Max Planck was in a bad way. The German physicist was the leader in the field of quantum theory – understanding the universe on the tiniest of scales. As World War II in Europe ground to its end, though, the 87-year-old scientist and his wife were hiding in a one-room farmhouse. Germany had surrendered, and desperate soldiers were scavenging through the countryside. At the same time, the Soviet army was approaching from the east, killing or mistreating its prisoners.

On the other side of the Elbe River from the farmhouse, an American soldier heard rumors that Planck was close by.

Gerard Kuiper was a researcher with the McDonald and Yerkes observatories. As part of his wartime duties, he’d taught celestial navigation and worked on radar. Posted to Europe, he was part of a team that assessed the progress of Germany’s atom-bomb effort.

75 years ago today, Kuiper commandeered a Jeep and a couple of troops and headed across the Elbe, where the American advance had stopped.

Kuiper found Planck and his wife at the farmhouse. They hopped in the Jeep and dodged Russian patrols – an excruciating journey for Planck, who suffered severe back pain.

They returned to the American lines safely. Planck was taken to a hospital, where he recovered enough to resume his research. Kuiper returned to the U.S., and spent 10 years as director of McDonald and Yerkes – after his rescue of one of the giants of 20th-century science.

Script by Damond Benningfield