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FRED LAWRENCE WHIPPLE November 5, 1906âAugust 30, 2004 BY GEORGE FIELD THE PERSON W HEN HALLEYâS COMET APPROACHED THE Sun in 1910, Fred Whipple was three years old. When it approached again in 1986, he was 79. By then Fred had a brilliant career as an astronomer and scientific administrator behind him. Over the course of those years he had become the worldâs lead- ing authority on the nature of comets. His pair of papers on the subject in 1950-1951 had become classics, and the model of comets that they propounded was fully confirmed by space probes that were sent to study Halleyâs comet in 1986. I first met Fred in 1955 when I arrived at the Harvard College Observatory (HCO) as a postdoctoral fellow. At that time he was busy organizing the Smithsonian Astrophysical Observatory (SAO), so I did not get to know him well. When I returned to Harvard in 1972, we met in his office, sur- rounded by models of astronomical instruments that he had designed and built. At that time I was a candidate for the directorship of HCO, which is located in the same group of buildings as SAO, and Fred welcomed me graciously. The Smithsonian Astrophysical Observatory was a big institution, the home of many diverse astronomical projects, 393
394 BIOGRAPHICAL MEMOIRS almost all of them initiated by Fred since becoming the SAO director in 1955. His quick intelligence was obvious. His dedication to science became apparent as he described his research on comets. I shared his delight in being able to estimate the magnitude of all sorts of things, from costs of building telescopes to the sizes of astronomical objects. Despite his administrative responsibilities, he was directly involved in interpreting observations of comets. He en- thusiatically told me of his latest ideas, and how they were faring. This was a style everyone recognized as Fredâs. If colleagues or others were ignorant of comets, he would rapidly introduce them to the subject, and get them inter- ested. My wife, Susan, caught his enthusiasm, and came to ad- mire and love Fred, finding him enormously entertaining. When he and his wife, Babette (also called âBabbieâ), first entertained us at their home, we were startled to find a huge kinetic painting on the wall in the dining room, which morphed from one color pallet to another in ever-chang- ing patterns. In their living room a variety of sculptures, surrounded by flowering plants, set the stage for a sweep- ing view of Boston. Looking down into the yard, we saw a lovely rose garden tended by Fred. Talk on those evenings involved astronomy, politics, psy- chology, and of course, our children. Babbie has a Ph.D. in psychology, and her thoughts on the love and care of chil- dren were always worthwhile. Fred was an energetic and optimistic person. He had played tennis at the University of California, Los Angeles, and loved to do so whenever he could. Unfortunately, he was struck by polio when he was younger, leaving him with one leg shorter than the other, and thus unable to compete at his skill level. But he noticed that there was space for a tennis court on the observatory grounds, and was one of
FRED LAWRENCE WHIPPLE 395 the people who helped build it. Were it not for his disabil- ity, he might have been the Harvard College Observatory tennis champion every year. Fred biked to work six days a week throughout the year, rain or shine. The round trip was 5 miles on busy streets, but Fred kept biking into his nineties. When illness over- took him, his doctors suggested that he walk a mile or so every day to keep his leg muscles working. He walked around the block in Cambridge until he could no longer do so, and then began to walk the corridors of the observatory. Then in his middle nineties, he would walk by the seminar room where we were working, and we all thought, âThere goes one tough guy.