China Completes Key Step in $300M Neutrino Detector Construction

The Jiangmen Underground Neutrino Observatory will soon begin studying elusive particles to unlock mysteries of the universe's origins.

The Jiangmen Underground Neutrino Observatory (JUNO), located 700 meters underground in southern China, is nearing completion after nine years of construction.
Workers have started filling the detector with ultrapure water, a critical step before its operational launch in the second half of 2025.
The $300 million facility aims to study neutrinos, nearly massless particles from the Big Bang, to answer fundamental questions about the universe's formation and evolution.
JUNO's 35.4-meter-diameter acrylic sphere will be filled with 20,000 tonnes of liquid scintillator and surrounded by 35,000 tonnes of pure water to detect antineutrinos from nearby nuclear reactors.
This observatory is part of a global effort, alongside detectors in Japan and the U.S., to advance neutrino research and cross-verify findings in the coming decades.