Interview: Clyde Tombaugh
Discoverer of Planet Pluto

Let's begin at the beginning. How did you first know what you wanted to do in your life?

Clyde Tombaugh: When I was in the fourth grade, I became intensely interested in geography and I learned it well. In fact, by the time I was in sixth grade I could bound every country in the world from memory. By then the thought occurred to me, "What would the geography be like on the other planets?" So that was my natural entrance into astronomy, you see. So I've been interested in that area particularly ever since.

Of course, I took all the science and math that was offered in high school. I had an uncle in Illinois who lived about nine miles from us. He was an amateur astronomer, and he had a three-inch telescope. The views with that telescope were my first views of the rings of Saturn and Jupiter's moons and the craters of the moon.

What event inspired you in this field as a young person?

Clyde Tombaugh: I was interested in eclipses when they occurred, things like that. Later, my uncle and my father invested in a Sears Roebuck better grade telescope which I used thousands of times to look at objects in the sky I read about. That was always a thrill to find them in the sky.

What did your parents think when you told them you wanted to do this seriously when you grew up?

Clyde Tombaugh: I guess they just took it for granted that that was what I was interested in and let nature take its course. They always encouraged me and, of course, the day came when I left to go to Arizona, they realized that I was going to do what I really wanted to do: become an astronomer.

How did they encourage you?

Clyde Tombaugh: They would get books on astronomy out of the city library for me. They would allow me stay up late at night to look at things in the sky. I didn't have any regular bedtime hours to abide by, so it was a pretty good environment.

What were some of the books they took out?

Clyde Tombaugh: I don't remember the titles of them, but I got out one book called The Pith of Astronomy, a very popular amateur book, which I read so many times, I practically memorized it. And then other books I don't recall the names. Of course, a lot of them are now obsolete, but they were the best they had at the time. I got them from the Streator Library in Streator, Illinois. That was my home town and I went to high school there for two years.

Your uncle gave you one booklet on Mars, didn't he?

Clyde Tombaugh: It was Mars's Mysteries, I think, written by Latimer Wilson. He was an amateur telescope maker, and an amateur astronomer. He lived in Nashville. In later years, I went there and saw his telescope, but he was deceased by that time. I had kind of a correspondence with him in earlier years.

How did that come about?

Clyde Tombaugh: In Popular Astronomy magazine, in 1924, he had a paper with drawings of Jupiter, beautiful drawings of Jupiter and its markings. He remarked that he had made that with his 11-inch home-made refractor. Boy, that just sent me! I had to write him and say, how do you make a telescope like that? So I wrote to him and he responded. That's how I got started making telescopes.

Why were you fascinated by this kind of reading at that age?

Clyde Tombaugh: Well, I just had this curiosity. I wanted to see these things I'd read about.

What did your friends in grade school think of you?

Clyde Tombaugh: I guess they thought I was a little odd. I was always interested in intellectual things. I was always interested in sports too. I played baseball in grade school and then in high school I was on the track and field team. I was the school's star pole vaulter.

So you did have other interests.

Clyde Tombaugh: Oh yes. I guess the two things I was most interested in were telescopes and steam engines. My father was an engineer on a threshing rig steam engine and I loved the machinery.

How did you make the choice?

Clyde Tombaugh: I was interested in telescopes and the way they worked because I had an intense desire to see what things looked like, so I learned how to use telescopes and find things in the sky. Although my early equipment was very modest, later I made my own and they were more powerful.

There must have been a driving curiosity with you.

Clyde Tombaugh: Yes, a very strong curiosity about the universe and so on. I just had the urge to see on the other side of the mountain. It was on the moon and the planets and all that you see. I wanted to extend my horizon of interest. It was a challenge to my thought life.

Did you have fantasies about space travel when you were young?

Clyde Tombaugh: Yes. I used to think about how nice it would be to visit the planets. Of course, I didn't expect to see in my lifetime what has happened. I knew it would happen some day, but it came along faster than I at first thought.

What did you fantasize was going on out there?

Clyde Tombaugh: I used to believe there were people on Mars, and of course now we know there aren't. Mars held particular interest. I was curious what kind of beings they would look like. We thought they were super intelligent because of the canals of Mars, that they were an old civilization and had learned a lot more than we had.

What teachers inspired you?

Clyde Tombaugh: I had one teacher in grade school named Susie Szabo when I lived in Illinois. She encouraged me to study science and so on, and she appreciated my interest in geography because she loved geography also.

How did she encourage you?

Clyde Tombaugh: She talked to me about what I had seen in the telescope the night before, and she was just a marvelous person, a real teacher.

How old were you when you built your first telescope?

Clyde Tombaugh: That was in 1926. I was 20. It wasn't a very good one because I had such meager instructions. It worked fairly well, but not good enough to suit me. The following year, Scientific American published a book called AmateurTelescope Making. I bought a copy and digested it and realized where I'd made mistakes. My next telescopes were much better because I had more information.

The nine-inch in my backyard, for instance, was my third telescope of excellent quality. It was the drawings I made of the markings on Mars and Jupiter with that telescope that I sent to the Lowell Observatory in 1928. That impressed them favorably so that they invited me to come out for a trial work with the new telescope at Flagstaff. That was a big break.

