Deep beneath the Antarctic ice sheet, a new generation of German-developed technology is helping scientists look deeper into the universe.
During the 2025-26 Antarctic summer season, the international IceCube collaboration completed a major upgrade of the IceCube Neutrino Observatory at the South Pole. A team of 51 scientists and technicians deployed around 670 new sensors and calibration instruments into boreholes reaching depths of up to 2,600 metres beneath the ice. The new equipment is expected to improve the observatory’s ability to detect low-energy neutrinos, elusive particles that can travel across the cosmos largely unaffected by matter.
German researchers played a central role in the project. Scientists and engineers from TU Dortmund University, Ruhr University Bochum, Karlsruhe Institute of Technology (KIT), DESY, and several other German universities contributed to the design, testing and deployment of the new sensor systems.
At the heart of the upgrade are pressure-resistant glass spheres known as multi-PMT Digital Optical Modules, or mDOMs. These devices contain multiple photomultiplier tubes that detect tiny flashes of light produced when neutrinos interact with the Antarctic ice. Suspended on long instrumented cables, the modules were lowered deep into the ice where they will operate as highly sensitive "eyes" watching for traces of cosmic events.
TU Dortmund researchers tested and calibrated approximately 5,000 photomultiplier tubes before they were assembled into the final sensor modules. Ruhr University Bochum contributed a new camera system designed to improve understanding of the optical properties of the ice surrounding the detector.
Two Dortmund physicists also participated directly in the South Pole deployment effort. Among them was Dr Alicia Fattorini, who previously spent a full year as an IceCube winter-over, helping maintain operations through the Antarctic winter.
The upgrade marks another step toward the planned IceCube-Gen2 observatory and highlights Germany's growing contribution to Antarctic science beyond climate research, extending into particle physics, advanced engineering and year-round polar operations.