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Oral History Transcript — Dr. Brian Marsden

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Interview with Dr. Brian Marsden
By David DeVorkin
At Minor Planet Center, SAO, Cambridge, Massachusetts
October 17, 2005

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Brian Marsden; October 17, 2005

ABSTRACT: Biographical profile for the astronomer Brian Marsden, emphasizing his career at the Smithsonian Astrophysical Observatory. Yorkshire family roots. Parents and early home life in Cambridge, England. Father’s training and occupation as schoolteacher at Cambridge High School with specialty in mathematics. Recollections of World War II. Childhood scarlet fever. Early experiences with astronomical phenomena: solar eclipse of 1942. Fascination with bus schedules and predictive phenomena. Schooling — the Perse School for Boys. Fascination with calendars and calendrical systems. Sports. First look through a telescope. Discussion of private observatories in England. Visits to observatories as a child. Contact with David Dewhirst. Involvement in an “experimental education” program and facility with languages. Interest in languages, mathematics and general science – passed Ordinary Level Examinations in those areas. Established an astronomical society at his school. Discussion of reading literature of various types. Decision about attending New College, Oxford. Predicting eclipses of planetary satellites. Discussion of Fred Whipple and their mutual rejection of pure mathematics. Oxford professors. Contact with Gerald Merton at Oxford and discussion of various uses of ephemerides. Joins the Comet Section of the British Astronomical Association at age 16. Assisting in translations of cometary works, working with Arthur Beer, and hand calculating machines. Sky & Telescope subscription and Sputnik. Recollections of Sputnik and predicting its appearance over Oxford. Dedication to orbit calculations. Letters from Dorothy Sayers. Ending of undergraduate years and thinking of a career. Astronomers contacted. Olin Eggen leaves Cambridge. Cometary orbit calculations. Decision to take position at Yale to study with Dirk Brouwer — Employment and matriculation at Yale in 1958. SAO not a viable option. Yale faculty. Computer programming on an IBM 650. Meeting Fred Whipple. Recollections of Arthur Beer. Impressions of SAO. Recollections of Edgar Everhart and G. van Biesbroeck and comet work. Discussion of methods of data reduction and orbit analysis and the small circle of orbit specialists he encountered. The need for manpower in orbit computing in the early years of the space age. Paul Herget and the Minor Planet Center. Description of Yale facilities. Brouwer’s projects. Yale Zone Catalogues. Comment on the SAO Star Catalogue and the incorporation of newer methods of analysis in celestial mechanics ands fundamental astronomy. Marsden’s PhD thesis on the Jovian satellite system. Comments on the state of celestial mechanics at the time of his dissertation in the late 1950s and early 1960s.

Transcript

Session I | Session II

DeVorkin:

This is a second oral history session with Brian Marsden. The date is Monday October 17. And, all the auspices are the same as they were before. And Brian, you’re holding in your hand, the Letters of Dorothy L. Sayers, chosen and edited by Barbara Reynolds with a preface by P.D. James. Volume four. And you’re about to read from the preface?

Marsden:

From the introduction: “These letters show, the degree to which her intellect was passionately involved with what she considered important or worth her creative dedication. A most remarkable example was her annoyance at what she believed was a dishonest interpretation by Robert Graves of the Roman poet Lucan. In the last year of her life, thinking to relax her mind from her efforts to translate Dante’s Paradiso she read Graves’ ‘Translation of Pharsalia.’ Her misgivings were at once aroused and through letter after letter we see them increase in indignation, culminating in an impassioned resolve to clear the name of an ancient poet dead two thousand years. The question was extremely intricate, involving early notions of astronomy and geography and required the most detailed application. Her involvement was personal as well as intellectual. Writing to a young astronomer who was recruited to help her, she said, ‘I’m not doing this for anybody. I just can’t bear to see the man treated like that even though he is two thousand years dead and I believe Lucan is substantially talking sense and I want to get to the bottom of it. I don’t care what it costs or how long it takes. I want justice. I want honest scholarship and accurate translation.’ Thirty years later the young astronomer, Dr. Brian J. Marsden, wrote an account of the investigations they carried out together in which he vindicated both the Roman poet and his impassioned defender.”

DeVorkin:

Right.

Marsden:

Yes. [Laugh] All right. Where were we?

DeVorkin:

You were talking about members of your Yale graduate class, and, we were toward the end of your Yale graduate work. And, you were talking about Mike Lecar, Steve Gross, Jim Rodman, and you gave me a good profile of all of them, and of students generally at Yale, and then you were going to talk about options for employment after Yale, and when you started thinking about that and what you did about it.

Marsden:

Yes. Those particular students started in astronomy in the same year that I did in 1959. Only two of us were really doing celestial mechanics, Steve Gross and myself. Brouwer, I think the U.S. was quite desperate to bring young people into celestial mechanics because of all the problems posed by Sputnik. And so, the fact that two of us started as graduate students was felt to be rather good. There was at least one, earlier student [Jocelyn Gill] still working on her Ph.D. in celestial mechanics at that time. Then the following year, there were two students but one dropped out. The real effort I would say started two years later. In 1961 we had a lot of students with well-known names like Bill Jefferys, Myles Standish, Jay Lieske, Carol Williams, and also some from the Naval Observatory, Doug O’Handley, and then the next year Tom Van Flandern and David Dunham. There were about eight students who came by special arrangement with the Air Force Cartographic Information Center in St. Louis to learn about celestial mechanics and astrometry. I fear only one of them actually made it through to a PhD. That was Charlie Martin.

DeVorkin:

These were people who were in service, active service?

Marsden:

They were civilians working at the Air Force Cartographic Information Center. There was a genuine effort by about 1961, ‘62. In a way it was three or four years later after Sputnik, but clearly there was very much an impetus to continue to get more people into celestial mechanics. Brouwer got money to form a research center in celestial mechanics in another building in New Haven, which was actually on Edwards Street.

DeVorkin:

So you did move to Edwards Street?

Marsden:

Yes. I mentioned last week, on a previous tape that we worked on deriving the astronomical unit using the radar data. This very much tied with what Brouwer was trying to do with the people at JPL, and their efforts there to produce ephemeredes for the major planets for space missions. That was the ultimate aim as we went into space missions, to have good ephemerides for them, supplementing the work that was done at the Nautical Almanac Office. So, Brouwer worked very much with them. [Laugh] I remember when the first radar data came in. He wasn’t terribly happy with it in comparison with the Lincoln Lab data, and given his frugal, ways, (he went around the observatory turning lights out at night), I remember he complained to me about the way the people at JPL would keep calling him up on the telephone. “Why didn’t they write letters?” [Laugh] Just the expense of these long distance phone calls really bothered him.

DeVorkin:

Lincoln Labs was radar?

Marsden:

They were radar and they were doing some at Goldstone as well, and there was some inconsistency that we did manage to work out. Well, I worked at JPL two summers there in ‘63 and ‘64 and there was one occasion, at least one occasion, when Brouwer and I went out there during the year to try and straighten things out, because it came to be very clear that they were trying to do things but just didn’t know quite what they were doing. They made the most elementary mistakes, which I probably needn’t go into.

DeVorkin:

Who were they? What group?

Marsden:

It was a group that was doing planetary ephemeredes. Neil Block was one of the people doing the work. Doug Holdreidge was a bit out of it. He had a nervous breakdown but he, was their brains. The man in charge was a man called Peabody. Although around here we call it Peabody [ pron. peeb-di].

DeVorkin:

Are all of these names in Orbit Theory then?

Marsden:

No. You wouldn’t know the names. They were just people who were on the JPL staff. Dewey Muhleman was partly involved in it. He was a, he was a Harvard astronomy Ph.D. He did a lot of the work on radar. He wasn’t directly involved with this effort but he was very much interested in the outcome of course.

Marsden:

So, this kind of thing was going on, and this now ties into, what I was going to do when I finished my Ph.D. Certainly, to go to JPL and work there was one of the options. It was wonderful, actually, how many options there were. I know I had at least six that were relatively serious. One was, of course, to stay at Yale. One was to go to Tampa, South Florida where Heinrich Eichhorn had set up a program, having moved from Middletown. Carol Williams eventually went to work with him. As far as JPL was concerned, Jay Lieske and Myles Standish went there. Well only a year or so later. I mean they were a year or two behind me.

DeVorkin:

Well, Myles was one of my teachers in the ‘70s.

Marsden:

Oh. Maybe he did stay at Yale that long, but he was very much interested earlier on in the effort, and he was the one who did go finally and rescued the JPL ephemeris efforts. He’s still in charge of it. And, that’s great because he knew what he was doing. Brouwer trained him well; Brouwer trained all of us. [Laugh] And, for myself, as I looked at, various options The two that I considered most seriously were to go to take up Gerard Kuiper’s offer and go to the Lunar and Planetary Lab in Tucson, or to take up Fred Whipple’s offer and come here to SAO. Those were the two I was most considering but there were four or so other options including JPL and Tampa.

DeVorkin:

Did you go out to Tucson?

Marsden:

Yes. Kuiper, as I mentioned before, had still been at Yerkes when I first went there, which was over New Years 1959-60. In fact, I spent that New Year Eve at Kuiper’s house. Then during 1960 he was moving out to Tucson. I think they still have this interesting custom at Yerkes where the staff votes the Director out if they want to remove him, and that often happened at Yerkes.

DeVorkin:

Is that what literally happened?

Marsden:

I think it did in this case.

Marsden:

No. But anyway, I was in Tucson briefly in the summer of 1960 and I’m trying to recall whether he’d moved then, because I was definitely there in the summer of 1961. Yale holds summer institutes in dynamical astronomy and the one in 1961 was in Tucson.

DeVorkin:

Oh, so they were held in different places?

Marsden:

Yes. I didn’t go to them every year and but I do very much remember the one in ‘61, which was just before the IAU meeting at Berkeley. It nicely gelled with that, and I had a visit to Flagstaff on the way. That’s where I met Jim Gibson, in August 1961.

DeVorkin:

So, you went to the IAU?

Marsden:

I went to the IAU having spent six weeks or so at the summer institute in Tucson. And Kuiper was definitely there then, and Carpenter was running the Steward Observatory. Kuiper was doing things like projecting maps of the moon onto a sphere, so that you really got the three dimensional effect. Because, by then we already did have observations from the other side of the moon, beginning in ‘59.

DeVorkin:

Did you talk to Kuiper or know about his controversy with Urey during this time?

Marsden:

No. I didn’t. No.

DeVorkin:

That was not an issue about a reason for or against going to Arizona?

Marsden:

I don’t know. Of course, Urey was known for moving planetary astronomers around, as with Carl Sagan here. I mean, Carl Sagan left here because of Urey.

DeVorkin:

No, I didn’t know that.

Marsden:

It’s not widely known, and Fred Whipple knew it but wouldn’t tell anybody during his lifetime. [Laugh]

DeVorkin:

Well, what did Urey do to him?

Marsden:

I don’t know. It was Babbie Whipple who told me that it was Urey who was responsible for removing Carl Sagan from Harvard and that Fred was very upset about it.

DeVorkin:

Oh, how interesting. That was certainly well after Menzel?

Marsden:

Yes. Of course it was.

DeVorkin:

I mean, Goldberg?

Marsden:

Yes. It was in Goldberg’s time and one of the things that led to some unpleasantness, shall we say, between Whipple and Goldberg.

DeVorkin:

There are two biographies of Sagan. I’ll have to look at them. One of them by Keay Davidson is pretty darn good. The other one I don’t know quite well.

Marsden:

Yes, you might pursue that a little bit I think.

DeVorkin:

Do you know Jeff Goldstein? He was an infrared astronomer.

Marsden:

I don’t know him.

DeVorkin:

Apparently he’s negotiated with Carl Sagan’s widow Ann Druyan; to open up a center in Carl’s name.

Marsden:

That would be wonderful.

DeVorkin:

Somewhere in the Greenbelt area. And, obviously with Maryland, and NASA right there and everything, and then to somehow collect his voluminous papers.

Marsden:

I think that would be a wonderful thing to do. I always liked Carl. He and I, you know, we got on. And, in contact, I know there was someone running the Central Bureau for Astronomical Telegrams. He didn’t use my name.

DeVorkin:

Well, we all knew it was you.

Marsden:

[Laugh] Yes. That’s, that’s right.

DeVorkin:

Who else was running it?

Marsden:

Carl sent me a copy. I’ve still got it. What did he say though? I think that was the name.

DeVorkin:

Auerbach?

Marsden:

Yes. I think that was the name and he said something about how “he couldn’t possibly replace me.” [Laugh] Words to that effect.

DeVorkin:

Auerbach couldn’t?

Marsden:

[Laugh] Yes.

DeVorkin:

Well, it’s interesting about science fiction and astronomers who write science fiction, and then put characteristics on who are recognizable to other astronomers then.

Marsden:

Yes. [Laugh]

DeVorkin:

Do you have any thoughts about that?

Marsden:

Not, not really. I mean I think it’s a nice thing to do. But, I onlyif it’s done in a positive way, of course. I’m not so sure it’s a good idea if it’s negative.

DeVorkin:

Well, Fred Hoyle’s depiction of the Astronomer Royal, for instance.

Marsden:

Yes, but that was Woolly then?

DeVorkin:

That was Woolly.

Marsden:

Or Spencer Jones even.

DeVorkin:

Could have been.