Let's talk about that time in your life; how this young man had the guts to send his primitive drawings to the Lowell Observatory.

Clyde Tombaugh: What you do is, you have your drawing board and a pencil in hand at the telescope. You look in and you make some markings on the paper and you look in again. Back and forth, many, many times, so as to get the stuff in the right proportion, the right intensity. It takes about a half-hour to make a good drawing that way. When the temperature is freezing, it's a bit hard on your fingers, but I was interested in putting down what I saw. And that's what paid off.

To be an amateur and be confident that your drawings had some significance must have taken a lot of nerve.

Clyde Tombaugh: At that time the Lowell Observatory was the only planetary observatory in the country, and I was particularly interested in planets at that time, and so I thought I would just like to see what they thought of them. The planets are never the same twice, they're always different, so they could compare the markings I had drawn with their current photographs and they knew that I was drawing what I was really seeing and it wasn't copied from somewhere.

They realized that I was careful, I saw well, and so on, and they thought I would be a good candidate to run this new photographic telescope they were installing. I was invited to come out on three months' trial and stayed 14 years.

What was the level of your education at that time?

Clyde Tombaugh: High school, but I studied solid geometry and trigonometry on my own because they didn't offer those in high school at that time. Can you imagine young people nowadays making a study of trigonometry for the fun of it? Well I did. I was very much interested in mathematics and physics and so on. Physics is one of my best subjects.

When did you go to college?

Clyde Tombaugh: Not until two years after the discovery of Pluto. I went to the University of Kansas as a freshmen in the fall of 1932 and Pluto was discovered in 1930. When I went to Flagstaff all my astronomy was self-taught.

It must have been a strange feeling to go back as an underclassman when you already had a world reputation.

Clyde Tombaugh: It was. As a matter of fact, I wanted to take the beginning course in astronomy, but the professor of astronomy wouldn't let me. He said that would be absurd. I guess he thought it would create awkward academic implications for a discoverer of a planet to be taking beginning astronomy.

It would have been peculiar to sit in class and learn about yourself! Did you always think you were destined to be an achiever in this field?

Clyde Tombaugh: I never thought that way. I think the driving thing was curiosity about the universe. That fascinated me. I didn't think anything about being famous or anything like that, I was just interested in the concepts involved.

How much luck was involved in the opportunity that you got?

Clyde Tombaugh: Being invited to come to Flagstaff was a big stroke of luck. The other was pluck, not really realizing I had been preparing myself for that for years before that: building that telescope, learning the finer objects in the sky, reading everything on astronomy I could get and to be very careful. I was somewhat of a perfectionist. So, those were the traits that made me a good candidate for this type of job.

What can you tell me about why you succeeded where others didn't?

Clyde Tombaugh: I had a strong sense of responsibility, I wanted to be flexible also, and I just worshipped knowledge and spared no pains to do the job very well. I also had an enormous amount of perseverance. I learned that on the farm. And I guess those are the qualities that got me there.

You credit your success to perseverance. What do you mean by that?

Clyde Tombaugh: You carry on through even despite of discouraging situations and you never lose sight of the goal. Often, you experience hardships involved like freezing in that cold dome at night, loss of sleep, and that gets pretty wicked, but I was interested in getting the results. It takes a dedication to achieve that kind of thing. A lot of people would give up and quit.

Any setbacks along the way that were really more serious than others?

Clyde Tombaugh: When I was on the farm, we got hailed out. That meant total lack of money and I couldn't afford to go to college. This was a blow. I realized that I would have some very tough sledding, and I was very discouraged because I didn't see much hope of getting into the field I wanted to get into with no college education. I didn't know anybody particularly important in the field, so I felt I was under a great disadvantage and could hardly hope to do what I did.

How did you deal with that disappointment?

Clyde Tombaugh: It was depressing, very depressing. I worried about how I would make a living. I didn't want to stay on the farm. It didn't offer the challenge I wanted and yet, without a college education, I felt that I was really out of luck.

I just kept on studying and then the breaks came. I kept making telescopes and learning more about optics and that's the knowledge that paid off. I was really preparing myself for a better thing than I realized at the time.

Getting the invitation to go to Flagstaff was a real piece of luck, but the other was preparing myself. I think of the Chinese philosopher, Confucius. He said, "The future belongs to those who prepare for it," and I never forgot that.

So in your way, you were always preparing. Let's relive that experience of when you realized you had discovered a real planet.

Clyde Tombaugh: I was assigned to taking photographs at night with the telescope. It was a wide-angle photographic telescope with a one-hour exposure. I developed the plates and so on, and a few days later I'd put them on a special machine called the Blink-Comparator, where you compared two plates rapidly in alternating views, to see if any change occurred on the star field, from one plate to the other made a few nights later. That was the technique, because these plates would have several hundred thousand star images a piece. That's an awesome thing to look at and realize you had to see, out of all those images, which one moved. The challenge was far more difficult than most people ever realized.

