Neutrino observatory IceCube receives over 600 new sensors

The IceCube observatory in Antarctica has received an expansion: six new strings of sensors have been embedded in the ice, as announced by the IceCube Neutrino Observatory.

Between December 2025 and January 2026, the strings were lowered into shafts 2400 meters deep, melted into the ice using a hot-water drill. In each shaft, 1.5-kilometer-long cable strings were lowered, each with about 100 glass containers strung like beads on a necklace. The approximately 40-centimeter-sized containers house optical sensors, known as mDOMs (multi-PMT Digital Optical Modules), as well as other measuring instruments that researchers use to detect neutrinos.

It is according to the IceCube Neutrino Observatory "the first significant expansion of IceCube since its completion 15 years ago." The new sensors can also detect low-energy neutrinos.

Sensors from Germany

The new sensors were partly developed in Germany. Researchers from the German Electron Synchrotron (DESY), the Karlsruhe Institute of Technology (KIT), RWTH Aachen University, TU Dortmund University, and the universities in Münster, Wuppertal, Mainz, and Erlangen-Nuremberg were involved.

"What's new about the optical sensors in the upgrade is that they are equipped with photomultiplier tubes that detect light in all directions. This allows us a 360-degree view into the ice," says Andreas Haungs, scientific director of the IceCube working group at the Institute for Astroparticle Physics at KIT. "This allows us to observe neutrino interactions at lower energies and thus determine neutrino properties, complementing the KATRIN experiment at KIT."

Neutrinos are electrically neutral, largely massless particles. They travel at almost the speed of light and hardly ever interact with atoms. They can, for example, pass through the Earth almost unimpeded.

Hints of High-Energy Events in Space

These particles are scientifically very interesting because researchers hope to gain insights into their origin. Neutrinos are released during very high-energy events in space, such as stellar explosions, gamma-ray bursts, or supermassive black holes at the center of a galaxy.

Neutrinos are detected through interactions with matter: when a neutrino collides with an atom, electrically charged particles called muons are created. As they move through the ice, they produce faint, bluish cones of light that the detectors capture.

To detect these faint light signals, enormous observatories are needed. IceCube is one of them, but not the only one. Another is located in the Mediterranean Sea: the European observatory Cubic Kilometre Neutrino Telescope (KM3NeT) currently consists of two large sensor fields in the Mediterranean Sea, one off the coast of Sicily and the other off the coast of southern France.

(wpl)