Greenstein, Jesse L. (Jesse Leonard), 1909-2002

William Carlos Williams was an American poet, often considered part of the Imagist and Modernist movements.

Greenstein was a Harvard educated astronomer who came to the California Institute of Technology in 1948 to run the astronomy program, which then included the administration of the Palomar 200-inch telescope. While at Caltech he also did research on stellar composition and high resolution spectra using the Palomar telescope. Became a leader in the profession, and an administrator in professional scientific organizations.

Biography

Jesse Leonard Greenstein was born in New York City, where his family ran a prosperous real estate business. Although he was expected to join the family business, Greenstein had other interests. As a boy he was an avid reader and an enthusiastic student. His interests ranged from classical languages and literature to science. When he was eight years old his grandfather presented him with a brass telescope and a tripod, and his interest in astronomy flourished. He was soon lecturing to his friends about the planets and stars. Something of a child prodigy, he skipped through the New York public schools and went on to attend a private high school, the Horace Mann School for Boys, from the ages of 11 to 15. His interest in science continued to grow, and when he entered Harvard at age 16, he was committed to pursuing a life in science.

Greenstein received his AB degree from Harvard in 1929, just a few months before the stock market crash. By that time he was already working on his Master's degree in astronomy, which he received the next year. The continuing economic crisis, however, forced him to return to New York to aid his family through the bleak years of the early 1930s. Greenstein recalls these stressful years as having a decisive effect upon his character: he learned the skills of management, communication and financial planning under the most extreme conditions. During these years in New York, Greenstein became acquainted with the physicist I.I. Rabi, who kept Greenstein in touch with the world of science by inviting him to do volunteer work in his lab at Columbia. At Columbia, Greenstein also met astronomers J. Schilt and W. J. Eckert, who kept him in touch with the developments in the field. By 1934, Greenstein felt that he could leave the family business and return to graduate work in astronomy. He returned to Harvard and received his PhD three years later.

Upon the completion of his degree in 1937, Greenstein received a National Research Council Fellowship that permitted him to choose a site for his work. Greenstein's choice was the Yerkes Observatory of the University of Chicago located in Williams Bay, Wisconsin. Yerkes bore the stamp of its builder, George Ellery Hale, and was just entering a golden age under the leadership of Otto Struve. Yerkes was a center of both theoretical and observational astronomy, and was at that time just completing the construction of a new 82-inch reflector at McDonald. At Yerkes, Greenstein began work on nebular spectrography in collaboration with the young theorist L. G. Henyey. Together, they discovered diffuse galactic light, the scattering of starlight by dust in the Milky Way. After making these significant contributions to the field of interstellar matter, Greenstein switched over to working on high resolution stellar spectra. This spectrographic work led to new insights on the atomic composition of stars.

Greenstein continued to work at Yerkes throughout the Second World War. In 1948, he accepted an offer from Caltech to take over the leadership of astronomy at the Institute, particularly the new 200-inch telescope at Mount Palomar. Prior to Greenstein's arrival, Caltech had essentially no astronomy department, although it had a tradition of work in astrophysics and a close association with the Mount Wilson observatory initiated by Hale. At Caltech, Greenstein proved to be as good an administrative leader as a researcher, building up astronomy at Caltech into one of the premier programs in the nation. The catalog of Greenstein's accomplishments over the next thirty years is impressive and is richly documented in the collection of his papers. He continued his research into stellar composition and high resolution spectra using the Palomar telescope. He also became deeply involved in the leadership of the astronomical profession, both as a mentor for a new generation of astronomers and as an administrator on numerous national and professional scientific organizations.

To all his varied activities, Greenstein brought a warmth and charm which made him an effective leader and a superb spokesman for science. Throughout his long career in science, he was supported by his wife of many years, the former Naomi Kitay, his boyhood sweetheart.