I had some soul-searching questions for myself. Do I want to go through this very tedious job or not? I didn't want to go back to the farm to pitch hay, and I knew I had to do this job or go back to the farm. So I went through some pretty tedious hardship to accomplish this, but I was dedicated and I liked the work really, and I was very, very careful. All the suspects are checked with a third plate. I did the job very thoroughly, and it paid off. Now, I had figured out beforehand, if there was a Planet X, how I would recognize it if I encountered it. So I thought all this out beforehand.

What started you looking for this Planet X?

Clyde Tombaugh: Percival Lowell interpreted some of what they call residuals -- slight irregularities in the orbit of Uranus and Neptune -- as indicative of a mass out there as yet unseen. Like the case of Neptune being discovered mathematically before it was seen.

These residuals were so small that it was questionable whether they were real or not, but they were the best he had. He predicted that there was a planet out there about seven times more massive than the earth, beyond the orbit of Neptune. Of course, Pluto does not have that much mass.

Tell me about the day that you actually discovered the planet Pluto.

Clyde Tombaugh: When I took the photographs, I had no idea that Pluto's image was on those plates, not until I began to scan them carefully some time later. In fact, it was several weeks later when I got to that pair. I had taken the plates of the telescope the previous month, in January, 1930.

I did not know that I had recorded the image of Pluto on those plates, not until I scanned them later in February. You passed your gaze over all these stars that you have to be conscious of seeing every star image, because you don't know which one's going to shift, if they shift. It's very tedious work and you go through tens of thousands of star images. I came to one place where it actually was, turned the next field and there it was! Instantly, I knew I had a planet beyond the orbit of Neptune because I knew the amount of shift was what fitted the situation. That was the most instantaneous thrill you can imagine. It just electrified me!

That was the 18th of February, 1930, about four o'clock in the afternoon. I realized in a few seconds' flash that I'd made a great discovery, that I'd become famous, and I didn't know what would happen after that. It was a very intense thrill. You don't have that kind of a thrill very often.

Bet you couldn't wait to tell someone.

Clyde Tombaugh: Well at first I had a little sense of caution. I thought I'd better check this third plate, which is another date, see if there's an image there in the right place that would be consistent with the images on the other plates. That was the final proof. Sure enough, it was there. That was when I was 100 percent sure.

Who was the first person you shared your discovery with?

Clyde Tombaugh: I told the assistant director [Dr. Lampland] across the hall from me. This machine makes a clicking noise that could be heard in that part of the building. His office was across the hall and he understood the blinking business, too. He'd been involved in some of the earlier searches. He said, "I heard the clicking suddenly stop and a long silence," and he surmised I had run into something. I was checking out the third plate, and here this poor man was sitting at his desk in terrible suspense, waiting to be invited in for a look. I didn't know about that until he told me later. I showed him the plates, the dates and all and that everything seemed to be consistent with putting the object beyond the orbit of Neptune, and then I went down and told the director. He came up and looked and saw. The Lowell Observatory was changed from that day on. Dr. Slipher was the Director. He had gone through the platal field and missed Pluto, one year earlier, missed it on the plates. He wanted to be the one to find Pluto and he failed. I suppose he probably felt a little chagrined, but he knew that I had something because the aspects were very convincing. Then, they got in touch with the observatory trustee, Lowell's nephew who was living in Massachusetts, and told him about it. It was kept secret for a few weeks so we could follow up and we could learn more about it so we published right about when it came out because we knew that when it was announced, there'd be an avalanche, and there was, exceeded what we expected.

What did the avalanche bring?

Clyde Tombaugh: Newspaper reporters, swarming over us like a bunch of bees - interviewers, photographers and everything. We were all a little bit awed about this. We felt overwhelmed.

So there you were, a young man, already a national hero.

Clyde Tombaugh: International. It puts you in a different category real quickly.

How did you live with the success?

Clyde Tombaugh: It took quite a little adjustment because I didn't expect to live that kind of life. I've been making adjustments to it ever since. People want autographs by the thousands. They want to talk to me. I gave a series of lectures for four years, traveling over the United States and Canada to raise money for Tombaugh scholarship for post-docs in astronomy here at New Mexico State University. We raised close to half a million dollars.

When was this?

Clyde Tombaugh: This happened in the last four years.

How did you name it Pluto?

Clyde Tombaugh: Pluto was the god of the underworld. The lower world, I guess it would be better to say -- of Hades. Pluto's out there far from the sun, where sunlight, at the average distance, is only one sixteen-hundredth as bright as on earth. Rather dark. And if you think of Hades as a dimly lighted place or outer darkness, it kind of fits in somewhat with the characteristics of Pluto probably, or of Hades. So it seemed fairly appropriate from that standpoint. And, then when the satellite of Pluto was discovered in 1978 by Christy at the Naval Observatory, he named it Charon because his wife's name was Charlene. Charon was the boatman who ferried the souls of the dead across the river Styx to Pluto's realm of Hades. So the satellite name fits in very well with Pluto, you see.

The almanac says that the name came from the initials Percival Lowell.

