  Deviations from expectations have been claimed for solar, atmospheric and
high energy prompt neutrinos from charm decay. This information, supplemented
only by the existing very good upper limits for oscillations of the $\nu_{\mu}$
at accelerator energies, is used as input to a phenomenological three-flavour
analysis of neutrino mixing. The solution found is unique and completely
determines the mass eigenstates as well as the mixing matrix relating mass and
flavour eigenstates. Assuming the mass eigenstates to follow the hierarchy
$m_{1} \ll m_{2} \ll m_{3}$, their values are found to be $m_{1} \ll 10^{-2}$
eV, $m_{2} = (0.18 \pm 0.06)$ eV, $m_{3} = (19.4 \pm 0.7)$ eV. These masses are
in agreement with the leptonic quadratic hierarchy of the see-saw model and
large enough to render energy-independent any oscillation-induced phenomenon in
solar neutrino physics observable on Earth. This possibility is not excluded by
the present knowledge of solar neutrino physics. The mixing angles are
determined to be $\theta_{12} = 0.55 \pm 0.08$, $\theta_{13} = 0.38 \pm 0.06$,
$\theta_{23} < 0.03$. Small values of $\theta_{23}$ are typical of any solution
in which $m_{3}$ lies in the cosmological interesting region. The solution
found is not in serious contradiction with any of the present limits to the
existence of neutrino oscillations. The most relevant implications in particle
physics, astrophysics and cosmology are discussed.
