Talks About Her Life, SL-9 and Gene
interview by Gordon Bond
Originally appeared in TPO Volume 10, Issue 1. ©1999 Typographica Publishing.
May not be reproduced for commercial purposes.
The best guess is that it happened sometime in 1929. A comet in the far reaches of our Solar System felt the first tugs of the Sun's gravity - the beginnings of a fateful course. This is just a best guess. It might also have happened anywhere from 1920 to 1930. We know with a much more obvious certainty, however, that on earth - Gallup, New Mexico, to be exact - 1929 was the year a woman was born whose destiny would be intertwined with that comet.
Carolyn Shoemaker delivered her story in soft-spoken, measured tones to the hall packed with amateur astronomers, punctuated by the occasional flash from cameras. She was the key speaker at the eighth annual Northeast Astronomy Forum & Show in Suffern, New York (see sidebar). Afterwards, crowds of well-wishers and autograph-seekers gathered around this grandmotherly woman as if paying homage to their own relative. Someone gave her a rather nice, large Tektite specimen as a gift. Another hugs her. She takes it all in her stride and yet still with a little amazement.
"It still rather astonishes me." she says of her celebrity, "I always feel like turning around to see whose being talked about, because it canít be me! But itís been fun because Iíve gotten to meet so many people - do so many interesting things. Thatís been a special pleasure."
As the noise of the crowds gave way to that of the maintenance crews clearing the chairs, I had the opportunity to sit down with her for an enjoyable interview about her life, her late husband Gene and the contributions they made both to science and to each otherís lives.
Through the Backdoor
Carolyn Shoemaker feels rather lucky to have been able to contribute to the sciences of geology and astronomy. As she put it in her talk, she came to science "through the backdoor".
"I really became interested in science because of Gene." she admits, "I was not interested in science when I was going through school, when I was going through college. When I went to college, it was right at the time that the veterans were returning from World War II and the classes hadn't really geared up that much yet. I took a geology course and I thought, 'This is dull!' - it was dull except for the fact that the professor could write on the blackboard with two hands simultaneously!"
Carolyn majored in history and business at Chico State College, now the University of California, Chico. She trained to be a junior high school teacher, but it didn't work out. "Taught one year" she laughs, "and said 'This is not for me!'."
Thankfully, whatever Carolyn's ambidextrous geology professor apparently lacked, Gene Shoemaker more than made up for. Before and after they were married, he took her on field trips to the Colorado Plateau during what was the last mining boom in the US - the uranium mining boom. "It was fun to go along with someone who was a born teacher and liked to explain things. He would patiently explain to me and point out to me the differences in varying shades of orange and red and the indications of 'Oh, a different formation here!'ÖHe was above all a field geologist. He loved mapping, field work, deciphering 'How did the world get this way?' and he loved to explain it. It was a process of thinking out loud in a sense for him too. And I loved that."
Though the whole family would go on field trips together, raising their three children left little room for Carolyn to explore her budding interests in geology too deeply - yet.
"I met Gene when he came to be the best man at my brotherís wedding." Carolyn recalls of their meeting in 1950, "He and my brother had been roommates at Cal Tech - great friends. And I had heard about Gene for quite sometime before I had ever met him. I heard about him - particularly from my mother who had met him - so I back-peddled hard! [laughs]."
It was to be a short meeting, but it was the proverbial love at first sight. "It was not a difficult decision on our part!"
"He left a few days after the wedding to go back to Princeton and I went off to teach. And we corresponded and the next summer he invited [me and] my mother - because that was proper in those days [laughs] - on this two weeks camping trip. It was really sort of a checkout - ĎWould she be a good geologistís wife?í And after the first week he asked me to marry him and I suppose before our marriage Iíd seen him a total of three weeks...but we wrote a lot in the year weíd been apart from each other. We both knew. We were lucky!"
