For Charles Gehrke, a single photograph represents a high point in his scientific career. The picture shows Gehrke, 30 years younger, smiling and wearing a lab coat. In his white-gloved hands he holds a test tube, which holds a tiny piece of the moon.
In the 1960s, Gehrke was working for the MU School of Agriculture, where he was using a process called gas chromatography to analyze soil samples. Gas chromatography is used to determine if amino acids are present in a substance.
Amino acids, also called “life molecules,” indicate the presence of proteins in something that is, or once was, alive.
After several years of trying, Gehrke and dozens of graduate and doctoral students were able to develop the most sensitive chromatographic method in the United States.
“We had a sensitivity of a factor of 1,000 over anybody else in the world at that time of being able to measure amino acids,” Gehrke said.
This method enabled scientists to determine if moon rocks contained any life molecules.
When the Apollo 11 mission returned in 1969, “NASA immediately asked me because we had a technology that nobody else could match in the 1960s,” Gehrke said.
Gehrke and other scientists were commissioned by the National Academy of Sciences to go to Berkeley, Calif., where a new facility allowed them to analyze the moon rock samples with reduced risk of contamination.
“Now that was something unusual, for a Missourian to go to Berkeley in the 1970s and tell them what to do,” Gehrke said.
The scientists labored to analyze the samples at increasingly minute specifications.
“It turned out, we didn’t have to measure a microgram, we had to measure a nanogram, which is 1/1,000 of the microgram,” Gehrke said. “And we could do that.
“In 1970, we told science — we told NASA — that there aren’t any life molecules on the moon at the level of 2 nanograms,” he said.
Gehrke analyzed samples from Apollo missions 11 through 17, with the exception of Apollo 13, which never landed on the moon.
“I never realized that I would analyze something like this,” he said. “I was honored and pleased to analyze something that’s four billion years old. Not many people have done that.”