Clyde Tombaugh: Well, that was another reason, but not the main reason. Of course, they used the first two letters, Percival Lowell. But that was not the main reason. That was somewhat of a coincidence.

How soon did the planet get its name?

Clyde Tombaugh: In April, the following month. We considered many names of course, and Pluto was the final. It was chosen by the staff of the Lowell Observatory. The Lowell Observatory Director proposed to the American Astronomical Society and the Royal Astronomical Society of Great Britain that this name be given to the planet, and both bodies accepted it unanimously. So we knew the name would stick.

Where did your life go from there?

Clyde Tombaugh: Soon after the discovery, there was some apprehension that maybe this object I'd found was only an interloper and that the real Planet X was yet to be found, so they wanted me to go on searching. I searched a lot more of the sky and no Planet X ever showed up. It may be out there, still unseen. Then I got a scholarship to the University of Kansas to go to school and I went to school there from 1932 to 1936. But I'd come out every summer and scan more of these plates, and then I went back two years later and got my Master's degree. All that time, I was searching for the Lowell Observatory. I took courses in higher mathematics and physics and the sciences and so on, at the University of Kansas. That's where I met my wife, Patricia.

How did you balance your personal life and this intense curiosity and interest?

Clyde Tombaugh: Well you have to kind of work it out. A person that much interested in science is going to neglect his social life somewhat, but not completely, because that isn't healthy either. So, one has to work it out according to one's own inclinations, how one wants to proportion these things.

Is there a talent you don't have that you've always admired?

Clyde Tombaugh: I would like to have been a better master mathematician than I am. I'm not a slouch either, but I would like to have been better. Probably also more skill in administrative work than I had, although I did a lot of it later. I really had a sense of reasonable satisfaction the way things were going. I had no great regrets, and if I had to do it all over again, I don't know that I'd want it much different. So I have that to be thankful for, but it did take a lot of intense dedication to do that.

Did it take as much dedication even after people recognized your ability?

Clyde Tombaugh: Yes. You have to compete with others in the field. Sometimes the competition gets pretty fierce because you're competing for funds or grants to do your work, the financial work.

How would you explain what you do and what you care about to someone who doesn't know anything about your field? How would you impart to them how exciting it is to them?

Clyde Tombaugh: I like to raise the question, "Have you ever thought about what lies in the sky above you, that earth is not the only place in the universe?" There's a great universe out there. We're only a small part of it. I like to try to raise the curiosity: what is out there in space? A lot of unsolved mysteries. It's a never-ending challenge.

You've devoted many years to teaching as well.

Clyde Tombaugh: Yes. My first experience at teaching was during World War II. I was assigned to teaching navigation in Navy school for seven semesters. I put hundreds of young men though a tough navigation course. It was very overloaded because they didn't have enough teachers.

Astronomers were good candidates for teaching navigation because they understood the basics of navigation theory. A lot of astronomers were pressed into teaching navigation because of the terrible shortage of teachers. We were suddenly faced with the necessity of training a lot of young men in the art of navigation. That's how these things got set up all over the country. They had one at Flagstaff at the Arizona State College at that time.

Let's talk about White Sands now.

Clyde Tombaugh: During the war, I was teaching navigation in the Navy school, and when I wanted to go back to the Lowell Observatory to resume astronomical work, the observatory was short of funds and they let me go. That hurt my feelings, but in the meantime, I was invited to come to White Sands Missile Range to supervise the optical instrumentation. Some of the people thought with my experience with telescopes that I could do that kind of work. It turned out I was just the man for the job.

I came to White Sands in August 1946 and saw almost all the German V2 rockets fired along with our American rockets. I had about 80 men under my supervision; about half of them were military people and others were civil service. My rank in civil service was equivalent to Lieutenant Colonel and I had a big responsibility getting the ballistic data on these rockets.

It was up to me to decide where to put my instruments for the strategic positions to measure these high-speed rockets. It was a real challenge, but we did it. I used a lot of trigonometry out there and knowledge of optics. I designed super cameras and got marvelous results, which really put the White Sands Missile Range on the map. So I had a lot to do with the modern instrumentation of rockets.

Tell me about the satisfactions of changing careers for a while.

Clyde Tombaugh: At first I wasn't sure I'd like it, but the optical problems rather fascinated me. After the war, the Russians turned suddenly unfriendly and that bothered me. We were testing a new brand of rockets and missiles. We needed somebody who knew how to get instrumental data on them in flight and I thought this was where I could make a contribution.

I'm glad I did. We had some dangerously close calls, but it was very challenging, very exciting. I saw a lot of them explode on the launch or in the air. Very spectacular fireworks, I can tell you. These were powerful missiles. I tracked a lot of them myself with satellites and telescopes.

I got thoroughly acquainted with the Army, which I'd never known much about before. I worked with every rank in the Army from the commanding general to the buck private, and I had several military people under my supervision. I designed new instruments for particular jobs of the work which proved to be very successful. In fact, this one instrument which we called the IGOR, meaning Intercept Ground Optical Recording, was a super camera, and they worked so well that they were used at White Sands for the next 30 years before they retired them. Then they got some a little bit bigger of the same kind.

