The Sudbury Neutrino Observatory, or SNO for short, differs from other neutrino observatories in that it uses heavy water as its detection material, allowing mu and tau type neutrinos to be detected, while most others, such as Super Kamiokande, can only detect the electron neutrino. This is important, as it allows the theory of neutrino oscillations to be tested. Neutrino oscillations, if they exist, could resolve the Solar Neutrino Problem. Preliminary data from SNO seems to support the theory, but no official papers have been published as of October 19, 2000.

SNO is situated 6800 feet under ground, in the second-to-bottom drift (jokingly referred to as the SNO drift) of INCO's Creighton Mine, near Sudbury, Ontario, Canada. Queen's University is heavily involved in the project.

A more recent note: the results are in. The observatory did indeed detect mu and tau neutrinos, indicating that neutrinos do have mass, do oscillate, and effectively resolving the Solar Neutrino Problem.

Lord Brawl says: "This facility features prominently in Robert Sawyer's Hugo-winner Hominids and sequels." Thanks!