â Fred loved scuba diving at his and Babbieâs home on Great Camanoe Island in the British Virgin Islands. He was known among the divers there as an incorrigible explorer. No sooner would a group of divers reach the bottom, than Fred was off on his own, far from any help should he need it (personal communication, J. Giacinto of Dive BVI, Virgin Gorda, British Virgin Islands, May 31, 2006). For those visi- tors who did not dive, Fred graciously introduced them to snorkeling, a much less strenuous sport, but still a thrilling way of seeing the varieties of fish and coral that are avail- able. When he addressed the staff of the Smithsonian Astro- physical Observatory, he did so with a twinkle in his eye. Invariably the staff ended up smiling and laughing. On such occasions he would be wearing a tie from his large collec- tion of comet designs. He ate lunch at Armandoâs Pizza, where he became such a fast friend of Armando that Armando treated all astronomers who came in as friends of his also. No doubt Armandoâs attitude toward Fred was affected by the fact that when Fred returned from a visit to the Vatican,
396 BIOGRAPHICAL MEMOIRS he thoughtfully gave to Armando a medal that had been blessed by the Pope. One of Fredâs famous habits was to ask that jam be on the table at home at all times, whatever was being served for dinner. Another was his interest in gadgets. There were several hard-to-solve puzzles in the living room, and I recall his pleasure in demonstrating to me a new acquisition, a shaver activated by a wind-up spring. Somewhat surprising was his fascination with occult phenomena, such as clair- voyance and astrology; he concluded that classical astrology has no scientific basis. His own religious beliefs appeared in an unpublished paper titled My Conversion to Atheism.1 Fred appreciated the many honors bestowed upon him. He bore them lightly but was justly proud of his accom- plishments. In particular, I recall how happy he was to have been chosen as the UCLA alumnus of the year in 1976. In his published interview with Ursala Marvin, a senior scien- tist at the Smithsonian Astrophysical Observatory, he was reminded that in the year 2000 he had been named a âliv- ing legendâ by the Library of Congress. Fredâs comment was, âI donât feel very legendary, but I am pleased to be still living.â2 Although he was intolerant of persiflage and would dismiss it with a wave of the hand, he chatted easily with everybody, earning the respect of the entire staff of SAO. THE SCIENTIST From 1924 to 1927 Fred attended UCLA, where he ob- tained a B.A. degree in mathematics. At UCLA he took an astronomy course with Frederick Leonard, which he found to be âextremely interesting.â3 He decided to pursue as- tronomy as a career, but because UCLA had no astronomy department at the time, in 1927, he moved up the coast to the University of California, Berkeley, where he obtained a Ph.D. in astronomy in 1931. Fred studied under A. O.
FRED LAWRENCE WHIPPLE 397 Leuschner, whose work centered on celestial mechanics, including the orbits of comets. Fredâs membership in the Berkeley astronomy depart- ment afforded him access to the Lick Observatory on Mount Hamilton in California, one of the leading observatories in the United States. Within a short time Fred became an ac- complished observer. When he completed his Ph.D. in 1931, he was offered a research position at Harvard College Observatory (HCO) by its director, Harlow Shapley. The astronomy department was in the HCO building, and Fred became a faculty member there. Fred demonstrated a strong interest in comets by examining 70,000 plates in the HCO collection of astronomical photographic plates for seren- dipitous images of comets. He was successful in this search, finding six new comets, for each of which he was awarded the Donahoe Medal of the Astronomical Society of the Pa- cific. In this period he was aware of the claim of Ernst Ãpik, a famous Estonian astronomer whom Fred admired greatly, that contrary to common opinion not all meteors follow closed orbits around the Sun. Ãpik believed that some me- teors follow a hyperbolic trajectory that comes in from outer space and goes out again. Meteors are objects that often are ejected by comets and are later seen entering Earthâs atmosphere when Earth crosses the orbit of a comet. Thus, studies of meteors have implications for the study of com- ets. To investigate Ãpikâs claim, Fred set up a network of cameras that could track meteors as they entered the atmo- sphere. This called for a fast camera with a wide field of view, with a rotating shutter that would interrupt the trail of the meteor as it streaked across the sky, enabling one to calculate its velocity. Viewing it with cameras located at dif- ferent points enabled its geometric path to be defined. The results were clear: None of the meteors observed follows a
