National medalist

MARQUETTE – Sallie “Penny” Chisholm stood next to President Barack Obama on the stage in the East Room of the White House Feb. 1, smiling as dozens of cameras snapped photos of the two.

Chisholm, a biology professor at the Massachusetts Institute of Technology and 1965 Marquette Senior High School graduate, had just received a National Medal of Science from Obama, one of only a dozen people this year to receive the nation’s highest honor in the field of science.

“It was pretty amazing. (Obama) was very energetic and very positive,” Chisholm said from her room inside Marquette’s Landmark Inn Friday morning.

Chisholm was back in her hometown for a cross-country ski weekend with two long-time friends and sisters, Mary (Sponberg) Pedley and Ingrid (Sponberg) Stafford. Pedley and Stafford are also Marquette natives. The trio has been friends since elementary school and have been reuniting annually in Marquette for the past 13 years.

This year’s trip was originally scheduled for the weekend of Feb. 1, but when Chisholm was told she had won the award and would have to be at the White House that day to receive it, she knew they’d have to change the date.

A long-standing tradition among the three women, the weekend has earned itself a nickname – Cacklefest.

“I emailed them when I learned about (winning the award) and I saw the date. It overlapped with when were supposed to be (in Marquette), so I said, ‘Cackleproblem,’ something’s come up and we’re going to have to change the date,” Chisholm said.

“I wrote back and I said, ‘Nothing changes the date of our Cacklefest,'” Pedley said. ” ‘Maybe if the White House called, or the president wanted to see you.’ And Penny, of course, wrote back and said ‘As a matter of fact…’ “

Chisholm said Pedley and Stafford were quick to forgive her and all three – along with Chisholm’s brother, Doug Chisholm, and her husband Don Sisson – spent the original Cacklefest weekend wining and dining with the nation’s top scientists and politicians.

Chisholm won the prestigious National Medal of Science for her research on phytoplankton, specifically prochlorococcus, a cyanobacterium found in the ocean.

“We work on the smallest and most abundant of the phytoplankton, which was only discovered in 1985,” Chisholm said. “It’s so small you can barely see it under a microscope. Now that we know it’s there, we can see it. In the old days, microscopes weren’t as good. It just looked like tiny pieces of plant matter.”

Chisholm – along with a group of graduate students, post-doctoral associates, research scientists, research assistants and MIT undergraduates – has spent the last 25 years studying prochlorococcus, mapping out its genome and gaining a broad understanding of its place in the ocean’s ecosystem.

“It’s basic research to understand how the ocean ecosystem functions,” Chisholm said. “We study their genetic makeup. It was one of the first microbial genomes to be sequenced. …

“I was on the leading edge of that because we were able to get the genome sequence of our beloved prochlorococcus. Now, we have the sequences of all kinds of microbes from the oceans, but ours was one of the first.”

Chisholm credits her love of science all the way back to her junior high school days in Marquette, when she took her first science class with junior high science teacher Fred Rydholm, the former historian, author and Marquette mayor.

Described by the women as “dynamic” and “warm,” they said Rydholm was creative in his educational endeavors.

“He used to get roadkill and hang it out the window in our classroom,” Pedley said, adding that he would also dissect the animals in class.

A video of Chisholm receiving her award can be found on The Mining Journal’s website at

Jackie Stark can be reached at 906-228-2500, ext. 242. Her email address is