Marsden:

Yes. The way he depicted the Royal Astronomical Society meetings and the British Astronomical Association, as well. And some remark about “It couldn’t be amateurs that had shown that Jupiter wasn’t in its right place.” [Laugh] Or something like that.

DeVorkin:

Did you read the Black Cloud first run? First Edition?

Marsden:

When it first came out. It’s a long time ago now. Its ‘58 or so. I do remember the first part. I don’t remember all of the details other than what I just said, but I remember reading it at the time as that’s the way astronomers really are.

DeVorkin:

Well, the fact that there were perturbations.

Marsden:

Yes, well I think by the time the people in the BA noticed it it was considerably off. [Laughter] A substantial part of a degree, as I recall. I could be wrong. [Laugh] I don’t remember exactly.

DeVorkin:

So, what decided you against, Tucson? Staying in Tucson.

Marsden:

One visit I made there really with the idea that he wanted me to go there. I mean that he specifically invited me, in April 1963. And, Van Biesbroeck was there. My old friend Van Biesbroeck was there as well. We were both being interviewed for a job. Well, “interviewed” is a slightly strong word, I think. Kuiper was trying to persuade us both to go there. Of course, I hadn’t finished my thesis yet.

DeVorkin:

Van Biesbroeck was almost ninety?

Marsden:

At that time he was eighty-three. Kuiper took Van B and me up to what was going to be the Catalina Station, where he would have the 1.5 meter reflector. And, we went to the top of the hill, or to the part where the telescope was going to be, and I remember in particular the way Van B was running around with a surveyor’s tape. Running! Running; at the age of eighty-three. Of course, he had been trained as a civil engineer way back in Belgium at the very end of the 19th Century. So, it was all rather entertaining. But Van B agreed to go and work there.

DeVorkin:

It’s at least six thousand feet?

Marsden:

It’s not quite that high. Yeah, he was running with the tape. One of those summers when I was at JPL I remember Fred called me on the phone very much wanting me to come here. That was probably in ‘64. Well, actually I got married at the end of 1964. So, that might have hurried me a little on a bit to finish my thesis, sometime. One needs an incentive like that when you’re having such a great time being a graduate student involved in all kinds of things.

DeVorkin:

Well, let’s focus on why you didn’t go to Tucson and why you didn’t stay at Yale.

Marsden:

I think it was really, “Why did I come here?”

DeVorkin:

Well, okay.

Marsden:

Although Bouwer was clearly interested in my staying on he didn’t actually make an offer. I think he could have done if he wanted to. He was sort of interested in my staying there. Kuiper clearly was more interested, and he did make an offer. And then with regard to coming here, I suppose there were a couple of things. One, involved the Central Bureau of Astronomical Telegrams, because the Harvard Announcement Cards had been prepared here, by Frances Wright in the 1980’s and by Martha Liller in the early 1960’s. And, then in the summer of 1964, Martha and Bill Liller went to Cambridge, England, for a year on sabbatical. That’s when Owen [Gingerich] took over the Harvard Announcement Cards. That was in June 1964. The IAU Central Bureau had been run in Copenhagen until 1960 by Julie VinterHansen. Then Karl Thernöe took over. I visited him in Copenhagen in the summer of 1962. I’d met him at Berkeley in ‘61 and I was giving him a lot of business for the Central Telegram Bureau with comet orbits while I was at Yale. On that 1962 visit to Copenhagen he told me that he really wasn’t very happy about continuing there at the observatory. For one thing he didn’t get on too well with the new director. Whipple had tried to get here in the late ‘50s. But, what interested Thernöe was teaching astronomy to high school teachers. Also, he was one of the best known astronomers to the public in Denmark because he had a regularly TV program that he did in those days. On this 1962 trip he asked me to a restaurant all around the island of Zealand, [pron. zayland] the main island, and we’d be eating dinner and the waiter would sort of come up slyly and speak to him in Danish. The waiter had recognized him from the television. [Laugh] Anyway, he told me already in 1962 that he would (???) sire up the Central Bureau. While I knew I didn’t know that it was going to come here. I was at the meeting of IAU Commission 6 (the telegram commission) in Hamburg in August 1964 when the announcement was officially made that Thernöe and therefore Copenhagen would give it up, and Whipple offered to bring it here. There being no objections, it was brought here at that time.

DeVorkin:

You had no prior knowledge?

Marsden:

I did not know that Whipple was going to bring it here. I knew Owen was doing the Harvard Announcement Cards here at SAO. Well, they were Harvard Announcement Cards but Owen had a joint position. Although, this was the first I had heard that Whipple was wanting to bring IAU Centeral Bureau here, but that struck me as very logical. Obviously, he had the capability of doing it here. The Harvard Announcement Cards would cease and the IAU Central Telegram Bureau would take over. He was very much interested in that. Fred had of course been involved with the Harvard Announcement Cards for a long time. In fact, his name appeared on them, even while Frances Wright was preparing them.

DeVorkin:

Really?

Marsden:

When Martha Liller took over that was the first time the name changed. She must have insisted that her name appear on the cards. But, I know Fred was doing them while Harlow Shapley’s name appeared on them. And then it was only when Shapley bowed out that Fred took over.

DeVorkin:

Did the designation here, with the IAU, bring with it any added support?

Marsden:

There was a small amount of money that the IAU gave to the Central Telegram Bureau and that was transferred here. It was not very much. I mean, it was of the order of a $1,000 a year. I can’t remember exactly what it was because it was always and still is, in Swiss Francs. And so, as I say at that meeting in Hamburg, of Commission 6, and that registered with me since, I had been interested at one time in possibly going to work at the IAU Bureau in Copenhagen. That had been one of the things I’d been thinking about in 1959, while I was still an undergraduate. Before 1959.

DeVorkin:

Well, the important thing to know is that you made your decision coming here, but you haven’t still finalized?

Marsden:

We hadn’t finalized it. Yeah.

DeVorkin:

But, you made it without the knowledge that the Central Bureau [would come here.].

Marsden:

Initially it was very high on my list, but I hadn’t, I suppose, fully decided between here and going to Tucson with Kuiper. I did discuss it with my wife, she doesn’t like the desert, and she’s from Connecticut, so clearly she much preferred the idea of coming here than going to Tucson. So, that also figured in the decision. One of the things that happened in April 1965 was that there was a meeting in Paris, a celestial mechanics meeting. I didn’t go to it. Brouwer was there, and so was Imre Izsak, who had come over to SAO from Hungary in 1958, or soon afterwards. He died suddenly during the Paris meeting. He was only, what, thirty-six or so? Whipple called me shortly afterwards and said, “Well, now we need you even more, with Izsak’s death.” So, I came up for an interview in May of ‘65. That was less than a month after Izsak had died. I was also then in the final steps of my thesis. I came up and talked to Whipple, Dick Southworth, Luigi, Jacchia, and Gerald Hawkins. There were four people who interviewed me.

Marsden:

Southworth wa a rather quiet person who worked in the planetary area and I (???) interviewed him as much as he did me. He left quite a few years ago. After the interview, which went very well, we made the arrangements for me to come in September. I finished my thesis and handed it in just in time for the August 27th deadline. I started work on Wednesday the 29th of September, which was just the day that Fred had realized that the comet that had been found in mid-September by Ikea and Seki in Japan, was a member of the famous Sun Grazing Group. I was ruled of out of it myself. What with cleaning up (???) in Connection and traveling here, so I hadn’t paid too much attention to it. There were people were trying to compute an orbit, not with a great amount of success, and Fred said, “Well, this must be a Kreutz sungrazer.” So, Friday afternoon, October 1st, my third day of work; I was in a press conference with Fred and Owen, because by then I had calculated an orbit. That was my first experience with press conferences.

DeVorkin:

Is it symbolic of your career here?

Marsden:

[Laugh] Well, we don’t often have press conferences but there’s a lot of interaction with individual members of the press. That was formal press conference was arranged because it seemed that this coment would be about as good as theGreat Comet of 1882. Owen and I worked very hard in the month of October, organizing this comet. I He said he “lost a whole month of his life to that comet.” [Laugh] One of the things that made him particularly happy was I was here to help out with the Central Telegram Bureau, and at the same time, I was, starting some research projects as well. There were two basic projects I wanted to do. Yes, I should back up a little bit. One of the nice things about Fred as director, was — and he told me this when I came for my interview — that, he would suggest to staff members, various projects that they might like to work on. He would make suggestions, but he wanted me to know — and I presume he said this to everybody—that he never wanted to insist that they worked on Owen. He wanted them to be free to explore whatever problems they wanted to.

DeVorkin:

Did he make good on that?

Marsden:

Yes. Oh yes. Very definitely, I always felt that way with Fred. And, there were times, of course, when I did take up what he, what he wanted.

DeVorkin:

W ould you know the difference?

Marsden:

I know there were some things that very much interested him. One in particular was Encke’s Comet. After all that was the comet that he was using in his fission 1950 papers on the Icy Conglomerate Model. The first paper, the important one on the nongravitational effects. I was actually a bit skeptical about whether comets were seriously affected, by non-gravitational forces, because a lot of the trouble was with the calculations. He knew of my skepticism, I had been doing predictions of returns of comets by hand for the British Astronomical Association Computing Section in the mid ‘50s already. And, I knew we made various approximations. And this was always the question. Pat Roemer gave a talk on the origins too. She was the one who was observing most of the comets and using the various predictions. She gave a talk at a mini symposium on comets that the American Astronomical Society in June 1961 in Nantucket. And, she gave, a very, critical paper. She felt that it was by no means proven that nongravitational effects existed in the motions of comets. This was a decade after Fred, which of course, Fred had developed, his model. In this case Fred was essentially correct, of course. But there was another paper he wrote about comets around1964. That used variations in brightness to make specific predictions of the data of demise of various comets. He had Encke’s Comet kicking the bucket in the early 1990s, as I remember. In fact, the dates that he had for the demise of comets were pretty much all in the second half of the 20th Century, or first half of the 21st. He had very few comets left at the end of that time. And, this was clearly a case where he was wrong. Fortunately he never published it, but I remember at my interview telling him I didn’t believe it. [Laugh]

DeVorkin:

That’s why there wouldn’t be any record of that.

Marsden:

I’m not sure whether I know where my copy is. [Laugh]

DeVorkin:

The manuscript copy?

Marsden:

Yes. But it was, of course, something that very much interested him and later on, he realized that most comets lived rather longer than that. One of the things I’d done at Yale was pick some comets that previously had been observed many times but they hadn’t been seen formany decades. And again, the question was whether this was because the calculations were wrong or because the comets no longer existed? There were seven comets that I picked that had not been seen for at least half a dozen returns. And some of them a lot more, way back in the 19th Century, like Biela’s Comet. I’d done new predictions and had/was working with Pat Roemer to try and recover these comets. She found the first of my lost six, which hadn’t been seen since 1906. She found it in 1964, Comet Holmes, so that was good. And then in 1965, she found deVico-Swift, which was another one observed only in 1844 and 1894, but had a period of half a dozen years for so. And, then there was the infamous Tempel-1, which had the mission recently. That had been observed only in 1867, ‘73, and ‘79. And so, I did the calculations while I was at Yale. We had a grant from IBM to do these calculations on the IBM 7090, at MIT. And so, we had a visit up here with punch cards and submitted the jobs and then we received as results a week or two later back at Yale. So, I wrote a paper about those lost comets in 1963 and by 1967, I was here. That’s when Pat found Comet Tempel-1. That was the third of the seven to be found. And two more were recognized just a few years ago. There are just two lost out of the seven. But this, in a way, tied in very much with Fred’s interest in “Do they survive, and what do the nongravitational forces do? Are the nongravitational forces the reason some of the predictions are off?” and this sort of thing.

DeVorkin:

Right. What I’m hearing here is a feeling that your work would be more useful and more relevant to some of the mainstream research that takes place at Harvard rather than possibly at other places. Did you see what you do as a service as well as being an independent line investigation?

Marsden:

Yes. I did always see this as a service. Even when I was an undergraduate doing the calculations there was some sort of service part to it, working with the Computing Section of the BAA, but at the same time I was learning how things were done, picking up a few ideas of my own, and carrying out the research. So that when I actually got here in the end of September ‘65, there were two projects I was planning to do.One was to get a set of orbit programs that would be, working very nicely. I’d had a reasonably good setup that I’d done at Yale and we’d brainstormed Owen to MIT for the long-term calculations over a century. We used to call that long-term but now it’s not. But, back then doing comets on computers was still very rare at that time. And so, I got into this and asked Fred “Could I have an assistant, a programmer, to work with me?” I knew that was the way (???) worked here in Fred’s time. “Could I have, a programmer assigned?” And since I had two totally different projects I had two programmers assigned to me, one for one project and one for the other. The one doing the orbit work was Kaare Aksnes; a well-known astronomer in Norway, now. And, he had come over from Norway because he had an interest in the artificial satellites and was working with those. But, he was also clearly interested in natural bodies as well. As I said before although I knew all the work on artificial satellites at Yale and here, and what Luigi and Imre were doing, I really wanted to work with the natural bodies, the comets in particular, where I felt that I could make a difference. And so, Kaare also clearly was becoming interested in natural objects.

DeVorkin:

But, you knew also that they were doing an awful lot of artificial satellite tracking here?

Marsden:

I did. And, of course they had the Baker-Nunns. The Baker-Nunns the twelve of them at that time around the world, were an excellent way of getting new comets confirmed. When the Central Telegram Bureau received a report from somebody suggesting there was a new comet, we immediately got onto the satellite tracking. We would send a TWX to the satellite tracking stations asking for observations. And if a comet existed, they would come back pretty quickly with observations of it.

