October 01, 2011
The Geochemical Society lost a great scientist and leader in Michael J. Drake, who passed away in Tucson on September 21, 2011. He engaged in research of great breadth, extending across disciplines that included meteoritics, geochemistry and planetary sciences, and reaching across the inner solar system (Earth, Moon, Mars, Venus, asteroid 4 Vesta, and other asteroid parent bodies). He considered himself first and foremost a geochemist. He was simultaneously president of the Geochemical Society (1998-1999) and the Meteoritical Society (1999-2000), and his service to the societies and greater geochemical community was enormous, as exemplified below.
Michael Julian Drake was born July 8, 1946 in Bristol, England. He grew up in England and attended college at Victoria University of Manchester, where he received a Bachelor of Science degree in Geology with honors in 1967. Mike earned his Ph.D. in Geology working with Dan Weill at the University of Oregon in 1972. At Oregon, he took full advantage of the great opportunities to study returned samples from all of the Apollo missions to the Moon. The Oregon geochemistry group of the 1970's, (led by Weill, Gordon Goles, and Alexander McBirney) produced many prominent geochemists and petrologists, including Mike Drake, Jan Bottinga, Bill Leeman, David and Marilyn Lindstrom, Stewart McCallum, T. Murase, H.R. Naslund, R.A.F. Grieve, and Gordon McKay. One of the fundamental discoveries of the Apollo mission was the presence of Eu anomalies in lunar igneous rocks, caused by plagioclase fractionation. Mike's doctoral work on the partitioning of Eu and the variation of Eu2+/Eu3+ with oxygen fugacity was one of the first true experimental studies of trace element partitioning, and led to basic insights into the differentiation history of the Moon. Mike then spent a year as a postdoctoral research associate with John Wood at the Harvard Smithsonian Astrophysical Observatory (1972-1973), which enhanced our understanding of lunar anorthosite and crustal formation (Wood's group had been instrumental in developing the idea of flotation of plagioclase on an early lunar magma ocean, to form an ancient anorthositic crust).
Mike moved to a faculty position with the Lunar and Planetary Laboratory at the University of Arizona in 1973, where he remained until his death. The LPL was a unique and exceptionally fruitful environment, which brought geochemists, geophysicists, space physicists, meteoriticists, planetary scientists, and astronomers together in the same institute. In this setting, Mike's research thrived and expanded. He continued working on the concept of a lunar magma ocean, and collegial interactions at the LPL allowed him to combine geochemical and geophysical constraints. He established an electron microprobe lab of world-class caliber, overseen first by Tom Teska and later Ken Domanik; the microprobe formed the heart of the Drake group analytical capability.
The discovery of spectral similarities between eucrite (basaltic) meteorites and asteroid 4 Vesta by some of the LPL scientists compelled Mike to pursue this link. His initial work on rare earth element (REE) modeling led to studies over several decades that addressed magmatism, core formation, differentiation, and ultimately the application of a magma ocean model to 4 Vesta. His influence on understanding the origin, differentiation and geologic history of 4 Vesta has been fundamental and unwavering.
Mike's studies of differentiation and core formation in small bodies continued, and his emphasis focused on the siderophile elements such as Ni, Co, W, Ga, Ge, P, Ir, and Au. Work in his lab over several decades focused on the partitioning of these elements between solid and liquid metal, simulating the crystallization of molten metallic cores from which we have remnants represented by the various iron meteorite groups. Although many students and post-docs participated in these studies, one of the first indications that this was fertile field of study came from the experiments of an undergraduate researcher. These efforts led to a detailed understanding of the chemical and physical evolution of metal cores. His group also started studying the partitioning of siderophile elements between metal and silicate melt, to simulate the conditions of core formation, and to test whether metallic cores equilibrated with silicate mantles of differentiated bodies. These studies were applied to the Moon and asteroid 4 Vesta, and demonstrated the physical and chemical conditions under which their cores may have equilibrated with their mantles. Applications were made to the Earth and Mars, but later it was realized that applications to these larger bodies required additional lab capabilities.