Was this when you became interested in optics?

Clyde Tombaugh: I was always interested in optics. All this came about from what I learned personally working on mirrors back in Kansas.

How old were you?

Clyde Tombaugh: I was 22 when I made my third telescope. The nine-inch was a very successful instrument. You need to have a place where the temperature's constant, like an underground cave, so you don't have thermal problems with the glass when you're working with it. In fact, we had built this cave ourselves years earlier. The farmers like to have a place like that for keeping milk and cream and butter and eggs and stuff. Cool in summer and warm in winter. Also, as a storm protection, because sometimes we had some bad storms and you didn't know if a tornado would come along and blow your house away. The best thing was to get down in that concrete cave. It had a very special purpose, but it was a marvelous optical workshop for me.

I would grind these mirrors. I had two disks of glass. One would be on a stand or a barrel and you rubbed that over with strokes and rotation and so on, so you'd grind the curve into it, you see. And then you'd go through the finer grades and then finally you use rouge and water to polish it. You polish the exact curve at the very last. It's very fine work, and then you have a test for watching and seeing these errors that's unbelievably simple. You can see errors down to within a few millionths of an inch. It's simple, but it's tricky.

You designed something from knowledge that you read in a book, which was equivalent to what scientists use.

Clyde Tombaugh: Yes. The first telescope was not so good because I didn't know that much about it, but I learned rapidly. You learn from mistakes.

Did you realize how much you had accomplished by developing that?

Clyde Tombaugh: No, I didn't think of it that way. I was just driven by the desire to see more things in the sky. That was the driving force. Everything else was secondary.

Was it a surprise to you to find out that you had developed an instrument that was as sophisticated as they come?

Clyde Tombaugh: Well I realized it more later and then I felt a little bit more proud of myself that I had done better than I thought I was doing. But I never thought of it as being particularly difficult. I had to do a lot of thinking about it, but I've always been a thinker. I don't think there was any problem ever that I refused to try to grapple with.

Do you plan the steps and see them happening in your mind?

Clyde Tombaugh: Yes. You wonder about it and wonder how will I make an instrument that can handle this kind of a problem. And you think about it, do a lot more thinking. Sometimes you make mistakes and you go back and do it over. That's the way I got along in life. I don't ever remember being particularly jealous of anybody, because I figured if I can't do it myself, I don't deserve to get it.

Do you visualize the end result before you start?

Clyde Tombaugh: Yes. For example, this big telescope out here. I had a vision of the whole thing before I ever put in one single bolt. I calculated the movements of force and balance and so on. I'm somewhat of an engineer too, I guess. I sent my nine-inch mirror to Wichita, Kansas to a French telescope maker to silver my mirror because I didn't have those facilities. He tested my nine-inch mirror and thought it was very high quality, so he offered me a lukewarm invitation to come and help him make telescopes. I could have gone that way.

In the meantime, I was wondering what I would do if I didn't do that. I loved steam engines, so I really had a secret ambition to become an apprentice fireman and a railroad engineer, because I just loved machinery and travel, and I had a profound love of trains. I loved engines and machinery. To me, the noise of a threshing machine is better music than a lot of music I hear nowadays. I took a man's place in the threshing crew when I was only 14 years old. That was during World War I and they were short of manpower and so every boy in his early teens had to take a man's place on the farm with the fieldwork and threshing. That's where I learned to work hard.

I shed many a tear when the steam engines went out of style on the railroads. I'd like to seem them come back, but I realize the diesels are more efficient.

What about the career you never had on the railroad?

Clyde Tombaugh: When the offer from Flagstaff came, that all changed all that. I had found something more to my liking so I didn't have any regrets about it. It was just another way out.

You've mentioned two books you read often as a young person: the Bible and the encyclopedia. How did you reconcile the religious beliefs of the Bible with the scientific reading you were doing?

Clyde Tombaugh: Unfortunately, a lot of the concepts in the Bible are based on ancient mythology that doesn't fit the findings of science. So I had to choose one or the other. I regard it as a history in a way, valuable for teaching morals and all of that, but for teaching science, it was no good. It was misleading. That was the attitude I took.

What did that do for your religious conviction?

Clyde Tombaugh: I had a drastic revision in my religion during the Scopes trial in Tennessee. That was 1925. I was 19 then, and I became thoroughly disillusioned with what I considered ignorant, fundamentalist points of view. Our minister would rant and rave against science every Sunday, all summer long. I got thoroughly disgusted with that kind of stupidity. I never got over that. I'm not a Christian at all. I cannot reconcile myself to that point of view. I used to be, but I abandoned it.

You must be a spiritual man.

Clyde Tombaugh: Well I am. I think there's a supreme power behind the whole thing, an intelligence. Look at all of the instincts of nature, both animals and plants, the very ingenious ways they survive. If you cut yourself, you don't have to think about it. Something there heals it, stops the bleeding, puts the scab on. There's something marvelous and miraculous there.

How does a pansy, for example, select the ingredients from soil to get the right colors for the flower? Now there's a great miracle. I think there's a supreme power behind all of this. I see it in nature.