398 BIOGRAPHICAL MEMOIRS hyperbolic orbit. Ãpik disagreed with this result for many years, but in 1959 wrote Fred a letter apologizing for his stubborn opposition.4 The Harvard Meteor Project succeeded in tracking thou- sands of meteors. The physics of the entry of a meteor into the atmosphere depends upon both the atmospheric den- sity at the observed altitudes and the physical properties of the meteor. Separating the two effects in the data was fi- nally accomplished. One important result indicated that the density of most meteors is less than that of water, suggest- ing a spongy ice composition. Because at least some mete- ors are known to originate from comets, this raised the possibility that comets also contain ice, an idea that Fred developed much further in two famous papers to be consid- ered more fully below. A very useful result of the meteor project was a table of the density of Earthâs atmosphere at altitudes above 100 kilometers, data hard to obtain by other methods. Fred harbored the hope of measuring the track of a meteorite, that is, a solid body large enough to survive en- try into the atmosphere and reach the ground intact (known as a âfallâ). Such a meteorite could be analyzed in the labo- ratory to find its age, type, and composition. By observing its track through the atmosphere one could infer where in the Solar System it originated. To accomplish this Fred es- tablished another network of telescopes, this time 16 sta- tions spread over the Great Plains, called âThe Prairie Net.â A number of near misses ensued until January 4, 1970, when a participating scientist drove out to look for a meteorite in the neighborhood where its track indicated it had fallen. There was snow on the ground, perhaps favorable to spot- ting a meteorite. In Lost City, Oklahoma, there was a rock in the middle of the road that turned out to be a meteor- ite.5 Its orbit indicated that it originated in the asteroid
FRED LAWRENCE WHIPPLE 399 belt, well known to astronomers as the home of countless solid bodies believed to be fragments of a long-gone planet. The Lost City meteorite had a high density, not the low density associated with meteors. Fred realized that because of their low densities, meteors are more likely to burn up in the atmosphere, and are therefore unlikely to reach the ground. In 1946 Fred joined the Rocket and Satellite Research Panel, a group of scientists charged with advising the Naval Research Laboratory on the best ways to acquire informa- tion about space, using rockets acquired from Germany af- ter World War II. The panel also considered the future use of artificial satellites, enabling observations of Earth and its surroundings, and the use of orbiting telescopes, pointing away from Earth, allowing astronomical research. This panel played an important role in space research before the es- tablishment of NASA in 1958. In 1952 a series of articles originally printed in Collierâs magazine were published as a book, Across the Space Frontier.6 With articles by Wernher von Braun and Willy Ley, this book served to inform the public about the possibilities of science in space. Fred authored a chapter titled âThe Heavens Open,â which de- scribed how telescopes in Earth orbit could open the whole electromagnetic spectrum to observation, including ultra- violet radiation, X rays, and gamma rays. With his experience in tracking meteors, Fred pointed out to the panel that a network of telescopes should be established to track artificial satellites and compute their orbits. When the National Aeronautics and Space Adminis- tration was created in 1958, Fred was ready to take on the responsibility of tracking scientific satellites if and when they should be launched. But that is another story to which I will return below.