DeVorkin:

It sounds like they were happy to do that?

Marsden:

They were. And, this was a very good arrangement. They’d had the 704, IBM 704 at that time. At this there was a CDC3200, Computer here.

Marsden:

We were in the process of changing to a 6400.

DeVorkin:

That’s a pretty big machine for that time.

Marsden:

Yes it was. And so, that was the computer that we were using, and Kaare did some programming for me. There was also, around the same time, Joachim Schubart, in Heidelberg. He was (???) in Sonneberg in East Germany and he had gone to the IAU meeting in Berkeley in August 1961. And that Sunday evening, August 13, 1961, the day the wall was built, I remember saying to him in my straightforward way, “You’re not going to go back to East Germany are you?” And he made some diplomatic remarks to the effect of, “Well, Professor Hoffmeister would need him there.” Hoffmeister was actually at the meeting. Hoffmeister did go back, but Schubart did not. [Laugh] He visited his brother in Spain and eventually ended up in West Germany, in Heidelberg where he still is. He and I have been good friends for a long time. We were already in correspondence before then. He’d written a perturbation program. He worked here for a while, gone back to Heidelberg as (???) come to Yale just around the time I came here. He had written a program that he’d wanted me to use and so we incorporated it, into our system here for doing the perturbations. Then I wrote ways of doing the preliminary orbits of the differential corrections. So that’s what we built up at that, at that time.

DeVorkin:

But, what I’d like to do is finish two things up from Yale. Number one, you wrote a paper that was published in 1965 in the AJ, the Summary Information on the Positions of Supposed SupeNova of AD 1006?

Marsden:

Yes. Bernie Goldstein was in the History of Science Department at that time, and he took a great interest in the 1006 SuperNova. There was the possibility of some European observations, from southern Switzerland. We knew the SuperNova was far south, but could it have been seen from a latitude like that. And, Bernie wrote a paper for the AJ and Brouwer wanted me to referee it. I think Brouwer felt a little uneasy about some aspects of the paper because this is the sort of thing that intrigued him, maybe some remnant possible, and indeed one was found eventually. So the paper, as originally written by Goldstein didn’t address some of the points about it that he was interested in so he had me write some little addendum. And he liked the addendum so much that it was published in the AJ as well.

DeVorkin:

That’s what that was?

Marsden:

That’s how that happened. Brouwer asked me to do it. Of course, I discussed it with Bernie, and we got on very well with it.

DeVorkin:

But you were pretty much, professionally at least, next door neighbors?

Marsden:

Yes. The History of Science Department was just, to the other side of the Watson Building in an old house there. I remember Owen coming down and talking about Kepler, and all the errors Kepler had made. It was in that building.

DeVorkin:

Was there any interaction between the History of Science and the astronomers other than this one episode?

Marsden:

Not, a great deal, I suppose. A little bit. Derek de Solla Price was there then. It wasn’t very much. It wasn’t very formal, shall we say, but clearly, there was a little bit of interest.

DeVorkin:

A good number of them were interested in what you might call the classical roots of celestial mechanics more than theory. Noel Swerdlow I think was there.

Marsden:

Was he there?

DeVorkin:

Maybe a little after that, in the mid ‘60s. Aaboe was there too.

Marsden:

Yes. That’s right. I remember talking to them a little bit, because I was interested in the clay tablets he had from Babylonia. I was interested in records of comets.That really intrigued me. And he told me that it wasn’t so easy. Of course, I knew of Ho Peng Yoke’s work with the Chinese records. In fact, Ho Peng Yoke had published on (???) in Vistas in Astronomy with Arthur Beer. I met him in Arthur Beer’s home in the late ‘50’s as he was working on that. I noticed that a lot was being done on the oriental aspects and then when I heard of the Babylonian tablets I thought that would be a good, source as well. But, Aaboe said that, “It’s very difficult because the astronomical records are all mixed up with messages about the price of wheat and things like that.” Of course Richard Stevenson did finally do some work on that and found the 1163 B.C., I record of Halley’s Comet. But, there’s probably still quite a lot that can be done with the Babylonian records.

DeVorkin:

The important thing for me to understand is that Bernie Goldstein generated this paper and you had no prior interest other than the comet?

Marsden:

Right. He started it. I think it came to me through Brouwer, rather. I might have met Bernie before — I can’t quite remember. But, clearly with his paper Brouwer very much wanted me to add to it.

DeVorkin:

And so that’s the origin of that paper?

Marsden:

Yes.

DeVorkin:

The other major question I have about that period was how you met your wife? Should we talk about her?

Marsden:

Well, I think I briefly mentioned that her father was in charge of programs — lining up speakers and that sort of thing — for the New Haven Astronomical Society. So he lined me up for a talk, and my future wife, came to that talk. We met, on that occasion. I think it was earlier that he’d introduced me to her brother as being someone, interested in astronomy. But, I know she came on that occasion and we talked a bit. And, she didn’t like my talk too much, given the way she talks about it on occasion now. The following month I was away at Randolph Macon Womon’s College. I was invited to a weekend there. And then in March I was back in New Haven and did talk to Nancy more. In April, also, that was the annual meeting, and I, as a speaker, was supposed to sit at the head table. But there was no place for her there. So, Dorrit Hoffleit offered her place to Nancy. But, another young woman had come with Nancy, and so she would have been on her own. So, the three of us sat at the table and there was an empty space at the head table, as I recall. Then in May we met a couple of times. This was 1964. Yeah. I was going out to JPL for the summer and so I left at the end of May. Nancy was still teaching for another two or three weeks. She taught fifth grade in Trumbull, Connecticut and so she came out to California around about the 20th of June. Carol Williams was there for the summer as well, and Carol had an apartment, and that’s where Nancy stayed during the summer.

DeVorkin:

In the JPL area?

Marsden:

In La Cañada, or I suppose on the border with Montrose. I planned to come back at the end of July so that I could go to the IAU meeting in Hamburg. So, I wasn’t staying the whole summer the way I had done the previous year. Nancy came along too to the IAU meeting in Hamburg. We had our usual fights about things, but that was a good way to know each other, and we married the day after Christmas.

DeVorkin:

Very nice.

Marsden:

Yes. [Laugh]

DeVorkin:

Why didn’t you consider JPL more seriously, or was there no job offer?

Marsden:

I’m sure there could have been a job offer, because others were offered jobs. And I was, in a way I was the leading student because I’d been there since ‘59. The other students had all come along later. Brouwer took me out there. He didn’t take the other students out there during this time. I discovered so much wrong with the way they did things. One thing that they did, in calculating the orbit of Jupiter, say was they would take from a book the equations designed for bodies of negligible mass. In setting up the equations of motion they neglected to add the mass of Jupiter to (???).

DeVorkin:

Isn’t that rather basic?

Marsden:

Yes. This is what struck me in 1963 when I realized they had done this. It was incredible, in 1963, to find that in the course of my discussions with them. Another thing was that they were correcting the orbit of Venus, and Ray Duncombe, in his thesis, had given some corrections to the longitude of Venus and to the longitude of perihelion of Venus. But not, but the argument being used in Newcom’s work was the mean anomaly, being the difference of those. And since he didn’t give any correction to the mean anomaly they didn’t apply one even though it’s the difference of the other two corrections. There were things like that and they may disillusioned me a bit. I suppose . . .

DeVorkin:

You said they didn’t have anybody to discuss things with?

Marsden:

They didn’t really have anybody that I could, discuss things at a higher level with. I could go and straighten them out, but when I compared that to the other possibilities, like staying at Yale or going and working with Kuiper, or coming here, I realizied in some cases that I would be in an environment with knowledgeable people, people with whom I could discuss things, and together we could learn things. And maybe also let’s face it, there’s a lot of bureaucracy at JPL.

DeVorkin:

Oh yeah.

Marsden:

I mean, compared to these [Laugh] other three places. There’s bureaucracy everywhere, but, it was particularly evident at JPL, shall we say. [Laugh]

DeVorkin:

Did Brouwer give you advice?

Marsden:

I don’t know that he really did. Clearly he was interested in having someone go to JPL and that was why, in the second summer I was there — in ‘63 I was the only person from Yale — but in the second summer Carol Williams and Jay Lieske were both there. So, there were three of us there that year. And then in ’65, I think Myles, well; Myles Standish must have gone around that time.

DeVorkin:

Right.

Marsden:

For a summer, or certainly a visit. And, so clearly there were others available for this, whereas in my case my interests, perhaps, were a little broader, one might say. I was interested in the kind of thing that Kuiper and Whipple were doingI’ve not done too much with physical, but I realized that they were the two leading people in this country for physical studies of the solar system. In addition to the orbital work; Kuiper didn’t have a great deal of involvement with the orbital. Whipple, of course, did. And so, it really came down to those two.

DeVorkin:

And your wife’s?

Marsden:

Well that was part of it. The Central Bureau probably played some role in it as well.

DeVorkin:

At what point were you in.

Marsden:

I didn’t really make the decision until after April ‘65 when Izsak died, because it was within a month of that I have an interview set up.

DeVorkin:

So, you got here by the, by the fall of ‘65?

Marsden:

Yes, in ‘65.

DeVorkin:

And so, well before this was well (???) you knew the Central Bureau was here?

Marsden:

Yes. Fully a year because in August ‘64 I was at the Commission 6 meeting.

DeVorkin:

And that was a positive thing?

Marsden:

Yes. So, that was a positive thing for me. And also, early in ‘65 Owen was, let’s say Own was feeling his way with the international responsibility of the Central Telegram Bureau, slightly different from the Harvard Announcement Cards. If they did something wrong on the Harvard Announcement CardsCentral Telegram Bureau would correct them. [Laugh] Owen ran into one or two little difficulties and I straightened him out. [Laugh] And so it was clear that this was something that was waiting for me when I got here, if I were to come here. In addition to doing the more general comet work and I knew that Fred Whipple wanted me to produce a model that would fit all the observations of Encke’s Comet all the way back to 1786. In the summer of 1966, when I’d been here nine months or so, Fred sent me out to California, to Berkeley, to see Cunningham who he thought had a lot of these Encke observations. It turned out he didn’t have an enormous number, or at least not in any form that could be used, but again we talked about it. This is what Whipple did in those days. He would send people to (???), people would come here. I’d been here about a month — Ikea-Seki was nice and bright in the latter part of October ‘65. We couldn’t see it too well from here. I never did succeed in seeing the whole comet from here. You could see the tail sticking up above the horizon, butand if you looked (???) in binoculars you could see the head, but by (???) was (???) a little bit missing. So, I was sent out to check out a Baker-Nunn station, the one at Organ Pass, New Mexico, near White Sands. I was sent out there for a couple of days, just to go and see the station, and coincidentally be able to see Comet Ikea-Seki in all its splendor because the shift of ten degrees in latitude made all the difference.

DeVorkin:

Oh yeah in a rather dark sky?

Marsden:

Yes. And that was, hat was very nice. I remember meeting Clyde Tombaugh and Brad Smith on that trip as well.

DeVorkin:

Let me ask you about that. One of my curiosities about the Organ Pass facility was why it was moved to Tucson? Is Tucson a better site?

Marsden:

I don’t know. I mean, Fred hasalways had an interest in that area.What with the meteor program there, and having White Sands nearby had been rather useful for comparing meteors to rocket reentries.

DeVorkin:

And that was the Organ Mountains that were in sight of White Sands?

Marsden:

Yes. That’s right. But it was quite a long time later that it the (???) was moved. A number of the stations were moved around for various reasons. And then there were a couple of extra Air Force Baker-Nunns were added in a few places as well. I think one in Otago, New Zealand? Wasn’t there? Otago is the name of the county of New Zealand. It’s near the Dunedin area. I don’t know exactly where.

DeVorkin:

Did you have anything to do with the Air Force?

Marsden:

No.

DeVorkin:

Or the Baker-Nunns, or any of it?

Marsden:

No. So I wnt to Oregan Pass and (???) had the trip out to see Cunningham. This was a case where Fred’s aim was to try and get some model that would fit the whole of the observed history of Encke’s Comet, all the way back to 1786. So, yes, I did have that very much in mind as something I’d like to do. And, over the next year or two, I was doing a fair bit of work on trying to do long-term integrations or at least a few centuries, sometimes even longer, for a lot of the short-period comets, including Encke’s Comet. I was asked to write an article for Science, I think it was published early in ‘67, where I took a hundred short-period comets and ran them back a few centuries and compared the general kind of perturbations (???) showers.

DeVorkin:

Right. That’s 1967, Science, Volume 155.

Marsden:

February, I think.

DeVorkin:

Yeah. One Hundred Periodic Comets

Marsden:

That’s the one. That was a sort of a fun article. Oh yes, and following Ikea-Seki I became very much interested in the sungrazing comets, and had an extensive paper on them in November 1967. Actually, I had some ideas even earlier that are in an abstract in ‘66. We were very puzzled by the eighty-three-year period, you might say. Why the Ikea-Seki came eighty-three years after the Great Comet of 1882, and then Pereyra comet in 1963 had come eighty-three years after another member in 1880. I even went so far in an oral presentation at the Cornell meeting of the AAS in mid to predict that the next Kreutz sungrazer would come in 1970. And, it did! Quite by chance. [Laugh] We haven’t had any since that have been seen from the ground. [Laugh]

DeVorkin:

So, it was empirical?

