Earlier this week, a five-country team of scientists planned to toss a net into the Mediterranean to lay a trap for an unusual deep-sea quarry: neutrinos from the reaches of deep space. It was the first step in constructing a cubic-kilometer-sized underwater detector for tracking the elusive particles which, scientists hope, will offer clues about the origin of cosmic rays.
The "net" is a string of photomultiplier tubes--extremely sensitive light detectors--for ANTARES, an underwater neutrino telescope. The telescope works by sensing muons, particles created when neutrinos plow into atomic nuclei in the sea. The muons travel through water faster than light does, emitting flashes, called Cerenkov radiation, that reveal the direction and energy of incoming neutrinos.
When the 10,000-tube project is completed sometime in the next decade, physicists say it should be able to detect very rare neutrinos that pack 1 million times more energy than those registered by the world's largest existing underground detector, Japan's Superkamiokande.
