  Results of calculations of distribution and motion of dark matter are
presented. Considering neutrino as one of the components of dark matter and
taking into account peculiar features of the interactions of slow neutrinos
with matter, allow to make the conclusion that they may have tangible
manifestations not only in the depths of the Universe but also on the Earth.
Experimental results confirming predicted effects are described, including
periodic variations of the beta radioactivity as well as count rate bursts for
a beta radioactive source placed at the focal point of a parabolic mirror.
Based on the data of astronomical observations, estimates of the mass of the
particles influencing on beta radioactivity (about 20 eV) and their flux
density (about 10^13 particles/cm^2 s) have been made. The discrepancy between
our mass estimate and the 2 eV limit for the neutrino mass, established in the
tritium experiments, is discussed.
