Neutrinos From Supernova Explosion and the Mikheyev-Smirnov-Wolfenstein Effect

It is shown that by taking the effect of the Earth into account the possible observation of electron neutrinos from the supernova SN1987A at the Kamiokande II is compatible with the solution of the solar neutrino puzzle by the Mikheyev-Smirnov-Wolfenstein mechanism. Our scenario requires relatively large mixing angles sin 2 2θ ≳ 0.3 and, most probably, ∆m2 of the order of 10−6 ~ 10−5 (eV) 2. The implications of possible observation in other neutrino detectors are briefly discussed.