metal. immediately you can look at it and say this is not from here. >> any others? all right. from twitter. how has studying the moon and other planetary bodies helped us better understand the earth that we wouldn't have known
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otherwise? to me this is enormously important. to me we are so lucky to have venus and earths to compare. we know from lunar material and other material that our solar system came together 4.6 billion years ago. they have all evolved. what's happened on venus can happen on earth. what's happened on mars can happen on earth in many different ways. comparing other planets really tells us a lot about how we evolved and how we will continue to evolve and what will happen to us. >> i think my studying the other planets it's really important to understand the earth and part of that comes from the same physic, the same chemistry operate throughout the universe. clearly there are different outcomes when we look at the different planets in our solar
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system. this is real opportunity because it allows us to understand how those things, how those processes work in different environments. for example, jim, you were talk about how venus and earth have had different outcomes. venus is this hot greenhouse planet. it has undergone a massive amount of change in its surface and is a relatively young planet at its surface. one of the things that's really important and one of the fundamental questions is why do we have plate techtonics. we can start to look at other planets to help us understand that question and what's really interesting is that mercury doesn't have plate techtonics, venus probably haven't plate
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techtonics. we can start to question what is special about here on earth. we can ask those questions. >> and systematically start answering it. my favorite angle is the bombardment record. we mentioned the history is preserved on the lunar surface and that's what makes it unique. that's not recorded on earth. we have erosion. it destroys everything. particulars is eroded. mercury is covered in lava. venus is covered in lava and horrible atmosphere gets in the way of everything. the moon really is a unique place to see this. the bombardment record, those are preserved there where they are not otherwise preserved. if you had a large flux of impacts and had it all the time,
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if you had all these impacts going on you couldn't evolve life. it had to happen like way before this massive influx or had to have happened after. that gives us some clues where else to look for life but also just on our own planet like what piece of history are we talking about. the life a new thing or is it way older. we don't know. the moon is one of the keys to unlocking that question. >> sean. >> the hypothesis it was an asteroid impact that killed the dinosaurs 66 million years ago would not have been accepted without the lunar program. we would not have appreciated it.
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we have no rocks that date from the first half billion years of earth's history. as well as we can study our own planet, the earliest chapters are not available to us. it took how chaotic and how giant impacts were common. how the growth of planet themselves was long drawn out process involving multiple politicia collisions and gravational interactions. how positions of major planets around the sun change over the
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early history of the solar system. that impacted the other planets as well. the time that is lost to us on earth is found on the moon and on the other planets and in the dynamics of the solar system and tells us something about the really challenging environment that our planet first faced and the contrast between venus, earth and mars in terms of starting conditions that are more nearly comparable and yet outcomes today that are so different with run away greenhouse on venus and atmosphere on mars that was largely lost after the planet lost its magnetic field leaving a cold arrid body of our neighbor out from the sun. those are important lessons for
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sensitivity of the evolution of our own planet and climate to small differences and conditions, distance from the sun and differences in the history of the magnetic field and hold up they can have profound consequences for the difference in surface outcomes. >> sonya. >> i think because the moon is such a well preserved body like the crust basic pulls onto what was going on at the beginning of the solar system, it's great for understanding what the earth was like early on and not just from an impact standpoint but also from planetary evolution standpoint. at some point plate techtonics turned on but the earth may not have started right off the back with plate techtonics. the world may have resembled mercury and mars at the
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beginning with a solid undercrust and then a mantle underneath it that was c convecting and doing things. what you might not know is if you look at the outer side of the moon it doesn't look like that. they are also not filled with as much lava. you don't have these dark regions on the far side of the moon moon. it tells you in these bodies that you have a lid crust you might have some weird magmatism happening. maybe from a giant impact and
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maybe from some internal process, all these hypotheses are raging. >> this is a very important topic and we can spend a whole several hours on it, i'm sure. let's go to another question from the audience. who made the lunar laser light reflector and what have we learned from those flashing laser lights coming back to us from the moon? >> i don't remember. >> i don't remember. >> okay, so that's lost in history. what are we learning from those? >> retro reflectors were left by
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several of the apollo missions. what we learn is to extraordinary precision, precision between my fingers the rotation rate and the distance to the moon. by measuring that over many, many, many years we can understand essentially how is imagine spinning an egg but it's hard boiled or one that isn't and how the different of that tells us about what the interior of that egg looks like. is it hard boiled or is it not. that's one of the main questions is trying to understand in the interior what is it like. what is the core of the moon look like? is it still liquid today. those are the kinds of things that we're using. we're trying to understand in many ways the deepest interior through measure ms that are
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still made today. >> okay, but 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 not changing. >> what's happening? >> the moon is moving away from there about an inch and a half a year. >> wow. >> that tells us about the title interaction between the earth and the moon. that's an important way of understanding that interaction of the earth and moon system. >> okay. all right. another question. if the moon doesn't show scieig of contraction while it cooled as mercury did, is it possible the moon is hallow? >> no. >> okay. let's tease this out a little bit. i saw the ringing of the moon and that ringing is in the
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crust. there's seismic impacts and it really rings the crust. are there traces from the seismic measurement that are interior of that. that go down the core. that's the dead give away. >> this is an example of why you you are david. this apollo experiment ran from apollo 12 till the end of fiscal year 1977. it collected about eight years of data on moon quakes, shallow and deep and on meteoroid impacts during that period.