It seems that when people seek contact with a supreme power, they look upward. You spent so much of your life looking up to the skies. Is there any relationship there?

Clyde Tombaugh: Well, of course, heaven is no place in the space out there. I don't know where it would be. There's one place where I think they could say where hell is, that's on the planet Venus because the temperature's 900 degrees and no water and it rains sulfuric acid and the atmosphere is 90 times more oppressive than here, so that's a good place for hell. It's just the next planet over.

You've said that as a young person you were kind of a loner. What advice would you give a young person who also feels different and isolated?

Clyde Tombaugh: I have a lot of sympathy for young people because I realize how disturbed I was. How would I deal with life in the future? What would I do for a living? These things worried me considerably. In fact, I could see failure down the road for me. That wasn't very encouraging. But I never gave up hope of trying to be something.

What advice would you give someone with similar feelings to yours?

Clyde Tombaugh: Never give up, be industrious as possible, acquire all the knowledge you can get, be honest, and hope for the future. You have to have hope. Otherwise, I don't think you could handle it. Of course, you have to have both luck and pluck to make it. Some people are not that lucky even though they try and one cannot help but feel sorry for them because they tried and met defeat. Defeat's a terrible feeling.

Tell me about some of the defeats in your life.

Clyde Tombaugh: When I realized I couldn't work at Lowell Observatory anymore, that was kind of a defeat for me. They were short of funds. There were a lot of byproduct materials I wanted to work up after I got done with the scanning. I discovered new star clusters, clusters of galaxies and one great super cluster of galaxies as byproducts. Hundreds and hundreds of new variable stars, hundreds of new asteroids, two comets. I had learned a lot about the distribution of galaxies in the sky. I counted over 29,000 galaxies on my plates and I found that what I saw did not agree with Hubble's view of the galaxies at all. I had arguments with him about that. It turned out I was right, as everybody knows now. If I had stayed, I would have worked all this out a decade earlier than when it was finally worked out as byproducts of the planet search.

It worked out for the best anyway. The best thing that ever happened was to leave there. I had quite a rewarding life and I got all kinds of honors for my work in science. I also have a prized medal: Pioneer of the White Sands Missile Range.

So you look at what you did accomplish and not what you didn't.

Clyde Tombaugh: It was my philosophy all through life. I never had much sense of jealousy.

How does criticism affect you?

Clyde Tombaugh: Well, I never really got much of it. I remember one time at the White Sands Missile Range. They fired the bumper, the two stage rocket which was successful finally after four tries. I could see that the next thing around the corner was the age of multiple stage rockets, and artificial satellites. So I suggested to the various people, we ought to think about how we are going to instrument these things. Oh, he says, you are wasting your time, we are just going to deal with Honest Johns and Nike Missiles and stuff like that. They kind of reprimanded me. Well, a few years later, the Space Age came in, they came around and apologized to me. That was a bit satisfactory, I tell you. They apologized and said, "You saw what we didn't see." That's imagination and curiosity. You can see ahead to what is likely to happen.

You're a scientist, but I want to ask you about intuition, instinct, gut feeling. How does that fit in?

Clyde Tombaugh: I think it's part of being a scientist. You have to have an alertness to deal with the unexpected. The history of science is filled with almost-made discoveries, missed by a hairline because they didn't have the alertness to realize they had a discovery.

Take the case of the French astronomer Lalande in 1795. He was making a star catalog and he was a very careful observer. He would sketch the position of stars in the field, and he'd go back a few nights later to recheck and make sure he hadn't made a mistake. Well he happened to have Neptune in one field on the eighth of May, 1795, and then two nights later he went back and it was in the same place, but in a different position. He thought he'd made an error in the position. He was actually witnessing the movement of planet Neptune and didn't have the alertness to realize that he'd found a planet. He couldn't have had a better clue. Where was his imagination? I find a lot of scientists do not have much imagination and they do not make big discoveries because they miss 'em.

How do they lose their imagination?

Clyde Tombaugh: I don't think they ever had it. There are some people who are just plodders and work right along doing routine stuff and they seem to like it. It's all they're capable of doing, but they do it well. Others have the imagination to see the unknown and interpret the unexpected, so you have these various different kinds of scientists.

How did you develop you own scientific imagination?

Clyde Tombaugh: I was always looking ahead. I used to do all kinds of things for entertainment. When I was young, we had no radio, no TV. We were 30 miles from the public library, out in the sticks in Western Kansas, and so I'd do arithmetic exercises.

For example, I'd calculate how many kernels of wheat were in 10,000 bushels of grain, just for the heck of it, to see how big the number was. I'd even calculate how many cubic inches there were in the super giant star, Betelgeuse. It's one followed by 39 ciphers. I can still read the number. By this, I learned to get a grasp of the meaning of numbers. I see nowadays in media, they say million when they mean billion and vice versa. They don't seem to understand the difference between a million and a billion. It's a terrific difference, a thousand fold difference, and yet they don't seem to have the intuition to realize that that's the wrong answer.

Also, the thing that really pains me is the ignorance of geography among people today. It is astounding. When you have a lot of people who cannot identify the United States on a world map, that's really bad. There's no excuse for that kind of ignorance. People travel a lot, why don't they learn some geography? It's interesting. Then you know where you're going.