In 1963, Gene Shoemaker chaired the committee for the National Academy of Sciences that was to select and train astronaut-scientists for the Apollo lunar program. It would prove an uphill battle. "The Apollo missions, first of all, were designed to get man safely to the moon and back - period." Carolyn asserts, "They were engineering feats. And great engineering - there's no doubt about that. But [Gene] wanted to go [to the moon as an astronaut] himself because he invisioned all of the things a geologist could find out about the moon. Just from a background of experience, he would know what questions to ask of the rocks."
A medical condition prevented Gene from becoming an astronaut - ironically, one which wouldnít prevent someone from being one today. But even without the problem, it is unlikely that he would have gotten on a mission. "After Jack Schmidt - Harrison Schmidt [the first geologist-astronaut, Apollo 17] - was selected, there was the possibility that he would never get to go because, as time went along, and public interest waned, missions started getting cut off and Jack only got on by the skin of his teeth. Because I think NASA realized theyíd better have something scientific to show for all of this. It wasnít that the other astronauts were not good - they were - but they werenít geologists to begin with."
It all became too much for Gene and according to Carolyn, "He left the Apollo program because he was a little disillusioned with the fact that it was so very difficult to really get science on the missions and he was tired of fighting those battles."
Gene and Carolyn got to know several of the astronauts. Among Geneís first students (who he had climbing about Meteor Crater in Arizona) were Neil Armstrong, Frank Borman, Charles Conrad, James Lovell, Thomas Stafford and James McDivit. "[Gene] said Neil Armstrong was the ideal astronaut...to be the first man on the moon because he was so very observant. A very acute observer; very cool-headed - just a good person that way."
"I wish Iíd known sooner!" Carolyn says of discovering her passion for science. "That was at a time when our children were grown - because I stayed home with our three children and it was at a time when many women did not hold a second job outside of the home; and I stayed home until they were through with school and had moved out of the home, and then I wondered, ĎWhat am I going to do now?í I have all this Ďnewfound freedomí!"
She asked Gene if he had any ideas. "[I] said, ĎGene, what I really want is to find something that I would enjoy doing as much as you do geology.í Because Gene could enjoy geology all the time. It was his hobby, his work, it was a fulltime thing for him. It was the sort of thing he went to sleep with on his mind and woke up with and to the greatest pleasure in. And I wanted something just as absorbing because I could see how much pleasure he had in it.
"And he said, ĎWell, I have a couple of projects that need volunteers [laughs]! Well, that was alright, I wasnít looking for the money. One of the projects was in geology doing paleomagnetic work, which was a form of dating the rocks. Iíd been out in the field with him on those projects, done a little bit of the lab work, it did not thrill me. And the other project was the search for Earth-crossing asteroids, and I had heard just a little bit about that. He had started the program with Eleanor Helin [whose nickname was Glow] at Palomar in 1973 and that was when I was still into the Ďhome bití with our children."
"She had persisted with the program." Carolyn says of Glow, "She did a great deal of the observing and usually had students with her, but at that time the program was not finding a great deal. And it needed to move faster, Gene figured, if he was ever going to learn enough about the objects that impact the Earth."
The basic idea was to study photographic plates and films taken of the night sky, looking for objects that moved and working out what they were and what their orbits might be. Carolyn volunteered for the project and learned the process by scanning plates taken in Australia.
"I had a very good-student teacher by the name of Bobby Bus - who has just finished his PhD at M.I.T. - he was very patient and he was a lot of fun. He was very particular about how the work was done. It had to be done just right. And I discovered that this work indeed consists of a lot of steps - small steps, none of them extraordinarily difficult - but they have to be done right or your results are no good.
"Ultimately, after looking at films that Glow and Bobby would take for us, on the stereomicroscope, I decided, ĎWell, maybe I could try my hand at observing.í That was going to be difficult because Iím a morning person!" she says with a laugh, "And Iíd never stayed awake a whole night in my life!"
Carolyn had also "concluded early on that probably [astronomy] was one of the Ďcolderí occupations." She explains, "In those days, more of the observing - at least on small telescopes - you were up there in the dome, open to the nighttime sky."
