China buried a 10-storey sphere of liquid 700 metres underground to catch ghost particles. In 59 days it became the most precise neutrino experiment on Earth. Its first result was just published in Nature.
Neutrinos are the most difficult particles in the universe to study.
Trillions of them pass through your body every second. They carry no electric charge. They have almost no mass. They interact with matter so weakly that they pass through the entire Earth without stopping. Physics calls them ghost particles.
They are also one of the keys to understanding why the universe contains matter at all.
On August 26, 2025, an experiment called JUNO switched on beneath Dashi Hill in Guangdong Province, China. Its central detector is a sphere 35.4 metres in diameter filled with 20,000 tonnes of liquid that flashes when a neutrino passes through it. That sphere is monitored by 45,000 light sensors and sits 700 metres underground to shield it from interference. The water pool surrounding it is 44 metres deep.
After 59 days of data collection, JUNO published its first result in Nature on June 10, 2026, as the cover article.
Using data from 59 days of operation, JUNO reduced measurement uncertainty on two fundamental neutrino oscillation parameters by a factor of 1.6 compared to the combined results of every previous experiment conducted across several decades.
The primary question JUNO was built to answer: neutrinos come in three types. Do they follow normal mass ordering, where the first type is lightest, or inverted ordering, where the third type is lightest? That answer has implications for why matter dominated antimatter in the early universe.
59 days of data. A decade of construction. 700 metres of rock overhead.
The most precise measurement of its kind. Published in Nature. First result from an experiment designed to run for 30 years.
The ghost particles are beginning to yield their answers.
Source: JUNO Collaboration. Nature, June 10, 2026. Institute of High Energy Physics, Chinese Academy of Sciences.