See, I value knowledge very highly and it never hurts you. In fact, it gets you jobs, if you have knowledge. A lot of people aren't willing to take that attitude or take the trouble to learn. It does require effort to learn and if you're too lazy to think, well then you've got to learn.

Could you tell us what you're doing now?

Clyde Tombaugh: Well I get pressed by the public all the time. Dozens of people are after me all the time for favors. It really takes up a lot of time and I just don't have time to do the things I really want to do. I can ignore some of it, some it I can't. We have a new school a mile south of here called the Clyde W. Tombaugh Elementary School which the people of Las Cruces named in my honor. Every young kid in that school knows I found Pluto and it thrills them to death that they're going to the Tombaugh School. So I'm doing all right in this community. They give me great honor.

Do they ever come and visit you in your backyard?

Clyde Tombaugh: Oh yes. Many times. I've shown a lot of people my telescopes.

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Tell me about your backyard.

Clyde Tombaugh: I have the big 16-inch out there, and the nine-inch you see right next to it. I have another telescope on an old lawnmower that wheels around to dodge the lights and trees. I looked at Halley's Comet with that. It's a beautiful ten-inch telescope. I made that also. I've made lots of mirrors.

And you mounted that telescope on an old lawnmower?

Clyde Tombaugh: Yes, because I can wheel it around to different parts of the yard. Some of the comets are so low in the sky, I'd have to move it around to dodge the house and trees. I couldn't do that with these other telescopes. So it's my portable telescope. I've taken it with me on trips up in the mountains sometimes, on outings with an RV and so on. I've had lots of fun with it.

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Are you looking for anything in particular through those telescopes?

Clyde Tombaugh: No, just playing around, looking at the beautiful star fields and so on.

I have this feeling of wonder what it's like to kind of look there and just sweep around through the Milky Way and say, "Oh there's hundreds and hundreds of stars and star clusters." It gives me a feeling of great elation. It's a therapy for me, just idle, plowing through the sky. It's fun. I wonder about all the wonderful things that must be going on there that we don't see, realizing there are thousands and thousands -- millions -- of alien civilizations out there, doing things, maybe something like we are. This is something you think about.

You do believe there are alien civilizations out there.

Clyde Tombaugh: Oh yes.

Our sun couldn't be so peculiar as to be the only one, out of octillions of stars, to have a planet with life on it. That's totally against the odds, even if you have only one star out of ten thousand that has a planet that is right for life. We know now from sampling with big telescopes, that the number of stars in the skies is ten to the 21st power. Now, that doesn't mean anything until I tell you that the number of grains of sand in all of the earth's ocean beaches is only ten to the 19th power. So there are a hundred stars to every grain of sand in all the ocean's beaches. They're not all sterile. How could they be? You have to realize there's this enormous potentiality of trillions of planets out there with alien civilizations on them. We are not the center of the universe. We are not all that important. And we're not alone. That's my perspective.

You see these things in the sky in your plates and it's a wonderful education. You're made aware of the enormous vastness of the universe and all of the things that may be in it. That to me is a very challenging thought. I love to dwell on that, that wonderment.

Do you think finding other life out there is the next great scientific challenge?

Clyde Tombaugh: I think so. There are some facilities where they are trying to listen for somebody radioing to us that shows intelligence somewhere else in the universe. They haven't found it yet, but who knows what they may find. The only trouble is, a lot of them are too far away. They don't have the signal strength to get here to be picked up. But they're listening.

Is that the idea that most fascinates you right now?

Clyde Tombaugh: Well it's one of the things. One of the things that fascinates me as a question is, "Is the universe finite or infinite?" Either way, it's impossible to imagine. So how do you handle it? I finally gave up and settled for a compromise and say I guess the universe is semi-infinite. We don't know. We have never found the edge of the universe. We've gone out to about eleven billion light years and haven't found the end. There are millions of galaxies like our Milky Way. Our Milky Way is one galaxy that contains about two-hundred billion suns. Now all of those stars cannot be sterile with no plants or life on them, can they? It just doesn't make any sense.

So you wonder - what is the purpose of the universe - if there is a purpose. We don't know. I am afraid that we sometimes are a little bit vain and we think the universe is made for us. That's our own vanity showing up.

You like to ponder these subjects, the universe?

Clyde Tombaugh: That's sort of my religion, to ponder on these things. A lot of the answers I don't know, never will know. But it's fun to think about them.

Some of the ideas and inventions on our time were first imagined in science fiction. Does that have anything to do with some of the things you imagine?

Clyde Tombaugh: I remember some of the science fiction which has come true. One of the things that really fascinates me is the speed of light and electromagnetic radiation. For example, we can radio to astronauts on the moon. It gets there in one and a quarter seconds. How can it get there that fast? Now that's something to marvel about. Can you visualize a mechanism that would permit that kind of speed? I'm simply flabbergasted. I cannot imagine a mechanism that is able to accomplish that kind of a miracle, yet we talk to the astronauts on the moon like they're next door, you know? Isn't that a marvel? That's a tremendous accomplishment in communications, to talk to people on another world.