Learning to adapt to the odd hours kept by the astronomer and braving the chill of the night, step by step, Carolyn was discovering her passion for science - though satisfaction could come from less romantic accomplishments. "I scanned the glass plates and then with Bobby I learned how to measure the positions. That was when computers were not what they are today. You submitted punched cards and you got this big computer printout. And I was so elated when I got my first computer printout! I felt like one of the Ďreal peopleí then because everyone walked around Cal Tech with a computer printout!"
Seeing in Stereo
The heart of Geneís search for Earth-crossing asteroids was something he developed called a stereomicroscope. Essentially, itís what it sounds like - a microscope that allows a person to view two separate photographic plates or negatives simultaneously and in register.
"The process" Carolyn explains, "is to take two films, guided on the same star so youíre getting the same field exactly. And if you do that - we tried out 30 minutes, 45 minutes, an hour - if you do it ideally about 45 minutes apart, then the objects that are the closest to Earth will appear to float because of parallax with the Earthís movement in that period of time."
It is not, however, as simple as it sounds. Some people do not have a strong enough ability to see in stereo to use the steromicroscope. Gene had left the microscope with Glow during one summer when he and Carolyn went back to Flagstaff, Arizona (in fact, they travelled back and forth between Flagstaff and Pasadena, California all during this period). He returned to find Glow had hardly used it and "was not enthused and I think basically she had a problem with stereo vision and if you canít see stereo, why, you canít really use that."
Gene took the steromicroscope back to Flagstaff and found Carolyn had no problem with it. Glow and Bobby would take the films with the 18" Schmidt and send them to Carolyn to scan. The telescope was the same that saw first light in 1936 and Fritz Zwicky used for his supernovae searches. At first, they were just experimenting to develop a practical system and see what they could find.
"It was a lot of fun" Carolyn recalls, "you see everything to begin with, you see all the dust, and...clumps of emulsion - all the artifacts - so much stuff. And occassionally you would recognize something was an asteroid and after you train your eyes to do this, you donít see that other stuff.
"If itís an Earth-crossing asteroid, it might not float as a single little object. Usually you would have two little objects - two little spots that look just like stars except they float, one in one position and one in the other because theyíve moved that far in the 45 minutes. Sometimes if itís really a near Earth object, youíd see little hyphens and if something were very close, youíd see dashes - thatís extraordinarily exciting!
"One of those I found that was really close I found after we had gone back to Flagstaff from an observing run once. I found it two weeks later, so I knew it had come and gone and we werenít going to know where it had gone to. But three years later, it came back - and we could link it - and that was great!"
Trojans, Amours, Apollos and Comets
All the hours of scanning films paid off in 1982. "The first thing I discovered that no one else had seen was an asteroid. The first asteroid was exciting, but the first near-Earth asteroid was terribly exciting!...[when] I found that I thought, ĎWhatís this weird thing? Gene, why am I getting this funny looking thing?í and he said, ĎAh, a near-Earth asteroid!í that was one of a group that are called Amours. Many Amours are Earth-crossing and many are not. But their orbits almost come in close enough to sort of Ďkissí the orbit of the Earth, hence the name."
Carolyn also "incidentally" disovered a Trojan asteroid. These are asteroids in swarms within 60 degrees of either side of Jupiter.
"Those were intriguing" she says of Trojans, "because they were so far out. They were bigger than most of the objects Iíd found, but they were also fainter, because they were that far away. And so on my films, it was not easy to find them and anything the distance of Jupiter just barley moved within that 45 minutes. So those just barely floated. Trying to see that difference was a matter of training the eye."
Of her first comet, 1983-P, Carloyn says that, "was the one that really captured my imagination!"
"Those were nice, [but] I was still looking for Apollos." she admits with obvious affection for the asteroid type, "Now, an Apollo often could assume a different position on our films. It could look instead of like it was floating, it could look like it was down in a hole. And that was a strange effect! And I saw one once but I was too tired to notice and the Japanese discovered it. Immediately, I knew ĎOh, thatís what that was!í."
