Marcel Nicolet (1912–1996)

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Marcel Nicolet was born on February, 26, 1912, in Basse-Bodeux, Belgium, and died in Uccle/Brussels on October 8, 1996. He received his Ph.D. in 1937 from the University of Liege. He did meteorological forecasting for several years prior to the war, which stopped this activity and launched him into a comprehensive study of the atmospheric attenuation of solar radiation, leading to his famous memoir of 1945, Contribution à 1’Etude de la Structure de l’Ionosphère, which included the ingenious proposal that the quiet D region was formed by the ionization of nitric oxide (NO) by hydrogen Lyman alpha.

Nicolet crossed paths with many of the pioneers of upper atmosphere research. He made ultraviolet observations of the night sky during 1938–1939 at Arosa and studied ozone problems there with Gotz and Dobson. He first met Appleton, Chapman, and Ratcliffe at one of the first international scientific meetings after World War II, a 1946 Union Radio Scientifique International (URSI) meeting held in Paris. Nicolet came to the United States for the first time in January 1950. Invited by Roach to work with Bates in Pasadena on airglow, he met prominent researchers from the University of California, Los Angeles, Caltech, and Mount Wilson Observatory. The collaboration with Bates was fruitful. They had four fundamental papers published in 1950: on hydroxyl (OH) emissions, atmospheric hydrogen, water vapor photochemistry, and sodium D-line emissions. However, most of Nicolet’s papers were of sole authorship and often were quite comprehensive in scope, such as his 1975 thesis on stratospheric ozone. While in California, he and Bates aided Chapman on the proposed division of atmospheric layers from the troposphere to the exosphere. From their knowledge of Greek, Katherine Chapman and Nicolet suggested “mesosphere” for the layer between the stratosphere and the thermosphere.

Passing through Washington, D.C., on his way to California, Nicolet met Berkner and Tuve and spent some time at the Naval Research Laboratory with Hulburt and Tousey. Before returning to Belgium, Nicolet attended a meeting at Penn State, where Berkner and others suggested a campaign similar to the Second International Polar Year (1932–1933), i.e., the International Geophysical Year (IGY). Waynick invited Nicolet to become a Visiting Professor at Penn State, which led to the five Ph.D. degrees granted under his tutelage over the next 20 years. Throughout his career, however, Nicolet remained at the Royal Meteorological Institute, beginning in 1935 as a forecaster for aviation, and in 1946 as Head of its Radiation Division. In 1964 he became the first Director of the Institut D’Aeronomie Spatiale De Belgique, which broke off as a separate entity, a post he retained until 1977. He also served as Secretary-General of the IGY, 1953–1960; President of the International Association of Geomagnetism and Aeronomy, 1963–1967; and longtime member of the Committee on Space Programs and Research (COSPAR) Executive Committee. Concurrently, he held professorships at the Universities of Brussels and Liege and at the Pennsylvania State University.

Nicolet was blessed with a near-photographic memory and began his aeronomic career by reading virtually every pertinent paper. (Now impossible!) He was a pleasure to speak with since he was like a walking library and could cite references in detail, and he was always current. Many benefitted from such talks. A brilliant student, he received first prize, University Exam of Belgium (1935–1937) and Triennial de Potter Prize of the Belgium Royal Academy (1940–1942). His achievements in scientific research (300 published papers) and administration earned him the Guggenheim prize for discovery in Astronautics (1963), the Hodgkins Medal of the Smithsonian Institution for achievements in Aeronomy (1965), the American Geophysical Union’s William Bowie Medal in 1984, memberships in international scientific academies (Belgium, United States, France, and Northern Ireland), and many other distinctions, notably the title of hereditary Baron, conferred by King Boudouin in 1987.

—William Swider

U.S. Air Force Research Laboratory
Hanscom Air Force Base, Massachusetts

James A. Van Allen (1914–2006)

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vanallenJames A. Van Allen was born in Mount Pleasant, Iowa, on September 7, 1914. He received his Ph.D. in physics from the University of Iowa in 1939 and was a Research Fellow at the Carnegie Institution of Washington’s Department of Terrestrial Magnetism until 1942. As a Navy officer during World War II, he worked at the Johns Hopkins University Applied Physics Laboratory (APL), where he helped develop the proximity fuse, and then sailed with the Pacific Fleet to advise on the use and operation of this important device. After the war, he worked at APL on instrumenting V-2 rockets for scientific research and on various rocket- and balloon-borne instruments for studying cosmic rays at high altitudes and high latitudes. He also headed the development of the first sounding rocket, the Aerobee. In 1951 he returned to the University of Iowa as Head of the Department of Physics and Astronomy, where he remained an active and respected scientist and teacher.

