The Jiangmen Underground Neutrino Observatory (JUNO) in China has released its first major results from two months of data, published in Nature, focusing on precise measurements of neutrino flavor oscillations.

JUNO detects electron antineutrinos from eight nearby nuclear reactors at about 53 kilometers away, using 43,183 photomultiplier tubes to capture light in a 20,000-ton liquid scintillator volume.

The team aims to test subtle neutrino behavior and mass differences, contributing to the broader effort to understand fundamental particle properties rooted in the Big Bang.

Spokesperson Wang Yifang noted initial skepticism about reaching the planned sensitivity but emphasized the eventual success and high confidence in the results.

The collaboration includes multiple researchers and institutions, with ongoing work to compare results across global detectors.

The initial data cover two months of collection, with continued data accumulation expected to refine measurements and address outstanding questions about neutrino masses.

JUNO’s design cost around $300 million, featuring a large mass and novel phototube technology to maximize light collection and energy resolution.

In a Nature article dated June 10, 2026, signatories report that after construction in six months and just under two months of data collection in late 2025, JUNO achieved improvements over KamLAND, roughly 20 times larger in scale.

With 59 days of data, JUNO reduced uncertainty on two oscillation parameters by about one-third and already observes pronounced spectral ripples indicative of the mass ordering.

Within 59 days of data collection, JUNO measured two crucial oscillation parameters with precision about 1.6 times better than previous decades-long measurements.

Neutrino mass can take three values; current evidence suggests two masses are very close with a larger gap to the third, implying either two small masses and one larger, or the reverse.

The results mark JUNO’s first major milestone, with anticipation for more results as data collection continues.