By 1983, career changes were making Gene and Carolyn realize that if they wanted to kick the search for near-Earth asteroids into a higher gear, theyíd need to have a program of their own.
"We had decided that maybe we had better separate our two programs." Carolyn said of the time, "Glow had been moved up to the Jet Propulsion Laboratory and Gene had, you see, decided to leave Cal Tech and go back to the US Geological Survey in Flagstaff because he felt like, ĎThere are only so many years and I want to do the science - forget the administrative bit!í. Much as he loved teaching, he felt that when he was teaching he owed the students his attention - very hard to do his own research.
"We had ways that we wanted to do the work and Glow had other ways and it just seemed better to separate the projects," she says, hinting at more than just career changes as the reason for the split, "which in the end was very productive because we would split the dark time on the telescope. We took seven nights and she wanted six nights and we would alternate first and last part of the dark run. It worked pretty well."
A Formal Search
The split with Glowís project marked the beginnings of the Shoemakerís own formal survey project. They not only made discoveries but developed more efficient methods for searching. In addition to the stereomicroscope, by 1985 they started using 4415 Technical Pan emulsion on the suggestion of a colleague at Palomar.
The film they had been using, 2215, "had the consistency of saran wrap!" Carolyn says with a laugh, "Very hard to handle! That was a big advance. And then when they started making the 4415 on a stronger base, we cold use it very successfully and that was a real breakthrough for us. After that, the discoveries really increased a lot because we werenít hitting the grain with that film. We would go down almost that far, but we were able to see so much more."
They experimented with better hypering techniques too. "We were constantly thinking of ways to go faster."
They also had help from colleagues and students. Henry Holt, a retired astrogeologist with the U.S.G.S. joined in 1987 and worked three months a year during the summer while the Shoemakers were in Australia. By 1989, David Levy joined, working six months per year.
"It worked out very well for us," Carolyn says of the volunteers, "because when we started, we [Gene and Carolyn] were taking four minute exposures - one long winters night we took 96 exposures from dawn to dusk [laughs] running up and down those stairs, trading off every four films. But we didnít have time to develop [the films] at night, so the days would be spent developing, doing the log books, planning the menu for the next night and occasionally there was time to look at some films! There had to be a better system and it helped when we had three people. Then all of a sudden we had a little luxury, we could actually grab a cup of coffee in the night!"
Impacts and Australia
Occasionally in the past one of those near-Earth asteroids the Shoemakers had been looking for had actually collided with our home-planet. The scars of those impacts act as a sort of record book from which astrogeologists can gain some understanding of the role such events have played in the history of the Earth.
Unlike the Moonís obvious craters, however, the pages of the Earthís cratering history have been torn and smeared by the fact that our planet is still very geologically active. There are, however, locations where the trained eye can make out reasonably sized passages. Perhaps the best is Australia and in 1984, when they werenít busy taking and scanning films, they headed Down Under with the intention of identifying impact features.
"It hasnít had a lot of mountain-building." Carolyn explains of Australia, "There are some mountains in the east and southeast, but otherwise itís a pretty flat country."
The biggest eraser of the record is tectonic activity. "Itís catastrophes of a sort that destroy these other catastrophies! It isnít the simple wearing away of grain by grain in dust storms or rain."
Australia was a place to make discoveries. "Some of the structures had been found in the course of the regular geologic, topographic mapping; but Australian geologists are primarily occupied with mineral exploration. Theyíre almost 50 years behind the United States in their exploration. So theyíre still looking for minerals, for oil, for all of those things that we have stopped long since because weíve mostly found those things. So we could go there [Australia] and we could do this Ďexoticí work!"
Of the sites they would study, many turned out to have less-than-cosmic origins. "We looked at a lot of sinkholes, animal burrows, just all sorts of things that were not impact-caused. But we verified a lot of others. Now, there are only about 15 meteorite craters in the world that are known. That means craters with associated meteorites. You can have impact structures, and usually those are much larger, and you donít have the meteorites to go with them. Meteor Crater [in Arizona] is a small crater - a small impact."