Marsden:

It was empirical because it, we’ve never been able to figure out why there’s an eighty-three-year period there. It makes no sense, as I pointed out in my 1967 paper. It’s just one of those curious things that happen. [Laugh]

DeVorkin:

There’s a paper you did with S.S. Hamid in on the “Influence of Beyond Neptune.”

Marsden:

Yes.

DeVorkin:

On the Motions of Periodic Comets. What was this discussion?

Marsden:

There were a couple of things. I was building up towards studying the effects of the non-gravitational forces on comets. At first I didn’t believe in them, but I convinced myself they existed. Then in 1969 I worked out a way of handling them. In the meantime Fred had written a couple of papers in 1964, talking about a belt of comets beyond Neptune. And, it’s interesting that he talked about that the way he did because there’s absolutely no mention in either paper, there’s no mention of Kuiper, and [Laugh] Kuiper was talking about objects in that part of the solar system in 1951. Kuiper and Whipple were good friends. It wasn’t a question that, [Laugh] he was having a fight with Kuiper and so he wouldn’t mention him in his papers or anything like that. He honestly, felt that what Kuiper had done was something very different. And, we feel that way too. Kuiper was trying to explain the Oort Cloud, which was just being — Oort had come up with that in 1950. Whipple had come up with the Icy Conglomerate in 1950, and Kuiper said, “Yes, all right there are icy comets and there’s this cloud out there. How did it get there?” And so, yes he postulated some stuff beyond Neptune, and as I recall he had a fairly massive Pluto and Pluto throwing the stuff out into the Oort cloud to the extent that there’d be nothing left. It would all have gone. And that’s the point when people talk about the Kuiper Belt. They usually don’t consider that Kuiper removed it all. They’re thinking that Kuiper was talking about something that really is there now. Apart from the fact that Edgeworth had talked about something similar a few years earlier, originally in 1943. Edgeworth had done so without knowing of the Icy Conglomerate Model, and even in 1949, in his paper in the Monthly Notices the Icy Conglomerate Model hadn’t come out. So, he was considering just dusty comets, sandbanks or whatever. Realizing that maybe it was cometary stuff beyond Neptune, “Why did the solar system end at Neptune?” sort of thing. But, if you look in one of Fred’s 1964 papers you’ll see a beautiful diagram that I always like to show in my talks, showing the orbits of Jupiter through Neptune.Then he has a comet ring beyond therewith lots of little dots where the comets are. And, Pluto is vaguely in there. I f you look you’ll see Pluto right in faint type at the bottom. The orbit of Pluto isn’t shown, but (???). That’s very different from what Kuiper was thinking. Further, Whipple was thinking these things for the most part are a hundred kilometers across, apparent magnitude twenty-two, so it’s hopeless to look for them. In fact, he said as much. At that time, of course, it was.

DeVorkin:

This is Whipple?

Marsden:

Here’s Whipple saying this in ’64. But why? He said it because he felt that there was something wrong with Pluto. Remember, my thesis adviser, Dirk Brouwer was really involved with determining the mass of Pluto, because he had been involved in 1951 with the early calculation with some of the Naval Observatory people of the orbits of the five outer planets. This numerical integration from 1660 to 2060, four hundred years. Brouwer needed to get orbits to start from and it seemed to him that Pluto had to have a mass about nine-tenths that of the earth.Owen’s people had been saying this all. There was what the perturbations seemed to indicate. Now Kuiper, of course, knew something was a little screwy because he tried to determine the diameter of Pluto. And, if you put these together you get a density eight times that of the earth, which of course is nonsense. So, there was a, there was a lot of speculation at that time but nobody could really say that the mass wasn’t as high as .9 that of the earth. This clearly bothered Whipple, and so in this 1964 paper he was trying to attribute the perturbations to Uranus and Neptune that had been attributed, to Pluto, (???) he wanted to attribute to this comet ring. This was the essence of his 1964 paper. He got a fairly massive ring, an earth mass or something like that. This bothered him. And so, he had me together with Hamid work on trying to use Halley’s Comet and maybe some other comets of similar inital (???) to see if we could confirm or deny this. We were looking into perturbations on the plane, the orbital plane, and Hamid had done a lot of work on secular perturbations so he was considering that sort of procedure for long-term things. I was doing some more short-term stuff, because I was a little bothered about the secular perturbations because of resonances some of these comets had with Jupiter. And, we came to the conclusion that we couldn’t see any effect of Whipple’s comet ring. So, althought he had something massive affecking Uranus and Neptune, we couldn’t see it affecking Halley’s Comet, or any of these other comets. I must confess, this sort of put me off the comet ring completely, and I rarely felt was nothing there at all. [Laugh] But, Whipple always persisted that there was something there, and beginning in 1992, was proven, right. Well not quite, because the perturbations were wrong in the first place and as Myles Standish finally showed in 1993 using the Voyager data that there was nothing to explain anyway. But was that supposed perturbation that led Whipple much more than any of his predecessors to describe what was going on in the outer solar system. His description of the Transneptunian Belt is much better than anything anybody else had before 1992 and we started finding many more objects there. So, I was pleased to be involved with that. It’s the only paper I actually wrote with Fred.

DeVorkin:

Now I’m placing you here, at SAO, where you’ve been ever since?

Marsden:

Ever since.

DeVorkin:

And, what was your orientation like? Can you remember anything that you could call an orientation?

Marsden:

I didn’t have one because that Wednesday morning, the 29th of September, I was immediately pressed into doing something with comet Ikea-Seki. So, I never went through the formal process, I suppose. I mean obviously I did the paperwork and everything that was needed. [Laugh] And fingerprinting and all that kind of thing pictures taken. But orientation well, I don’t know what they do. I suppose they just give you rules and regulations. It’s done by Human Resources.

DeVorkin:

How did you learn your way around?

Marsden:

We had Building B, but we didn’t yet have the Perkin Building. I had an office— B312. Initially I had another one, sharing it with somebody, and then that became available. So, I moved into there and stayed until 1972 when I was moved over to the Perkin Building when they finished it, then I was brought to Building A in 1981.

DeVorkin:

How did you find the atmosphere here? How did it seem? Did it suit you?

Marsden:

Yes.

DeVorkin:

Did you have to adjust?

Marsden:

I talked to some of the planetary people, particularly Fred, and Southworth. Not so much I think with John Wood or Ursula. Ursula Marvin was already here. I knew of them but they were doing more with the meteors and meteorites. Dick McCrosky, of course, I met earlier on. Owen had an office on the fourth floor of Building B, and Dick McCrosky was just across from him. Soyes, I did see a fair bit of them. And also some of the people with the satellite tracking. The fact that Kaare Aksnes was programming for me put me in touch with those people, and the fact that the Baker-Nunn films were being inspected also put me in touch. And the Communications Center and the Computing Center. It was a hive of activity you might say. A lot of different things going on. I didn’t have so much to do with the Harvard side. I suppose, a lot of them were doing solar physics. But, this seemed to be the kind of place I wanted to work. It would have been somewhat similar at the Lunar and Planetary Lab, Sweiter building wasn’t complete yet. They were in temporary quarters. So, I mean the Lunar and Planetary Lab, when it was built was a separate building for Planetary Sciences. But, across the street there there was the Steward Observatory, and next door Kitt Peak headquarters. I won’t say everything here was under one roof but all the scientific work was done under one roof. We had more administrative things going on in other buildings in Cambridge.

DeVorkin:

Right. It was all over the place?

Marsden:

Yes, all over the place.

DeVorkin:

Okay, the first place you appear, that’s what I am trying to get to here.

Marsden:

Yes, I was wondered what you were looking in.

DeVorkin:

We set up this division in programs, and you didn’t appear, in 1965.

Marsden:

Well, I was here then. [Laugh]

DeVorkin:

You were working here, and let me just say that in ‘65 the closest I would get to saying, “Why didn’t you appear?” And that could just be, this is based on annual reports.

Marsden:

Oh yeah. Of course I would be in it too.

DeVorkin:

The international bureaus. There was the Central Bureau of Satellite Geodesy?

Marsden:

Yes. There was.

DeVorkin:

And there was the Central Bureau for Astronomical Telegrams?

Marsden:

Yes, that’s right.

DeVorkin:

And, that was Owen, for the telegrams and Whipple and Jan Rolf?

Marsden:

Jan Rolf. I remember him. Yes. That’s right. That stopped a year or so later. I didn’t have anything to do with that.

DeVorkin:

Well in, ‘67, Geodesy was mentioned but nobody was involved as far as staff?

Marsden:

I think Jan Rolf left in ‘67, or maybe even ‘66. I don’t know what it did.

DeVorkin:

The Central Bureau for Astronomical Telegrams was still under Owen?

Marsden:

Yes, it was. He ran it only for three years, and as I said earlier he was a little upset, and “upset” is quite the word, the fact that he lost one whole month on comet Ikea-Seki clearly bothered him. And in 1967 at the IAU meeting in Prague he handed it over to me. And, I took over from the beginning of 1968.

DeVorkin:

And I would assume that’s with Whipple’s approval?

Marsden:

Oh yes, of course. A. R. Hogg, the President of Commin-G, died at the end of March 1966. Whipple was the vice president so he completed the term, and also had the next term. Whipple very much knew that Owen was passing it over to me. Dick Southworth worked with me a bit as a substitute and so did Owen. If I were away then Southworth or Owen did the work in my place. And then in1967, I had developed a friendship by correspondence, with Sekanina, who was working in Prague at that time. He and I saw quite a lot of each other during the 1967 IAU meeting. It was very clear to me that he was suffering under the communist system, since he was not a communist himself. [Laugh] He wanted nothing to do with it. He had met Whipple at a meeting in Liege in 1965 and he very much wanted to come here. I tried to persuade Whipple, already in 1967, to bring him here, after the IAU meeting. Whipple didn’t seem, too anxious to do so. I think they’d had a slight disagreement at the Liege meeting in 1965, a scientific disagreement. [Laugh]

DeVorkin:

Yeah.

Marsden:

And then in 1968, I knew that Sekanina was spending the summer months in Liège. Swings had invited Sekanina to Liège in April and he went from Czechoslovakia to Liège in Belgium with his wife. His wife was allowed to go with him, and they were to go back to Czechoslovakia on Augusts 30th. And on August the 20th the Russian tanks moved into Prague. That day I sent Sekanina a TWX in Liège saying, “You’re not going back to Czechoslovakia are you?” And, of course he wrote, “No.” He “didn’t know what to do.” So, at this stage I mentioned this to Whipple and he made efforts to bring Sekanina here as a refugee. I was at a meeting in Europe in October-November ‘68, and I visited them in Liège, discussing arrangements and things like that. And they came on a refugee flight in March. I picked them up at the airport, at Logan, and then he was working here. He was assigned, initially to work with the radio meteor project here. This was early 1969.

DeVorkin:

I’m only in ‘67 right now. That’s where you first appear under Comets and Meteors. Whipple created [rationalized sections] in these reports and in here you are under Orbits of Short-Period Comets, and then you’re working with Salah Hamid?

Marsden:

Yes, that would have been this project on Halley. Salah was also working on the Radio Meteor Project, but he was interested in the secular perturbations, and that work may have started already in ‘67, or the beginning of ‘68. That was part of it.

DeVorkin:

You said that all of that area, comets, meteors, and things like that, everything was funded under (???) ?

Marsden:

Yes. When I came here in 1965, this is what I understood to be the case, SAO was satellite tracking. There was an enormous amount of funding that Whipple had managed to get, beginning, of course, in the mid ‘50s, soon after he took over as director. This was still very much the case in 1965 and ‘66. Satellite tracking was it. And so, he funded everything he possibly could, including stuff on comets and meteors and there were, of course, people working on meteors. The radio meteor project and all this and I was working on the orbits of short-period comets because I was trying, ultimately, to get this model for Encke’s Comet. There was the Central Telegram Bureau, with long-period comets; sungrazing comets, which I worked in there as well. There were many different things, but all basically under Comets and Meteors. Aksnes was programming for me into 1967 or even the summer of ‘68, when he said to me one day, “Did I think he could be a graduate student?” And actually I said, “Yes. Go to Yale.” Maybe we had discussed that even at the very beginning of 1966, but see Brouwer died on January 31, 1966, suddenly. Well, he’d had a heart attack the previous week. And so, that made me think I’d made the right decision in coming here, in not staying at Yale, because things started going downhill after Brouwer died, at least I thought so. You may have thought differently. Of course, when did you go?

DeVorkin:

I showed up in September ‘68.

Marsden:

That late? But, you weren’t doing celestial mechanics?

DeVorkin:

No I wasn’t.

Marsden:

So, I mean it was different. Like Aksnes wanting to do celestial mechanics. I know Clemence was there and Garfinkel was there, but the rest of it was falling apart. I imagine had left by then, hadn’t he? He’d gone back to Japan.

DeVorkin:

He was in and out. He was there for a while, with Boris.

Marsden:

Yes. He would do that. And then he went back to Japan.

DeVorkin:

Yes.

Marsden:

That’s right. But, it wasn’t the way it had been earlier. Danby, had left by the time you got there, hadn’t he?

DeVorkin:

Yes.

Marsden:

So, It sort of started breaking up, and so that made me think that I made the right choice in coming here. Of course, after 1973, (???) were somewhat differ. Both Whipple and Kuiper retired on the same day as director, June 30, 1973.

