The telescope, once complete, will be made of hundreds of spherical detectors suspended at the bottom of the sea. (Credit: KM3NeT)

Deep under the Mediterranean Sea, hundreds of watchful eyes hang suspended on cables, waiting for a rare and valuable flash. Their quarry are ghostly neutrino particles, capable of tunneling through light-years of space and a planet’s worth of rock without ever coming into contact with matter.

But, here, under the ocean, they just might hit a detector from the