So, what happened to the impacting bodies in all those other instances? Carolyn describes the amazing forces at work. "When an impact occurs, you have a strong shockwave ahead of [the impacting body] as well as a strong shockwave behind it and the meteor breaks up. As it hits the host rock...the host rock and the meteor just flow like they were water - they mesh. So you get the crater form and this stuff lines the impact crater and a lot of it sprays out into the atmosphere and goes for long distance...You also have undeneath this, ahead of the impact, you have a lot of brechiated rock, just rock that is severely broken up and you have things like quartz...theyíre planar surfaces and fractures of a different kind than you ordinarily see on Earth - they only happen when you get an impact...you cannot find the...meteor because itís not there as a body. Itís been transformed - and all of it happens within seconds, thatís the amazing thing too."
Gene would apply the statistics gathered from their Australian survey to his theory that the Earth may have been visited by periodic "comet showers".
"When the planets were forming" Carolyn explains, "you had this really active period of really active bombardment. And then that tailed off and you got a period of later bombardment...at this point in time, we feel that the cratering record has increased [during this later bombardment period] - the numbers have increased - and itís comets that have increased - we get comet showers. The question is in part, do we really get comet showers? And are the periodic? Thatís one of the big issues...we know that mass extinctions appear periodic. We donít necessarily believe impacts caused all mass extinctions, but we think they caused part of them. There are five really major mass extinctions. Out of those, I would hazard to guess three are definitely impact - one positively, which would be Chixaluba [an impact in the Yucatan believed to have caused the extinction of most of the dinosaurs]. But the farther back in time you go, the less evidence you have."
What is perhaps a bit surprising is that the notion of impacts playing a role in the evolution of life on Earth was not taken very seriously by either geologists or paleontologists - even as late as the mid-1980s. There was a resistance to the idea of cataclysms in general and there still is among some scientists today.
"Part of it is that you can find certain kinds of life in the layer below the impact layer" Carolyn explains, "and the question is, ĎAlright, did they go out right at the boundary or were they on their way out anyway?í because there are species that come and go just in the normal case of life - they disappear and itís not a mass extinction. Itís when all of them that were living - or a huge percentage that were living at the time - do."
In spite of the inertia to the idea, events conspired to make it more credible. Jack Sepkoski and David Raup from the University of Chicago had "compiled this huge catalog of species and their comings and goings and forms of life over thousands of millions of years." Carolyn explains, "In doing so, [they] noticed there seemed to be a periodic time when large numbers would just disappear. It was about the time that Walter Alvarez had become aware of the Cretaceous-Tertiary boundary layer there in Europe, and people started looking for the crater. So all of this sort of was coming together at about the same time."
Some readers may recall the "Nemesis", or "Death Star" theory. This held that the Sun had a hidden companion star which periodically came close enough to perturb the Oort Cloud and send a cascade of comets into the Solar System, some of which would impact Earth, causing mass extinctions. It is a theory which, for the most part, is no longer considered viable. But it evidences an important change in thinking among at least some in the scientific community about the role cosmic impacts might play in life on Earth. The discovery of the Chixaluba crater in the Yucatan has also lent credence to the idea. This is believed to be the proverbial "smoking gun" - the crater that resulted from an impact which resulted in the almost complete extermination of the dinosaur population, knocking them out of their place as the dominant species on the planet. Like the Shoemakers, some see a periodicity to these events and seek a cause.
"One of the latest hypotheses is that...the Solar System periodically...goes across the galactic plane...and it crosses with regularity, and perhaps that has become a little more frequent due to the passage of a star close by - something that changed the timing." Carolyn says, explaining that such a passage might disturb the Oort Cloud. "It could be that. It could [also] be molecular clouds - those dense clouds, if we pass through one...itís still something to be studied...I donít think we have really good proof any which way!"