As models for these small bodies matured, emphasis turned to the Earth, and its differentiation history, where conditions of high pressure and temperature are so important. Mike's dedication and interest in this problem led him to pursue new experimental techniques at high pressures with the help of several of his colleagues - John Holloway, Dave Rubie, Tibor Gasparik, and Dave Walker. Under their tutelage, Mike learned piston cylinder and multi-anvil techniques, established his own high-pressure experimental petrology lab, and began to make fundamental contributions to this field as well. His group took on the problem of explaining the excess of siderophile elements in the Earth's primitive upper mantle that had been traditionally explained by late accretion of chondritic materials (heterogeneous accretion). He also addressed the question of how Earth's major, minor and trace elements were fractionated during its early stages by deep mantle phases such as majorite garnet, magnesiowüstite, and Mg-perovskite. These studies, with parallel studies by several other groups, have shown that the Earth likely had an early deep magma ocean, and that the mantle could not have fractionated much of these deep mantle minerals, or it would have attained non-chondritic values of key elemental ratios. The detailed knowledge of Earth led Mike and his group to consider general models for planetary building blocks.
Although the origin of Earth's water became a special interest in his later years, his group had worked consistently on planetary volatiles. Early work in the 1980's examined the evolution of Ar and N in Earth, Mars and Venus - again this work was enhanced by the unique environment at the LPL where planetary atmospheric scientists worked just down the hallway. Solubilities of noble gases (Xe, Kr, Ar, and Ne) in silicate phases their partitioning among them was the next emphasis, which logically evolved into study of the I-Xe chronometer system during planetary differentiation. The differences between water-bearing and water-free systems led to an explanation for the fundamental difference in Xe isotopes between the Earth and Mars. With deep magma ocean models proposed by his group in the 1990s, came the realization that water could easily be dissolved into such deep melts, and these could be significant reservoirs of primordial water. Because the difference in D/H ratios measured in comets from those in Earth's oceans began to erode the traditional hypothesis that Earth's water came from comets, Mike began to consider the origin of Earth's water by looking at the entire accretion process from adsorption onto early dust grains, to delivery during accretion, to possible later sources delivered by various dynamic mechanisms.
Mike left his mark on a number of influential meetings. Mike and John Holloway co-chaired the notorious 1977 Sedona (AZ) conference on trace element partitioning between magmatic phases and silicate melt. This landmark meeting, and its published proceedings, influenced a generation of geochemists and set the stage for decades of research. The 1984 conference on the Origin of the Moon, in Kona (HI) saw the emergence of the Giant impact hypothesis of the Moon's origin. Mike was there and was a key contributor to the discussions. Implications of this hypothesis for the Earth were still debated at the 1988 Origin of the Earth conference in Berkeley (CA); the proceedings volume of that conference was edited by two members of Mike's group, H. Newsom and J. Jones. In 1997, Mike and Joaquin Ruiz organized the Goldschmidt meeting of the Geochemical Society in Tucson, a large and scientifically stimulating meeting enjoyed by many. Finally, Mike and Alex Halliday organized the 1998 meeting on the Origin of the Earth and Moon in Monterey (CA). Partly due to this meeting, this field has been stirred several times since, and continues to be a topic of great progress and change, strengthening our understanding of the origin of terrestrial planets and the Earth-Moon system.
Working with Mike was a pleasure and a privilege, sometimes not realized until after the fact. He was articulate and pointed in his engagements and debates at meetings, and helped the members of his research group achieve a comparable level of clarity and direction. Group practice talks before meetings were the norm, and commonly led to a new set of slides being produced hours before departing for a meeting! Mike was easy and fun to tease - stories from his graduate school days indicate that his immaculately clean and organized desk was frequently 'disorganized' by his fellow students, much to his displeasure. In his experimental lab at LPL, his students and postdocs created an empty drawer labeled 'successful Drake experiments'. Graduate students at the Lunar and Planetary Laboratory annually pranked Mike on April Fools Day - some eggs hidden in his office about 15 years ago have, for example, never been found. Once on a day trip at a conference in France his group accused him of being 'high maintenance' and he was shocked to hear this...but was a good sport about it. Mike took all of the teasing in great stride and dished it back when opportunity arose. His sense of humor and good will were an important part of his success.