DeVorkin:

Kuiper too?

Marsden:

June 30, 1973 they both retired. The new Directors at LPL and here took office July 1, 1973.

DeVorkin:

That was ‘73 not ‘72?

Marsden:

Seventy-three. July. Sonnet took over from Kuiper, and Field took over from Whipple. And, I think it is well-known, Kuiper did not take that at all well and Kuiper was dead within six months.

DeVorkin:

Oh, gees. Yeah.

Marsden:

He died in Whipple’s arms at a meeting. They were in Mexico. There was an annual eclipse of the sun on Christmas Eve and it must have been that morning, Sarah Kuiper called the Whipples in their room, “Come quickly. We’ve called the doctor,” but of course this was Mexico and the doctor wasn’t going to come very quickly, and Fred went and Kuiper died in his arms.

Marsden:

Yeah. Then the following month Van Biesbroeck died. Of course, he was ninety-four. Pat Roemer had gone from Flagstaff to Tucsan later. She was still in Flagstaff when Van B and I were interviewed in ‘63. She went by Tuscan in ‘66. So, we had a new director here, but Whipple very much continued and, again this made me think I did make the right decision, [Laugh] of all the possibilities with regard to staying power, shall we say?

DeVorkin:

Now, how closely did you work with Whipple through this time?

Marsden:

Not, excessively closely. He was a director after all and was doing so many things, involved with so many different things that, I didn’t feel I should monopolize his time. He knew what I was doing and was interested in results. And when Sekanina came, in particular, Sekanina and I worked together very closely at that time on the non-gravitational forces. We had a number of papers that we wrote together around that time, beginning already by 1970.

DeVorkin:

The divisions kept on changing their names.

Marsden:

We didn’t have divisions until George Field started divisions.

DeVorkin:

So, what would these things be? Like Geodesy and Earth Physics from Space? [Laugh] Is that sort of a problem area?

Marsden:

I think it’s a problem area. There was no formal, organization of SAO into various groups. You sort of knew where you belonged and did your thing. I was invited to become a federal employee in 1970.

DeVorkin:

So you were hired on the trust side?

Marsden:

Initially from the satellite tracking. Beginning in 1967 things started, getting a little shaky already in 1967. Money was drying up a little bit already in ‘67. There was the Vietnam War going on, and already in ‘67 and ‘68 there were clearly signs that it wasn’t as good as it had been from 1955 to 1965. Sixty-six was okay. Sixty-seven, you might say things started going downhill a bit. And Whipple himself, I heard him once say while, he was sitting on the floor of his office this would have been in the late ‘60s as he was looking at some files — and he made some comment about, “What kind of monster have I built?”

DeVorkin:

Really?

Marsden:

Because things were getting a little shaky. And maybe also this was when he was having trouble with Leo, and those things were coming up. Leo apparently felt that Whipple didn’t do as much teaching as Leo would have liked Whipple to do.

DeVorkin:

I see. Was there an issue about Smithsonian people doing teaching?

Marsden:

This is one of the things that I asked at my interview. I said, “Can I, do some teaching?” And he said, “Yes. We can certainly make arrangements for that.” This actually shows the situation well because I was then assigned to teach my course in celestial mechanics in the spring of 1967. And, when I did it there were six students. I think four were taking it for credit, two auditors, and I was put on ninety percent private role Smithsonian time. I was teaching during a few months, and Harvard then more than made up the difference in salary

DeVorkin:

More than made up?

Marsden:

Not an enormous amount but I got extra money out of it from Harvard.

DeVorkin:

I see.

Marsden:

Now, when I gave the course a second time, which was in the spring of 1969, this time I was put on ninety percent Smithsonian time and Harvard just made up the difference. [Laugh] The third time was late in the spring of 1972 and Alex Delgarno was actually running Harvard then. Fred was still the SAO director, of course. This time I was one hundred percent Smithsonian, and the feeling that Alex sent around was that we should, as Smithsonian lecturers, teach Harvard graduate students and consider this part of our Smithsonian duties. Something that has always bothered me.

DeVorkin:

That was ‘72?

Marsden:

Yes. That was said by Alex. You can find this out from other Smithsonian lecturers whether they felt this same thing. So, I did not teach, after 1972 – it bothered me, so much. For one thing, I wasn’t getting social security, [Laugh] because by then I was federal. So, it bothered me even more, I suppose, as a federal employee why was I teaching Harvard students at Federal expense? It actually bothered me. I mean, not to the extent I went out and complained, because after all it was no loss to me. I enjoyed teaching.

DeVorkin:

Was this something that Whipple didn’t worry about, or did?

Marsden:

I’ve never found that out.

DeVorkin:

People have advised me that, in fact, Smithsonian did a good bit of teaching.

Marsden:

Yes but earlier, we were paid by Harvard.

DeVorkin:

So, you did have some pay from Harvard?

Marsden:

In ‘67, ‘67 I was, ten percent of my salary plus. And, in ’69 — ten percent.

DeVorkin:

How many courses does a Harvard professor teach per semester, maybe one or two?

Marsden:

Well yes, of course, some do more. Only one I think.

DeVorkin:

Usually one.

Marsden:

And as I say, I was doing one course every two years, basically, three years from ‘69 and ‘72.

DeVorkin:

But at that point you were still, being paid ten percent for what a Harvard person would be paid for that amount of work?

Marsden:

That is true. Well, the first time in ‘67 times were still good, you see. So, I did make a little bit. I can’t remember exactly how much it was.

Marsden:

Then George Field took over as director. I did not teach until toward the end of his tenure. I did give that course once more in the spring of 1982, ten years later. Again, paid entirely by Smithsonian. But George was still the director then. I gave the talk then because Dan Green was here then and he wanted me to give the course. He was a quasi Harvard student. So, I gave the course to him and another student at that time.

DeVorkin:

There was a big deal in the ‘50s about cross disciplinary activities, people communicating broadly and I’m wondering if Whipple did carry that through into the ‘60s? And, it seems like he did. Looking at the ways that he described, the different problem areas, the programs at Smithsonian, there was just an enormous range of things. I’m looking here at 1967 where you are in the Comets and Meteors problem area.

Marsden:

Yes. Of course. That would make sense.

DeVorkin:

But, there’s also Meteorites and Cosmic Dust.

Marsden:

Yes, well Dick McCrosky, was doing the Prairie Network then.

DeVorkin:

He was doing the Prairie, but that’s even different than this.

Marsden:

All right. [Laugh]

DeVorkin:

While here you have Decay of Comets and Asteroids, Greenland Ice Samples, Carbonaceous Chondrites. That’s John Wood. Isotopic Abundances in A-Chondrites, Mass Loss Due to High-Velocity Dust Particle Impacts, a Thomas Cummerford. [Laugh]

Marsden:

Oh, I remember him, but only vaguely. [Laugh]

DeVorkin:

Yeah. It’s just one thing after another. Spherules, (Frances Wright and Fred Franklin wrote that one. Was this the O’Keefe stuff?

Marsden:

I talked to Fred Franklin.

DeVorkin:

Yeah. Diamonds in Meteorites. Primordial Nebula Conditions. Are these more like just the types of things that staff were engaged in?

Marsden:

I think, yes

DeVorkin:

You tried to organize them?

Marsden:

I think that’s really it. We followed what he had suggested. We did what interested us and then, we were sort of catalogued afterwards you might say. I think that’s what happened. It wasn’t until George Field came and took over directorship of Harvard as well as the Smithsonian that he developed eight divisions. There were eight divisions originally with the geophysics, geodesy, and geoastronomy. That’s distinct from radio. Then it joined with radio within a year or so.

DeVorkin:

What caused these various mergers and separations?

Marsden:

Well, obviously some divisions were bigger than others. I was immediately put into the Planetary Sciences Division in 1973 or even the end of ‘72. George talked to us about it then so we could think about it. And, all the people doing Comets and Meteors, and Meteorites and Dust were put in the Planetary Sciences Division. Cameron was hired, in the summer of 1973 to run that division. And, this continued until 1980, when John Wood took over I think it was 1980, plus or minus, round about then. And, I took over as associate director in 1987 and remained associate director for Planetary Sciences for fifteen and three-quarters years, which is a record for associate directors.

DeVorkin:

You especially headed the division?

Marsden:

Yes. That’s what they called us. But the trouble was, we were shrinking. Ed Fireman died in 1990 and wasn’t replaced. Right at the beginning of my tenure, McCrosky gave up his federal position so that Oak Ridge could function. He made an arrangement that the money for his salary would pay Bob Stefanik, and someone else out at Oak Ridge. I think Bob Stefanik had some of his salary paid anyway. So, Mac’s salary got divided among two people to keep Oak Ridge going, and then as Mac has probably told you, Oak Ridge was threatened in 1980 with closure by George Field. That’s when Harvard gave up on it and the Smithsonian rented it from Harvard for a dollar a year, plus the salaries.SAO spent $140,000 on Oak Ridge in those years.

DeVorkin:

So that means McCrosky’s salary, was Smithsonian’s salary?

Marsden:

Smithsonian. He was federal, and that went to pay Stefanik and probably Joe Caruso I think.

DeVorkin:

Since Agassi was largely teaching by then, at least in the mind of Harvard, did Fred have other ideas for Agassi?

Marsden:

Yes, this is actually in Fred’s time. McCrosky was doing the Prairie Network. They had their success with Lost City Meteorite early in 1970. That success meant that Mac could finish with that. He gave up on the Prairie Network after they had their (???) of success. But, because he had proven the point that most bright fireballs don’t produce meteorites because they’re bits of comets, and yet one of them did, [Laugh] he decided he would do something else.He became interested and discussed with me the possibility of observing comets at Oak Ridge. Pat Roemer was still observing, in Tucson, until, the end of 1976. But, clearly there were more comets coming along. The discovery rate was picking up a little bit with (???) Schmidt discoveries and she was running into trouble. The University of Arizona, Ray Weyman caused her a lot of grief in getting telescope time and all that. So, Mac thought that we could use the sixty-one inch at Oak Ridge and observe comets along with Jerome Shau and Skip Schwartz. Skip was the one who’d actually found the Lost City Meteorite on the road in Oklahoma.

DeVorkin:

On the road?

Marsden:

On the road. Oh yes, it was on the snow. It was January. He was driving up this road and went around something, and then realized, “What was that I’ve gone around?” So, he backed down and there was the meteorite. A dog had found it first. [Laugh] Well, you could tell there in the snow. That’s how Skip found the Lost City Meteorite. [Laugh] There were little pieces of it in the fields nearby as well, which were found in the spring after the snow had gone.

DeVorkin:

This was nickel iron I take it?

Marsden:

No. It’s a chondrite, isn’t it? I am not sure but I’m sure you can get that information from a meteorite expert. [Laugh] It’s not a nickel iron. It’s a stony meteorite of some kind.

DeVorkin:

But the fact that it existed at all, that it survived.

Marsden:

Well, it had only just fallen.

DeVorkin:

Well no, what I’m trying to say is McCrosky was trying to show that . . .

Marsden:

There are stone meteorites, stony meteorites, and most of the ones that seem to fall are stony. Most of the old ones you find are iron because the stone merges into the background and disintegrates. The irons survive better in that respect, but the irons are a lot rarer than stony ones. There are carbonaceous meteorites, but maybe there would have been more if bits of comets could survive and make it to the ground. I mean, the bright fireballs were bits of comets burning up completely.

DeVorkin:

How, in your mind, did McCrosky prove his point?

Marsden:

By not finding as many meteorites as initially expected.Going from the meteor projects to the Prairie Network and triangulating, where they should land if they’re going to land. You don’t find them, and then you wonder. I mean, they don’t make it to the ground. It’s not that somebody goes and picks them up. They don’t make it.

DeVorkin:

Their point was to get to those sites as quickly as possible?

Marsden:

As quickly as possible.

DeVorkin:

How accurately could they triangulate?

Marsden:

Oh, pretty well.

DeVorkin:

Would they be able to see a small crater, at least, or something of that kind?

Marsden:

Well, yes. I mean, the meteorite is fresh. In the prairies, in the winter, on the snow on a road sometimes if you’re lucky. [Laugh] And, a road that hadn’t been traveled in three days except by this dog. [Laugh]

DeVorkin:

Yes. And what, that fellow was out there looking for it?

Marsden:

Oh, Skip was specifically looking for it. Skip was one of Mac’s right-hand men and Jack-of-all-Trades, and he did some of the observing then later on. Maybe by early ‘72 or maybe even late ‘71, Mac was saying to me, “Maybe we could observe the comets at Oak Ridge?” I always wanted observations of faint comets, and only Pat was getting them, and she was having less telescope time, or more problems getting telescope time. So, he took a few plates in May of ‘72, and then by November we thought “Well, we should get some money from NASA for this.” And so, on November the 1st — there was a series of talks being given on Wednesday evenings at the Smithsonian, and — it’s Man and Cosmos, the book Man and Cosmos which Jim Cornell edited. I remember going two weeks in a row, and Mac came down one of those weeks, I think on the 8th of November.We talked to Bill Brunk at NASA headquarters, who had been invited by the Smithsonian to a dinner at the Cosmos Club beforehand because that’s where we stayed when we gave our talks. And, the reason I mentioned November the 1st is because it was that morning that Leon Campbell, Jr., who was the ombudsperson, as Fred always called him. Who told me that Fred was going to announce his retirement that afternoon. Actually his official title was the executive officer at the Smithsonian. If you had some problem you went and talked to Leon Campbell, Jr. His father was the AAVSO person and Leon Jr. had been a newspaper person. When I was told though that I was going to be a federal employee in 1970, and I filled out some forms or something, then I received one day a message from the Personnel at the Smithsonian in Washington, the big chief of Personnel there, he said, “No, I’m sorry we don’t have a job for you at this time.” Now, several people here including Fred, had talked to me about having a federal position, so when I received this message from the director of Human Resources, “Personnel” we called it then, I was a little distressed. So, whom did I go to see? I went to see Leon Campbell Jr.