So I don't see how people nowadays, with all these marvels they're finding, can possibly be bored with life. I just don't understand that. To me it's all exciting. How can they be bored? That's beyond my understanding.

You still seem to have a great sense of wonder.

Clyde Tombaugh: Oh yes. The world fascinates me. There are innumerable things that are an absorbing interest for me. Trying to understand them. I always wanted to reach out and extend my horizons. I always wanted to know what's on the other side of the mountain. Never got over that.

What advice would you give a young person who wants to achieve something in this world?

Clyde Tombaugh: I would say be interested in knowledge and develop a curiosity if you don't have one. Do a lot of studying. Try to achieve a balanced life as much as possible. Be persevering, be honest, stay away from drugs, and act with some common sense, and you'll get there.

What about developing a specific passion?

Clyde Tombaugh: That may come when they start working on these problems. Of course, each one's different. Each one has a different idea of what he or she would like to do in life. That depends on their temperament. There are a lot of wonderful challenges in every walk of life, whatever they take a fancy to. And if possible, try to get into that field of work that particularly interests you because that's where you would do it better.

Do you have a lot of communication and conversations with other astronomers?

Clyde Tombaugh: All the time. Letters pour in by dozens and dozens. I go to conventions and meetings every year, so I'm in constant contact. It's fun to chat with people. For example, a year ago last June, we had a meeting of the American Astronomical Society in Albuquerque and the Voyager Mission people invited me to have lunch with them. That was a high for me. Those men are marvelous talent.

It was a high for them.

Clyde Tombaugh: I suppose so. I don't think of it that way. I look up to them as if they were the achievers. To me, what I achieved was the most logical thing. I don't think it was particularly difficult, but other people say that was very difficult. It came kind of easy for me because I understood it for some reason. That had to be my latent talent.

What are you reading right now?

Clyde Tombaugh: I've been reading some books on astrophysics, and cosmology. All kinds of books. Of course, astronomy now has knowledge that's comparable to medicine. Very vast indeed. You have to specialize after you have some general instruction, because no one can know it all. It's too much. The fact is that you will spend a good deal of your life trying to be an expert in one field. It's amazing how much you really need to know and learn to find new discoveries. You have to know what's been done before and know the old in order to forge ahead. This requires a lot of background.

Would you say you are still learning?

Clyde Tombaugh: Oh, yes. I'll never get tired of learning. I'm always reading books. New stuff about the universe. Cosmology is occupying my attention right now. Quasars! We don't know what they are. They sure are fascinating things. Is the universe finite or infinite? This still just bugs me. I don't know what the answer is.

Do you think the early encouragement from your parents, your uncle, and teachers, made a lot of difference?

Clyde Tombaugh: Yes, I think it did. I might have made it anyway because I had this driving curiosity, but they helped a lot.

A lot of kids feel they are different, if they are interested in serious things like science. Other kids will call them a nerd and so on.

Clyde Tombaugh: I felt a little bit embarrassed about that. I realized that I did not care for the things that other kids seemed to like, so I thought, well, I'll go my way, they can go theirs. I had my own thought life, so that didn't worry me.

Is there any advice that you'd give to some kid who doesn't know what to do, who isn't part of the crowd, and who's embarrassed and frightened and lonely.

Clyde Tombaugh: I'd say, get books and study books. That is the key to the future. You will find comfort there, you will find knowledge, you will find inspiration. You will learn to think. The better you think, the higher you will rise. Each person has his own struggle. You know yourself better than anybody else knows you. It's your responsibility to make your life what you want it to be.

I don't know if young people realize that it's their responsibility.

Clyde Tombaugh: I felt that rather early. I wasn't troubled with peer pressure. I just ignored it. I didn't let it bother me. You might say books were my best companions.

Of course, life has its ups and down, and some people have better luck than others, just the way fate bounced. But a lot does depend on the individual, your attitude and what you are willing to endure to achieve and get ahead. You cannot afford to be lazy. You have to be challenging something. That way you grow, you develop more abilities, and it leads to success. That's my outlook.

You were interested in all kinds of knowledge, weren't you? Literature? Poetry?

Clyde Tombaugh: Yes. I always liked poetry. Longfellow is one of my favorites, Whittier, Tennyson and so on. Poetry is a beautiful means of expression which I still have a profound love for. In fact, at one time I thought I might become an astronomical poet, but it never quite materialized.

Are there poems that relate to astronomy?

Clyde Tombaugh: Oh yes. A lot of them. Tennyson says, "Then I saw the Pleiades rising above the middle shade... like a swarm of fireflies tangled in a silver braid." Beautiful. It's a long poem, but that's just a part of it.

What about Keats's poem, "On First Looking Into Chapman's Homer?"

Clyde Tombaugh: I lifted a line from that and put it at the head of one of the chapters in my book.

"Then felt I like some watcher of the skies when a new planet swims into his ken."

I think I understood that better than Keats did. I thought that was appropriate.

It was indeed. Thank you for taking the time to speak with us today.