Far beneath the Mediterranean, where sunlight disappears and only pressure and silence dominate, two of the world’s most ambitious scientific instruments are slowly coming to life. Known as ORCA and ARCA, these detectors are the centerpiece of the KM3NeT project, a European effort designed to track particles so elusive that trillions pass through every human being every second without consequence. These particles are neutrinos, electrically neutral, nearly massless, and capable of traveling unhindered through stars, planets, and galaxies. To detect one is to witness a cosmic whisper, a faint trace of some of the universe’s most violent and energetic processes.