DeVorkin:

He was directly across from Fred?

Marsden:

His office was next door to Fred there. He worked directly for Fred. He was between Fred and the associate director for management who’d been Tillinghast, until Tillinghast died in 1969.

DeVorkin:

I have the others.

Marsden:

Yeah, you’ve got all that. There was a man . . .

DeVorkin:

Not Butler.

Marsden:

Jack Coffey ran it for a while. And then there was a man Bartnik. Bartnik was a bit of a crook, as you may have heard? [Laugh]

DeVorkin:

Not quite that strongly, but okay.

Marsden:

[Laugh] Bartnik was there at this time. He came in ‘69 after, Tillinghast died and they got this man Bartnik.A notice appeared on the bulletin board on September 13, 1971, saying, “As of noon today,” it was a Monday, “ Mr. Bartnik is no longer the associate director for management, and Jack Coffey is taking over.” Bartnik was dismissed at noon on a Monday, which seems a very bad time to be dismissed. But, so he was still in charge of management when I spoke to Leon Campbell that day. And, I remember Leon, was reading the newspaper and he had the newspaper on his desk. He threw it up in the air and said, “Idiots!” Threw the newspaper up in the air, and was talking about the people in Washington being idiots. He assured me that everything would be taken care of and it was. He was amazing.

DeVorkin:

Was that, your first encounter with Personnel in Washington?

Marsden:

Yes. All the rest of it had been done up here, because I was a private role.It was all done through the satellite tracking and everything worked smoothly because Fred had arranged it so things would work smoothly around here. But couldn’t control everything in Washington. This was straightened out and I became a federal employee shortly afterwards on the appointed day in May 1970.

DeVorkin:

Let’s go back and trace the development of the Central Bureau, and how the Minor Planet Center came here. Let’s start with the Central Bureau.

Marsden:

Well, Owen was running the Harvard Announcement Cards and they became the Central Bureau and I became involved in working with (???). Barbara Welther was also doing some of the administrative work. Owen wanted to give it up and so I took over officially January 1, 1968.

Marsden:

Sekanina came here early in 1969. We got him involved with it. We brought him over as a refugee. And, as I say he was working largely with the radio meteor project but was also interested in, comets. He and I worked together and we also involved him with the Central Telegram Bureau as well. So, he took care of things if I were away.

DeVorkin:

What was your motivation being agreeable to take over this Bureau?

Marsden:

I was very much interested in what the Bureau did. I’d submitted informal (???) to it when I was in Oxford and the Bureau was in Copenhagen. Certainly at Yale. So, it seemed if I were on the premises I would be involved and other people would send things in, reports of comets and supernovae and things like that. The IAU Circulars were typewritten on a Selectric typewriter at that time and I did them largely myself so that they fitted on a page. I took a Selectric typewriter home so I could do them at home. I could also do them in the office, and I typed those myself. Earlier Barbara Welther had done some of the typing, and Lex Hayes, a wife of Nebo-Hays, did some of it. She was typing for Owen when I first came here.

DeVorkin:

Nebo wrote the book Tracker of the Sky?

Marsden:

Trackers of the Skies. Yes. And Lex that the Waiter. Quite a crazy woman Lex was, but we got on. [Laugh]

DeVorkin:

Crazy? Lex?

Marsden:

Alexia.

DeVorkin:

And, she’s known as Lex?

Marsden:

Yes. We called her Lex. And so after 1969, Sekanina and I did the Waiter (?) because Owen was doing other (???). And, Southworth left. So, we continued into the Field era. I also had some interest, as I said earlier, in minor planets, I’d worked some with minor planets, a little bit with Conrad Bardwell, when he was in Cincinnati, I was particularly interested in doing something with the near-earth objects. There’d been, of course, Apollo, Adonis, and Hermes discovered in the 1930s and the loss. There were also a few objects in the late ‘40s, and some of those were recovered. I gave a prediction to Pat Roemer for 1948 EA in 1969, and she recovered it. And, this was something I was doing on my own here in the ‘60s. I was working with Apollo objects, the lost ones, in addition to the comets. We’d only, we’d only got a couple that had been seen more than one opposition, Icarus of course, and 1948 OA, Toro was recovered in 1964.

DeVorkin:

OA?

Marsden:

That was it’s provisional designation. 1948, OA There was also 1953 EA near Apollo I had Pat work on. So, I became particularly interested in the boundary of finding Apollo (???) for (???) 1932.

DeVorkin:

But how did your management of the Bureau aid you then in these interests?

Marsden:

Well, it did and it didn’t. I made some predictions for Apollo, for late 1971. And, I was working with Charlie Kowal, actually. He was working on the supernova project there, having taken over from Zwicky. So, he was sending us reports of supernovae, but he was also interested in looking for comets, and he found a couple of comets that had been lost. They weren’t, so lost that they were in my 1963 paper but they were somewhat lost. There were a couple he found in 1970 and ‘71. So I interested him in looking for Apollo in the latter part of 1971. And, I put predictions for it on an IAU circular.

DeVorkin:

So, you could use the circular to stimulate observers?

Marsden:

Yes, very much so. Of comets and near-earth objects in particular. Sometimes I had to interest people in supernovae as well if no follow-up observation were made when something had been reported. But, I took it seriously from the point of view, that if we put things out I wanted them to be observed. I also wanted them to be confirmed. I did put discoveries out until they were confirmed. We have lots of reports of comets that we had the satellite tracking people looking for. We didn’t put anything out until they’d confirmed it.

DeVorkin:

But, in the case of getting observers to observe, and using the telegrams, but that’s the Central Bureau’s function?

Marsden:

Yes. That’s the Central Bureau’s function.We did a lot of it privately.

DeVorkin:

But you use the same mechanism?

Marsden:

We worked with people privately. We had our private list of people. You don’t want to embarrass people too much by putting too many erroneous things on the Waiter (?) (???). I don’t want to embarrass myself actually.

DeVorkin:

What do you mean by “erroneous”?

Marsden:

Nonexistent comets, SuperNova and Nova. It happens occasionally.

DeVorkin:

When you first started sending out telegrams, how did you arrange for that? Was it Western Union?

Marsden:

We did it through the SAO Communications Center. This was dealing with all of the satellite tracking stations. They were sending TWXs out. They were in touch with Western Union as well.

DeVorkin:

What’s TWX? A telex?

Marsden:

A telex. We called them T-W-X — that was a different system, slightly different from telex. The U.S. had telex and TWX.

DeVorkin:

So, how big was this Communication Center?

Marsden:

Somebody was running it twenty-four hours a day. They had three or four people in the daytime, and one overnight person.

DeVorkin:

And, this was in place when you guys brought the Central Bureau with Whipple?

Marsden:

Yes. It was at the Alewife Brook 185 Alewife Brook Parkway building.

DeVorkin:

Oh yes, where I’m staying.

Marsden:

Actually it says 1 blank 5 I think. The eight is missing in the lights on the top of the building. They renovated that building after SAO left it, but we had a computer there. And, in particular, the communications were there. And so, this was all done by telephone. If a telegram came to Western Union, for the observatory, it was sent there. They called Owen or me at home or in the office, as the case may be, and if we wanted to send something out we called it over to them, or dropped it off. So, often I was on my way into work in the morning and I would drop a message off for them to find out.

DeVorkin:

So, is it accurate to say the infrastructure for this kind of thing . . .

Marsden:

Was already in place with the satellite tracking. That was the whole point. That is why Whipple, in 1964, could tell the IAU that “We have satellite tracking. We have all this.” That’s why we could do it and why nobody else could say otherwise. [Laugh] And, we printed the circulars as well. Of course, the Harvard Announcement Cards had been printed by a commercial printer in Cambridge, and we later sent the IAU circulars there as well. We have the address labels made, or envelopes made on a computer, and so on. And then we ran into a problem they didn’t like. Initially we just sent the cards and stapled them. The post office objected because things got stuck inside. So then we started putting them in envelopes. We preface them on a Selectric typewriter all the time, up until 1982 when I started using Tex for them. Wait, it couldn’t have been Tex. That was a different typewriter. It was a Spinwriter. Yeah. You could do right justification. That’s right. That was an early one for doing that. The Spinwriter. It was 1988 that we used TeX [pron. Tech]. Inlate 1988 we started usingTeX as we still do. As for telegrams, these were all handled through the Communications Center. We didn’t usually deal with Western Union directly. That was very rare. Let’s go back to the NEOs. I’d interested Charlie Kowal in looking for Apollo, and there was quite a bit of uncertainty but I felt, “Why don’t we try and find it in 1971?” And before he got a chance to look for it, he got told off by Babcock not to. Babcock wrote me a nasty letter saying, “If I wanted to observe with the forty-eight inch Schmidt I should apply to do that and not work with his staff. Anyway, Charlie did do a few things on the side, because he was disgusted with Babcock as well. [Laugh] So we couldn’t find Apollo — 1971. But he was (???) then when I was going to come to Oak Ridge and Mac Chance in 1973, at Mac we observing at Oak Ridge then. He had found the Lost City Meteorite in 1970 and took an interest in looking for Apollo.

DeVorkin:

He headed the project?

Marsden:

Yes. His project with Skip. So, Skip and Jerome Shao and Mac were observing at oak Ridge by early 1973. We had already gone and spoken to Bill Brunk at NASA to try and get some money. He’d found some money for us in late ‘72. And so in ‘73 Mac decided he would look for Apollo. It was observed for only three weeks in 1932, the prototype Apollo. I figured there was a ninety-degree uncertainty and this meant you’d need two hundred plates to cover the region of uncertainty. It was February and March and April. You know, how many clear nights do we get here then? Twenty-minute exposures. And so, one night just before midnight Mac called me on the phone at home. I answered and said jokingly, “Have you found Apollo?” And he said, “Yes.” [Laugh] It was on the very first plate. It was on the very [clap] first [clap] plate [clap]So, I said “Get another one.” “Well, we are getting another one.” Then we did three days in a row just to make sure. I measured them. That's the last time I measured ary plates, actually. I measured those myself, and we put out and IAU (???) (??? pg. 72) Apollo was found after forty-one years. That was quite something. I know it impressed George Field, because he was just about to become director. I think he was quite impressed that we found Apollo. But, of course, it was a stroke of luck. But, Mac always said that it was about a one-percent chance. Well, maybe even less than that. And, he felt the way it was found on the road by Skip was also one percent. So, here there were, the same kind of objects, one arrives on the road and the other’s still out there still in space. [Laugh] This appealed to Mac very much. So during the ‘70s we tried to do more with NEOs. We got Adonis recovered in 1977. Charlie Kowal did do that. Again forty-one years after the original discovery. That was an easier one to do. The uncertainty wasn’t so enormous, but it had been lost for forty-one years.

DeVorkin:

Right. The importance of these near-earth objects, NEOs, like Apollo, and Adonis, and the group called that? Okay. What was the importance of this?

Marsden:

Well, at that time not too many people were excited by them. Fred was always interested in them. It’s always amused Fred. Fred was trying to figure out how many there were, and he came up with about a hundred, when we had only a half a dozen, and he used arguments like the fact they’d not been independently rediscovered. I mean, if you started finding the same thing accidentally in different years that would mean there are not very many. So, he increased the number, but not enough. But then, there was a feeling perhaps then they might be a danger to the earth. Nobody took it very seriously. Well, [Eugene] Shoemaker did, you see. Shoemaker was interested and Eleanor Helin already . . .

DeVorkin:

Eleanor?

