Behind the Cover: April 2023

Each month, Physics Today editors explore the research and design choices that inspired the latest cover of the magazine.

The April issue of Physics Today has two stories about research in Antarctica. One is about using instruments that swim beneath Thwaites Glacier to study its melting . The other concerns the search for Earth’s oldest ice , conducted by identifying likely locations and retrieving ice cores for study.

The cover photo shows an Antarctic field camp where eight people—five researchers, two drillers, and a camp manager—spent six weeks this past December and January hunting for ancient ice. The camp is a roughly 45-minute flight from the US Antarctic base, McMurdo Station.

Julia Marks Peterson, a third-year graduate student at Oregon State University, snapped the photo at 7:20am on 5 December 2022. The tent in the foreground is the toilet tent, the conical ones behind it are two-person sleeping tents, and the dome-shaped tents farther back and to the right are single sleeping tents. Not visible are the kitchen and communal tents. In the background to the right are the Allan Hills; researchers have identified ice drilled there to be as old as 4 million years, and Marks Peterson and her colleagues were there this past austral summer to gather more.

The speckly appearance of the Sun is from snow that was blown around by the wind, says Marks Peterson. The intense wind and snow delayed setting up the drilling tent, which is larger than the field camp tents, she says, so on a blustery day like the one shown, “you could find us playing Twister in the communal tent.”

In Antarctica, Marks Peterson started out as an ice-core handler. “My role was to help the drillers by removing the cores from the barrel, marking their depths, and keeping track of their orientation,” she says. She also cut up some of the shallower core pieces so they would not exceed weight limits for transporting ice—by air, sea, and land—to the NSF ice core facility in Denver, Colorado. By the end of the season she had graduated to drilling assistant, which meant she could help bring the barrel out of the borehole and clean the core cutters. The experience was “incredible,” she says. Back home, Marks Peterson’s research focuses on the carbon dioxide and methane found in the ice cores, which contain a unique archive of ancient air.

Physics Today‘s art director, Donna Padian, selected the cover photo from among many “stunning” candidates because of its “ethereal quality” and because it showed the landscape best. The composition also worked with the portrait orientation of the cover. For the main cover line, Padian chose the typeface Uniwars Light, with its thin lines and simple shapes, to go with the isolated feeling of the icy image. The glowing Physics Today logotype at the top matches the snow-filtered Sun.