NOVA; To the Moon; Interview with Leon "Lee" Silver, Ph.D., Professor of Geology at the California Institute of Technology, part 3 of 4

anyone take one? Talk to me about that. Who paid for the first couple? We did. Actually Gene Shoemaker, more than anybody else, because he was chairman of the division. He allowed me to take a couple of curials out. I met the crews when they flew in. I transported them down there. I bought all the groceries. I did all the cooking. I had a very good post-doc who helped me wash the dishes, and then I did all the other stuff. The crews would do anything necessary to make it work. We had them sleeping on the ground, and we had them sitting at a folding table. I've got some slides upstairs if you want to see them. I think it might not hurt for you to get a sense of that, to see what these guys put up with. There were some tense moments, but they were intellectually challenged. I used several different gimmicks. I had a nice half crater with an old desert armwood tree in the middle, and I said, that's your landing mud. What can you see? They liked that. They would walk

around to do the whole thing. Then there's a story that I should tell. I don't think Jim Leveller told it. We're walking down a wash. Once again, my technique was to give the crews the assignment, require that they talk about what they were seeing. The thing that was most important was effective communication. That meant that they had to practice articulating, and I would walk behind them. As I walked down, and I was perhaps as far as from here to that cabinet over there, there were a series of outcrops of straight, tilted on end, and up on top of one of these straight up, was a pieute pot. It was the kind of pot that the pieudes used to put out with seeds. The pieuts still live very high on the hog. Put out filled with seeds so that they're chiefs when they pass away. If their spirits are

wandering, they can in fact have something to eat. Jim hadn't seen that. Somehow, without my insane anything, I had to maneuver them to where he finally became aware of that pot. He didn't even know what it was. It was this big globular thing about that bottom and falling out. It was probably several hundred years old, but he didn't find it. He liked that pot. I wouldn't say, I didn't put that pot there. I didn't do anything. The good Lord put it there, but that little incident raised the level of interest in enthusiasm. Jim still has that pot, so you can ask him about it. He did find it himself, but I will claim a little credit for sort of staring at him. What about some of your students, like Lovell, for instance? Did he fall in love with geology or did he become very enthusiastic? Did you watch these guys transform? Well, for Lovell,

it wasn't a transformation. Lovell, a very pragmatic guy. He played a key role in the science back room. I mentioned to you a little while. Lovell knew his mission, could see the role in the mission, was enthusiastic. The enthusiast in the prime crew was Fred Hayes. Fred Hayes had become good buddies with Jack Schmidt. I don't know what they did down there. He used most of the time, but that worked. The second enthusiast was the commander of the back of crew, John Young. John Young was a tremendous enthusiast. Charlie Duke was the guy who was easy to get along with and was interested in everything. That crew was first rate, and there was Schmidt, as I say, for half that first session in there. I didn't have to transform anybody as much as to ignite what I think was the challenge of being able to do things. What about a lot of people saying, well, robots could have done it as well?

Bob Humboldt. Robots could not do it as well, and I'll just simply say that the amount of science that came out of the robot we just put on Mars is about that big compared to what these crews did. That's not to say that we won't eventually develop unmanned methodologies, but don't let the hype get to you. These guys with their thinking and understanding, and just their sheer observational capability. Well, an example is on Apollo 15. I'll give you five examples on Apollo 15. After the first EVA, and the crews are returning from their visit to a big crater called St. George, the rim of it, where they did their assignments perfectly. But they hadn't been able to get very many rocks, and Dave Scott's writing along. Apollo said, the rover stops, and Dave says, I got to fix my seatbelt, and he came back, fixed his seatbelt, and drove on back to the landing module. What

had he done? He'd picked up the biggest single sample of the salt that we'd gotten in there, which we have forever after called the seatbelt of the salt in there. The point was, we had not gotten that kind of rock up to that point in this mission. He knew what we had gotten. He knew what he hadn't gotten, and he was not going to pass up this gem of a rock. I'll show you a picture of that rock, if you want to see it. Okay. But that's only one. They're on the second EVA. They're going up the side of Hadley Delta to get the steeper and steeper. They see a boulder up there. They stopped the rover, and they get off the rover, and when they remove their weight from the rover, they start to slide back down hill. So one of them had to stand there and hold the rover in place. They went to the boulder, and I think it was Jim Arwen first, who said, hey, that looks green. Now everything on the moon to that point had been in shades of gray, white, black. Okay. And Dave, I

may have it reversed now, threw up his gold visor. He said, I got it, it is green. Let's get it, and they took it. That's the green glass that Dave was talking to you about the other day. That glass and the orange glass, which Schmidt and Surnin saw, turned out to be two of the most important samples, and they tell us how much we know and don't know about the moon. And I want to tell you about that later on when we talk about science. But it was their observation of an anomaly, which the chances are we would never have seen if at that time we'd flown a man rover up there. But I can go on. There are so many other things it just goes on. Okay. Okay. I would make sure I don't forget these points today. I'm going to tell you about that later on. Okay. Well, what was the highlands versus the sea? Well, two distinctions. Part of it's in the name. Okay. The highlands are the regions of higher elevation