Marsden:

Eleanor Helin, She was Shoemaker’s right-hand woman. She contacted Mac McCrosky about it already in 1969. Shoemaker had become interested and had her call McCroskyI was interested in doing these predictions, and they were interested in searching for new Apollo objects at Palomar. They started this during the 1970s. And then, they split into two separate programs around about 1980. Shoemaker got his wife involved. The children had grown up, so Carolyn got involved, and Eleanor Helin continued with her own program, both with the eighteen-inch Schmidt telescope at Palomar. So, I worked quite a lot with them during the 1970s. On behalf, if you like, of myself or of the Central Telegram Bureau. Meanwhile the Minor Planet Center was continuing in Cincinnati, and as I said before I worked with Bardwell a bit. We consulted on things, because he didn’t really have anybody else to consult with. Herget, Herget was getting a little bit more distant, I think. Herget and Bardwell didn’t always see eye to eye on things. Bardwell was doing getting work on his own, and as I say, I met him in 1960 when I’d gone out to Cincinnati. Again in 1973, I went to a meeting in Cincinnati. It was around that time that Herget was thinking that he’d have to retire at some time. He was trying to get someone to come to Cincinnati. He asked me, and he asked one or two other people. I know Jay Lieske, who had been at Yale with me and gone to work at JPL was one person who was being considered. I wasn’t all that enthusiastic about going. I was happy here, and as time went by during the mid to late ‘70s, it was clear what was happening. The Cincinnati Observatory had originally been owned by the city. It was established by the city in 1843, even before by subscription. It had some connection with the university which was always belonged to the City of Cincinnati. Then around the early ‘70s the State of Ohio took over the management of the University of Cincinnati. This was the death knell for the observatory. And, Herget had to retire at seventy, so the observatory closed in 1978. In 1977, he wrote to the president of the IAUwho was Blaauw at this time.Blaauw passed it on to Richard West, who was in line to be the General Secretary. Richard suggested me, and so I was asked if I would run the Minor Planet Center here, have it moved from Cincinnati. I felt I could, and that this could usefully happen because I could combine it the Central Telegram Bureau. I could do both Central Bureau and the Minor Planet Center as slightly separate things. After CU, they are different funraisers of the IAU. How was I going to do this? I would bring Bardwell here from Cincinnati. And that was the key, because at that time he was the Minor Planet Center, basically, in Cincinnati as Herget retired. So, we brought him here. How was I going to pay for it? I did get some temporary money from NASA, from Bill Brunk, enough money to pay Bardwell for eighteen months, during which time I set up subscriptions. Herget had it that the Minor Planet Circulars were free to professionals but amateurs had to pay. I had it that professionals would pay and amateurs would also pay, but I would give amateurs a bit of a break. If they didn’t have too much bureaucracy and could just send money, then why shouldn’t they have a cheaper rate? [Laugh] We were funding the IAU circulars that way as well. I had a subscription system for the IAU circulars. So we put the Minor Planet Center in as well, the same sort of thing. But, I hadn’t really had, any outside assistance. It had been Sekanina and myself, basically. So, we hadn’t too much in the way of expenses. He was working on grants anyway. But, bringing Bardwell here I needed money, and also we brought Dan Green here that summer of 1978, as well. Dan came and worked here the summer of ‘78 and ‘79, and I believe over Christmas as well. And, we could take him on permanently in 1980 using the subscription money. Even though the NASA money was running out, we had a good subscription system that paid both Bardwell and Green, so we could continue. I got Dan doing more with the Central Telegram Bureau and Bardwell the Minor Planet Center. I oversaw both and we had, a very good system until Bardwell retired at the end of 1989.

DeVorkin:

Did the Smithsonian ever say anything about these bureaus? Did anybody from the Smithsonian ever ask you about them?

Marsden:

No. Fred was interested, obviously. And, George Field had taken an interest in the recovery of Apollo in 1973 recognizing, Oak Ridge had done that and the Central Telegram Bureau had been involded. When I was asked to take the MPC over by the IAU, he said “Okay, As long as I would still be able to do some research.” It wouldn’t cost him any money. So, those were the conditions, both of which I kept, because I got there seed money, from NASA for eighteen months. And when that was finished I had the subscriptions that paid. And, I was federal.

DeVorkin:

There was never any question about it?

Marsden:

There was never any question. Nobody in Washington seemed to, seemed bothered when Irwin [Shapiro] took over. Irwin, shall we say, was more interested in it than George Field was because Irwin was particularly interested in doing radar bouncing off asteroids and commets. We had a close comet in 1983 just before Irwin became director.Araki-Alcock came within three-hundredths of an AU, and so I was involved with some of Irwin’s work on that. There were, other research activities to be done, continuing the non-gravitational studies and, finding ways of doing identifications of asteroids. I kept up that part of the bargain writing papers as well as running both the Minor Planet Center and the Central Telegram Bureau.

DeVorkin:

Were you ever in a position of having to defend either one of these while you were at Harvard?

Marsden:

No. I would say not. We were having to defend Oak Ridge from time to time. That battle would keep coming up. We had the the observing contract with NASA for the comets and minor planets. This continued to around 1996 or so. In 1989, Mac was developing CCD use. He was one of the first to use the CCD for astrometry.

DeVorkin:

McCrosky?

Marsden:

McCrosky. For minor planets and comets. Space Watch was going into that as well. Space Watch with Tom Gehrels. But, Mac was one of the first really to superside conventional photography. So, that was something we were doing.

DeVorkin:

With Dave Latham?

Marsden:

Dave wasn’t so much involved with the astrometry, he, had an interest in the CCD for photometric observations. Our program continued until when Shoemaker and Helin both gave up their photographic search programs in ‘94. Helin then started with the NEAT Program, Near-Earth Asteroid Tracking, electronic survey, at the end of ‘95, to join Space Watch. Some other groups were coming along. Amateurs were also starting CCD work, thanks to the Santa Barbara Instrument Group in Santa Barbara, California selling relatively inexpensive CCD setups for telescopes for amateurs. This was in the mid ‘90s. In the meantime, after Bardwell retired, I brought Gareth Williams over from England, who had done an undergraduate thesis on (??? PG78) at the University College London in 1987. He sent it to me at the time, and it struck me immediately that he was obviously the person we needed to have here when Bardwell retired.

DeVorkin:

Was he another you?

Marsden:

He’s worse than me. [Laugh]

DeVorkin:

Oh yeah? How so?

Marsden:

Oh he’s very much into computers and things. He’s brilliant. Gareth is brilliant. But then why did my daughter marry him after putting up with me and saying she wasn’t going to marry an astronomer? She married Gareth in 2002

DeVorkin:

[Laugh] Okay.

Marsden:

Gareth is Gareth. So, bringing Bardwell here was the right thing to do at that time, clearly, but then he retired — actually he still comes in for a while, most Saturday afternoons. And then Gareth, that also was the right thing to do, to bring him here in 1990 to take over to do more and more improving of the computer programs. Gareth and I did this together and Dan Green and I did the Central Telegram Bureau until 2000.

DeVorkin:

Dan Green, right.

Marsden:

He first came as a student in the summer of ‘78 and has been on the staff since 1980. I passed over the Central Bureau to Dan in 2000, at the IAU meeting in Manchester after running it for almost a third of a century. I’d actually been planning to go until 2003 and maybe give up both of them at the same time, but during the last few years we’ve run into a number of problems with the Minor Planet Center and the IAU.

DeVorkin:

And what’s that?

Marsden:

You might say, I was having more disagreements with some astronomers out there, particularly in 1998; with 1997 XF11. The 1997 XF11 was a near-earth object discovered in December 1997, and it was being observed a bit, not much. It was clearly very interesting with the possibility of a very close approach to the Earth, or the likelihood of a very close approach to the Earth in 2028. I was not pleased with the way the observing was going and we did a calculation, somewhat by chance, Showing that the nominal orbit gave a very close approach to the earth, about forty-five thousand kilometers. And, so we mentioned this on an IAU circular trying to encourage further observations. Yes, I indicated it might be as far away as the moon. I did a preliminary study of that and put that out. But this got into the press. And, in particular, Steve Maran heard about it froma Dallas Morning News reporter and so he then decided he’d like to put out some press release. Did I have anything? Well, we were actually busily preparing the Minor Planet Circulars at the time, but I had something I’d jotted down and we put it in the Internet and I sent it to Steve saying, “Okay, you can use this.” And it had my name on it and the date. And, what did he do? In sending it out he put International Astronomical Union between my name and the date. This meant that the IAU secretariat in Paris started receiving phone calls from reporters and there was a real hullabaloo.Johannes [Anderson] was the general secretary of the IAU at the time and he sort of took this personally. I talked to him about it and I talked to Richard West about it first because Richard, also Danish, was Anderson’s mentor, but Anderson really went off-beam on this and decided we needed to have a contract. There needed to be a contract between SAO and the IAU to run the Minor Planet Center. Now, the Minor Planet Center had been running here perfectly well for twenty years. And, there’s also a Central Telegram Bureau that had been running here for thirty years without a contract, but he decided that there had to be a contract, and he made a big thing about this. There had to be terms of reference and all that and somehow he got some of the NASA people involved. Some of the NASA people were upset too because they kept getting phone calls and they didn’t know what was going on either.

DeVorkin:

Did Steve Marans press release include the uncertainty?

Marsden:

Yes. Oh it was an accurate representation. He didn’t alter it other than put in International Astronomical Union, and that was the mistake as far as the IAU was concerned. NASA also, perhaps, was a little displeased by the fuss that was being made because my main emphasis was to encourage some further observations. In fact, what happened was the recon (??? Pg81) of 1997xF11 on some old photographs from 1990 because then we could extend the arc from three months to eight years, and have the obit in much better shape. Perhaps I could have asked an observer privately to do that. But, I didn’t know who had photographs. Eleanor Helin turned out to have some. But, even if I’d asked her privately she might not have got around to it for a while, and in the meantime the object was getting fainter, moving away from the Earth, and we needed to get something on it. So yes, because of the publicity she got around to finding it and measuring it the next day. We had it immediately and the whole thing went away, as so often happens. But then, people started criticizing me about that. But, you know, with all the criticism going on, it was a while before I finally got a chance to look into it in more, to look into things in more detail. I had never calculated that it would hit the Earth in 2028, but I knew it would come close.

DeVorkin:

And Steve didn’t say anything about that meteor shower?

Marsden:

He didn’t. The closest was about thirty thousand kilometers. I didn’t initially investigate this minimum because I knew it could be as far away as the moon, maybe a bit further. And, actually it turned out about twice the distance of the moon. But, nevertheless, without the 1990 observations there was considerable uncertainty. And, with all this criticism going on, nobody after from me caught onto the idea, that we didn’t exactly know how close it coming in 2028. Therefore, we didn’t know exactly what the effect of the Earth on it would be in 2028. What we do know is that, sure, the minimum distance between the orbit of the object and the Earth is fairly large now, like 100,000 kilometers, but it’s getting down to 30,000 kilometers, by 2028, and it’s getting smaller. So, a few years after 2028 we did have the possibility of an impact if the object were to be in the right place in its orbit. So, I did some calculations, and it took me a couple of months. I found an impact possibility in 2037 and another one, a better one, in 2040. I mentioned these (??? pg 83) at a meeting in the summer of 1998 and said “Look, you people who are criticizing me; here is a project you can work on. You don’t need to be monitoring the observations. You have the observations. Consider the uncertainty. Run the trajectories, various trajectories, forward and see what the chances are of an impact. I did that first with 1997 XF11. Then a group in Pisa, in Italy, did take my idea up the next year. They found there 1999 ANIP could hit the Earth a decade or so after a close afflication in 2027. They wrote a paper about it for Astronomy and Astrophysics and also said, “This might, hit the Earth.” They included in the paper the possibility of an Earth impact. And then we found some old observations of that object from the Palomar Sky Survey 1955, and that again showed no promise of in-pack. This was the star of the whole procedure of doing (???pg83) calculations. The people there in Pisa started doing it regularly. One of the people they had on the staff was an American postdoc, and when he finished his tour there he went to JPL, so JPL started that, doing these (??? Pg83) routinely. He’s still at JPL, Steve Chesley. None of this would have happened if I hadn’t predicted 1997 XF11. So, both Pisa and JPL have these systems now where they can take what we put out from the Minor Planet Center on a new NEO, and whereas we are only interested in the short-term effect, reallywe do an orbit and the uncertainty for a short-period of time — and they examine all possibilities of impacts over the next century, and of course, they often find some, (??? Pg83) hundred of (??? pg83) for the same object. They work out a probability of impact.This led to all sorts of silly things like the Torino Scale, which was brought up at a meeting we had in 1999, in Torino. And then there’s a Palermo Scale, which is a bit better.

DeVorkin:

Who created these things and why are they Italian?

Marsden:

They’re Italian because we were having meetings in Italy.

DeVorkin:

And are they Italian?

Marsden:

The Torino Scale was devised by Rick Binzel at MIT. He had tried to pedal it in 1995 at a UN conference, on NEOs in New York. He’d written a paper about it. I had not been too happy about it. It was published in the proceedings. Not a very good paper. But, at the time of the Torino meeting he came up with this scale that really pits impact probability against impact energy.

DeVorkin:

What good is that?

Marsden:

You want my honest opinion? Not much. But it’s supposed to help the public decide whether to take the thing seriously. This is suitable for the press and the public. That is what he’s thinking. It’s not. Because, the press gets carried away when they see the Torino numbers, all color coded. It’s white for nothing, then green. It is said that the colored alerts for terrorist attacks came from the colors for this. There are like a lot of green, yellow, orange, and red, what you expect.

DeVorkin:

Pretty standard?

Marsden:

Yeah. Pretty standard. [Laugh]

DeVorkin:

So there’s something bigger happening here?

Marsden:

Yes.

DeVorkin:

I guess going back to the 1997 XF11 and how IAU reacted and how NASA reacted? What’s really going on with some of those people?

Marsden:

Yes. They gave me a hard time. I would say things were pretty nasty for a while. It wasted an awful lot of time. I mean, people coming along thinking they can do things better, and that they’re experts on NEOs, and all this sort of thing. As I said, we had a conference already in 1995 while things were reasonably friendly, I suppose, but its people wanting to take over. As I say, I told the people in Pisa to do it and they did it. Then there is the matter of support for the work. In 1996 there were funding (??? pg85) CCD search programs in the U.S. (??? Pg85) there was SpaceWatch and NEAT. LINEAR was coming along but not yet ready then, also LONEOS Lowell Observatory Near-Earth Object Survey in Flagstaff. We had a meeting to discuss how the work would be supported at NASA. The search programs are funded by NASA and the question is, “Do they want each search program also to have somebody to calculate orbits? Or, is it better to have the orbits computed centrally for all of the programs?” Central con (??? pg85) has the advantage that, if each program has its own person then the program don’t connect. But with the Minor Planet Center doing this coordination they do connect. And we have no vested interest in any particular (??? Pg85) program. We work with all the programs, and so then it was a question whether each NASA program would pay us to do this work or whether NASA would pay us, bearing in mind I’d had some money eighteen years earlier, from NASA to run the Minor Planet Center for (???? Pg 85) eighteen months, and had they said they didn’t want to support us anymore.