The Wake-up Call
In July of 1994, the comet that was first drawn by the Sunís gravity in 1929, impacted Jupiter in what many consider the astronomical "event of the century". It had become known as Comet Shoemaker-Levy 9 (SL9, for short) because it was discovered by the Shoemaker team with David Levy. Itís orbit had been disturbed by the Jupiter until instead of orbiting the Sun, it orbited the Jovian giant. In the process, it had been pulled apart into a long train of individual fragments, each of which plunged into Jupiterís atmosphere, leaving dark scars that could be seen even in amateur telescopes for some time afterwards. Carolyn was the very first person on Earth to see the odd looking trail of cometary fragments on the plates taken by Gene and David.
Much has been written about SL9, its discovery and its spectacular demise. It is perhaps what Carolyn is best known for among the general public as it thrust Gene, Carolyn and David into the spotlight for their fifteen minutes of fame. But as amazing as this once-in-a-lifetime event was, it isnít the thing Carolyn is most proud of in her career.
"The discovery of SL9 was no doubt the most exciting thing to have discovered and it ranks very high in my estimation of what Iíve done" Carolyn concedes, "but I think the fact that within 12 years time I discovered 32 comets is maybe the thing that Iím most proud of. I donít have time to waste on finding these bodies! [laughs]
"One of the things that I am very proud of in the work that Gene and I did together was the fact that when we started out doing asteroid astronomy and comet astronomy, there were very few people interested in it. When we went to Palomar, I know the other astronomers sort of looked at us, you know, Ďand what crazy things are they doing now!?í" she says with a laugh. "They couldnít understand because most astronomy had moved out of the Solar System and they didnít necessarily have any conception of the importance of knowing something about these bodies and how that related to impact on Earth and possibly our future as a species."
Not only were the Shoemakers among the pioneers in getting the scientific community to pay attention to the reality of impacts, they also helped awaken an awareness among the popular culture as well. Both Gene and Carolyn were among the consultants on the movie "Deep Impact". Carolyn jokes, "That means we only went to one meeting and then we went off to Australia!"
Of "Deep Impact" she concludes, "[It] was sort of a mix...it wasnít all good and it wasnít all bad."
Scientific accuracy aside, she sees a positive result from such entertainment "I think those movies have played a rather important part in raising public consciousness and not only of the general public, but the general public who contacts their congressman and says, ĎLook, this really looks serious! Weíd better pay attention to this! They need money!!í."
And what should we do if we find ourselves in a real life scenario? While the defense departments of other nations take the threat seriously, "the weapons we have now...are not the weapons of great choice."
Itís another reason why we need to study these objects more closely. Some evidence suggests that asteroids may be much more fragile than we suspected. Such considerations have great impact on how we can deal with them.
While Carolyn sees the threat of impact from a comet or asteroid perhaps clearer than most, she isnít out to create a panic. "We never pretend or say that the threat of impact is something to stay awake nights over - unless youíre observing [laughs] - itís not something I worry about constantly. But on the other hand, it would be pretty stupid and foolish of us not to pay some attention to it and do what we can. And if personally we canít do it, to make it possible for others."
"So Sudden and So Unlikely"
"We were on our way to one of the features that we were not going to map, but we wanted to look at with Dan Milton who was a geologist who had worked on the map at an earlier time and we were hoping to get him to go ahead and get the map out and the information." Carolyn told me of that terrible day in 1997 in the Australian outback in soft tones that imparted an almost quiet strength. "So we had driven to Alice Springs and supplied up and set out in our pick-up...we left Alice Springs one day and drove out across the Tanamine Track which weíd been over a number of times. Itís not a very exciting route across the desert after you leave the area around Alice Springs. You leave the mountains...and youíre going across very flat land. You could see a vehicle coming for miles and miles and miles. And generally speaking, when we crossed that track, it would be a case of only seeing two or three vehicles in a day - if that. It was not well-travelled."
They camped for the night before passing some gold mines where they re-fueled from the fuel drums they carried with them ("No gas stations out there!") before starting off again.