on any particular part of the lunar surface, although they don't have a constant elevation all the way around them. Same as true for the marae. The marae are very dark. The highlands have a very high reflectance and the contrast and reflectance. Made the marae look like which were great fields of basalt, volcanic rock. Made them look like they might be seas, which is where the name Marae came from. So the lower areas with the very dark reflectance, low reflectance, and the very higher areas with the very bright reflectance, where the highlands are the marae first and then the highlands. Okay. What about the basaltic volcanic? All right. Basaltic rocks are the most abundant rocks on the surface of the earth. And their rocks would have a particular composition if you listed about eight oxides that would define the composition. They'd be relatively low

in silicon oxide, relatively high in iron and magnesium oxide, relatively low in sodium and potassium oxide, relatively high in calcium oxide. And everything else in just tree elements stuck around there. Before we went to the moon, there was speculation on what the dark areas, which had been seen by astronomers, planetary astronomers for generations. And Mike Dukinai, among others, we're certainly not the first, speculated that the dark areas might in fact be basalts. And Mike did his PhD thesis studying a class of meteorites known as basaltic acondrites. Didn't have the controls that make acondrites very distinct, controls spherical bodies. Instead, they had textures like terrestrial basalts, but they're clearly extraterrestrial. And they had yielded the oldest ages we had to that point in time in anything in the solar system. So one of the speculations that Mike and I had was that

perhaps these were marae basalts apples. They weren't. I mean, but after all, remote sensing and standing a long way off. But as it now has transpired from our work on Mars or work on Venus in elsewhere, basalts are the most common rocks in the upper crust of all the crestial planets. So they're an extremely important ingredient in planetary construction. How did you feel that Armstrong and Aldrin, I know you were the PI on there, but how did you feel that their geology was a little bit that they got a chance to do? Remember what I told you, how good astronauts are, what raw material there is. The first thing is, they didn't learn where they planned to land. And if you remember, Neil had to take manual control and dance around to avoid big fields of boulders. And he finally put

it down. And he put it down with just, uh, variously, I'm told, okay, we're going to stop it. Well, I was an observer on Apollo 11 with my family, my wife and my two kids, I remember the kids were in their night clothes and all the other stuff in there. And, uh, it was absolutely thrilling scene. I didn't know what was really going on. Apollo 11 crew was lost. They knew where they were in the sense that they were down and they had their landing module on that other stuff. But the science back room didn't know where they

were and the mocker didn't know where they were, okay. And it was Gene Schumacher who figured out where they were and found it. And that in the face of very poor, uh, primitive, preliminary photography so that they could try to recognize craters and bolder fields and things like that. So that was one of the exciting things. Given all that, they only had a limited time on the ground. This is Apollo 11, the first landing on the moon. All of a sudden, Neil disappears from the television field of view. Neil was never supposed to leave the television field of view. Then he's back. What has he done? He's taken one of these special sample boxes and contrary to anybody else's advice, he had jammed that thing full of rocks and soil and everything and brought back a fantastic sweet of rocks. Okay. Now, who will ever give him credit for having given us the first return samples in such abundance? So we haven't even gone to analyze it all to understand, but from which we could select things in the

preliminary ceiling left. It was just due to pendants feet and buzz was doing the same kind of thing. So if you want to hear that story, hear it from Gordon Swann when you see it, because Gordon was there in the science back room. Most of what I'm telling you, I've learned from him. When, um, we're skipping around one Apollo 13, when that crew that you had trained ran into their mishap. What went through your mind here? Did you have great promise? I mean, you were thinking, oh, yeah, I, in a case like that, you're at the beginning of an experiment. You got good people working on it. You're enthused and all. And I'm down at the cape and I watch the launch to understand, said goodbye to the guys and, and, and then I headed for Houston. And then the word came back. Houston, we have a problem, you know. And so in the end, right, at Houston, I just kept on going to Pasadena. There was no use might being there because it was somebody else's thing. My concern was for the crew. These are

people I worked with. Beyond concerns for their health, when you're thinking geologically, oh, it without question, I was disappointed, but priorities are priorities. Now, how important target was co-incrader for the Apollo 14? What were the possibilities there? And was it, were there missed opportunities? The co-incrader, like every impact crater and the fresher the incorrect crater, the true or the cases, is a three dimensional probe that is the impact itself brought material from down deep. So we get the third dimension of materials. And this comes from the fundamental understanding of what impact craters do that Gene Schumacher and his many colleagues established. We expected to get pristine samples of the throw-out from the Yimbian impact. And we'd already had some clues from the stuff that we got back from 12 that this was very special stuff. It wasn't almost like nothing that we had seen on Apollo 11. So we wanted to

get way down in there to understand, to understand this particular formation that the co-incrader had sampled. The fact is that the crew had been on the Rema co-incrader, almost certainly, and had even done some sampling on there. But their sampling wasn't guided either by their own preparation or by the back rooms inputs to understand the way it would have been if we had been able to confirm where we were. And once again, we didn't have enough preliminary photography. That was the last time that we went on a flight like that without having really good photography. And when we did 15, we understood that. And now let me tell you something again. Sitting in the science back room, but I was not a member of the science team for 14 was Dave Scott and myself. And we were learning about things that we thought were important in that. And this was this mutual training and education in there.