DeVorkin:

So, they gave you those eighteen months and didn’t continue it?

Marsden:

They didn’t continue it, and I knew they wouldn’t. That’s why we boworred the subscriptions. The IAU would give us a small amount of money, much as they gave money to the Central Telegram Bureau. In 1994 they didn’t give us any money. In 1997 the meeting in Kyoto, I remember at the closing banquet beseeching Johannes Anderson the new general secretary, for some money and he said, “No, we don’t have any money.” But then after this fuss in 1998 when he wanted to have a contract, then he did find a little bit of money.

DeVorkin:

So, there was money with the contract?

Marsden:

There was money with the contract, about $6,000 a year, which doesn’t exactly go very far. It’s a token amount of money. Sometimes I wonder maybe if I refused the money then I wouldn’t get in this problem with the IAU.

DeVorkin:

There’s something else going on.

Marsden:

[Laugh] Yes, politics.

DeVorkin:

But even, even a stranger form of politics.

Marsden:

It’s very strange.

DeVorkin:

Somebody in, let’s say, our government, saying, “Well, you know, this kind of knowledge has to be controlled for the public’s good?”

Marsden:

Yes. That’s a very good point because all the astronomers are concerned about that the last thing we want is when somebody predicts something’s going to hit the Earth and it’s a specific secret. Yes. That is a very important consideration, and obviously complete anathema to me. And, of course, we had already started in 1996 a process that would handle the NEOs in a semiautomatic manner. When we received a report, from an observing program we’d do some calculations, decide whether we think we had a NEOs, just on the basis of a single night data, and put predictions on the NEO Confirmation Page in the World Wide Web. Typically it takes a few hours after the observations for this to happen. So, observations made on a certain night, from the LINEAR Program, Lincoln Near-Earth Asteroid Research, which has been the biggest program during the last several years. We typically get that information fairly late in the afternoon here , mid to late afternoon here. So, we put candidates on the web. It’s then mid evening in Central Europe and there are observers there who take what we put on the Web, look for these objects. If they find them they report them. We can then update the prediction in time for observations that night in the U.S. and Canada, and we get observations from there in the morning. Then we update it again. So there’s no way it can be a secret. And then, with the third set of observations we’re usually reasonably happy about the orbit, and we put out a formal publication with all the observations then. But, so many things can go wrong at the start. Maybe even as many as thirty-five percent or the object reported don’t exist, or aren’t NEOs. Some of them are comets, but that’s okay. Comets can be NEOs too, and we work with comets in conjunction with the Central Bureau for Astronomical Telegrams. So, I would say this process works very, very well. And, we’ve been doing it since 1996. New programs have come along, but that arrangement we had then was with NASA headquarters, after 1997 XF11, for political reasons, got moved to JPL for an NEO program office there. They’re involved with these more extended calculations of any possibility of impact for the next century. And that could cause it to register on the Torino scale. If something is at ninety-nine percent probability and is more than a couple kilometers across, that’s a ten on the scale. Nine and eight are pretty bad too. But, as you go down to, even to five or six, there’s only one percent probability and that can happen quite easily, and it did happen a few months ago with this thing 2004 MN-4 which came through the Minor Planet Center last December. 2004 MN4 came through the Minor Planet Center from a program in Australia, which was actually funded by NASA. They found it and the person here working on it realized that it had also been observed six months earlier, rather badly and on two nights at Kitt Peak. But they did fit no better (??? pg88) so he put it out. And then, the JPL people realized there was a possibility of an impact in 2029. And as we got more observations over Christmas, it actually went up as high as a 1:37 probability. Three percent probability of an impact in 2029. Fortunately, this occurred all over Christmas and the press was not paying attention. Then we had the tsunami in Asia that took over the interest of the science writers. And by then we’d found some observations from March last year that seemed to indicate that the 2029 thing was off. But, it’s the same kind of thing then as 1997 XF11. You get a very close approach in 2029. We know it’s a very close approach, but there is some uncertainty, and this means we cannot predict very well what it’s going to do in the 2030s, and there were possibilities for impact in 2035 and 2036. I think the 2035 one has now gone away because we’ve got some radar on this as well. Radar is good to have on these things.

DeVorkin:

There was radar?

Marsden:

There was radar in January 2008 and again in August. So, there is a chance of about 1:6000 I think it is, of a hit in 2036. But again this is precisely the kind of thing as I was suggesting with 1997 XF11. Better data of course, and a better example, but, the idea is there. It was our work that led to this kind of awareness. But, at the same time it’s meant that the scales, like the Torino Scale, have become rather stupid, because the Torino number went up to a four on that scale but then completely disappeared. The Palermo Scale is somewhat similar but a bit more quantitative, but it still is basically putting energy and probability together. They’re not compatible. The impact probability just changes out of all recognition. The energy, of course, does relate to the size and the impact velocity. But, then there really is the question in all of this. Why are we interested in the impact energy? If we know something’s going to hit us in thirty years, we’re going to go to a lot of trouble to prevent it from hitting us. And so, the energy that we need to know is what energy does it take to deflect it?

DeVorkin:

To deflect it?

Marsden:

That is the energy that’s important. The impact energy is a meaningless concept. I’ve suggested something that I think is much more meaningful and much simpler to consider. All you need to consider is the ratio of the period of time covered by the observations to the period of time from the present to the first possible impact date.

DeVorkin:

Ah, I see.

Marsden:

Just the ratio of two times. In a very rough sort of way it’s doing that. And, if that number is less than one percent, forget it. Even if it’s five percent I don’t get too worried about it. But, if it’s less than one percent, completely forget about it. That’s the way we’ve had in so many of these cases. Actually, 2004 MN4 for 2036 is three percent, which is a fairly good. It’s one of the best ones. The best one we have is for the year 2880. It’s six percent because the object (??? Pg90) has been under observation for fifty-five years. [Laugh]

DeVorkin:

Fifty-five years. That’s good. Now Tom Gehrels gives a very dramatic talk, and I don’t know if he still does, but about ten years ago I heard him try to scare the pants off of a professional audience. [Laugh] Let’s put it that way.

Marsden:

Yes. Tom would do that sort of thing.

DeVorkin:

This was a regional IAU meeting in (???).

Marsden:

Oh, yes.

DeVorkin:

And, I was there to talk about SAMA. Tom gave this big talk and I noticed that the primarily Southeast Asian audience seemed not to be too impressed. They didn’t criticize Tom about it.

Marsden:

Tom has a love affair with that part of the world. Yes. In India and Ceylon, Sri Lanka. He goes there as often as he can and works with the people there for several months, and he really likes their mystical way of thinking about things. He’s a bit of a mystic himself.

DeVorkin:

Oh, I see.

Marsden:

Yes. At Space Watch telescope, you can actually climb up and look out the top of the dome. And, he likes to go up there, look around, and meditate.

DeVorkin:

Where is the telescope?

Marsden:

At Kitt Peak. Yes. I’ve been there and I’ve observed with him. He’s a bit of a mystic, but a great fellow. He really pioneered so much (??? Pg 92) he was working with Kuiper, in the 1950s with the McDonald Survey, which Kuiper initiated. Then it was he who took the plates for the Palomar–Leiden Survey in 1960 that really gave a lot of information about minor planets.He got interested in NEOs around 1971, with the discovery of Daedalus. He, more than anybody else, has carried out observing work ever since, moving away from photography to the CCD Space Watch Program.Other programs have come along, but Space Watch still a great program, and he’s still involved with it.

DeVorkin:

Do you think though he’s something of an alarmist?

Marsden:

No. Tom is not an alarmist. I don’t think any of us really intended to be an alarmist on this, but the fact is that the Earth has been hit by these things in the past with disastrous effect on occasion. Yes, there is a small probability of some impact by some modest sized objects during the next century. After all, we had Tunguska less than a hundred years ago. Sure, in 1990 and 1991 NASA was having meetings on this subject and was begining to develop a concerted program to search for NEOs,the “Space gauard Project”, Program as it was called, in honor of Arthur Clarke’s use of that name. We talked about various possibilities. This evolved into looking for kilometer-sized objects and finding ninety percent of them. Of course, we didn’t know how many there were and estimated here generally (??? Pg92) from 3000, to 2000, 1800, 1200, and maybe a thousand. We don’t know of course. Finding ninety percent of them in ten years. The beginning of the ten years wasn’t established until 1998, with all the fuss. They set the date and so it means that we’ve got to find ninety percent of them by the end of 2008. So far we found (??? Pg93) sixty or seventy percent, depending how you want to count them. The number of new big ones found is dropping off, I think. That’s where you (??? Pg 93) experiment. As you get near the end you don’t find as many. You find the easy ones first. So, we may not find ninety percent of them by 2008, but this doesn’t matter very much. What matters, is that we find smaller objects as well. The British government had a task force look into this in 2000 and they recommended going down to three hundred meters, but all the British government provided in the way of money was for Public Relations Office for a while. The reform recommended a bit of support for the Minor Planet Center, but that never came to pass. In the U.S. NASA has had some further meetings in the last couple of years, and now the official limit of interest is a hundred and forty meters.But that costs a lot more and to get 90 percent is a lot harder to do. We actually have (??? Pg93) progress with the fairly large objects and seventy-percent’s not bad. But as you go down to a hundred forty meters, those numbers really are enormous number of them. So, the fraction we can easily find is very small. It’s very likely we would be hit first by something that size. We don’t know about.

DeVorkin:

Do you have any idea what is possible behind the classified barrier?

Marsden:

I don’t, quite frankly, think very much. What’s happening now is going in the direction of PanSTARRS and LSST are Large Synoptic Survey Telescope.

Marsden:

LSST is Large Synoptic Survey Telescope. These are astrophysical projects, basically, to look at objects far beyond the solar system.

DeVorkin:

Probably dark matter for the LSST?

Marsden:

Yes, exactly. That’s the scientific impetus for it. But, of course the people involved with the object are aware of the publicity that goes with the NEOs.

DeVorkin:

Well, the reason why I asked about the classified areas, or the classified world, I try not to be conspiratorial.

Marsden:

Right, of course.

DeVorkin:

I went to a meeting of the, Consortium of Astronomy Departments, in Pennsylvania, and a fellow from Pittsburgh, Contraves Corporation, also, I guess it’s the successors to Brashear?

Marsden:

Oh yeah, of course.

DeVorkin:

They brought a very sophisticated PowerPoint presentation, including video, of a four-meter telescope that they have.They built these things off the shelf almost, an assembly line, for places like the Kirkland Air Force Base and other places like that. They are three-axis four-meter telescope.

Marsden:

There is a four-meter telescope in Hawaii that has been there quite some time, The Air Force has control over it but as far as I know they’ve never done anything with it.

DeVorkin:

But, they have one at Kirkland Air Force Base?

Marsden:

Are we doing anything with it?

DeVorkin:

Well, tracking satellites.

Marsden:

Yes, well of course, LINEAR tracks satellites as well. That’s the main purpose of the LINEAR telescopes that are used and they filter the satellites out before they send the data to us. They send only positions of objects not images (??? Pg95) us and they ask us not to (??? Pg95) unconfirmed single-night data. We should only (??? Pg95) known objects, or something (??? Pg95) That’s clearly asteroidal. Most (??? Pg95) main-belt asteroids, 99.9 percent, then that’s okay. But, they don’t want us to make the other data available. And, this has been a bone of contention with the IAU, as well.

DeVorkin:

Okay.

Marsden:

Because they feel that we should make all of the data available. But as I say, also with the Central Telegram Bureau, I want objects to be confirmed before I put out the circulars.This is partly to preserve the credibility of the observers, partly to preserve my own credibility. When the IAU circulars were done from Copenhagen there were a lot of mistakes that went out. I said Owen made a few mistakes here, but we’ve actually minimized them since I was involved in 1965. That isn’t to say we don’t put anything out that’s bad. We have the terrible case of an alleged supernova in M31, which caused a lot of trouble in 1987. There was a misunderstanding.

DeVorkin:

I don’t remember that.

Marsden:

Yes, it was rather unfortunate. It caused Jerry Neugebauer to drive out from Pasadena to Palomar to (??? Pg96) observe it.

DeVorkin:

Oh my.

Marsden:

It was a three-hour drive.Then finding when he got there that it didn’t exist, he turned around and drove back home. I’d like to avoid that sort of thing. [Laugh]

DeVorkin:

Yeah. I can agree. Before the tape runs out, I think we’ve gone a total of six hours. And, I can well imagine that there are other things to raise, but I think this is a good place to end.

Marsden:

I think we’ve actually covered things rather well. On the matter of the IAU, they’ve been insistent on this contract business. Irwin went along with it as director, but he really felt that they were getting the better side of the bargain. After all, if they’re paying us only six thousand dollars a year. In the last few years we’ve added two more people to the MPC staff paid largely by NASA, (??? Pg97) us with the terms of reference, is therefore quite outrageous. (??? Pg97) Charles Alcock, our new director, is resisting the IAU on this. I think that’s good.

Session I| Session II