The 2026 Nobel Prize in Physics has been awarded to Francis Halzen for “decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin.” Halzen is a Belgium-born physicist, a professor at the University of Wisconsin–Madison and principal investigator at the IceCube Neutrino Observatory in Antarctica.

“It’s a great pleasure to hear about this prize,” said Halzen during the press conference that followed the announcement. “I hope this reflects on the really courageous people who joined me in the beginning of this project.”

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“It’s very exciting,” says Michael H. Moloney, CEO of the American Institute of Physics. “It’s a timely and an important recognition of the extraordinary work that Dr. Halzen did to open up a whole new window on the universe.”

Indeed, IceCube—Halzen’s brainchild—gave humankind a fresh glimpse of the cosmos when it came online in 2010. Unlike the majority of the globe’s telescopes. which gather starlight, this unique observatory sees the universe via ghostly messengers called neutrinos. Combining the two has improved our understanding of some of the most distant and violent physical processes in the cosmos.

Neutrinos are the least understood of the 17 fundamental particles known to exist. They nearly always move through matter as if it isn’t there. So massive detectors are required to capture and study their exceedingly rare collisions with atoms.

IceCube does this with arrays of specialized sensors dispersed in the crystal-clear ice a mile beneath the surface of Antarctica. A high-energy neutrino, accelerated at the center of a faraway galaxy, will usually zip right through this subsurface deep freeze. But occasionally, it will hit an atom in a molecule of water ice, producing a shower of light that the sensors collect and use to reconstruct the neutrinos’ energies and directions of origin.

After just a couple of years, IceCube confirmed it had measured the first high-energy neutrinos from beyond the solar system. Thanks in large part to IceCube, astronomers are heralding a new era of “multimessenger astronomy,” where neutrino measurements, traditional telescopes and gravitational-wave detectors together triangulate to pinpoint and scrutinize distant, obscure phenomena.

“People didn’t know that the extragalactic sources would be bright enough to be detected, so it was a risk,” says Jonathan Bagger, a theoretical physicist and CEO of the American Physical Society. “Halzen analyzed this subject and wrote proposals and got them through peer review—this was ultimately a testament to the system working.”

The observatory is an ambitious and unprecedented feat of engineering. It was constructed by boring deep holes across a cubic kilometer of Antarctic ice using jets of hot water and then carefully lowering long strings of sensors into them. It remains the largest neutrino telescope in the world. This year’s Nobel therefore awards exactly the kind of modern, large-scale experimental science that is under financial threat in places like the U.S., where IceCube originated. (The Trump administration’s budget proposal for 2027 calls for halving IceCube’s funding.)

“It’s big, publicly funded science,” Moloney says. “It shows that when we design audacious experiments, we can discover extraordinary things.”

The Nobel Prize in Physics, first given in 1901, was previously awarded 119 times to a total of 229 individuals. Those recipients included Marie Curie, who was awarded in 1903 for making sense of radioactivity; Albert Einstein, who was awarded in 1921 for discovering how light and matter interact; I. I. Rabi, who was awarded in 1944 for discovering what would become the science behind magnetic resonance imaging (MRI); and Frederick Reines, who was awarded in 1995 for discovering low-energy neutrinos. Before Halzen’s win today, the last time the Nobel Prize in Physics was awarded to a single person was in 1992, when it went to French physicist Georges Charpak.

More recently, the physics Nobel Prize recognized a tool for studying the motion of electrons in 2023, the development of core techniques for building many of today’s artificial intelligence models in 2024, and the creation and study of weird quantum phenomena in macroscopic, handheld devices in 2025.

The prize will be presented in Stockholm on December 10, the anniversary of Alfred Nobel’s death.

Editor’s Note (10/6/26): This is a breaking news story and will be updated.

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