What did you resolve as you watched the crew of 14? What we resolved was that the rover was going to be absolutely essential to do anything. You cannot fault the crew of 14 or their physical effort. It was extraordinary. And they're pulling this little rickshaw with the sample materials and the sample tools and all the other things. It was an immense feat. And Alan Shepherd deserves a lot of credit for that. I just wished he'd spend more time working with the people who were trying to explain the geology of the scientific term. What was the biggest disappointment of 14 in terms of what you didn't get geology? We didn't get documented samples the way we wanted. But we learned a great deal from the samples we did get. If you want to talk about what percentage of the experiment did we lose? Five percent. Okay. Something like that. You know, you have to deal with each mission separately. And in dealing with expectations,

you have to know what we learned at that time for prior to that mission as we prepared for that mission. Remember, it was an accruing knowledge base as we went from mission to mission in here. On Apollo 15, we were trying to do too much. And we didn't do it all. Okay. We wanted to explore the highest mountain that we were going to visit. That was Hadley Delta. We wanted to explore what's called the basalts of the palace putredness, the stinking swamp. And we wanted to explore this reel, a kind of grand canyon. Wasn't a grand canyon. It was more like the canyon and the real grand at Touse, which we used as a training spot, some of those pictures in there. These are all new features. These are things that we want to do new things. And we also had to set hills off there that just might have been volcanoes, might have been volcanoes. We wanted to get to those. Now, we never did get to

the maybe volcanoes way out there. But we had such a rich, plate full of targets to understand the question was how much we could do. Now, one thing we had not done to this point, is we had never seen bedrock. We'd never taken a sample of rock that says this is from that part of the crust, which just goes down and down. Everything we'd picked up were fragments. Cone crater. Even though we knew the stuff came from down there, they were all fragments. That was true for 11 and 12 and what have it. Here we had a chance of getting bedrock. Well, we're not absolutely sure, but I'll bet 95% probability that we did get to bedrock on the edge of the river where the crew started to get down over and they were warned to come back up a little bit. Don't get down that too far because that's a 350 meter drop down into the bottom in there. We got that. We got chunks of stuff on the rim of the St. George crater. Now,

let me talk about that. One of the things we really learned about the moon from the first Apollo 11 was the fact that the moon is an un-shielded surface. It has neither the magnetic field, which shields us from charged particles from space and the sun and what have you. And we have an atmosphere which burns things up to understand which shields us once again. No such thing on the moon. So we began to understand that there was a solar flux and a cosmic ray flux. And we wanted to do experiments which would tell us how long a given surface had been exposed to that flux. And it's very clever science doing beautiful work on that. My job was to translate what these guys wanted into collecting actions. And I did this with a lot of help. I don't want to make it too first person. They were to take a big boulder. They were to the sample the outside the

boulder. They were to roll the boulder over and sample the underside of the boulder. They're going to take the sunny side of the boulder. They're going to take the shaded side of the boulder and look what happened to the soil in all these things. They were ahead of their timelines. They were doing beautifully because they had trained and were prepared. And above all, they were following a protocol which Jean Chumaker originally started to set up of documenting exactly what they were doing. More photographs than we know it to do it. I have a whole set of those upstairs to be glad to show them to you. So the crew was doing everything you could possibly ask. But as I say, those were instructions. Find a boulder, do this, do that, do the other. But then there are all these other things to be done. How close can you get to the edge of the rail and see whether you're in bedrock? What does it look like going down that slope? You can't get the camera over down to look at it. It was the crew that looked and saw and thought and recorded and translated. And we were working from the

back room. As they progressed through the experiment, we began to see what our accumulative yield was. Then we could make decisions about what to give up, what not to give up, to understand. Great. All right. It brought us back in time. Or it could have been done better. And it worked back and forth. And a very important element of this was that when the crews that finally flew, like in London, like 15, 16, and 17, they knew who the guys were in the back room. There was an understanding of how each astronaut operated. And it became a working system, you understand? This was a team effort. You never saw us. We weren't in the mocker. That big room. We're in a tiny room and back, which had its own interesting history, episodes and what have you. But in fact, the crews knew what was going on there. They knew how we did it. You understand?

Yeah. Just read it out. Perfect. Perfect. All right. Switch over. Excellent. Excellent. Don't worry. I won't drop on you. I don't mind. He's got, she's got to stand.