This strange structure is the IceCube Neutrino Observatory, and the things it will discover over the next few years will eventually lead to one of its creators and driving forces - Francis Halzen - winning the 2026 Nobel Prize for Physics.
It was designed to search for mysterious particles coming from deep space called high energy neutrinos.
High energy neutrinos are interesting to physicists, because they are predicted to be produced in exotic processes in deep space which we can’t easily see with traditional telescopes.
But even today, while IceCube is detecting high energy neutrinos from across the cosmos, we still don't know where most of them originate.
So, congratulations to Professor Halzen and the IceCube team for the 2026 Nobel Prize in Physics.
Every October, the Swedish capital, Stockholm, becomes the centre of the scientific world as Nobel Prizes are awarded for discoveries that reshape our understanding of life, the universe and everything. We’re going to hear about each of the science prizes, beginning with physics. Ben McAllister reports…
The year is 2010. TiK ToK by Ke$ha is topping the charts, Chelsea has just won the Premier League, and you are in Antarctica - specifically at the Amundsen-Scott South Pole Station - watching a giant mechanical rig lower a custom-made drill deep into the ice.
The drill is using hot water to melt a near-perfect vertical hole with a diameter of about 60 centimetres and an astonishing depth of 2,450 metres - one of 86 similar holes to be arranged in a hexagonal grid about 1 kilometre across. Soon, a long cable connecting 60 glass spheres like a bead necklace will be lowered into the hole.
The glass spheres contain detector electronics, and are spaced about 17 metres apart on the cable. They will be distributed in the bottom kilometre of the hole. When all 86 holes are completed, there will be a network of 5,160 detector modules embedded deep inside a full cubic kilometre of the Antarctic ice.
This strange structure is the IceCube Neutrino Observatory, and the things it will discover over the next few years will eventually lead to one of its creators and driving forces - Francis Halzen - winning the 2026 Nobel Prize for Physics.
IceCube is one of the coolest (pun intended) international physics projects we’ve ever built. It was designed to search for mysterious particles coming from deep space called high energy neutrinos.
Neutrinos are very tiny subatomic particles that arise in a number of different physical processes, both plain and exotic. They are extremely elusive and hard to detect, as they only interact very weakly with other forms of matter.
Detecting that weak interaction is very difficult. Neutrinos usually pass through matter without really doing much, but very occasionally they bump into the nucleus of an atom, and impart some energy. Because those ‘bumps’ are so rare, you need a lot of material containing a lot of atomic nuclei to increase your chances of an interaction.
That is the idea behind IceCube, using 1 cubic kilometre of polar ice as the detector target itself, and embedding a large network of sensors deep in the ice to catch the signals emitted when the neutrinos bump into the ice molecules on their way through. When one of these high energy neutrinos hits an atom, it can create energetic charged particles, which themselves give off flashes of light as they travel through the ice. These flashes of light are what those spherical detector modules on strings actually observe, and by looking at where and when in the array those flashes are detected, scientists are able to reconstruct the path of the incoming neutrino.
High energy neutrinos are interesting to physicists, because they are predicted to be produced in exotic processes in deep space which we can’t easily see with traditional telescopes. The IceCube team hoped that by detecting them, we could learn more about these exciting events.
In the first few years after its construction, IceCube succeeded, detecting a population of extremely high energy neutrinos hitting the Earth from deep space, but we didn’t know exactly where they were coming from. Over the next few years, by combining its observations with those of conventional telescopes, scientists were eventually able to identify likely sources, including the space around supermassive black holes at the centres of distant galaxies, and learn more about these extreme parts of the Universe.
But even today, while IceCube is detecting high energy neutrinos from across the cosmos, we still don't know where most of them originate. It's opening up a whole new window on the Universe, and creating a tonne of exciting mysteries and questions for physicists to solve.
We really are still in the early days of neutrino-based astronomy, and IceCube is making it possible.
So, congratulations to Professor Halzen and the IceCube team for the 2026 Nobel Prize in Physics.
