This Giant Sphere Just Joined the Hunt for 'Ghost Particles'

The elusive neutrino—a near massless particle with no charge—tests the limits of physicists’ creativity, but sometimes the answer is just to go big . And the biggest detector of them all has finally joined the search for the so-called “ghost particles.”

After a decade of construction, China’s Jiangmen Underground Neutrino Observatory (JUNO) officially began taking data on August 26. The giant, spherical detector lies about 2,300 feet (700 meters) underground and collects antineutrino signals from two nuclear plants 33 miles (53 kilometers) away.

The sphere holds a whopping 20,000 tons of liquid scintillator that flickers whenever an antineutrino zips by. Surrounding the detector is a 144-foot-deep (44-meter-deep) water pool lined with tubes that capture these flashes and convert them i