The Royal Swedish Academy of Sciences awarded the 2026 physics Nobel to University of Wisconsin–Madison professor Francis Halzen for leadership of the IceCube Neutrino Observatory and the discovery of high-energy neutrinos from beyond the solar system.
The Royal Swedish Academy of Sciences awarded the 2026 Nobel Prize in Physics on Tuesday to Francis Halzen, a professor at the University of Wisconsin–Madison, for decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin.
Halzen, born in 1944 in Tienen, Belgium, earned his PhD at KU Leuven in 1969. The Academy said he first set out a plan in 1988 to detect neutrinos in South Pole ice. IceCube, a cubic kilometre of glacial ice fitted with light sensors, was completed in 2011. The prize is 12 million Swedish kronor.
Neutrinos rarely interact with matter, so an enormous detector volume is needed. When one strikes an atomic nucleus it can produce a flash of light that sensors in clear ice can track. The Academy said researchers later published evidence of neutrinos that must have come from far outside the solar system.
Mark Pearce, chair of the Nobel Committee for Physics, said Halzen had led an international team and that his work had paved the way for a new kind of astronomy. Halzen told reporters he had been surprised the idea worked so well, saying few people, including himself, had expected it to succeed when the project began.
Announcements continue through 12 October. The Academy said ongoing IceCube detections should add detail on the violent environments that produce the highest-energy neutrinos.