400 BIOGRAPHICAL MEMOIRS Without doubt, Fredâs most significant contribution to science was the pair of papers he published in 1950 and 1951 in the Astrophysical Journal, titled âA Comet Model.â7 In them he used what he had learned about comets from a study of their orbits, in particular, information gleaned from the fact that the orbits often do not conform exactly to the predictions from strictly Newtonian gravitation. Specifically, both Halleyâs and Enckeâs comets deviated from their ex- pected arrival times. Fred realized that material that leaves the comet nucleus to form the fuzzy head must, by the law of action and reaction, exert a force on the nucleus, effec- tively forming a rocket. Fred calculated the magnitude of the force, drawing on the chemistry of the material, the physics of evaporation, the theory of heat transfer into the nucleus, and the properties of frangible material. Compar- ing his calculations with the observed deviations of orbits from the Newtonian values, he was able to fit the data only if the cometâs nucleus were composed of ices of water and other volatile materials, forming a fluffy matrix in which mineral grains were embedded. His theory fits the data, and thus began the modern era of research into the nature of comets. Fred referred to his model as the âIcy Conglom- erate Model,â but the press quickly coined the term âdirty snowball,â and Fred became famous as its originator. The nucleus of a comet is too small to image from Earth, so for years Fredâs model provided the best concept of what a comet really is. In 1986 mankind got its first look at the nucleus of a comet when Halleyâs comet approached the Sun. The European Giotto mission to Halleyâs comet found that its size, composition, and surface properties agreed with Fredâs 1950 model.8 In paper II of the series Fred compared his model with what he and others had learned about meteor streams associated with the tails of known comets. As indicated above, many meteors required a low
FRED LAWRENCE WHIPPLE 401 density to fit the observations, agreeing with Fredâs conclu- sion that the nucleus of a comet is made primarily of ice. The Stardust mission to Comet Wild 2 returned a sample of the comet to Earth on January 15, 2006. Crystalline sili- cates have been found in the particles that have been ana- lyzed.9 It will take years to completely analyze the data, and unfortunately, Fred did not live to see it. Babbie Whipple writes, âFred was deeply interested in this project, which would bring back to Earth samples of the material that formed the Solar System, dating from 4.5 billion years ago, material he believed would answer many big questions as to the source of life on Earth. For example, did it originate in interstellar space (a theory supported by Sir Fred Hoyle) or did it originate here?â10 Fred was both an observational astronomer and a theo- rist, a rare combination nowadays. As time went on, he spent less time at the telescope and in the Harvard Collec- tion of Astronomical Photographs, and more time analyz- ing data and proposing and testing theoretical models. He was always involved in advancing the art of instrumenta- tion, through endeavors such as the Harvard Meteor Project and the Prairie Net. Fred choose to focus his research on comets and mete- ors. Other leading astronomers of his generation chose to study stars and galaxies. Although Fred began his career analyzing cometary orbits, his Ph. D. thesis at Lick Observa- tory, supervised by Donald Menzel, was on variable stars, and when he arrived at Harvard in 1932, he started to work on galaxies. But âI soon learned that [Harlow] Shapley con- sidered galaxies to be his own topic and he did not care to have any competition.â11 As new techniques were developed, the physics of planets and comets posed challenging ques- tions.
402 BIOGRAPHICAL MEMOIRS Fred anticipated this development by focusing on the physics of comets: Their tails could be studied with current telescopes, and the meteors they left behind could be stud- ied as they fell toward the ground. Everything changed in 1958 when President Kennedy decided to send a man to the Moon. Up until then few scientists studied the Moon. Suddenly large sums were avail- able from NASA to study its surface and plan experiments that astronauts would carry out. NASAâs contractor at Caltech, the Jet Propulsion Laboratory, initiated unmanned missions to the Moon, Venus, and Mars, and later to the outer plan- ets, and still later to comets and asteroids. It does not take a rocket scientist to see that this activity would be a boon to Solar System science. When a spacecraft encountered Halleyâs comet in 1986, Fred lived to see the object of his 1950 research become the target of a major scientific and engi- neering effort. It has become increasingly