Joseph W. Chamberlain died at home with his family on April 14 2004 after a long illness. He was born August 24, 1928 and raised in Boonville, Missouri, where his father was the doctor. There was no doubt that both Joe and his elder brother Gilbert would also become doctors, but Joe's first class in comparative anatomy at the University of Missouri convinced him that this was not his destiny and he immediately switched to physics and astronomy. He obtained a Masters degree in physics and moved on to the University of Michigan; his advisor was Lawrence Aller and he was also strongly influenced by Leo Goldberg. Early in 1952 he was awarded a PhD and began work at the Air Force Cambridge Research Center where he changed his interests to the upper atmosphere. Among his duties was liaison with research groups at several universities, and I met him when he visited us at the University of Saskatchewan one very cold winter day. He was soon posted to work with Aden Meinel at Yerkes Observatory, where he was added to the faculty and became the leader of the group when Meinel departed to organize the Kitt Peak National Observatory. He himself moved there in 1962 as Associate Director for Space Science; the name of the division was later changed to Planetary Science. He recruited a strong group to work on planetary atmospheres and several group members played important roles in the Mariner 10, Pioneer Venus, Viking, Voyager and Galileo missions. He was elected to the National Academy of Sciences in 1965.
As leader of the group he recruited at Kitt Peak, Joe earned the admiration and loyalty of us all. He strongly preferred doing science to his administrative tasks, but he was still effective at the latter. He was considerably bothered that his superiors, especially the managing boards with which he had to deal, did not always meet his high standards. Joe's friends and colleagues felt, and still feel, that he would have been much happier as a member of a teaching faculty, and are glad that his last nineteen active years were spent in that role.
In the 1960's the AAS had no Division for Planetary Sciences (DPS), and the group organized an annual series of five Arizona Conferences on Planetary Atmospheres. By 1967 several members of the community felt that a DPS was needed; the AAS Council asked Joe to serve as chair of the organizing committee, and when the Division was formed he became the first Chairman. In 1971, he became Director of the NASA Lunar Science Institute and a few years later Professor of Space Physics and Astronomy at Rice University (Houston). After retirement as Professor Emeritus in 1992, he returned to Tucson where he continued an active interest in golf, opera, chess and satirical humor.
Joe's program at Yerkes began with observations of aurora and airglow, making use of the wonderful spectrographs designed and built by Meinel. Among his many contributions was the identification and analysis of a band system in the airglow that now bears his name. His interests shifted toward the theoretical; for example, he applied the radiative-transfer theory of his colleague Chandrasekhar to the sodium twilight airglow. In 1961 he published Theory of the Aurora and Airglow, a book so influential that it was reprinted a few years ago by the American Geophysical Union. In the same period his interest in interplanetary hydrogen led to a low-velocity model that was at odds with Eugene N. Parker's model of the solar wind, and a debate ensued until observations showed Parker to be essentially correct. But the Chamberlain ideas were applied to the structure of the Earth's hydrogen exosphere, and for 40 years this work has been accepted as definitive. Later he studied the reduction of the hydrogen escape rate by the "cooling" that results from the loss of the energy carried by the escaping atoms.
Joe was selected to deliver the 1961 Helen Warner lecture and chose the topic "The upper atmospheres of the planets." This paper clearly expounds the method by which the exospheric temperature can be calculated and applies it to Mars; it has been the basis of subsequent papers by many workers. After he returned to academic life at Rice in 1973, he collected his notes from a graduate course into the 1978 book Theory of Planetary Atmospheres, a second edition of which appeared in 1987 (with the collaboration of the undersigned). His other interest included early studies of changes in the ozone layer and the possible devastating effects from what has now become recognized as global warming.
He is survived by his wife of 54 years, Marilyn; daughter Joy of London; sons David of Austin and Jeffrey (Joel) of Seattle; and granddaughter Jacqueline. His brother Gilbert and numerous nieces and nephews also survive him.