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they were able to see features in the seismograms that they hadn't seen before. through in particular they were able to see reflections from the lunar core. they were able to see evidence that the core is divided into a fluid outer part and a solid inner part and see a distinctive player above the outer core that maybe close to partial melting of the rocks. they did that with waves that traveled down to the center of the moon and reflected back up. >> they had to find them in that data. that's the tough part. >> that rules out a hallow moon. >> okay. you could have started out with that hypothesis. that's an important way to look at it. would earth exist, meaning human life on earth, without the moon? >> this is a really good
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question. they all have been. i can partial answer that. the direct answer is difficult. there's an interesting contrast between the earth and mars in the history of climate over millions of years. mars does not have a mayor mojo. as a result the position of the spin axis relative to its orbit plane changes drastically over time scales of millions of years. the angle between the perpendicular is called the obliquity. as a result the climate, including the location of ice and co2 ice on mars has varied enormously with latitude. probably ice is left over near
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the equator from times when spin axis was pointing way different from the perpendicular plane. the earth, the reason we have seasons is there's a tilt to its spin axis. that is stabilized by our moon. the moon helps to keep the earth's orientation in space with the spin axis having the characteristic it does today. one of the challenges would be very different without the moon. >> very different. >> right now it's 23.t5 bedegre. it can be 22 and 24 degrees. it hardly moves. even that produces enormous
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changes in our climate. if you can imagine it lays over 45 degrees, the change in civilizations and migrations and everything else you'd have to do to survive that. the moon provides that. that's been an important stabilization force. this is another one, if you had a blank check, what instrument would you send to the moon on the very next mission? >> something they could drive the metric age of rocks so we wouldn't have to bring them back to earth. for sample return, you're limited by mass. if you had an instrument on site that could do that. there are instruments like this under development. >> there are. >> it's like trying to put a laboratory the size of this room into a tiny little box.
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it's very challenging. if you could do that then you could doll a whole lot and leara lot about the history of the solar system by roaming around the surface. >> i think we have to send back seismometers. >> they had some limitations. >> they had some dlimitations. one of those limitations was as sean mentioned the duration in which they were operated by nasa on the surface of the moon. another one had to do with the locations. they were all on the near side. that limited our ability to understand where earthquakes were throughout the moon and limited our ability to understand the structure of the moon. understanding the deepest interior is difficult and so we need more data in order to understand really how big is
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that. we know it's there now due to analyzing those archive data but there are questions in the sciey how big it is, exactly how big the solid portion of that is. and these are things that are really important for being able to understand the history of that core that can lead to the history of the magnetic field. >> yeah. also it fits into the theories in terms of when thia hit that pro toe earth, it lost its core to the earth. it's only the remnants of that that came together and created a core. one would expect that core to be smaller than if it decreted on its own without an impact. >> this has quite small. >> at least we think that. >>.
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>> if i had a blank checkbook, i probably wouldn't go to the moon next. >> but i would take advantage of the latest discoveries in the pole. i would want to go and core the ice. we know there's between 100 to 200 million tons of water ice in those craters, and that accumulated over time. when the moon had a magnetic field and when it didn't, and so we want to understand that and the only way to do it is to get a core and be able to look at it. and that's going to be really tough to go into a place that's dark, ice is there, and locate what you want and get that core and come back. >> give me your blank check. i'll do it. >> i really like the idea of drilling deeply into the moon. i think one thing that i would do is i would have a device that
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could drill, like, more than a kilometer down into the surface, and i probably would go into either a stack of lava flows or drill directly into the impact melt sheet inside a basin. a big impact that melted all the rocks and they cool down again. what's kind of cool about a big magmatic bodies that cooled slowly on earth is they sort of separate into layers and some layers are full of, like, ore minerals and stuff like that, and maybe something similar happened on the moon. some of the largest magnetic signatures, the most powerful fields on the moon are measured at impact crater locations, and i'd like to figure out where in the crater is that coming from? it's this big mystery right now. and so, therefore, that's what i would do. >> okay. all right. good. >> all right. next question. what are some of the exciting technological advances that you think will revolutionize space
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exploration over the next several decades. >> miniaturization. >> cube sets. >> we can make everything smaller now. we can send 100 shoe boxed sized probes crashing toward the moon and making every sensing measurement on the way down. you could learn so much from that, or just putting small instruments on a rover and actually dating moon rocks at the surface would be incredibly useful, and just the fact that we can do all of these small lab on a rover or just from the cube sets, you can learn so much from that. >> enhances our remote sensing. our ability to communicate. we're moving toward instead of radio communication, to laser communication. and so we can bring back an enormous amount of data. planetary science, we're limited in terms of the amount of data