apparent that there are ex- cellent scientific reasons for studying comets as part of an effort to understand the formation of the Solar System. Moreover, many planetary systems beyond our Solar System have been found recently. From the time that Immanuel Kant formulated the nebular hypothesis, astronomers have conjectured that the planets formed from a disk of gas and dust orbiting the Sun. Self-gravitation acting on an inter- stellar cloud drew the material of the Sun together, but any material that had large angular momentum was left behind to form a disk. Study of such disks orbiting other stars has proved that this idea is correct.13 Comets provide an important test of this picture. Their orbits, unlike those of planets, do not lie close to a single plane, and do not all revolve in the same direction. They travel vastly larger distances than the planets do. Fred showed that they are composed largely of ices, which could not
FRED LAWRENCE WHIPPLE 403 survive if they were formed close to the Sun. Thus, they may have predated the formation of the Sun, and thus, may represent a sample of interstellar matter that escaped in- corporation into the Sun or the planets. I believe with Fred that the study of a comet sample in the laboratory is of greatest importance.14 THE ADMINISTRATOR Many astronomers probably knew of Fred as the direc- tor of the Smithsonian Astrophysical Observatory. How did it come about that SAO is collocated with Harvard College Observatory? SAO is part of the Smithsonian Institution in Washington, D.C., best known as the quasi-governmental organization that runs museums like the Natural History Museum and the National Air and Space Museum. But it also supports research on many topics, including meteor- ites, the history of art, tidal estuaries, and at SAO, astro- physics. It all started when Samuel P. Langley was appointed secretary of the Smithsonian Institution in 1887. A former physics professor, he was interested in measuring the infra- red radiation from the Sunâa major contribution to the total solar energyâand in 1890 established a laboratory for that purpose called the Smithsonian Astrophysical Observa- tory, or SAO, with Charles C. Abbott as the director. Using ground-based instruments, Abbott measured the energy emitted by the Sun, and concluded that it varies over time by as much as 1 percent. Measurements from spacecraft have since shown that the emission does indeed vary, but only by about 0.1 percent. Abbott succeeded Langley as secretary of the Smithsonian, continuing to support SAO as a bureau within the institution, funded under the annual federal appropriation to the Smithsonian.
404 BIOGRAPHICAL MEMOIRS When Leonard Carmichael became secretary in 1953, he wanted to expand SAOâs mission to encompass the ma- jor fields of astrophysics and discussed this idea with Donald Menzel, the director of the Harvard College Observatory (HCO).15 Menzel suggested that SAO be linked with a uni- versity in Washington but later concluded that HCO would be a better match. When he proposed this to his HCO colleagues, including Fred Whipple, they responded enthu- siastically. In 1955 Harvard University and the Smithsonian Institution signed an agreement to move SAO to Cambridge, and Fred was appointed director of SAO, a federal civil service position, while remaining a Harvard professor. What happened next was unexpected. As a member of the Rocket and Satellite Research Panel, Fred had proposed a plan to establish a network of stations to track any artifi- cial satellites of Earth that might be launched. Various na- tions, including the United States and the Soviet Union, proposed to launch such satellites in support of the Inter- national Geophysical Year, sponsored by many nations in 1957 to improve our knowledge of Earth. Fred proposed to the U.S. government that SAO establish an optical satellite tracking network. This required a rapid expansion of SAO staff from 5 to 500. Overnight SAO became the largest ob- servatory in the United States.16 As luck would have it, the Soviet Union surprised the world by orbiting Sputnik I on October 4, 1957. The auto- mated SAO network was not ready to track Sputnik until October 17, but thanks to Fredâs foresight, SAO had set up a backup network staffed by volunteers with small telescopes and stopwatches who recorded enough information for SAO to find Sputnikâs orbit within four days. Fredâs photograph appeared on the cover of Life magazine when the press learned of this feat. The Satellite Tracking Network was soon up and running, and providing precise information to
