There was already the model of thermonuclear reactions that occur in the Sun, but according to this theory the number of neutrinos to be reached from the Sun did not correspond to what was observed.
Neutrinos are subatomic particles of very small mass and neutral electric charge. The interaction between matter and neutrinos is very weak and therefore it is very difficult to detect them. This is one of the peculiarities of neutrinos.
There are three types of neutrinos that correspond to three different subatomic particles: neutrino electrons, muonal neutrinos and tau neutrinos. Electron neutrinos occur in thermonuclear reactions taking place in the core of the Sun. Understanding this type of reaction has allowed us to determine the number of neutrinos emitted by our star. But so far only a third of that amount was detected, which has confused scientists for years. They doubted that the theory was going to be wrong.
At the Sudbury Neutrino Observatory (SNO) telescope in Canada, 1000 tons of very pure heavy water are used, which has detected not only electron neutrinos, which are the easiest to detect, but other types of neutrinos. Thus, taking into account the three types of neutrinos detected, the theory on reactions in the Sun has been confirmed. According to scientists, it has become clear that neutrinos become the path from the Sun to Earth.
Undoubtedly, the observations of Sudbury Neutrino Observatory will allow a better knowledge of neutrinos, a great step for basic physics.