World’s largest neutrino telescope wins its creator the 2026 Nobel Prize in Physics

A Belgian-American particle physicist has won the 2026 Nobel Prize in Physics for his work on the world’s largest neutrino telescope that can detect ghost particles beneath the Antarctic ice.

The Royal Swedish Academy of Sciences awarded the 2026 Nobel Prize in Physics to Francis Halzen on Tuesday, October 6. Halzen is the Hilldale and Gregory Breit Distinguished Professor at the University of Wisconsin-Madison, and director of its Institute for Elementary Particle Physics.

The laureate is the principal investigator of IceCube, the world’s largest neutrino telescope. The unique observatory uses thousands of light sensors embedded in Antarctic ice to detect elusive particles known as neutrinos, often called “ghost particles.”

“Francis Halzen has led an international team of researchers and engineers who have provided us with a fantastic instrument,” Mark Pearce, chair of the Nobel Committee for Physics, pointed out. “His tenacity and scientific vision has paved the way for a new kind of astronomy.”

A giant telescope beneath Antarctic ice

Neutrinos are tiny elementary particles with no electrical charge. They’re referred to as ghost particles, since they rarely interact with matter. They can travel across enormous cosmic distances almost completely undisturbed. This allows scientists to investigate some of the universe’s most energetic and mysterious events.

However, neutrinos occasionally collide with atoms and produce charged particles that generate faint flashes of light. These signals can be picked up by sensitive instruments embedded deep in the clear Antarctic ice. Halzen first proposed using South Pole ice to detect neutrinos in 1988.

The NSF IceCube Lab in Antarctica. Credit: Ilya Bodo, IceCube / NSF

The idea eventually led to IceCube (IceCube Neutrino Observatory), which surveys roughly 0.24 cubic miles (one cubic kilometer) of ice near the geographic South Pole. Supported by the US National Science Foundation (NSF), the detector was completed in 2011.

It reportedly contains 5,160 original digital optical modules (DOMs) embedded in the ice. Another 600 to 670 advanced sensors were added during an upgrade in early 2026.

“IceCube is like no other telescope in the world,” Eric Wilcots, PhD, UW-Madison Interim Chancellor, said in a statement. “And there is no other scientist quite like Francis Halzen, whose idea to create a neutrino detector under almost a mile of ice has led to a remarkable multinational and multi-institutional scientific collaboration and a fundamental shift in how we think about the universe.”

A new view of the universe

IceCube hit a milestone in 2013 when scientists announced the first detection of high-energy neutrinos originating outside the solar system. Then, in September 2017, it detected a high-energy neutrino that Halzen and his team traced to a distant active galaxy containing a supermassive black hole.

Together with observations from other telescopes, the finding helped scientists identify a source of high-energy cosmic rays for the first time. Their origins had puzzled researchers for more than a century.

IceCube also helped identify high-energy neutrino emission from an active galaxy about 47 million light-years away in 2022. In 2023, the researchers produced the first neutrino-based image of the Milky Way, demonstrating that our own galaxy also produces high-energy neutrinos.

The IceCube Lab with a sky showing the Milky Way and green auroras. Credit: Yuya Makino, IceCube / NSF

The discoveries helped establish “multi-messenger astronomy,” which studies the universe using light, neutrinos, gravitational waves, and other cosmic signals. The team hopes that IceCube will reveal more about the extreme environments that produce neutrinos and uncover previously unknown cosmic phenomena.

Meanwhile, the observatory recently underwent its first major expansion since its completion 15 years ago. Halzen, who was born in Belgium in 1944, joined the physics faculty at UW-Madison in 1972.

He is the sixth physicist associated with the university to win the honor and its 23rd Nobel laureate overall. The 2026 Nobel Prize in Physics carries an award of roughly USD 1.27 million (SEK 12 million).

Source: https://interestingengineering.com/science/francis-halzen-nobel-prize-icecube