FRED LAWRENCE WHIPPLE 405 NASA. The network continued into the 1970s, providing information on the shape of Earth and the density of its atmosphere. Fred was very interested in using space technology to put a telescope into space. Under contract with NASA, he organized the first Orbiting Astronomical Observatory (OAO), which successfully reached orbit on December 7, 1968. Un- fortunately, its batteries failed, and little data was obtained. However, the two follow-on missions OAO II and III suc- ceeded in gathering large amounts of information about both stars and diffuse matter between the stars. Fred always aspired to have a ground-based observatory at SAO. Recognizing that the skies of Massachusetts are too brightened by city lights for it to be located nearby, he settled on a site at Mount Hopkins, Arizona. Believing that it was important to have an instrument there as soon as possible, in 1968 he commissioned a telescope of novel de- sign to detect the tracks of incoming high-energy gamma rays by means of the Cerenkov radiation from the particles in their wake. This facility succeeded in detecting astro- nomical sources of such radiation, one of which turned out to be a massive black hole. Believing that understanding the source of such radiation may require new physics, physi- cists are now constructing a number of similar telescopes. In 1970 Fred also built a 1.5 meter optical telescope on Mount Hopkins in collaboration with the University of Ari- zona. This telescope was used to conduct the first major red shift survey of galaxies in 1983.17 The observed red shifts of galaxies were used with Hubbleâs law of the expan- sion of the universe to find the galaxiesâ positions in three dimensions. When a slice of the sky was plotted, it was ap- parent that galaxies form walls and filaments surrounding apparent voids, a great surprise at the time. Theorists have now reproduced these results by using computers to follow
406 BIOGRAPHICAL MEMOIRS small perturbations in the density of matter in the Universe as they grow by mutual gravitation to form galaxies. Thus, one of the great discoveries in cosmology was made with a telescope that Fred initiated. Fred wanted to build a larger telescope. He concluded that to keep costs down, one should use many smaller mir- rors, each focused on the same point, rather than a single large one. Thus was born the MMT, or Multiple Mirror Telescope, a joint SAO-University of Arizona project, com- pleted in 1979. In it, six 1.8 meter mirrors were combined to form the equivalent of a single 4.5 meter telescope, at the time one of the largest in the world. The principle having been established, two 10 meter Keck telescopes on Mauna Kea were later built, each with 36 mirrors. Fred could be proud of his participation in this revolution in telescope design. BIOGRAPHY Fred was born on November 5, 1906, in Red Oak, Iowa. In his words, âAs an Iowa farm boy, I contracted a case of polio, and it prevented me from becoming a professional tennis player. When I entered UCLA, it was my main ambi- tion to excel at tennis . . . but I never made the tennis team.â18 Before attending UCLA, Fred moved with his fam- ily to Long Beach, California in 1922, where he attended the Long Beach High School and worked in his familyâs grocery store. In 1923-1924 he attended Occidental College and from 1924 to 1927 he attended UCLA, where he re- ceived a B.A. degree in mathematics. When he decided to pursue astronomy as a career, he enrolled in the graduate program at UC, Berkeley, obtaining a Ph.D. in astronomy in 1931. His thesis on variable stars was supervised by Donald Menzel, who at the time was an astrophysicist on the staff of the Lick Observatory of the University of California, and
FRED LAWRENCE WHIPPLE 407 who later became director of the HCO. Fred was invited by Harlow Shapley to join the staff of HCO and to take charge of its Oak Ridge Station; appointed instructor in the as- tronomy department, he moved up through the ranks, at- taining the rank of professor in 1950 and becoming depart- ment chair in 1949. He was appointed Phillips Professor of Astronomy in 1968, serving in that position until his retire- ment from the faculty in 1977. His colleagues at Harvard included Shapley, Bart Bok, Cecilia Payne-Gaposhkin, and Donald Menzel. His first marriage, to Dorothy Woods, in 1928, ended in divorce in 1935; they had one son, Earle Raymond Whipple. Fred married Babette Frances Samelson in 1946, and they had two daughters, Dorothy Sandra (âSandyâ) Whipple and Laura Whipple. Fred served on advisory committees to the House Com- mittee on Science and Astronautics of the U.S. Congress, to NASA, the International Geophysical Year, the National Research Council, the U.S. Air Force, the National Science Foundation, the National Advisory Committee on Aeronau- tics, the Office of Naval Research, and the University Cor- poration for Atmospheric Research. He was a member of the International Astronomical Union, the International Scientific Radio Union, the Committee on Space Research, the International Astronautical Federation, and the Inter- national Academy of Astronautics. Fred was a member of many honorary societies, includ- ing, of course, the National Academy of Sciences, to which he was elected in 1959. Others included the Royal Society of Arts (London), the American Academy of Arts and Sci- ences, and the American Philosophical Society. His profes- sional societies included the American Astronomical Soci- ety, of which he served as vice-president from 1948 to 1950, the American Astronautical Society, the American Geophysical Union, the American Institute of Aeronautics and Astro-