Mike was appointed Head of the Department of Planetary Sciences and Director of the Lunar and Planetary Laboratory in 1994, a position he held until 2011. Under his leadership, LPL successfully built and flew a variety of spacecraft instruments including the Imager for Mars Pathfinder, the Descent Imager/Spectral Radiometer (DISR) on Cassini/Huygens, the IMAGE Extreme Ultraviolet Imager, and the Gamma-ray Spectrometer Suite (GRS) on Mars Odyssey. Under his watch, LPL built the Surface Stereo Imager and Robotic Arm cameras and the TEGA instrument on Phoenix, and successfully operated Phoenix on the Martian surface from the University of Arizona campus. In addition, under Mike's leadership, LPL scientists were selected as Team Leaders on the Visible and Infrared Mapping Spectrometer (VIMS) on the Cassini mission and the High-Resolution Imaging Science Experiment (HiRISE) on Mars Reconnaissance Orbiter.
His personal dedication to space exploration through missions involved both Mars Sample Return and later OSIRIS-Rex. In 1987 Mike and Gordon McKay organized the first Mars Sample Return Workshop. The OSIRIS-Rex mission was selected for funding by the New Frontiers Program in 2011, with Mike as Principal Investigator (PI) for the mission. OSIRIS-Rex will launch in 2016 to asteroid 1999 RQ36, a small B class (carbonaceous) near Earth asteroid, map and characterize the surface, collect a sample and return that sample safely to Earth in 2023. The dedication of Mike and his Deputy PI Dante Lauretta to this mission ensure Mike's legacy: inspiring new young scientists in the stages of this mission, and providing the science community with samples from an asteroid that can be studied long after the mission is completed.
Mike received many accolades for his research accomplishments. He was named a fellow of the Meteoritical Society in 1980, the American Geophysical Union and the Geochemical Society in 2002. He was a founding fellow of the Arizona Arts, Sciences and Technology Academy. He was awarded the Leonard Medal of the Meteoritical Society in 2004. Asteroid 1988 PC1 was named 9022 Drake in his honor by Carolyn Shoemaker. Mike also played key roles in defining the planetary science research priorities of the United States, serving on the NASA Space Science Advisory Committee, the Lunar Exploration Science Working Group and as Chair of the NASA Solar System Exploration Subcommittee, among many other service commitments.
Mike's dedication to education and training the next generation is evident in many of his activities and awards. He received the UA College of Science Career Distinguished Teaching Award in 1999 and the University of Arizona Senior Honorary BobCats Outstanding Faculty Member Award in 2006. He inspired many young scientists as the Director of State of Arizona Space Grant Consortium from 2000 to 2011. He served as the University of Arizona representative to the Universities Space Research Association from 2000 to 2011 and served on the Board of Trustees for the Universities Space Research Association from 2007 to 2011.
It is hard to believe he had any spare time after reading this, but Mike was an avid four wheeler, frequently going on adventures in various parts of Arizona, Utah and New Mexico. He was also a talented tennis player and many of our colleagues squared off against him at various meetings. Mike is survived by his wife, Gail Georgenson, whom he met and married in Tucson. Together they have two children, Matthew and Melissa, both medical doctors, and a granddaughter, Elsie. His loss will be felt by many and he will be deeply missed.
Kevin Righter, John Jones, David Mittlefehldt (NASA -JSC)
Allan Treiman (LPI)
Nancy Chabot (JHU-APL). September 2011
Students of M.J. Drake
Roger Nielsen, 1978; Charles Hostetler, 1982; Horton Newsom, 1982; Daniel Malvin, 1987; Leigh Broadhurst, 1989; Valerie Hillgren, 1993; Elisabeth McFarlane, 1994; Don Musselwhite, 1995; Nancy Chabot, 1999; Peter H. Smith, 2009; Naydene Hays, 2011.
Postdoctoral scientists of M.J. Drake
Edward Bailey, Jack Berkley, Richard Bild, Christopher Capobianco, Werner Ertel, Cyrena Goodrich, Eddie Hill, Mark Hutchinson, John Jones, David Mittlefehldt, Kevin Righter, Marilena Stimpfl, Allan Treiman.