It was at Van Allen’s home in 1950 that he, Sidney Chapman, Lloyd Berkner, S. Fred Singer, Harry Vestine, and others developed the first plans for an International Geophysical Year (IGY); a coordinated, international, and comprehensive study of Earth for an 18-month period from July 1957 through December 1958. This first integrated study of Earth as a planet ushered in the space age by providing the model for large-scale, government-funded science, and because the United States and the Soviet Union included the first satellite launchings in their contributions. Van Allen’s instruments were aboard the first successful American satellites, Explorers 1 and 3, launched in 1958, and provided data for the first space-age scientific discovery: the existence of a doughnut-shaped region of charged particle radiation trapped by Earth’s magnetic field. With various colleagues he sent instruments to the Moon (Explorer 35), Venus (Mariners 2 and 5), Mars (Mariner 4), Jupiter (Pioneers 10 and 11), and Saturn, and throughout interplanetary space, serving as principal investigator on more than 25 space science missions. Author of nearly 200 papers, he personally directed the dissertations of most of the scores young scientists receiving Ph.D. degrees in space physics from the University of Iowa.

Van Allen was been among the most sought-after committee members and advisers, working with the highest levels of government and scientific administration. A member of the National Academy of Sciences’ Space Science Board at its inception in 1958 and working with NASA since its creation in 1959, he helped plan and select the initial suite of space-based observations and experiments. He was among the most influential of individuals in the late 1960s, laying the groundwork for the exploration of the outer solar system and the missions that became Pioneer 10 and 11, Voyager, and Galileo. He was an articulate and outspoken advocate of small, inexpensive missions long before this view became popular.

A member of the American Geophysical Union since 1948, Van Allen helped to organize the first planetary sciences section in 1959 and served as its President from 1964 to 1968. He was President of AGU’s solar-planetary relationships section from 1976 to 1978. Van Allen was elected an AGU Fellow and named John Adam Fleming Medalist in 1963,was awarded the William Bowie Medal in 1977, and served as Union President from 1982-1984.

Joseph N. Tatarewicz

University of Maryland Baltimore County
Catonsville, Maryland

Eugene N. Parker (1912– )

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parkerEugene N. Parker was born in Houghton, Michigan, in 1927. After receiving a B.S. degree from Michigan State College in 1948 and a Ph.D. from the California Institute of Technology in 1951, he held various positions at the University of Utah from 1951 to 1955. In 1955, he joined the University of Chicago, where John Simpson and others were beginning to challenge the then-prevalent concept of interplanetary space being largely empty, traversed by a few fast-moving particles. With only a few in situ observations in the immediate neighborhood of the Earth, theorists had to rely on a variety of ambiguous observable geophysical and astronomical phenomena.

In 1958, Parker published his theory of the solar wind, in which the solar corona expands supersonically to the outer reaches of the solar system, now the foundation of modern solar-terrestrial research and solar-planetary relationships. Prior to Parker’s work, the existence of a continuous, but slight, flow of particles from the Sun was suggested by a variety of circumstantial evidence. The idea of such a vigorous, dense, and dynamically complex outflow was so radical for its time that it drew criticism and disbelief from most of the scientific community. In 1960, Soviet scientists reported suggestive observations by Lunik 2; in 1961, Explorer 10 data provided convincing confirmation, followed by Mariner 2 observations in 1962 between the orbits of Earth and Venus. Studying the detailed structure and dynamics of the solar wind animated much of the scientific exploration of the inner solar system during the 1960s, and the concept, extended to other stars, became one of the most important foundations of modern astrophysics.

Not just because of his theoretical work but also because of his active participation in advisory committees and his organizational work within the American Geophysical Union, Parker has been one of the most influential architects of the exploration of interplanetary space during the past four decades. His AGU awards include the John Adam Fleming Medal in 1968 and the William Bowie Medal in 1990. He was elected to the National Academy of Sciences in 1967 and in 1989 received the National Medal of Science. The astronomical community also recognized his contributions with the Henry Norris Russell lectureship and the George Ellery Hale Award (American Astronomical Society) and the Sydney Chapman Medal of the Royal Astronomical Society.

—Joseph N. Tatarewicz

University of Maryland Baltimore County
Catonsville, Maryland