Robert M. Walker

The last time Robert M. Walker, PhD, visited the university, he was very much looking forward to Commencement and was planning on attending. Walker received an honorary doctor of science degree in 2004.

Walker died Feb. 12 in Brussels, Belgium, after an extended struggle with stomach cancer. He was 75.

His wife, Ghislaine Crozaz, PhD, professor of earth and planetary sciences in Arts & Sciences, will accept the honorary doctorate in his honor.

Walker was the inaugural director of the McDonnell Center. He played a key role in planning the return of samples by the Apollo missions and in pathbreaking laboratory studies of “moon rocks.”

He was elected to the National Academy of Sciences in 1973.

In the past two decades, he was a world leader of microanalytical studies of tiny grains preserved for eons in meteorites, culminating in their identification as stardust.

Always in pursuit of more-powerful ways to analyze small amounts of material, Walker devoted the last years of his life to the implementation of nanoscale secondary-ion mass spectrometry — NanoSIMS — promoting the development, acquisition and application of the most advanced instrument of its kind.

This effort was rewarded with the discovery — which he had forecast years earlier — of presolar silicate grains in interplanetary dust particles.