Francis Halzen Wins 2026 Nobel Prize in Physics for Neutrino Astronomy
Francis Halzen has won the 2026 Nobel Prize in Physics for turning a cubic kilometer of Antarctic ice into a telescope for some of the most elusive particles in the universe.
The Royal Swedish Academy of Sciences announced the award Oct. 6 in Stockholm, naming the 82-year-old Belgian astrophysicist the sole laureate for decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos from space. He receives 12 million Swedish kronor.
Neutrinos are sometimes called ghost particles. They have almost no mass and no electric charge, and they pass through stars, planets and entire galaxies undisturbed, according to CNN. Because magnetic fields do not deflect them, they point straight back to where they came from.
That makes them ideal cosmic messengers. Light and other particles get absorbed or bent on their long journeys across the universe, but neutrinos arrive unchanged, carrying information about distant galaxies and exploding stars that no other signal can deliver, the academy said.
Catching them is the hard part. Halzen, a professor at the University of Wisconsin-Madison, first proposed in 1988 building a giant detector in the clear ice of the South Pole. When a neutrino collides with an atomic nucleus in the ice, it produces a faint flash of light that sensors can record.
IceCube was completed around 2010 with about 5,160 light sensors on 86 strings buried deep in the ice, according to reports on the project. In 2013 it produced the first evidence that some detected high-energy neutrinos came from beyond the solar system, and it later traced one to a blazar, a distant galaxy powered by a supermassive black hole.
Committee chair Mark Pearce said Halzen’s tenacity and scientific vision had paved the way for a new kind of astronomy, according to CNN. Halzen told the announcement by phone from Italy that few people thought the idea would work when it began.
The observatory keeps running, and an expansion called IceCube-Gen2 is planned to instrument eight cubic kilometers of ice and detect far more neutrinos, with operations expected in 2033, according to TechCentral. Physicists say the new window on the universe may reveal what powers the most violent events in the cosmos.