China tests deep-sea ‘Spider’ to track ghostly cosmic neutrinos

Chinese scientists from Shanghai Jiao Tong University’s Tsung-Dao Lee Institute have successfully conducted a full-scale sea trial of a device called the Subsea Precision Instrument Deployer with Elastic Releasing (Spider). This device is critical for deploying sensors needed to build the Hailing Tropical Deep-sea Neutrino Telescope (Trident) in the South China Sea. During the trial, the Spider descended to about 1,700 meters depth, uncoiling a 700-meter string with 20 sensors and buoyancy blocks, precisely positioning them to detect elusive neutrinos—nearly massless subatomic particles born in cosmic events. This successful test marks a significant step toward constructing the large-scale underwater neutrino observatory designed to capture rare neutrino interactions in a quiet, dark, and stable deep-sea environment. The Trident telescope will be located approximately 3,500 meters below the ocean surface, where conditions such as absence of sunlight, minimal vibrations, and low natural radiation optimize the detection of