408 BIOGRAPHICAL MEMOIRS nautics, the American Rocket Society, and the American Standards Association. His many honors included Donohoe medals (in 1933, 1934, 1937, 1941, 1942, and 1943), a Presidential Certifi- cate of Merit (for âWindow,â a radar countermeasure used by the Air Force in World War II), the J. Lawrence Smith Medal of the National Academy of Sciences, the Space Flight Award of the American Astronautical Society, the Distin- guished Federal Civil Service Award by President John F. Kennedy, the NASA Public Service Award, the Leonard Medal of the Meteoritical Society, the Kepler Medal of the Ameri- can Association for the Advancement of Science, the Jo- seph Henry Medal of the Smithsonian Institution, the Gold Medal of the Royal Astronomical Society, the Kuiper Award of the American Astronomical Society, the Bruce Medal of the Astronomical Society of the Pacific, the Henry Norris Russell Lectureship of the American Astronomical Society, and finally, the establishment of the Fred L. Whipple Lec- tureship of the Planetary Division of the American Geo- physical Union. From simple beginnings Fred became a world authority on the nature of comets. When he started his career, many astronomers were ignorant of the subject. Now, largely as a result of Fredâs work, we realize that comets carry unique information about the formation of the Solar System. Fred was an observer, an analyst, and a theorist, scientifically active in spite of heavy administrative commitments. He carried his physical disability without complaint, and he continued his commitment to rational thinking into every sphere he encountered. In short, he was a person that ev- ery scientist can admire. IT IS A PLEASURE TO acknowledge conversations with Ursula Marvin, my colleague at the Smithsonian Astrophysical Observatory. Brian
FRED LAWRENCE WHIPPLE 409 Marsden at SAO graciously helped me to select Whippleâs most significant works, reviewed a draft of the memoir, and made many helpful comments. I am indebted to Babbie Whipple for her com- ments on the manuscript. NOTES 1.F. L. Whipple. My conversion to atheism. Personal copy of G. Field. 2.U. B. Marvin. Oral histories in meteoritics and planetary science. XIII. Fred L. Whipple. Meteorit. Planet. Sci. 39(suppl.)(2004):A199- A213. 3.Ibid. 4.Ibid. 5.Ibid. 6.C. Ryan, ed. Across the Space Frontier. New York: Viking Press, 1952. 7.See âSelected Bibliographyâ (1950, 1951). 8.U. B. Marvin. Oral histories in meteoritics and planetary science. XIII. Fred L. Whipple. Meteorit. Planet. Sci. 39(suppl.)(2004):A199- A213. 9.D. S. Burnett. NASA returns rocks from a comet. Science 314 (2006):1709-1710. (See also other papers in this issue.) 10.E-mail message dated Jan. 11, 2006, from Babette Whipple. 11.U. B. Marvin. Oral histories in meteoritics and planetary science. XIII. Fred L. Whipple. Meteorit. Planet. Sci. 39(suppl.)(2004):A199- A213. 12.G. Marcy, R. P. Butler, D. Fischer, S. Vogt, J. T. Wright, C. J. Tinney, and H. R. A. Jones. Observed properties of exoplanets: Masses, orbits, and metallicities. Prog. Theor. Phys. 158(suppl.)(2005):24- 42. 13.K. E. Haisch, E. A. Lada, and C. J. Lada. Disk frequencies and lifetimes in young clusters. Astrophys. J. 553(2001):L153-156. 14.Personal communication from Fred L. Whipple; as indicated in Note 9, this wish has already been granted, although Fred did not live to see the sample returned from Comet Wild 2 by NASAâs Stardust mission. The crystalline nature of Stardust particles suggests to some that these particles cannot be unprocessed interstellar dust, as might be expected if Comet Wild 2 formed in the cold outer reaches of the solar system. However, lively debates will ensue before this issue
410 BIOGRAPHICAL MEMOIRS is settled. If Fred were now alive, he would surely be an active participant in the discussions. 15.U. B. Marvin. Oral histories in meteoritics and planetary science. XIII. Fred L. Whipple. Meteorit. Planet. Sci. 39(suppl.)(2004):A199- A213. 16.Ibid. 17.M. Davis, J. Huchra, D. Latham, and J. Tonry. A survey of galaxy redshifts, Astrophys. J. 253(1982):423-445. 18.F. L. Whipple. Of comets and meteors. Science 289(2000):728.
