“Underneath a granite hill in southern China, a massive detector is nearly complete that will sniff out the mysterious ghost particles lurking around us.

The Jiangmen Underground Neutrino Observatory will soon begin the difficult task of spotting neutrinos: tiny cosmic particles with a mind-bogglingly small mass.

The detector is one of three being built across the globe to study these elusive ghost particles in the finest detail yet. The other two, based in the United States and Japan, are still under construction…

It’ll study antineutrinos — an opposite to neutrinos which allow scientists to understand their behavior — produced from collisions inside two nuclear power plants located over 31 miles (50 kilometers) away. When the antineutrinos come into contact with particles inside the detector, they’ll produce a flash of light.

The detector is specially designed to answer a key question about a longstanding mystery. Neutrinos switch between three flavors as they zip through space, and scientists want to rank them from lightest to heaviest.”

From Associated Press.