At the core of the facility is a 35-metre-wide acrylic sphere filled with 20,000 tonnes of liquid scintillator, encased within a 44-metre-deep water pool.

This massive detector is designed to capture faint flashes of light produced when neutrinos—subatomic particles with no electric charge and almost no mass—interact with hydrogen nuclei in the liquid.

The project, first proposed in 2008, is led by the Institute of High Energy Physics under the Chinese Academy of Sciences.

According to project spokesperson Wang Yifang, JUNO marks a significant milestone in global research, offering unprecedented precision in studying neutrino mass and properties.

He stated that operating a detector of this scale will allow scientists to tackle fundamental questions about matter and the universe.

JUNO’s location was chosen to study antineutrinos emitted from two nearby nuclear power plants in Taishan and Yangjiang, situated about 53 kilometres away.

The detector’s measurements are expected to provide record accuracy in mapping neutrino energy spectra, helping determine neutrino mass ordering while avoiding interference from Earth’s matter effects.

Beyond nuclear neutrino studies, the observatory is also set to explore particles originating from the Sun, supernovae, the atmosphere, and Earth itself.

It may further contribute to research into unexplored physics, including searches for sterile neutrinos and proton decay.

Scientists anticipate that the scale and precision of JUNO will provide insights into one of the least understood areas of particle physics.

Construction of the detector involved international collaboration, with contributions from multiple research institutions worldwide.

The project represents one of the largest investments in particle physics infrastructure ever undertaken in China.