FRED LAWRENCE WHIPPLE 411 SELECTED BIBLIOGRAPHY 1932 A spectroscopic study of the Cepheid variables eta Aquilae and delta Cephei. Lick Obs. Bull. 16:1-23. 1935 The colors and spectra of external galaxies. Harvard College Obs. Circ. 404:1-21. 1938 Photographic meteor studies. I. Proc. Am. Phil. Soc. 79:499-548. 1939 On the physical characteristics and origin of the supernovae. Proc. Am. Phil. Soc. 83:253-264. 1943 Meteors and the earthâs upper atmosphere. Rev. Mod. Phys. 15:246- 264. 1946 Concentrations of the interstellar medium. Astrophys. J. 104:1-11. 1950 A comet model. I. The acceleration of Comet Encke. Astrophys. J. 111:375-394. 1951 A comet model. II. Physical relations for comets and meteors. Astrophys. J. 113:464-474. 1955 The physical theory of meteors. VII. On meteor luminosity and ionization. Astrophys. J. 121:241-249. A comet model. III. The zodiacal light. Astrophys. J. 121:750-770.
412 BIOGRAPHICAL MEMOIRS 1956 The scientific value of artificial satellites. J. Franklin Inst. 262:95- 109. 1959 Fundamental problems in predicting positions of artificial satellites. Proc. Symp. Appl. Math. 9:36-47. 1962 On the distribution of semimajor axes among comet orbits. Astron. J. 67:1-9. 1963 On meteoroids and penetration. J. Geophys. Res. 68:4429-4439. 1964 Evidence for a comet belt beyond Neptune. Proc. Natl. Acad. Sci. U. S. A. 51:711-718. The history of the solar system. Proc. Natl. Acad. Sci. U. S. A. 52:565- 594. 1965 Knowledge and understanding of the physical universe as determi- nants of manâs progress. In Knowledge among Men, ed. P. H. Oeser, pp. 173-191. New York: Simon and Schuster. 1967 On maintaining the meteoritic complex. In The Zodiacal Light and the Interplanetary Medium, ed. J. L. Weinberg, NASA S-P 150:409- 426. Washington, DC: NASA Scientific and Technical Informa- tion Division. On the satellite geodesy program at the Smithsonian Astrophysical Observatory. Space Res. 7:675-683.
FRED LAWRENCE WHIPPLE 413 1968 On fundamental scientific advances resulting from the space pro- gram. In Fourth International Symposium on Bioastronautics and the Exploration of Space, eds. C. H. Roadman, H. Strughold, and R. B. Mitchell, pp. 9-23.San Antonio, TX: Brooks Air Force Base. 1972 The origin of comets. In The Motion, Evolution of Orbits, and Origin of Comets, eds. G. A. Chebotarev, E. I. Kazimirchak-Polonskaya, and B. G. Marsden, pp. 401-408. Dordrecht: Reidel. 1977 The reality of comet groups and pairs. Icarus 30:736-746. 1980 Rotation and outbursts of comet P/Schwassmann-Wachmann 1. Astron. J. 85:305-313. 1989 Comets in the space age. Astrophys. J. 341:1-15. 1992 The activities of comets related to their aging and origin. Celestial Mech. 54:1-11