SNOLAB is an underground science laboratory situated two km below the surface in the Vale Inco Creighton Mine located near Sudbury (Ontario, Canada) approximately 400 km northwest of Toronto.The SNO (solar neutrino experiment) lab was constructed to address the Solar Neutrino Problem (SNP).
Solar Neutrino Problem?: In recent years, theoretical models of the sun have permitted detailed calculations of the number (or flux) of neutrinos - tiny, probably massless particles with no electrical charge - released from the sun.
Several neutrino experiments have detected solar neutrinos and found the flux was too low. That is, far too few neutrinos are detected than can be consistent with the known energy output of the sun.
Two research aims of the SNOLAB are:
The neutrinos are not much changed when they pour out of the sun, so they can help us learn more about the sun's interior.
Neutrinos are produced in massive numbers during supernovas, so they can help us learn more about the evolution of the universe. More on all this later.