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we can get back because the further you are away, the lower the data rate is. that's just one of the physical laws that we have to worry about. unless you changed the wavelength, and then up your game. so now those kind of technologies are right around the corner. also the ability to go from point a to point b with ion engines like we did with a mission called don. don was a spectacular, it's like a star trek impulse engines. these are them. we were able to saddle up to a huge asteroid called vesta, get it right into orbit. when we approached it, we 'approached it about the speed of an airplane landing on a runway. okay? and that's what that ion engine enabled us to do, and then we broke orbit and went out to another one, vesta. but those engines are getting better and better, and that will actually open up many more objects for us to be able to get
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to and really study and analyze. any others? >> roger? >> steve? >> well, you looked like you were going to say something. >> yes. one of the things i think is exciting that i think is already happening is drone technology. and so nasa just selected a mission that's going to use that technology to fly in the atmosphere of titan and to be able to explore its surface. i think the ability to take that sort of technology and be able to explore greater distances, to be able to choose where you're going to explore as you are exploring, i think is exceptionally exciting. and it's this great merger of arrow and space in what we do. and i think there are other places that we can imagine doing things that are more of flight, whether it is at venus or
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whether we can someday with that blank check be able to do those sort of things in the top atmospheres of the larger planets in our solar system. >> speaking of flight, okay, so we've already cashed this check. we have a helicopter on a mission going to mars. we're going to launch it in july. it's a rover. looks like curiosity. and it is underneath the belly pan of the rover. once it lands, that helicopter will be dropped. will drive away. will start it up, and it will have a go pro camera on it. it will look at its path ahead of the rover, and set down radio back that information for the rover to make decisions on how it will move forward. and this i think is just the start of how we might be able to use these kind of new vehicles. and because mars has an atmosphere, and although it's thin, we're able actually to navigate in it, and those planets that had at fears are
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next on our list. it's really exciting times. this will have to end our little overview, our panel. let me thank everyone. it's listen a delight. [ applause ] >> thank you for coming. i have a few minutes. i've been allowed a few minutes to wrap up, and so let me mention a couple things about what's coming up. you know, we're going to be going back to the moon. actually, we like to call it going forward to the moon with not only many more landed systems over the next several years but also the plans are to have humans on the surface of the moon by 2024. and so by 2024 you will
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witness -- the youngsters in the audience that hadn't seen the original, any of the landings will have the opportunity to live what we lived in our young careers, and i got to tell you, i don't think you'll be prepared to see what will happen. it will be so exciting. we're going to have the first woman and the next man stepping on the surface of the moon in the southern polar region. and so unlike what we see what the apollos with short shadows because the sun is nearly overhead, we're going to have erie views with long shadows and a whole host of new science things that we're going to do. so this is a tremendously exciting era coming up. and so once again, thanks so much for coming. allowing us to talk about our exciting first set of missions that have gone to the moon both in human exploration but robotic
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missions but let me tell you that is only the start of what we have planned for the next decade. thank you very much. >> all week we're featuring american history tv programs as a preview of what's available every weekend on c-span3. lectures in history, american artifacts. real america. the civil war. oral histories. the presidency. and special event coverage about our nation's history. enjoy american history tv now and every weekend on c-span3. >> here's a look at the prime time schedule on the c-span networks. starting at 10 p.m. eastern on
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c-span, summer interns at hold a debate on two political ideologies, libertarianism and conservatism. on c-span2 it's book tv with authors who have spoken at recent book fairs and festivals. on c-span3, american history tv with how world war ii american cartoons influenced the war effort. saturday, at 8:00 p.m. eastern on lectures in history a discussion about abe haraham lin and native american settlers. monday labor day, at 8:00 p.m. eastern, the commemoration of the 400th anniversary of virginia's first general assembly held at jamestown. explore our nation's past on
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american history tv every weekend on c-span3. >> sunday night on q and a. university of pennsylvania law school professor amy wax on free expression on college campuses and the conflict surrounding an opinion piece she co-authored in the philadelphia inquirer. >> i think this is what ruffled a lot of people that not all cultures are alike. we were trying to tout a code of behavior as being one that was particularly functional and suited to our current technological democratic capitalist society, and comparing it to other cultures which aren't as functional, and we gave some examples, and that immediately caused a fire storm. >> sunday night at 8:00 p.m. eastern on c-span's q and a. in the wake of the recent shootings in texas and ohio, the
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house judiciary committee will return early to mark up three gun violence prevention bills including babing high capacity ammunition magazines and preventing individuals convicted of misdemeanor hate crimes from purchasing a gun. live coverage begins wednesday, september 4th at 10:00 a.m. eastern on c-span and c-span.org. if you're on the go, listen to our live coverage using the free c-span radio app. >> up next, speakers associated with the nasa jet propulsion laboratory. they talk about what scientists learned from the rocks and other materials gathered during the missions. >> well, hello and welcome to nasa's jet propulsion

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