"We were just coming to what was becoming a little more interesting area because the road wasnít quite so straight. And there was this big, broad curve were were going around and this road is one that was used more...by the ore trucks than anything. It was very wide, very deep gravel. So in the outback, everyone drives where itís smoothest and that means one track...We were just beginning to go around this bend and I was looking at the scenery and I presumed Gene was looking at the road, but suddenly I glanced back and there was a Land Rover right in front of us. I knew we were going to hit. There wasnít time to be afraid. There wasnít time for Gene to really react. It was just it wasnít there one moment and it was there the next. And so the collision occured.
"Later, my two daughters...flew out because the wanted to see if they could figure out why it had happened. And the only thing they could think of was that...while it was a big, broad bend, there was a lot of shrubbery along the side on the built-up bank. That might have obscured any blowing dust, or might even have obscured the vehicle coming."
The Land Rover was driven by a family going back to Alice Springs after a spring break vacation for the children. "Happily," Carolyn says, "the children were OK in that car and he had a couple of fractured ribs and his wife a little bump on the head, so they were OK. But it was so sudden and so unlikely - if anyone had ever said, Ďyouíll have a car collision in Australiaí the last place you would think of would be in the outback. I guess his number was up."
Gene Shoemaker died in that crash. Carolyn suffered five fractured ribs, a fractured wrist, a dislocated shoulder and thumb and nerve damage in her legs ("The legs give me trouble.").
Physical wounds would heal. The emotional ones would be tougher. But she still had the work - their work.
"I guess I use the work as a substitute for Gene. So I spend my days and nights with it." she admits, her voice trailing off. "But I find that itís work that we enjoyed together and that I still enjoy. I wasnít sure how much I would want to do or could do for a while. But when I first went back to the office, it was pretty overwelming...because I knew that we had lots of stacks of [unfinished work]!"
Slowly, Carolyn began sifting through the work of a lifetime. When she heard that the college at Fort Collins, Colorado State University had their library washed away in a flood, she donated some 76 boxes of books to help them rebuild. Gene has assembled a vast library and subscribed to over 20 magazines and organizations. "He was always worried that he might end up someplace without a library!"
They had made several commitments which Carolyn was determined to meet. Among them was helping edit a book on the Solar System for Sky Publishing and publishing books based on lectures he had given in England (they worked on that just two nights before his death) and at Yale University. In a very real sense, it was therapy for Carolyn. "Itís sort of working through a lot that we did together."
However, it seems that in trying to complete the work of the past, she is discovering yet again her passion for doing science. "I had this new, fast respect for anyone who makes a geological map!" she laughs, "Because Iíve been working on the geological map for one of the Australian structures. When Gene mapped, he mapped on aerial photos and he used a 9H pencil which means he sort of engraved the geography on those! And impact structures are very complicated, so some of that is very fine detailed work - not easy!"
At times, the magnitude of finishing what they started can seem daunting. "I think one of the things that worries me is that all of the field work in Australia has not begun to be published and I just hate the idea that the wheel would have to be re-invented - done all over again. Because we worked on so many different structures. Some we did the mapping, some we did the gravity, or the magnetics - whatever hadnít been done. Just endeavoring to prove without a doubt that those were impact structures and not just because someone looked at a round hole in the ground and said it was. And I donít know that I can do all of that. But Iím going to try to get most of the maps out."
At 70, Carolyn Shoemaker shows little signs of slowing down. Talking before her lecture, she mentioned plans to take a hot air balloon ride the next weekend (she has a private pilotís license too). As of her last email to me, she was heading off in July for a conference in South Africa.
I was curious to know, if Carolyn could have time on the Hubble Space Telescope, what would she study? Her first reaction was that the HST is designed primarily for studying things well outside the Solar System.
"As a project," Carolyn says, thinking again, "I think that it would be terribly exciting to start doing more work on the Kuiper Belt objects. And if the HST can be used for observing some of that, so we would get a better notion of are those comets, are those asteroids, what does that swarm of asteroids or comets consist of? Whatís it like? What are the numbers? I think thatís a lot of exciting work thatís just being done now by big telescopes, but maybe it could be done better by the Hubble. I donít know. But the Kuiper Belt really interests me. Thatís sort of the next swarm of something out there - and I want to know something more about it!"