SNO can be thought of as a type of telescope, though it bears little resemblance to the image most of us associate with that word. It consists of an 18-meter-wide stainless steel geodesic sphere inside of which is an acrylic vessel filled with 1,000 tons of heavy water (deuterium oxide). Honeycombing the sphere are 9,522 ultra-sensitive light-sensors called photomultiplier tubes. When neutrinos passing through the heavy water interact with deuterium nuclei, faint flashes of light, called Cerenkov radiation, are emitted. The photomultiplier tubes detect these light flashes and convert them into electronic signals that scientists can analyze.

   
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