November 29, 2005

U of C prof snags top U.S. science award

Robert Clayton, the Enrico Fermi Distinguished Service Professor Emeritus in Chemistry, Geophysical Sciences, and the College, has been awarded the National Medal of Science, joining the ranks of 12 other University faculty members.

Clayton was one of eight recipients of the 2004 National Medal of Science, awarded by the National Science Foundation (NSF). President George W. Bush announced the recipients on November 14.

“The National Medal of Science is this country’s scientific honor and is awarded to only a handful of scientists every year,” said Andrew Davis, the senior scientist at the Fermi Institute and one of Clayton’s colleagues. “Professor Clayton’s discovery and exploitation of oxygen isotopic variations as probes of the early history of the solar system have had a profound effect on the field. As the [NSF] citation said, he is also being cited for ‘being an exemplary role model as a mentor, teacher, and advocate for rigorous science.’”

Clayton, who has been a member of the University’s Chemistry department since 1958, pioneered the study of intergalactic matter and its implications for the formation of planets. While researching dust samples collected from the six Apollo moon landings, Clayton discovered in 1973 that oxygen isotopes of the early solar system were fundamentally different from present oxygen forms on Earth.

This discovery, called the oxygen isotopic heterogeneity theory, highlighted the importance of “photochemistry” (the interaction of light with chemicals) in the formation of the universe and redefined predictions of the abundance of oxygen isotopes in the sun.

“For more than 30 years, nearly every new meteorite was analyzed in Clayton’s lab,” Davis said. “His measurements of lunar samples supported the idea that the Moon was the result of an impact of a Mars-size body with the Earth early in solar system history.”

Even though he officially retired from the University in 2001, Clayton is still active in the field of cosmic chemistry. His current research team includes three graduate students working on extraterrestrial meteorites and two graduate students studying the earth’s atmosphere.

“The extraterrestrial research deals with the earliest history of the solar system: the origin of organic molecules, the use of mineral grains as samples of pre-solar stars, and the role of short-lived radioactivity in the early solar system,” Clayton said. “The atmospheric studies deal with the interaction of the stratosphere with the troposphere in the present atmosphere, and the chemical evolution of the atmosphere through geologic time.”

Clayton’s contributions to cosmology are significant in recent studies of space. NASA will test the oxygen isotopic heterogeneity theory by analyzing the solar wind from its Genesis mission. And according to Davis, Clayton has produced one of cosmology’s latest theories, the “self-shielding” hypothesis, which states that all oxygen was generated by carbon monoxide near the sun during formation of the solar system that reacted with different wavelengths of light to produce the different oxygen isotopes found in the solar system.

Clayton said that receiving the award was a humbling and joyful experience. He was especially pleased to have gotten a congratulatory note from a former student who took Chemistry 113 in 2001, the last time Clayton taught it. But through it all, it is still the research that drives Clayton.

“At age 75, I continue to find fun and excitement in my research,” Clayton said. “It seems that the best message to students is to find something you love to do, and to immerse yourself in it.”